WorldWideScience
1

Signaling responses after exposure to 5?-dihydrotestosterone or 17?-estradiol in norepinephrine-induced hypertrophy of neonatal rat ventricular myocytes  

OpenAIRE

Androgens appear to enhance, whereas estrogens mitigate, cardiac hypertrophy. However, signaling pathways in cells for short (3 min) and longer term (48 h) treatment with 17?-estradiol (E2) or 5?-dihydrotestosterone (DHT) are understudied. We compared the effect of adrenergic stimulation by norepinephrine (NE; 1 ?M) alone or in combination with DHT (10 nM) or E2 (10 nM) treatment in neonatal rat ventricular myocytes (NRVMs) by cell area, protein synthesis, sarcomeric structure, gene expres...

Koshman, Yevgeniya E.; Piano, Mariann R.; Russell, Brenda; Schwertz, Dorie W.

2010-01-01

2

Some growth factors stimulate cultured adult rabbit ventricular myocyte hypertrophy in the absence of mechanical loading  

Science.gov (United States)

Cultured adult rabbit cardiac myocytes treated with recombinant growth factors display enhanced rates of protein accumulation (ie, growth) in response to insulin and insulin-like growth factors (IGFs), but epidermal growth factor, acidic or basic fibroblast growth factor, and platelet-derived growth factor failed to increase contractile protein synthesis or growth of the heart cells. Insulin and IGF-1 increased growth rates by stimulating anabolic while simultaneously inhibiting catabolic pathways, whereas IGF-2 elevated growth modestly by apparently inhibiting lysosomal proteolysis. Neutralizing antibodies directed against either IGF-1 or IGF-2 or IGF binding protein 3 blocked protein accumulation. A monoclonal antibody directed against the IGF-1 receptor also inhibited changes in protein turnover provoked by recombinant human IGF-1 but not IGF-2. Of the other growth factors tested, only transforming growth factor-beta 1 increased the fractional rate of myosin heavy chain (MHC) synthesis, with beta-MHC synthesis being elevated and alpha-MHC synthesis being suppressed. However, the other growth factors were able to modestly stimulate the rate of DNA synthesis in this preparation. Bromodeoxyuridine labeling revealed that these growth factors increased DNA synthesis in myocytes and nonmyocytes alike, but the heart cells displayed neither karyokinesis or cytokinesis. In contrast, cocultures of cardiac myocytes and nonmyocytes and nonmyocyte-conditioned culture medium failed to enhance the rate of cardiac MHC synthesis or its accumulation, implying that quiescent heart cells do not respond to "conditioning" by cardiac nonmyocytes. These findings demonstrated that insulin and the IGFs promote passively loaded cultured adult rabbit heart cells to hypertrophy but suggest that other growth factors tested may be limited in this regard.

Decker, R. S.; Cook, M. G.; Behnke-Barclay, M.; Decker, M. L.

1995-01-01

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An increased TREK-1-like potassium current in ventricular myocytes during rat cardiac hypertrophy.  

Science.gov (United States)

To elucidate the expression and identify the functional changes of 2 pore domain potassium channel TREK-1 during cardiac hypertrophy in rats, left ventricular hypertrophy was induced by subcutaneous injection with isoproterenol. Western blot was used to detect the expression of TREK-1 channel protein, and inside-out and whole-cell recordings were used to record TREK-1 currents. The results showed that TREK-1 protein expression in endocardium was slightly higher than that in epicardium in control left ventricles. However, it was obviously upregulated by 89.8% during hypertrophy, 2.3-fold higher than in epicardium. Mechanical stretch, intracellular acidification, and arachidonic acid could activate a TREK-1-like current in cardiomyocytes. The slope conductances of cardiac TREK-1 and CHO/TREK-1 channels were 123 ± 7 and 113 ± 17 pS, respectively. The TREK-1 inhibitor L-3-n-butylphthalide (10 ?M) reduced the currents in CHO/TREK-1 cells, normal cardiomyocytes, and hypertrophic cardiomyocytes by 48.5%, 54.3%, and 55.5%, respectively. The percentage of L-3-n-butylphthalide-inhibited outward whole-cell current in hypertrophic cardiomyocytes (23.7%) was larger than that in normal cardiomyocytes (14.2%). The percentage of chloroform-activated outward whole-cell current in hypertrophic cardiomyocytes (58.3%) was also larger than normal control (40.2%). Our results demonstrated that in hypertrophic rats, TREK-1 protein expression in endocardium was specifically increased and the ratio of TREK-1 channel current in cardiac outward currents was also enhanced. TREK-1 might balance potassium ion flow during hypertrophy and might be a potential drug target for heart protection. PMID:23232841

Wang, Weiping; Zhang, Man; Li, Pingping; Yuan, Hui; Feng, Nan; Peng, Ying; Wang, Ling; Wang, Xiaoliang

2013-04-01

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Activation of Mst1 causes dilated cardiomyopathy by stimulating apoptosis without compensatory ventricular myocyte hypertrophy  

OpenAIRE

Activation of mammalian sterile 20–like kinase 1 (Mst1) by genotoxic compounds is known to stimulate apoptosis in some cell types. The importance of Mst1 in cell death caused by clinically relevant pathologic stimuli is unknown, however. In this study, we show that Mst1 is a prominent myelin basic protein kinase activated by proapoptotic stimuli in cardiac myocytes and that Mst1 causes cardiac myocyte apoptosis in vitro in a kinase activity–dependent manner. In vivo, cardiac-specific over...

Yamamoto, Shimako; Yang, Guiping; Zablocki, Daniela; Liu, Jing; Hong, Chull; Kim, Song-jung; Soler, Sandra; Odashima, Mari; Thaisz, Jill; Yehia, Ghassan; Molina, Carlos A.; Yatani, Atsuko; Vatner, Dorothy E.; Vatner, Stephen F.; Sadoshima, Junichi

2003-01-01

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Myocyte cellular hypertrophy and hyperplasia contribute to ventricular wall remodeling in anemia-induced cardiac hypertrophy in rats.  

OpenAIRE

To determine the effects of chronic anemia on the functional and structural characteristics of the heart, 1-month-old male rats were fed a diet deficient in iron and copper, which led to a hemoglobin concentration of 4.63 g/dl, for 8 weeks. At sacrifice, under fentanyl citrate and droperidol anesthesia, systolic, diastolic, and mean arterial blood pressures were decreased, whereas differential pressure was increased. Left ventricular systolic pressure and the ventricular rate of pressure rise...

Olivetti, G.; Quaini, F.; Lagrasta, C.; Ricci, R.; Tiberti, G.; Capasso, J. M.; Anversa, P.

1992-01-01

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Ventricular hypertrophy--physiological mechanisms.  

Science.gov (United States)

Adult cardiac myocytes are incapable of mitosis. Dead cells are replaced by connective tissue so that after myocardial infarction (MI), function can only be restored by compensatory hypertrophy of the surviving myocardium. In physiological hypertrophy in response to exercise, high altitude, or mild hypertension, additional myoplasm expands cell diameter in an orderly fashion; Z-lines are in register and the normal ratio of volume densities of contractile elements, mitochondria, and capillaries is conserved. In hypertrophy induced by aortic or pulmonary artery banding or by experimental or congenital hypertension, the borderline between physiological and pathological hypertrophy may be crossed, causing disorganization of fibers and an unfavourable contractile element to capillary ratio. There was, therefore, a need for a graded model of hypertrophy, which involves simulating an altitude of 6,000 m at sea level by supplying rabbits with appropriate nitrogen/oxygen mixtures. In this environment, 50% right ventricular hypertrophy can be achieved without alteration of left ventricular weight or hematocrit. Longer exposures produced 100% right ventricular hypertrophy, with only moderate increases in hematocrit and left ventricular weight. It is well known that adrenergic stimulation causes cardiac hypertrophy, and it has been suggested that release of a trophic factor from sympathetic nerves, either noradrenaline or a protein, might be a necessary stimulus for growth. If so, long-term treatment of post-MI patients with beta-adrenergic blocking agents could inhibit a desirable compensatory hypertrophy of the surviving myocardium. In the above model it has been found, however, that neither beta-blockade nor chemical sympathectomy with guanethidine or 6-hydroxydopamine had any effect on the hypertrophy, nor did treatment with verapamil or nifedipine.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2429105

Vaughan Williams, E M

1986-01-01

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Impaired beta-adrenergic response and decreased L-type calcium current of hypertrophied left ventricular myocytes in postinfarction heart failure  

Directory of Open Access Journals (Sweden)

Full Text Available Infarct-induced heart failure is usually associated with cardiac hypertrophy and decreased ß-adrenergic responsiveness. However, conflicting results have been reported concerning the density of L-type calcium current (I Ca(L, and the mechanisms underlying the decreased ß-adrenergic inotropic response. We determined I Ca(L density, cytoplasmic calcium ([Ca2+]i transients, and the effects of ß-adrenergic stimulation (isoproterenol in a model of postinfarction heart failure in rats. Left ventricular myocytes were obtained by enzymatic digestion 8-10 weeks after infarction. Electrophysiological recordings were obtained using the patch-clamp technique. [Ca2+]i transients were investigated via fura-2 fluorescence. ß-Adrenergic receptor density was determined by [³H]-dihydroalprenolol binding to left ventricle homogenates. Postinfarction myocytes showed a significant 25% reduction in mean I Ca(L density (5.7 ± 0.28 vs 7.6 ± 0.32 pA/pF and a 19% reduction in mean peak [Ca2+]i transients (0.13 ± 0.007 vs 0.16 ± 0.009 compared to sham myocytes. The isoproterenol-stimulated increase in I Ca(L was significantly smaller in postinfarction myocytes (Emax: 63.6 ± 4.3 vs 123.3 ± 0.9% in sham myocytes, but EC50 was not altered. The isoproterenol-stimulated peak amplitude of [Ca2+]i transients was also blunted in postinfarction myocytes. Adenylate cyclase activation through forskolin produced similar I Ca(L increases in both groups. ß-Adrenergic receptor density was significantly reduced in homogenates from infarcted hearts (Bmax: 93.89 ± 20.22 vs 271.5 ± 31.43 fmol/mg protein in sham myocytes, while Kd values were similar. We conclude that postinfarction myocytes from large infarcts display reduced I Ca(L density and peak [Ca2+]i transients. The response to ß-adrenergic stimulation was also reduced and was probably related to ß-adrenergic receptor down-regulation and not to changes in adenylate cyclase activity.

R.M. Saraiva

2003-05-01

8

Impaired beta-adrenergic response and decreased L-type calcium current of hypertrophied left ventricular myocytes in postinfarction heart failure  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Infarct-induced heart failure is usually associated with cardiac hypertrophy and decreased ß-adrenergic responsiveness. However, conflicting results have been reported concerning the density of L-type calcium current (I Ca(L)), and the mechanisms underlying the decreased ß-adrenergic inotropic respo [...] nse. We determined I Ca(L) density, cytoplasmic calcium ([Ca2+]i) transients, and the effects of ß-adrenergic stimulation (isoproterenol) in a model of postinfarction heart failure in rats. Left ventricular myocytes were obtained by enzymatic digestion 8-10 weeks after infarction. Electrophysiological recordings were obtained using the patch-clamp technique. [Ca2+]i transients were investigated via fura-2 fluorescence. ß-Adrenergic receptor density was determined by [³H]-dihydroalprenolol binding to left ventricle homogenates. Postinfarction myocytes showed a significant 25% reduction in mean I Ca(L) density (5.7 ± 0.28 vs 7.6 ± 0.32 pA/pF) and a 19% reduction in mean peak [Ca2+]i transients (0.13 ± 0.007 vs 0.16 ± 0.009) compared to sham myocytes. The isoproterenol-stimulated increase in I Ca(L) was significantly smaller in postinfarction myocytes (Emax: 63.6 ± 4.3 vs 123.3 ± 0.9% in sham myocytes), but EC50 was not altered. The isoproterenol-stimulated peak amplitude of [Ca2+]i transients was also blunted in postinfarction myocytes. Adenylate cyclase activation through forskolin produced similar I Ca(L) increases in both groups. ß-Adrenergic receptor density was significantly reduced in homogenates from infarcted hearts (Bmax: 93.89 ± 20.22 vs 271.5 ± 31.43 fmol/mg protein in sham myocytes), while Kd values were similar. We conclude that postinfarction myocytes from large infarcts display reduced I Ca(L) density and peak [Ca2+]i transients. The response to ß-adrenergic stimulation was also reduced and was probably related to ß-adrenergic receptor down-regulation and not to changes in adenylate cyclase activity.

R.M., Saraiva; N.G.B., Chedid; C.C., Quintero H.; L.E., Díaz G.; M.O., Masuda.

2003-05-01

9

Trophic effect of human pericardial fluid on adult cardiac myocytes. Differential role of fibroblast growth factor-2 and factors related to ventricular hypertrophy.  

Science.gov (United States)

Pericardial fluid (PF) may contain myocardial growth factors that exert paracrine actions on cardiac myocytes. The aims of this study were (1) to investigate the effects of human PF and serum, collected from patients undergoing cardiac surgery, on the growth of cultured adult rat cardiac myocytes and (2) to relate the growth activity of both fluids to the adaptive changes in overloaded human hearts. Both PF and serum increased the rate of protein synthesis, measured by [14C]phenylalanine incorporation in adult rat cardiomyocytes (PF, +71.9 +/- 8.2% [n = 17]; serum, +14.9 +/- 6.5% [n = 13]; both P < .01 versus control medium). The effects of both PF and serum on cardiomyocyte growth correlated positively with the respective left ventricular (LV) mass. However, the magnitude of change with PF was 3-fold greater than with serum (P < .01). These trophic effects of PF were mimicked by exogenous basic fibroblast growth factor (FGF2) and inhibited by anti-FGF2 antibodies and transforming growth factor-beta (TGF-beta), suggesting a relationship to FGF2. In addition, FGF2 concentration in PF was 20 times greater than in serum. On the other hand, the LV mass-dependent trophic effect, present in both fluids, was independent of FGF2 concentration or other factors, such as angiotensin II, atrial natriuretic factor, and TGF-beta. These data suggest that FGF2 in human PF is a major determining factor in normal myocyte growth, whereas unidentified LV mass-dependent factor(s), present in both PF and serum, participates in the development of ventricular hypertrophy. PMID:9351441

Corda, S; Mebazaa, A; Gandolfini, M P; Fitting, C; Marotte, F; Peynet, J; Charlemagne, D; Cavaillon, J M; Payen, D; Rappaport, L; Samuel, J L

1997-11-01

10

Left ventricular hypertrophy in patients treated with regular hemodialyses  

Directory of Open Access Journals (Sweden)

Full Text Available Left ventricular hypertrophy is the main risk factor for development of cardiovascular morbidity and mortality in patients on hemodialysis. Left ventricular hypertrophy is found in 75% of the patients treated with hemodialysis. Risk factors for left ventricular hypertrophy in patients on hemodialysis include: blood flow through arterial-venous fistula, anemia, hypertension, increased extracellular fluid volume, oxidative stress, microinflammation, hyperhomocysteinemia, secondary hyperpara- thyroidism, and disturbed calcium and phosphate homeostasis. Left ventricular pressure overload leads to parallel placement of new sarcomeres and development of concentric hypertrophy of left ventricle. Left ventricular hypertrophy advances in two stages. In the stage of adaptation, left ventricular hypertrophy occurs as a response to increased tension stress of the left ventricular wall and its action is protective. When volume and pressure overload the left ventricle chronically and without control, adaptive hypertrophy becomes maladaptive hypertrophy of the left ventricle, where myocytes are lost, systolic function is deranged and heart insufficiency is developed. Left ventricular mass index-LVMi greater than 131 g/m2 in men and greater than 100 g/m2 in women, and relative wall thickness of the left ventricle above 0.45 indicate concentric hypertrophy of the left ventricle. Eccentric hypertrophy of the left ventricle is defined echocardiographically as LVMi above 131 g/m2 in men and greater than 100 g/m2 in women, with RWT ?0.45. Identification of patients with increased risk for development of left ventricular hypertrophy and application of appropriate therapy to attain target values of risk factors lead to regression of left ventricular hypertrophy, reduced cardiovascular morbidity and mortality rates and improved quality of life in patients treated with regular hemodialyses.

Petrovi? Dejan

2008-01-01

11

Effect of angiotensin II on calcium release phenomena in normal and hypertrophied single cardiac myocytes.  

Science.gov (United States)

The effects of angiotensin II (Ang II) (10(-9) M to 10(-7) M) on calcium releases were established in ventricular myocytes from normal and renal hypertensive adult rats. From each peak systolic indo-1 ratio (405 nm/480 nm), amplitude variation, duration (rise time and fall time), and frequency of spontaneous calcium releases were investigated on freshly isolated cardiomyocytes at rest or under electrical stimulation. The following changes were observed: (1) in spontaneous contracting myocytes, an increase in frequency of calcium transients at 10(-7) M in normal cells (+157%, P II concentration in hypertrophied cells (10(-9) M: +79% P II (P II induced the occurrence of calcium releases with increased sensitivity of hypertrophied cells to Ang II. Such calcium releases are known to be a possible cause of arrhythmias termed "triggered activity". PMID:7731059

Sempé, S; Stuyvers, B; Tariosse, L; Gouverneur, G; Besse, P; Bonoron-Adèle, S

1994-12-01

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Chronic coronary artery constriction leads to moderate myocyte loss and left ventricular dysfunction and failure in rats.  

OpenAIRE

Coronary artery narrowing, ranging from 19% to 61%, was induced in rats and ventricular performance, myocardial damage, and myocyte hypertrophy were examined 1 mo later. Animals were separated into two groups, exhibiting ventricular dysfunction and failure, respectively. Dysfunction consisted of a 2.4-fold increase in left ventricular end diastolic pressure (LVEDP), 15% decrease in left ventricular peak systolic pressure (LVPSP), 24% reduction in developed pressure (DP), and a 16% depression ...

Anversa, P.; Zhang, X.; Li, P.; Capasso, J. M.

1992-01-01

13

Mechanical effects on KATP channel gating in rat ventricular myocytes.  

Science.gov (United States)

Cardiac KATP channels link metabolism with electrical activity. They are implicated in arrhythmias, secretion of atrial natriuretic peptide and protection of the heart from hypertrophy and failure. These processes may involve mechanosensitivity. KATP channels can be activated by mechanical stimulation and disrupting the cortical actin increases the activity. We propose that KATP channels are modulated by local bilayer tension and this tension is affected by cortical F-actin. Here we measured KATP background activity and stretch sensitivity with inside-out patches of rat ventricular myocytes before and after disrupting F-actin. Disrupting F-actin potentiated background activity but did not influence the slope sensitivity in the semilog relationship of NPo vs. suction that is a measure of the change in dimensions between closed and open states. Thus actin alters prestress on the channel probably by parallel elastic sharing of mean cortical tension with the bilayer. PMID:23691027

Huang, Haixia; Liang, Lifang; Liu, Ping; Wei, Hua; Sachs, Frederick; Niu, Weizhen; Wang, Wei

2013-01-01

14

Genetic epidemiology of left ventricular hypertrophy  

OpenAIRE

Left ventricular (LV) hypertrophy is a strong independent predictor of increased cardiovascular morbidity and mortality in clinical and population-based samples. Clinical and hemodynamic stimuli to LV hypertrophy induce not only an increase in cardiac mass and wall thickness but also a fundamental reconfiguration of the protein, cellular and molecular components of the myocardium. Several studies have indicated that LV mass is influenced by genetic factors. The substantial heritability (h2) f...

Bella, Jonathan N.; Go?ring, Harald Hh

2012-01-01

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The ionic mechanism of reperfusion-induced early afterdepolarizations in feline left ventricular hypertrophy.  

OpenAIRE

Left ventricular hypertrophy (LVH) potentiates reperfusion-associated ventricular fibrillation. To study the mechanism responsible, patch-clamp techniques were used to evaluate transmembrane ionic currents during "reperfusion" after a CN(-)-induced metabolic surrogate for ischemia in isolated myocytes from a feline model of experimental LVH. Reperfusion caused the generation of early afterdepolarizations (EADs) from an average take-off potential of -33 mV in LVH cells but not in cells from no...

Furukawa, T.; Bassett, A. L.; Furukawa, N.; Kimura, S.; Myerburg, R. J.

1993-01-01

16

Post-translational modifications of tubulin and microtubule stability in adult rat ventricular myocytes and immortalized HL-1 cardiomyocytes.  

Science.gov (United States)

Little is known about the subcellular distribution and the dynamics of tubulins in adult cardiac myocytes although both are modified during cardiac hypertrophy and heart failure. Using confocal microscopy, we examined post-translational modifications of tubulin in fully differentiated ventricular myocytes isolated from adult rat hearts, as well as in immortalized and dividing HL-1 cardiomyocytes. Detyrosinated Glu-alpha-tubulin was the most abundant post-translationally modified tubulin found in ventricular myocytes, while acetylated- and delta2-alpha-tubulins were found in lower amounts or absent. In contrast, dividing HL-1 cardiomyocytes exhibited high levels of tyrosinated or acetylated alpha-tubulins. A mild nocodazole treatment (0.1 microM, 1 h) disrupted microtubules in HL-1 myocytes, but not in adult ventricular myocytes. A stronger treatment (10 microM, 2 h) was required to disassemble tubulins in adult myocytes. Glu-alpha-tubulin containing microtubules were more resistant to nocodazole treatment in HL-1 cardiomyocytes than in ventricular myocytes. Endogenous activation of the cAMP pathway with the forskolin analog L858051 (20 microM) or the beta-adrenergic agonist isoprenaline (10 microM) disrupted the most labile microtubules in HL-1 cardiomyocytes. In contrast, isoprenaline (10 microM), cholera toxin (200 ng/ml, a G(S)-protein activator), L858051 (20 microM) or forskolin (10 microM) had no effect on the microtubule network in ventricular myocytes. In addition, intracellular Ca2+ accumulation induced either by thapsigargin (2 microM) or caffeine (10 mM) did not modify microtubule stability in ventricular myocytes. Our data demonstrate the unique stability of the microtubule network in adult cardiac myocytes. We speculate that microtubule stability is required to support cellular integrity during cardiac contraction. PMID:15030168

Belmadani, Souad; Poüs, Christian; Fischmeister, Rodolphe; Méry, Pierre-François

2004-03-01

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Diagnostic electrocardiographic dyad criteria of emphysema in left ventricular hypertrophy  

Directory of Open Access Journals (Sweden)

Full Text Available Swapnil S Lanjewar,1 Lovely Chhabra,1 Vinod K Chaubey,1 Saurabh Joshi,1 Ganesh Kulkarni,1 Chandrasekhar Kothagundla,1 Sudesh Kaul,1 David H Spodick21Department of Internal Medicine, 2Department of Cardiovascular Medicine, Saint Vincent Hospital, University of Massachusetts Medical School, Worcester, MA, USABackground: The electrocardiographic diagnostic dyad of emphysema, namely a combination of the frontal vertical P-vector and a narrow QRS duration, can serve as a quasidiagnostic marker for emphysema, with specificity close to 100%. We postulated that the presence of left ventricular hypertrophy in emphysema may affect the sensitivity of this electrocardiographic criterion given that left ventricular hypertrophy generates prominent left ventricular forces and may increase the QRS duration.Methods: We reviewed the electrocardiograms and echocardiograms for 73 patients with emphysema. The patients were divided into two groups based on the presence or absence of echocardiographic evidence of left ventricular hypertrophy. The P-vector, QRS duration, and forced expiratory volume in one second (FEV1 were computed and compared between the two subgroups.Results: There was no statistically significant difference in qualitative lung function (FEV1 between the subgroups. There was no statistically significant difference in mean P-vector between the subgroups. The mean QRS duration was significantly longer in patients with left ventricular hypertrophy as compared with those without left ventricular hypertrophy.Conclusion: The presence of left ventricular hypertrophy may not affect the sensitivity of the P-vector verticalization when used as a lone criterion for diagnosing emphysema. However, the presence of left ventricular hypertrophy may significantly reduce the sensitivity of the electrocardiographic diagnostic dyad in emphysema, as it causes a widening of the QRS duration.Keywords: emphysema, electrocardiogram, left ventricular hypertrophy, chronic obstructive pulmonary disease, P-vector, QRS duration

Lanjewar SS

2013-11-01

18

[Left ventricular hypertrophy and ambulatory blood pressure].  

Science.gov (United States)

The relationship between ambulatory blood pressure and degree of left ventricular hypertrophy is analysed with a triple objective: to assess the value of ambulatory blood pressure recording; the observation of better correlations between left ventricular mass (LVM) and systolic BP with ambulatory rather than clinical recordings is one of the most convincing arguments in favour of the prognostic value of this technique; to guide analysis of ambulatory blood pressure recordings. These recordings provide a large number of measurements over a period of variable duration. The selection of the frequency of measurement, the duration of the recording and the periods of recording (at work, during the day or night), of the criteria of interpretation (average, variability, distribution of values) is partially arbitrary. The possibility of predicting the degree of LVH from these results is one of the only rational approaches while awaiting validation with respect to long-term outcome. In the author's experience, the average of the systolic blood pressure values during the period of activity is the parameter which is most closely related to LVM in untreated hypertensive patients; to improve our understanding of the relationship between the blood pressure, LVM and left ventricular function. There is evidence that the LVH of hypertensive patients has a multifactorial basis. The use of only occasional blood pressure measurements in clinical studies may have increased the apparent importance of one or another factor related to the degree of LVH. The precise influence of these factors, independent of their possible relationship to the blood pressure, should now be reevaluated with respect to ambulatory blood pressure recordings.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1835362

Gosse, P; Dallocchio, M

1991-09-01

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Automated image analysis identifies signaling pathways regulating distinct signatures of cardiac myocyte hypertrophy  

OpenAIRE

Cardiac hypertrophy is controlled by a complex signal transduction and gene regulatory network, containing multiple layers of crosstalk and feedback. While numerous individual components of this network have been identified, understanding how these elements are coordinated to regulate heart growth remains a challenge. Past approaches to measure cardiac myocyte hypertrophy have been manual and often qualitative, hindering the ability to systematically characterize the network's higher-order co...

Bass, Gregory T.; Ryall, Karen A.; Katikapalli, Ashwin; Taylor, Brooks E.; Dang, Stephen T.; Acton, Scott T.; Saucerman, Jeffrey J.

2011-01-01

20

Stochastic Simulation of Cardiac Ventricular Myocyte Calcium Dynamics and Waves  

OpenAIRE

A three dimensional model of calcium dynamics in the rat ventricular myocyte was developed to study the mechanism of calcium homeostasis and pathological calcium dynamics during calcium overload. The model contains 20,000 calcium release units (CRUs) each containing 49 ryanodine receptors. The model simulates calcium sparks with a realistic spontaneous calcium spark rate. It suggests that in addition to the calcium spark-based leak, there is an invisible calcium leak caused by the stochastic ...

Tuan, Hoang-trong Minh; Williams, George S. B.; Chikando, Aristide C.; Sobie, Eric A.; Lederer, W. Jonathan; Jafri, M. Saleet

2011-01-01

21

An analysis of electrocardiographic criteria for determining left ventricular hypertrophy  

OpenAIRE

OBJECTIVE: To determine the most sensitive criterion for the detection of left ventricular hypertrophy according to echocardiographically defined left ventricular mass. METHODS: The Sokolow-Lyon voltage, Sokolow-Lyon-Rappaport, Cornell voltage duration product, White-Bock, and Romhilt-Estes point scoring criteria were compared with left ventricular mass index, corrected for body surface, obtained from the echocardiograms of 306 outpatients (176 females, 130 males), of all age groups. RESULTS:...

Gasperin Carlos Alberto; Germiniani Helio; Facin Carlos Roberto; Souza Admar Moraes de; Cunha Cláudio Leinig Pereira da

2002-01-01

22

"Ischemic" ST elevation in a woman with left ventricular hypertrophy.  

Science.gov (United States)

We report the case of a woman who presented with ST elevation and episodes of chest pain, mimicking an acute myocardial infarction. At coronary angiography no sign of coronary stenosis was found and ECG anomalies were related to asymmetric left ventricular hypertrophy and aortic stenosis. PMID:22903684

Brunetti, Natale Daniele; Correale, Michele; Sai, Rafel; Santoro, Francesco; Ieva, Riccardo; De Gennaro, Luisa; Di Biase, Matteo

2013-01-01

23

Glycogen Synthase Kinase-3? Plays a Pro-Apoptotic Role in ?-Adrenergic Receptor-Stimulated Apoptosis in Adult Rat Ventricular Myocytes: Role of ?1 Integrins  

OpenAIRE

?-adrenergic receptor (?-AR) stimulation induces apoptosis in adult rat ventricular myocytes (ARVM). ?1 integrin signaling plays a protective role in ?-AR-stimulated apoptosis. Glycogen synthase kinase-3? (GSK-3?), a multifunctional serine/threonine kinase, negatively regulates cardiac hypertrophy. Here we show that ?-AR stimulation (isoproterenol; 15 min) increases tyr216 phosphorylation and GSK-3? activity. Inclusion of LiCl, inhibitor of GSK-3?, in the reaction mix or expression o...

Menon, Bindu; Johnson, Jennifer N.; Ross, Robert S.; Singh, Mahipal; Singh, Krishna

2006-01-01

24

[Effects of angiotensin II on spontaneous cytosolic calcium releases in ventricular myocytes of adult normal and hypertensive rats].  

Science.gov (United States)

This study investigated the effects of angiotensin II (Ang II) (10(-9)M to 10(-7)M) on calcium releases in ventricular myocytes from normal and renal hypertensive adult rats (Goldblatt 2K-1C). Newly, isolated myocytes were loaded with fluorescent indo-1/AM and studied at rest or under electrical stimulation. The variation of the ratio of indo-1 emission (405 nm/480 nm) was taken as a measure of cytosolic calcium variations. Five parameters were investigated from each peak systolic indo-1 ratio before and after Ang II addition: amplitude variation, duration with analysis of a rise time and a fall time, and frequency of spontaneous calcium releases. Following changes were observed: in unstimulated myocytes exhibiting spontaneous contractile activity, increase in frequency of calcium transients, at 10(-7)M, in normal cells (+ 157 +/- 27%; p II concentration in hypertrophied cells (+ 79 +/- 31%; p II concentration in hypertrophied cells (+ 36 +/- 20%, p < 0.05; + 39 +/- 18%, p < 0.01; + 77 +/- 34%, p < 0.01 à 10(-9)M, 10(-8)M, 10(-7)M) and only at 10(-7)M in normal cells (+ 68 +/- 22% p < 0.01). Similar results were observed in fall time.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7755454

Sempé, S; Stuyvers, B; Tariosse, L; Gouverneur, G; Besse, P; Bonoron-Adèle, S

1994-08-01

25

Skeletal myocyte hypertrophy requires mTOR kinase activity and S6K1  

International Nuclear Information System (INIS)

The protein kinase mammalian target of rapamycin (mTOR) is a central regulator of cell proliferation and growth, with the ribosomal subunit S6 kinase 1 (S6K1) as one of the key downstream signaling effectors. A critical role of mTOR signaling in skeletal muscle differentiation has been identified recently, and an unusual regulatory mechanism independent of mTOR kinase activity and S6K1 is revealed. An mTOR pathway has also been reported to regulate skeletal muscle hypertrophy, but the regulatory mechanism is not completely understood. Here, we report the investigation of mTOR's function in insulin growth factor I (IGF-I)-induced C2C12 myotube hypertrophy. Added at a later stage when rapamycin no longer had any effect on normal myocyte differentiation, rapamycin completely blocked myocyte hypertrophy as measured by myotube diameter. Importantly, a concerted increase of average myonuclei per myotube was observed in IGF-I-stimulated myotubes, which was also inhibited by rapamycin added at a time when it no longer affected normal differentiation. The mTOR protein level, its catalytic activity, its phosphorylation on Ser2448, and the activity of S6K1 were all found increased in IGF-I-stimulated myotubes compared to unstimulated myotubes. Using C2C12 cells stably expressing rapamycin-resistant forms of mTOR and S6K1, we provide genetic evidence for the requirement of mTOR and its downstream effector S6K1 in the regulation of myotube hypertrophy. Our results suggest distinct hypertrophy. Our results suggest distinct mTOR signaling mechanisms in different stages of skeletal muscle development: While mTOR regulates the initial myoblast differentiation in a kinase-independent and S6K1-independent manner, the hypertrophic function of mTOR requires its kinase activity and employs S6K1 as a downstream effector

26

Mitochondrial metabolic adaptation in right ventricular hypertrophy and failure  

OpenAIRE

Right ventricular failure (RVF) is the leading cause of death in pulmonary arterial hypertension (PAH). Some patients with pulmonary hypertension are adaptive remodelers and develop RV hypertrophy (RVH) but retain RV function; others are maladaptive remodelers and rapidly develop RVF. The cause of RVF is unclear and understudied and most PAH therapies focus on regressing pulmonary vascular disease. Studies in animal models and human RVH suggest that there is reduced glucose oxidation and incr...

Piao, Lin; Marsboom, Glenn; Archer, Stephen L.

2010-01-01

27

Left Ventricular Hypertrophy May Be Transient in the Emergency Department  

OpenAIRE

Background: While research has established that the bedside electrocardiogram (ECG) is an insensitive test for the presence or absence of left ventricular hypertrophy (LVH), the finding, when present, is thought to be reproducible.Objective: To assess the reproducibility of serial ECGs done in the emergency department (ED) with regard to the presence or absence of LVH.Method: A prospective study on consecutive patients admitted to an ED-run cardiac observation unit. A single reviewer collecte...

Shoenberger, Jan M.; Voskanian, Serineh; Johnson, Sara; Ahern, Terence; Henderson, Sean O.

2009-01-01

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Cell contact as an independent factor modulating cardiac myocyte hypertrophy and survival in long-term primary culture  

Science.gov (United States)

Cardiac myocytes maintained in cell culture develop hypertrophy both in response to mechanical loading as well as to receptor-mediated signaling mechanisms. However, it has been shown that the hypertrophic response to these stimuli may be modulated through effects of intercellular contact achieved by maintaining cells at different plating densities. In this study, we show that the myocyte plating density affects not only the hypertrophic response and features of the differentiated phenotype of isolated adult myocytes, but also plays a significant role influencing myocyte survival in vitro. The native rod-shaped phenotype of freshly isolated adult myocytes persists in an environment which minimizes myocyte attachment and spreading on the substratum. However, these conditions are not optimal for long-term maintenance of cultured adult cardiac myocytes. Conditions which promote myocyte attachment and spreading on the substratum, on the other hand, also promote the re-establishment of new intercellular contacts between myocytes. These contacts appear to play a significant role in the development of spontaneous activity, which enhances the redevelopment of highly differentiated contractile, junctional, and sarcoplasmic reticulum structures in the cultured adult cardiomyocyte. Although it has previously been shown that adult cardiac myocytes are typically quiescent in culture, the addition of beta-adrenergic agonists stimulates beating and myocyte hypertrophy, and thereby serves to increase the level of intercellular contact as well. However, in densely-plated cultures with intrinsically high levels of intercellular contact, spontaneous contractile activity develops without the addition of beta-adrenergic agonists. In this study, we compare the function, morphology, and natural history of adult feline cardiomyocytes which have been maintained in cultures with different levels of intercellular contact, with and without the addition of beta-adrenergic agonists. Intercellular contact, communication, and transmission of contractile forces between myocytes appears to play a primary role in remodeling the 2-dimensional cell layer into a parallel alignment of elongated myocytes with highly developed intercalated disk-like junctions. This highly differentiated state is very stable, and cultures which achieve this state exhibit significantly greater longevity than more sparsely plated myocytes. These myocytes typically continue beating, and survive from 6 to more than 12 weeks in culture. When this level of contact and differentiation are not achieved, even among beta-adrenergic stimulated myocytes, contractile activity is not sustained, myofibrils atrophy, there is little or no development of junctional complexes, and the period of myocyte viability is typically no more than 5 weeks in vitro.

Clark, W. A.; Decker, M. L.; Behnke-Barclay, M.; Janes, D. M.; Decker, R. S.

1998-01-01

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An analysis of electrocardiographic criteria for determining left ventricular hypertrophy  

Directory of Open Access Journals (Sweden)

Full Text Available OBJECTIVE: To determine the most sensitive criterion for the detection of left ventricular hypertrophy according to echocardiographically defined left ventricular mass. METHODS: The Sokolow-Lyon voltage, Sokolow-Lyon-Rappaport, Cornell voltage duration product, White-Bock, and Romhilt-Estes point scoring criteria were compared with left ventricular mass index, corrected for body surface, obtained from the echocardiograms of 306 outpatients (176 females, 130 males, of all age groups. RESULTS: The Cornell voltage duration product criteria index had the greatest sensitivity in women (54.90%, and the Sokolow-Lyon-Rappaport index was most sensitive in men (73.53%. When applied to men at the same voltage amplitude (20mm as that in women, the Cornell index showed increased sensitivity relative to the conventional index (28mm of 67.65% (P<=0.01 and a sensitivity similar to that of the Sokolow-Lyon-Rappaport index, with higher specificity (P<=0.01. The White-Bock and Romhilt-Estes criteria were the least sensitive in men and women, despite their high specificity. The electrocardiographic criteria were more efficient when dilatation predominated over left ventricular hypertrophy. CONCLUSION: The Cornell index had greater sensitivity in women, and the Sokolow-Lyon-Rappaport index was more sensitive in men. When applied to men at the same voltage amplitude as that of women, the Cornell index had an increase in sensitivity similar to that of the Sokolow-Lyon-Rappaport index.

Carlos Alberto Gasperin

2002-01-01

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An analysis of electrocardiographic criteria for determining left ventricular hypertrophy  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english OBJECTIVE: To determine the most sensitive criterion for the detection of left ventricular hypertrophy according to echocardiographically defined left ventricular mass. METHODS: The Sokolow-Lyon voltage, Sokolow-Lyon-Rappaport, Cornell voltage duration product, White-Bock, and Romhilt-Estes point sc [...] oring criteria were compared with left ventricular mass index, corrected for body surface, obtained from the echocardiograms of 306 outpatients (176 females, 130 males), of all age groups. RESULTS: The Cornell voltage duration product criteria index had the greatest sensitivity in women (54.90%), and the Sokolow-Lyon-Rappaport index was most sensitive in men (73.53%). When applied to men at the same voltage amplitude (20mm) as that in women, the Cornell index showed increased sensitivity relative to the conventional index (28mm) of 67.65% (P

Carlos Alberto, Gasperin; Helio, Germiniani; Carlos Roberto, Facin; Admar Moraes de, Souza; Cláudio Leinig Pereira da, Cunha.

2002-01-01

31

Physiological pathway of magnesium influx in rat ventricular myocytes.  

Science.gov (United States)

Cytoplasmic free Mg(2+) concentration ([Mg(2+)]i) was measured in rat ventricular myocytes with a fluorescent indicator furaptra (mag-fura-2) introduced by AM-loading. By incubation of the cells in a high-K(+) (Ca(2+)- and Mg(2+)-free) solution, [Mg(2+)]i decreased from ? 0.9 mM to 0.2 to 0.5 mM. The lowered [Mg(2+)]i was recovered by perfusion with Ca(2+)-free Tyrode's solution containing 1 mM Mg(2+). The time course of the [Mg(2+)]i recovery was fitted by a single exponential function, and the first derivative at time 0 was analyzed as being proportional to the initial Mg(2+) influx rate. The Mg(2+) influx rate was inversely related to [Mg(2+)]i, being higher at low [Mg(2+)]i. The Mg(2+) influx rate was augmented by the high extracellular Mg(2+) concentration (5 mM), whereas it was greatly reduced by cell membrane depolarization caused by high K(+). Known inhibitors of TRPM7 channels, 2-aminoethoxydiphenyl borate (2-APB), NS8593, and spermine reduced the Mg(2+) influx rate with half inhibitory concentrations (IC50) of, respectively, 17 ?M, 2.0 ?M, and 22 ?M. We also studied Ni(2+) influx by fluorescence quenching of intracellular furaptra by Ni(2+). The Ni(2+) influx was activated by lowering intra- and extracellular Mg(2+) concentrations, and it was inhibited by 2-APB and NS8593 with IC50 values comparable with those for the Mg(2+) influx. Intracellular alkalization (caused by pulse application of NH4Cl) enhanced, whereas intracellular acidification (induced after the removal of NH4Cl) slowed the Mg(2+) influx. Under the whole-cell patch-clamp configuration, the removal of intracellular and extracellular divalent cations induced large inward and outward currents, MIC (Mg-inhibited cation) currents or IMIC, carried by monovalent cations likely via TRPM7 channels. IMIC measured at -120 mV was diminished to ? 50% by 100 ?M 2-APB or 10 ?M NS8593. These results suggest that TRPM7/MIC channels serve as a major physiological pathway of Mg(2+) influx in rat ventricular myocytes. PMID:25418090

Tashiro, Michiko; Inoue, Hana; Konishi, Masato

2014-11-01

32

U waves in ventricular hypertrophy: possible demonstration of mechano-electrical feedback.  

OpenAIRE

The relation between ventricular function and electrocardiographic evidence of hypertrophy (by voltage criteria, "strain", and U wave inversion) was examined by means of M mode echocardiography and apex cardiography in 73 patients with diseases associated with left ventricular hypertrophy and 10 normal volunteers. In patients with disease, left ventricular cavity dimension and fractional shortening were unrelated to electrocardiographic findings, but left ventricular posterior wall thickness ...

Choo, M. H.; Gibson, D. G.

1986-01-01

33

Electrophysiology of adult cat cardiac ventricular myocytes: changes during primary culture.  

Science.gov (United States)

To investigate the nature of electrophysiological changes in adult cat cardiac ventricular myocytes that may occur when cells are maintained in primary culture for 1-2 wk, the electrophysiology of cells freshly isolated from collagenase-perfused hearts (day 0 controls) was compared with that of cells maintained in primary culture for up to 14 days 1) on a two-dimensional (2D) surface (laminin-coated coverslips), which allowed for changes in cellular morphology, or 2) in a three-dimensional (3D) alginate matrix, which minimized changes in cell shape. Action potentials and whole cell ionic currents were recorded using a conventional whole cell patch technique. Whereas cellular resting potential and the depth of the "notch" terminating phase 1 were diminished relative to controls in 2D- and 3D-cultured cells, the action potential duration and the incidence of early afterdepolarizations (EADs) were increased relative to controls in 2D- but not in 3D-cultured cells. Corresponding alterations in whole cell ionic currents included a 40% reduction in inwardly rectifying K current (IK1) conductance (GK1) and a 90% reduction in transient outward K current (Ito) conductance (Gto) in 2D- and 3D-cultured cells relative to day 0 controls and a 50% increase in L-type Ca current (ICa-L) conductance (GCa-L) in 2D-cultured cells relative to 3D-cultured cells and day 0 controls. The reduction in Gto in long-term culture was half-maximal by days 7 and 8 and could not be attributed to reduced Ito availability, involvement of a noninactivating Ito, the cell culture procedure itself, or the presence of serum in the culture media. Gto was larger in day 0 cells from a heart with right ventricular hypertrophy than in day 0 normal control cells and was reduced subsequent to placement of cells in 3D culture for 19 days. The results suggest that long-term culture and change in cellular morphology can affect the electrophysiology of cardiac ventricular myocytes. PMID:7733221

Schackow, T E; Decker, R S; Ten Eick, R E

1995-04-01

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Modeling CICR in rat ventricular myocytes: voltage clamp studies  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background The past thirty-five years have seen an intense search for the molecular mechanisms underlying calcium-induced calcium-release (CICR in cardiac myocytes, with voltage clamp (VC studies being the leading tool employed. Several VC protocols including lowering of extracellular calcium to affect Ca2+ loading of the sarcoplasmic reticulum (SR, and administration of blockers caffeine and thapsigargin have been utilized to probe the phenomena surrounding SR Ca2+ release. Here, we develop a deterministic mathematical model of a rat ventricular myocyte under VC conditions, to better understand mechanisms underlying the response of an isolated cell to calcium perturbation. Motivation for the study was to pinpoint key control variables influencing CICR and examine the role of CICR in the context of a physiological control system regulating cytosolic Ca2+ concentration ([Ca2+]myo. Methods The cell model consists of an electrical-equivalent model for the cell membrane and a fluid-compartment model describing the flux of ionic species between the extracellular and several intracellular compartments (cell cytosol, SR and the dyadic coupling unit (DCU, in which resides the mechanistic basis of CICR. The DCU is described as a controller-actuator mechanism, internally stabilized by negative feedback control of the unit's two diametrically-opposed Ca2+ channels (trigger-channel and release-channel. It releases Ca2+ flux into the cyto-plasm and is in turn enclosed within a negative feedback loop involving the SERCA pump, regulating[Ca2+]myo. Results Our model reproduces measured VC data published by several laboratories, and generates graded Ca2+ release at high Ca2+ gain in a homeostatically-controlled environment where [Ca2+]myo is precisely regulated. We elucidate the importance of the DCU elements in this process, particularly the role of the ryanodine receptor in controlling SR Ca2+ release, its activation by trigger Ca2+, and its refractory characteristics mediated by the luminal SR Ca2+ sensor. Proper functioning of the DCU, sodium-calcium exchangers and SERCA pump are important in achieving negative feedback control and hence Ca2+ homeostasis. Conclusions We examine the role of the above Ca2+ regulating mechanisms in handling various types of induced disturbances in Ca2+ levels by quantifying cellular Ca2+ balance. Our model provides biophysically-based explanations of phenomena associated with CICR generating useful and testable hypotheses.

Palade Philip T

2010-11-01

35

Left Ventricular Hypertrophy and Microalbuminuria in Patients With Essential Hypertension  

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Full Text Available Introduction. Microalbuminuria and left ventricular hypertrophy (LVH have both been shown to predict increased cardiovascular morbidity and mortality, especially in diabetic patients. The present study investigated the relationship between microalbuminuria and LVH in patients with essential hypertension. Materials and Methods. After a primary workup to rule out secondary hypertension, 110 essential hypertensive patients with LVH (mean age, 62.97 ± 11.02 years and 10 essential hypertensive patients without LVH (mean age, 65.13 ± 10.15 years were enrolled in this case-control study. Spot urine sample was collected for the assessment of microalbuminuria and creatinine concentrations in the two groups. Smoking status, blood pressure, and serum levels of total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and creatinine were evaluated.  Results. Patients with LVH had significantly higher microalbuminuria level compared with those without LVH (mean urine albumin-creatinine ratio, 54.4 ± 39.48 ?g/mg versus 33.56 ± 21.73 ?g/mg; P P Conclusions. Left ventricular hypertrophy is associated with microalbuminuria in patients with essential hypertension. These data are strengthening the role of microalbuminuria as an indicator of high cardiovascular risk.

Ali Monfared

2013-05-01

36

Changes of Ventricular Myocytes Membrane Capacitance in Rabbit with Myocardial Infarction and Effects of Carvedilol  

DEFF Research Database (Denmark)

Objective: To investigate effects of long-term treatment of oral Carvedilol on ventricular myocytes membrane capacitance in HMI. Methods: 30 rabbits were randomly assigned in three groups: HMI group, ligation of circumflex coronary artery; Carvedilol group, with operation the same as HMI group, and administration of oral Carvedilol 0.33 mg/kg×3 months beginning on the day of operation; Sham group, left thoracotomy with no coronary artery ligation. 3 months after surgery, rabbits were harvested. Myocytes were isolated by enzymatic method. The cell membrane capacitance was recorded by using the whole cell patch clamp technique. Results: The membrane capacitance of myocytes in CVD group was reduced significantly as compared with those in HMI group which was larger than those in Sham group (P<0.05). Conclusion: Long-term treatment of oral Carvedilol may reverse the increase of ventricular myocytes membrane capacitance.

Niu, Hui-Yan; Liang, Bo

2005-01-01

37

The Association of Growth Differentiation Factor-15 with Left Ventricular Hypertrophy in Hypertensive Patients  

OpenAIRE

Growth differentiation factor-15 (GDF-15) has been identified as an endogenous anti-hypertrophy effect. However, the association of plasma GDF-15 levels with left ventricular hypertrophy (LVH) in hypertension is poorly understood. We investigate the effect of plasma GDF-15 levels on left ventricular hypertrophy (LVH) in hypertension. We measured the plasma levels of GDF-15 in 299 untreated hypertensive patients which consisted of 99 with LVH and 200 without LVH using immunoradiometric assay. ...

Xue, Hao; Fu, Zhenhong; Chen, Yundai; Xing, Youhong; Liu, Jie; Zhu, Hang; Zhou, Xiao

2012-01-01

38

Diagnosis of left ventricular hypertrophy and distinction against hypertrophic cardiomyopathy in Krenzke's Body Surface Potential Mapping  

OpenAIRE

The diagnosis and quantification of left ventricular hypertrophy (LVH) is of particular prognostic importance since early therapy is associated with a decrease in cardiovascular mortality. The relative risk of cardiovascular events increases with the degree of hypertrophy. Existing 12-lead-ECG indices for predicting left ventricular hypertrophy are of limited diagnostic value as screening tools. This is partly due to the general limitations of electrocardiography where electrical signals of t...

Bangha-szabo, Daniel

2013-01-01

39

Carotid intima-media thickness and left ventricular hypertrophy in hemodialysis patients  

OpenAIRE

Introduction: Two principal findings of cardiovascular disease in end-stage renal disease patients undergoing regular hemodialysis are left ventricular hypertrophy (LVH) and arterial disease due to rapidly progressive atherosclerotic vascular disease that can be characterized by an enlargement and hypertrophy of arteries (intima-media complex thickening; IMT).Objectives: In this study, we sought to evaluate the relationship between left ventricular hypertrophy with intima-media complex thicke...

Rafieian-Kopaei Mahmoud; Nasri Hamid

2013-01-01

40

Subcellular heterogeneity of ryanodine receptor properties in ventricular myocytes with low T-tubule density  

OpenAIRE

Rationale: In ventricular myocytes of large mammals, not all ryanodine receptor (RyR) clusters are associated with T-tubules (TTs); this fraction increases with cellular remodeling after myocardial infarction (MI). Objective: To characterize RyR functional properties in relation to TT proximity, at baseline and after MI. Methods: Myocytes were isolated from left ventricle of healthy pigs (CTRL) or from the area adjacent to a myocardial infarction ...

Rota, M.; Biesmans, L.; Macquaide, N.; Heinzel, F. R.; Bito, V.; Smith, G. L.; Sipido, K. R.

2011-01-01

41

Cardiac arrhythmias and left ventricular hypertrophy in systemic hypertension  

International Nuclear Information System (INIS)

Background: Hypertensive left ventricular hypertrophy (LVH) is associated with increased risk of arrhythmias and mortality. Objective was to investigate the prevalence of cardiac arrhythmias and LVH in systemic hypertension. Methods: In all subjects blood pressure was measured, electrocardiography and echocardiography was done. Holter monitoring and exercise test perform in certain cases. There were 500 hypertensive patients, 156 (31.2%) men and 344 (69%) women >30 years of age in the study. Among them 177 (35.4%) were diabetic, 224 (45%) were dyslipidemia, 188 (37.6%) were smokers, and 14 (3%) had homocysteinemia. Mean systolic BP (SBP) was 180 +- 20 mm Hg and diastolic BP (DBP) was 95 +- 12 in male and female patients. Left ventricular mass index (LVMI) was 119.2 +- 30 2 2gm/m in male while 103 +- 22 gm/m in female patients. Palpitation was seen in 126 (25%) male and 299 (59.8%) female patients. Atrial fibrillation was noted in 108 (21.6%) male and 125 (25%) female patients, 30 (6%) male and 82 (16.4%) female patients had atrial flutter. Ventricular tachycardia was noted in 37 (7.4%) male and 59 (11.8%) female patients. Holter monitoring showed significant premature ventricular contractions (PVC'S) in 109 (21.8%) male and 128 (25.69%) female patients while Holter showed atrial arrhythmias (APC'S) in 89 (17.8%) males and 119 (23.8%) females. Angiography findings diagnosed coronary artery disease in 119 (23.8%) with CAD male and 225 (45%) without CAD while 47 (9.4%) fnd 225 (45%) without CAD while 47 (9.4%) females presented with CAD and 109 (21.8%) without CAD. Conclusion: A significant association has been demonstrated between hypertension and arrhythmias. Diastolic dysfunction of the left ventricle, left atrial size and function, as well as LVH have been suggested as the underlying risk factors for supraventricular, ventricular arrhythmias and sudden death in hypertensives with LVH. (author)

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Docosahexaenoic acid has influence on action potentials and transient outward potassium currents of ventricular myocytes  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background There are many reports about the anti-arrhythmic effects of ?-3 polyunsaturated fatty acids, however, the mechanisms are still not completely delineated. The purpose of this study was to investigate the characteristics of action potentials and transient outward potassium currents (Ito of Sprague-Dawley rat ventricular myocytes and the effects of docosahexaenoic acid (DHA on action potentials and Ito. Methods The calcium-tolerant rat ventricular myocytes were isolated by enzyme digestion. Action potentials and Ito of epicardial, mid-cardial and endocardial ventricular myocytes were recorded by whole-cell patch clamp technique. Results 1. Action potential durations (APDs were prolonged from epicardial to endocardial ventricular myocytes (P 2. Ito current densities were decreased from epicardial to endocardial ventricular myocytes, which were 59.50 ± 15.99 pA/pF, 29.15 ± 5.53 pA/pF, and 12.29 ± 3.62 pA/pF, respectively at +70 mV test potential (P 3. APDs were gradually prolonged with the increase of DHA concentrations from 1 ?mol/L to 100 ?mol/L, however, APDs changes were not significant as DHA concentrations were in the range of 0 ?mol/L to 1 ?mol/L. 4. Ito currents were gradually reduced with the increase of DHA concentrations from 1 ?mol/L to 100 ?mol/L, and its half-inhibited concentration was 5.3 ?mol/L. The results showed that there were regional differences in the distribution of action potentials and Ito in rat epicardial, mid-cardial and endocardial ventricular myocytes. APDs were prolonged and Ito current densities were gradually reduced with the increase of DHA concentrations. Conclusion The anti-arrhythmia mechanisms of DHA are complex, however, the effects of DHA on action potentials and Ito may be one of the important causes.

Yang Zhen-Yu

2010-04-01

43

Electrocardiographic measures of left ventricular hypertrophy show greater heritability than echocardiographic left ventricular mass.  

OpenAIRE

AIMS: To assess the heritability (i.e. relative contribution of genetic factors to the variability) of continuous measures of left ventricular hypertrophy determined by electrocardiography and echocardiography. METHODS AND RESULTS: We studied 955 members of 229 Caucasian families, ascertained through a hypertensive proband. Electrocardiographic measurements were performed manually on resting 12-lead electrocardiograms, and echocardiographic measurements were made on M-mode images. Sex-specifi...

Mayosi, Bm; Keavney, B.; Kardos, A.; Davies, Ch; Ratcliffe, Pj; Farrall, M.; Watkins, H.

2002-01-01

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Arritmias ventriculares e hipertrofia ventricular esquerda na cardiomiopatia hipertrófica / Ventricular arrhythmias and left ventricular hypertrophy in hypertrophic cardiomyopathy  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese FUNDAMENTO: Na Cardiomiopatia Hipertrófica (CMH), o grau de Hipertrofia Ventricular Esquerda (HVE) poderia influenciar o desenvolvimento de arritmias ventriculares. OBJETIVO: Analisar, na CMH, a associação entre a ocorrência de arritmias ventriculares no eletrocardiograma-Holter (ECG-Holter) e o gra [...] u de HVE determinado ao ecocardiograma pela espessura parietal máxima (EPM) e Índice de Massa (IM). MÉTODOS: Cinquenta e quatro pacientes consecutivos com CMH realizaram ECG-Holter de 24 horas e ecocardiograma para avaliação do grau de HVE através da EPM e IM. Foram estabelecidos dois níveis para a ocorrência de arritmias ventriculares: I - extrassístoles isoladas ou pareadas e II - Taquicardia Ventricular Não Sustentada (TVNS). RESULTADOS: Nos 13 pacientes (24%) com TVNS (nível II), houve maior frequência de EPM do ventrículo esquerdo (VE) > 21 mm (n = 10, 77%; 25 ± 4 mm) e IMVE > 144 g/m² (n = 10, 77%; 200 ± 30 g/m²), em relação àqueles que apresentavam apenas arritmia extrassistólica (nível I) (n = 41, 76%), em que essas medidas foram identificadas em, respectivamente, 37% (n = 15, 23 ± 1 mm), p = 0,023, e 39% (n = 16, 192 ± 53 g/m²) dos casos, p = 0,026. Os citados valores de corte foram determinados por curva ROC com intervalo de confiança de 95%. O registro de TVNS foi mais comum em pacientes com EPMVE > 21 mm e IMVE > 144 g/m² (8 de 13; 62%), do que naqueles com uma (4 de 13; 31%) ou nenhuma (1 de 13; 8%) variável ecocardiográfica acima dos valores de corte, p = 0,04. CONCLUSÃO: A ocorrência de arritmias ventriculares no Holter associou-se, na CMH, ao grau de HVE, avaliado pelo ecocardiograma através da respectiva EPM e IM. Abstract in english BACKGROUND: In hypertrophic cardiomyopathy (HCM), the degree of left ventricular hypertrophy (LVH) could influence the development of ventricular arrhythmias. OBJECTIVE: In HCM, analyze the association between the occurrence of ventricular arrhythmias determined by Holter electrocardiogram (ECG-Holt [...] er) and the degree of LVH determined by maximum wall thickness (MWT) in echocardiography and body mass index (BMI). METHODS: Fifty-four consecutive patients with HCM underwent 24-hour ECG-Holter and echocardiography for assessment of level of LVH through MWT and BMI. Two levels were established for the occurrence of Ventricular Arrhythmias: I - alone or paired extrasystoles and II - Non- Sustained Ventricular Tachycardia (NSVT). RESULTS: In 13 patients (24%) with NSVT (level II), there was a higher frequency of MWT of the left ventricle (LV) > 21 mm (n = 10, 77%, 25 ± 4 mm) and LLLV = 144 g/m² (n = 10, 77%, 200 ± 30 g/m²), in comparison with those presenting with extrasystole arrhythmias (level I) (n = 41, 76%), in which these measures were identified in, respectively, 37 % (n= 15, 23 ± 1 mm), p = 0.023, and 39% (n = 16, 192 ± 53 g / m²) of the cases (p = 0.026). The cut-off values mentioned were determined by the ROC curve with a confidence interval of 95%. NSVT was more common in patients with MWTLV > 21 mm and LLLV > 144 g/m² (8 of 13, 62%) than in those with (4 of 13, 31%) or without (1 of 13; 8%) echocardiographic variables above cut-off values (p = 0.04). CONCLUSION: In HCM, occurrence of ventricular arrhythmias by Holter was associated with the degree of LVH assessed by echocardiography through MWT and BMI.

Beatriz Piva e, Mattos; Marco Antonio Rodrigues, Torres; Valéria Centeno de, Freitas; Fernando Luís, Scolari; Melina Silva de, Loreto.

2013-05-01

45

Histologically Measured Cardiomyocyte Hypertrophy Correlates with Body Height as Strongly as with Body Mass Index  

OpenAIRE

Cardiac myocytes are presumed to enlarge with left ventricular hypertrophy (LVH). This study correlates histologically measured myocytes with lean and fat body mass. Cases of LVH without coronary heart disease and normal controls came from forensic autopsies. The cross-sectional widths of myocytes in H&E-stained paraffin sections ...

Sander, Gary E.; Tracy, Richard E.

2011-01-01

46

Changes in excitation-contraction coupling in an isolated ventricular myocyte model of cardiac stunning.  

Science.gov (United States)

To investigate cardiac stunning, we recorded intracellular [Ca(2+)], contractions, and electrical activity in isolated guinea pig ventricular myocytes exposed to simulated ischemia and reperfusion. After equilibration, ischemia was simulated by exposing myocytes to hypoxia, acidosis, hyperkalemia, hypercapnia, lactate accumulation, and substrate deprivation for 30 min at 37 degrees C. Reperfusion was simulated by exposure to Tyrode solution. Field-stimulated myocytes exhibited stunning upon reperfusion. By 10 min of reperfusion, contraction amplitude decreased to 43.0 +/- 5.5% of preischemic values (n = 15, P stunned myocytes. In voltage-clamped cells, peak L-type Ca(2+) current was reduced to 47.4 +/- 4.5% of preischemic values at 10 min of reperfusion (n = 21, P stunning is associated with reduced L-type Ca(2+) current but that alterations in Ca(2+) homeostasis and release are not directly responsible for stunning. PMID:12124230

Louch, William E; Ferrier, Gregory R; Howlett, Susan E

2002-08-01

47

Resveratrol protects rabbit ventricular myocytes against oxidative stress-induced arrhythmogenic activity and Ca2+ overload  

Science.gov (United States)

Aim: To investigate whether resveratrol suppressed oxidative stress-induced arrhythmogenic activity and Ca2+ overload in ventricular myocytes and to explore the underlying mechanisms. Methods: Hydrogen peroxide (H2O2, 200 ?mol/L)) was used to induce oxidative stress in rabbit ventricular myocytes. Cell shortening and calcium transients were simultaneously recorded to detect arrhythmogenic activity and to measure intracellular Ca2+ ([Ca2+]i). Ca2+/calmodulin-dependent protein kinases II (CaMKII) activity was measured using a CaMKII kit or Western blotting analysis. Voltage-activated Na+ and Ca2+ currents were examined using whole-cell recording in myocytes. Results: H2O2 markedly prolonged Ca2+ transient duration (CaTD), and induced early afterdepolarization (EAD)-like and delayed afterdepolarization (DAD)-like arrhythmogenic activity in myocytes paced at 0.16 Hz or 0.5 Hz. Application of resveratrol (30 or 50 ?mol/L) dose-dependently suppressed H2O2-induced EAD-like arrhythmogenic activity and attenuated CaTD prolongation. Co-treatment with resveratrol (50 ?mol/L) effectively prevented both EAD-like and DAD-like arrhythmogenic activity induced by H2O2. In addition, resveratrol markedly blunted H2O2-induced diastolic [Ca2+]i accumulation and prevented the myocytes from developing hypercontracture. In whole-cell recording studies, H2O2 significantly enhanced the late Na+ current (INa,L) and L-type Ca2+ current (ICa,L) in myocytes, which were dramatically suppressed or prevented by resveratrol. Furthermore, H2O2-induced ROS production and CaMKII activation were significantly prevented by resveratrol. Conclusion: Resveratrol protects ventricular myocytes against oxidative stress-induced arrhythmogenic activity and Ca2+ overload through inhibition of INa,L/ICa,L, reduction of ROS generation, and prevention of CaMKII activation. PMID:23912472

Li, Wei; Wang, Yue-peng; Gao, Ling; Zhang, Peng-pai; Zhou, Qing; Xu, Quan-fu; Zhou, Zhi-wen; Guo, Kai; Chen, Ren-hua; Yang, Huang-tian; Li, Yi-gang

2013-01-01

48

Pharmacological characterization of A1 adenosine receptors in isolated rat ventricular myocytes.  

Science.gov (United States)

The aim of the present study was the characterization of adenosine receptors in isolated rat ventricular myocytes. The cAMP-levels of rat ventricular myocytes in the presence of 1 mumol/l isoprenaline were reduced by up to 48% by adenosine analogues; the rank order of potency was: R-N6-phenylisopropyladenosine (IC50 60 nmol/l), 5'-N-ethylcarboxamidoadenosine (IC50 360 nmol/l) and S-N6-phenylisopropyladenosine (IC50 16 mumol/l). The adenosine receptor antagonist XAC ("xanthine amine congener") antagonized the effect of R-N6-phenylisopropyladenosine in a concentration-dependent manner with a Ki-value of 20 nmol/l. The A1 receptor-selective radioligand R-N6-125I-p-hydroxyphenylisopropyladenosine bound to membranes prepared from rat ventricular myocytes in a saturable manner with a Bmax of 17.7 fmol/mg protein and a KD-value of 1.1 nmol/l. Adenosine analogues competed for the binding with the same rank order of potency as for the inhibition of the isoprenaline-induced cAMP-increase. GTP inhibited radioligand binding with an IC50-value of 73 mumol/l. These results suggest the presence of A1 adenosine receptors on rat ventricular myocytes, which mediate an inhibition of adenylate cyclase. The receptors may be responsible for the effects of adenosine and its analogues on the heart. PMID:2825048

Martens, D; Lohse, M J; Rauch, B; Schwabe, U

1987-09-01

49

Prevalencia de hipertrofia ventricular izquierda en pacientes hipertensos / Prevalence of left ventricular hypertrophy in hypertensive patients  

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: Spanish Abstract in spanish Antecedentes: se ha documentado a la hipertrofia ventricular izquierda como una de las manifestaciones tempranas de afectación cardiaca en la enfermedad hipertensiva. Objetivo: evaluar la prevalencia de hipertrofia ventricular izquierda en los pacientes hipertensos que asisten a los programas de con [...] trol en instituciones de salud de Boyacá. Material y métodos: mediante muestreo secuencial aleatorio se ensambló una muestra de 1275 pacientes a quienes se realizó valoración de la presión arterial y electrocardiograma. Se evaluaron criterios de Cornell, Romhilt-Estest y Rodríguez-Padial para determinar la presencia de hipertrofia ventricular izquierda. Resultados: se encontró prevalencia global de 17.9% de HVI en los pacientes analizados, con marcadas diferencias por municipio. La HVI se encontró asociada con edad mayor de 65 años, sexo femenino, índice de masa corporal aumentado y cifras elevadas de presión sistólica y diastólica. Conclusión: estos resultados sugieren la necesidad de incrementar los programas de tamizaje y control de la presión arterial, así como de incluir capacitación a los agentes de salud en la valoración de evidencia sugestiva de HVI como alteraciones electrocardiográficas y diferencias en las presionesentre las dos extremidades superiores. Abstract in english Background: left ventricular hypertrophy has been documented as one of the early manifestations of cardiac involvement in hypertensive disease. Objectives: to assess the prevalence of left ventricular hypertrophy in hypertensive patients attending control programs in health institutions of Boyacá. M [...] aterials and methods: by sequential random sampling, a sample of 1275 patients for whom assessment of blood pressure and electrocardiogram was performed, was assembled. Cornell, Romhilt-ESTest and Rodriguez-Padial criteria were evaluated to determine the presence of left ventricular hypertrophy. Results: overall prevalence of LVH in the patients studied was 17.9%, with marked differences respect to the village of origin. LVH was found associated with age over 65, female gender, increased body mass index and high levels of systolic and diastolic pressure. Conclusion: these results suggest the need for increased screening programs and control of blood pressure as well as include training to health workers in assessing suggestive evidence of LVH as electrocardiographic changes and differences in pressure between the two upper limbs.

Fred Gustavo, Manrique; Juan Manuel, Ospina; Giomar Maritza, Herrera-Amaya.

2014-07-01

50

Evaluation of myocardial function in the presence of left ventricular hypertrophy in athletes and hypertensive patients  

OpenAIRE

Introduction Myocardial hypertrophy of the left ventricle may be of physiological or pathological nature. Distinction of these two types of hypertrophy is sometimes not easy and represents a diagnostic challenge. The aim of the study was to assess global diastolic and regional systolic and diastolic myocardial function in the presence of left ventricular hypertrophy in athletes and hypertensive patients. Material and methods In 18 male hypertensive patients and 14 male athletes global diastol...

Deljanin-Ili? Marina; Ili? Stevan; ?or?evi? Dragan; Zdravkovi? Marija; Ili? Vladimir

2008-01-01

51

Left ventricular hypertrophy induced by aortic banding impairs relaxation of isolated coronary arteries  

OpenAIRE

Abstract Background/Aims: Left ventricular hypertrophy is associated with impaired coronary vascular reserve. We examined the effect of pressure-overload hypertrophy on vasorelaxant responses of guinea-pig isolated coronary small arteries and compared them mesenteric small arteries. Methods: Pressure-overload was induced by banding the ascending aorta of guinea pigs. Haemodynamics, ventricular, atrial and lung weights were measured 168 days after banding. Isolated coronary and mese...

Mcgoldrick, Rory B.; Kingsbury, Martyn; Turner, Mark A.; Sheridan, Desmond J.; Hughes, Alun D.

2007-01-01

52

Altered ubiquitin-proteasome signaling in right ventricular hypertrophy and failure  

OpenAIRE

Alterations in the ubiquitin-proteasome system (UPS) have been described in left ventricular hypertrophy and failure, although results have been inconsistent. The role of the UPS in right ventricular (RV) hypertrophy (RVH) and RV failure (RVF) is unknown. Given the greater percent increase in RV mass associated with RV afterload stress, as present in many congenital heart lesions, we hypothesized that alterations in the UPS could play an important role in RVH/RVF. UPS expression and activity ...

Rajagopalan, Viswanathan; Zhao, Mingming; Reddy, Sushma; Fajardo, Giovanni; Wang, Xuejun; Dewey, Shannamar; Gomes, Aldrin V.; Bernstein, Daniel

2013-01-01

53

Symptomatic and silent myocardial ischaemia in hypertensive patients with left ventricular hypertrophy.  

OpenAIRE

OBJECTIVE--To assess the prevalence of symptomatic and silent myocardial ischaemia in patients with hypertensive left ventricular hypertrophy. DESIGN--Cross sectional study. SETTING--University department of medical cardiology. PATIENTS--90 patients (68 men and 22 women; mean age 57 (range 25 to 79)) with left ventricular hypertrophy due to essential hypertension. INTERVENTIONS--48 hour ambulatory ST segment monitoring (all patients), exercise electrocardiography (n = 79), stress thallium sci...

Pringle, S. D.; Dunn, F. G.; Tweddel, A. C.; Martin, W.; Macfarlane, P. W.; Mckillop, J. H.; Lorimer, A. R.; Cobbe, S. M.

1992-01-01

54

Left Ventricular Hypertrophy and Obesity: Only a Matter of Fat?  

Science.gov (United States)

Obesity can be regarded as an energy balance disorder in which inappropriate expansion and dys-function of adipose tissue lead to unfavorable outcomes. Even in the absence of hypertension, adiposity induces structural and functional changes in the heart through hemodynamic and non hemodynamic factors. In the "obese" heart, besides the growth of cardiomyocytes, interstitial fat infiltration and triglyceride accumulation in the contractile elements importantly contribute to left-ventricular mass (LVM) accrual, hypertrophy (LVH) and geometric pattern. In harmony with this, the likelihood of LVH is greater in either obese normotensive or hypertensive individuals than in their non-obese counterparts. Interestingly, recent observations highlight the increasing prevalence of the "concentric" (ie, combined remodeling and hypertrophy), rather than "eccentric" pattern of LV geometry in obesity. Nonetheless, obesity is linked with lack of decrease, or even increase, of LVM over time, independently of blood pressure control and hypertensive treatment. Although obesity-related LV changes result in progressive systolic and diastolic heart failure, the assessment of LVM and LVH in obese individuals still remains a difficult task. In this scenario, it is tempting to speculate that therapeutic interventions for reversal of LVH in obesity should either overcome the "non-hemodynamic" factors or reduce the hemodynamic load. Indeed, weight loss, either achieved by lifestyle changes or bariatric procedures, decreases LVM and improves LV function regardless of blood pressure status. These and other mechanistic insights are discussed in this review, which focuses on "adipose dysfunction" as potential instigator of, and putative therapeutic target for, LVH regression in the setting of obesity. PMID:25117210

Murdolo, Giuseppe; Angeli, Fabio; Reboldi, Gianpaolo; Di Giacomo, Letizia; Aita, Adolfo; Bartolini, Claudia; Vedecchia, Paolo

2014-08-13

55

Prevalencia de hipertrofia ventricular izquierda en pacientes diabéticos Prevalence of left ventricular hypertrophy in diabetic patients  

Directory of Open Access Journals (Sweden)

Full Text Available Con el objetivo de establecer la prevalencia de hipertrofia ventricular izquierda (HVI en pacientes con diabetes mellitus tipo 2 (DM, se realizó un estudio transversal en estos pacientes, estableciendo sus características antropométricas, presión arterial y control metabólico. Para evaluar la presencia de HVI se empleó ecocardiografía transtorácica. El estudio incluyó 91 pacientes, en los cuales la prevalencia de HVI fue de 63,7%, siendo más frecuente en mujeres que en varones (p=0,001. Adicionalmente, se encontró un 46,2% de pacientes con disfunción diastólica del ventrículo izquierdo. Se concluye que existe una importante prevalencia de HVI en pacientes diabéticos sin antecedentes de causas definidas de hipertrofia. No se encontró relación con sexo, control metabólico, IMC y tiempo de diagnósticoIn order to establish the prevalence of left ventricular hypertrophy (LVH in patients with type 2 diabetes mellitus, (DM a cross-sectional study was conducted in these patients studying their anthropometric characteristics, blood pressure and metabolic control. To evaluate the presence of LVH, a trans-thoracic echocardiogram was used. The study included 91 patients, finding a 63.7% prevalence of HVI, with women being more affected than men (p=0.001. Additionally, 46.2% of patients were found to have diastolic dysfunction of the left ventricle. We conclude that there is an important prevalence of LVH in diabetic patients without defined causes of hypertrophy. There was no association with sex, metabolic control, BMI and time of diagnosis

Diego Valarezo-Sevilla

2013-03-01

56

Alteration of the sodium current in cat cardiac ventricular myocytes during primary culture.  

Science.gov (United States)

To determine the response of cardiac Na current (INa) in adult cardiac ventricular myocytes to culture, single isolated ventricular myocytes from collagenase-perfused adult cat hearts were placed in primary culture for up to 2 wk on a two-dimensional (2D) surface (laminin-coated coverslips), which allowed the morphology of the myocytes to change markedly, or in a three-dimensional matrix (3D) of alginate, in which cell shape changed only minimally. Action potentials and INa were recorded from groups of 1) freshly isolated myocytes serving as the control (day 0),2) cells maintained in 2D culture for 9-14 days (2D, day 9-14), and 3) cells cultured in alginate for 9-14 days (3D, day 9-14) with use of a conventional whole cell patch technique. Maximal upstroke velocity (Vmax) of the action potential was reduced by approximately 50% in 2D- and 3D-cultured cells relative to controls. INa in 2D- and 3D-cultured cells was strikingly different from that in control myocytes. Half-maximal voltage (V 1/2) for the chord conductance-voltage relationship was shifted approximately 15 mV negatively to that for controls in 2D- and 3D-cultured cells. INa steady-state availability curve also shifted negatively relative to controls in 2D- and 3D-cultured myocytes, but the magnitude of this shift (approximately 16-20 mV) was greater than that for the chord conductance-voltage curve.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7733248

Schackow, T E; Sheets, M F; Decker, R S; Ten Eick, R E

1995-04-01

57

Relation between electrocardiographic repolarisation changes and mechanical events in left ventricular hypertrophy.  

OpenAIRE

The relation between ventricular function and the presence of electrocardiographic "strain" in patients with left ventricular hypertrophy was examined using digitised M mode echocardiography and 12 lead electrocardiograms in 64 patients with pressure overload, 21 with hypertrophic cardiomyopathy, and 14 athletes. Although all had increased left ventricular mass, those with strain had a prolonged interval from minimum cavity dimension to mitral valve opening and a reduced rate of early diastol...

Moore, R. B.; Shapiro, L. M.; Gibson, D. G.

1984-01-01

58

Differential effects of the peroxynitrite donor, SIN-1, on atrial and ventricular myocyte electrophysiology  

OpenAIRE

Oxidative stress has been implicated in the pathogenesis of heart failure and atrial fibrillation and can result in increased peroxynitrite production in the myocardium.. Atrial and ventricular canine cardiac myocytes were superfused with SIN-1 (3-morpholinosydnonimine N-ethylcarbamide), a peroxynitrite donor, to evaluate the acute electrophysiologic effects of peroxynitrite. Perforated whole cell patch clamp techniques were used to record action potentials. SIN-1 (200 ?M) increased the acti...

Bonilla, Ingrid M.; Sridhar, Arun; Nishijima, Yoshinori; Gyo?rke, Sandor; Cardounel, Arturo J.; Carnes, Cynthia A.

2013-01-01

59

Left Ventricular Hypertrophy May Be Transient in the Emergency Department  

Directory of Open Access Journals (Sweden)

Full Text Available Background: While research has established that the bedside electrocardiogram (ECG is an insensitive test for the presence or absence of left ventricular hypertrophy (LVH, the finding, when present, is thought to be reproducible.Objective: To assess the reproducibility of serial ECGs done in the emergency department (ED with regard to the presence or absence of LVH.Method: A prospective study on consecutive patients admitted to an ED-run cardiac observation unit. A single reviewer collected and scored ECGs for the presence of LVH, using three established criteria (Cornell, Sokolow-Lyon and Romhilt-Estes. Demographic and medical history was also collected.Results: Over a three-year time period, 295 patients were enrolled; 132 males and 163 females with a mean age of 54.4 years (range, 19-89 years. The prevalence of LVH ranged from 11-14% and the agreement among all three criteria was fair (kappa = 0.325. Using the Cornell criteria, 33 patients had ECG#1 consistent with LVH. Of the patients meeting LVH criteria on ECG #1, only 15 retained their diagnosis of LVH on ECG#2 (i.e. 55% of the LVH identified in ECG#1 was not seen in ECG#2. Additionally, nine patients developed an ECG diagnosis of LVH between ECG#1 and ECG#2. In total, 27 (nine percent of the total had ECG measurements that changed between ECG#1 and ECG#2. We made similar findings with the Sokolow-Lyon and Romhilt-Estes criteria. The results were not modified by gender, blood pressure or medication use.Conclusion: The finding of LVH on ECG was not very reproducible during serial measurements on the same person during a single 24-hour observation period.[WestJEM. 2009;10:140-143

Shoenberger, Jan M

2009-08-01

60

Heart rate variability and left ventricular diastolic function in patients with borderline hypertension with and without left ventricular hypertrophy.  

OpenAIRE

The relationships between heart rate variability (HRV), left ventricular mass and diastolic function in borderline hypertensive patients (BHT) were evaluated. 24 h Holter electrocardiogram (ECG) and blood pressure (BP) monitoring, M and 2 D echocardiogram and Doppler analysis in 42 BHT with and without left ventricular hypertrophy (LVH) and in 20 normotensive controls were assessed. From 24-h ECG, time domain indexes of HRV were calculated. Standard Deviation of all Cycles (SDNN) and Standard...

Veglio, Franco

2001-01-01

61

Prevalencia de hipertrofia ventricular izquierda en pacientes diabéticos / Prevalence of left ventricular hypertrophy in diabetic patients  

Scientific Electronic Library Online (English)

Full Text Available SciELO Public Health | Language: Spanish Abstract in spanish Con el objetivo de establecer la prevalencia de hipertrofia ventricular izquierda (HVI) en pacientes con diabetes mellitus tipo 2 (DM), se realizó un estudio transversal en estos pacientes, estableciendo sus características antropométricas, presión arterial y control metabólico. Para evaluar la pres [...] encia de HVI se empleó ecocardiografía transtorácica. El estudio incluyó 91 pacientes, en los cuales la prevalencia de HVI fue de 63,7%, siendo más frecuente en mujeres que en varones (p=0,001). Adicionalmente, se encontró un 46,2% de pacientes con disfunción diastólica del ventrículo izquierdo. Se concluye que existe una importante prevalencia de HVI en pacientes diabéticos sin antecedentes de causas definidas de hipertrofia. No se encontró relación con sexo, control metabólico, IMC y tiempo de diagnóstico Abstract in english In order to establish the prevalence of left ventricular hypertrophy (LVH) in patients with type 2 diabetes mellitus, (DM) a cross-sectional study was conducted in these patients studying their anthropometric characteristics, blood pressure and metabolic control. To evaluate the presence of LVH, a t [...] rans-thoracic echocardiogram was used. The study included 91 patients, finding a 63.7% prevalence of HVI, with women being more affected than men (p=0.001). Additionally, 46.2% of patients were found to have diastolic dysfunction of the left ventricle. We conclude that there is an important prevalence of LVH in diabetic patients without defined causes of hypertrophy. There was no association with sex, metabolic control, BMI and time of diagnosis

Diego, Valarezo-Sevilla; Armín, Pazmiño-Martínez; Nidya, Morales-Mora.

2013-03-01

62

Prevalencia de hipertrofia ventricular izquierda en pacientes diabéticos / Prevalence of left ventricular hypertrophy in diabetic patients  

Scientific Electronic Library Online (English)

Full Text Available SciELO Peru | Language: Spanish Abstract in spanish Con el objetivo de establecer la prevalencia de hipertrofia ventricular izquierda (HVI) en pacientes con diabetes mellitus tipo 2 (DM), se realizó un estudio transversal en estos pacientes, estableciendo sus características antropométricas, presión arterial y control metabólico. Para evaluar la pres [...] encia de HVI se empleó ecocardiografía transtorácica. El estudio incluyó 91 pacientes, en los cuales la prevalencia de HVI fue de 63,7%, siendo más frecuente en mujeres que en varones (p=0,001). Adicionalmente, se encontró un 46,2% de pacientes con disfunción diastólica del ventrículo izquierdo. Se concluye que existe una importante prevalencia de HVI en pacientes diabéticos sin antecedentes de causas definidas de hipertrofia. No se encontró relación con sexo, control metabólico, IMC y tiempo de diagnóstico Abstract in english In order to establish the prevalence of left ventricular hypertrophy (LVH) in patients with type 2 diabetes mellitus, (DM) a cross-sectional study was conducted in these patients studying their anthropometric characteristics, blood pressure and metabolic control. To evaluate the presence of LVH, a t [...] rans-thoracic echocardiogram was used. The study included 91 patients, finding a 63.7% prevalence of HVI, with women being more affected than men (p=0.001). Additionally, 46.2% of patients were found to have diastolic dysfunction of the left ventricle. We conclude that there is an important prevalence of LVH in diabetic patients without defined causes of hypertrophy. There was no association with sex, metabolic control, BMI and time of diagnosis

Diego, Valarezo-Sevilla; Armín, Pazmiño-Martínez; Nidya, Morales-Mora.

2013-01-01

63

Effects of endogenous cannabinoid anandamide on excitation-contraction coupling in rat ventricular myocytes.  

Science.gov (United States)

A role for anandamide (N-arachidonoyl ethanolamide; AEA), a major endocannabinoid, in the cardiovascular system in various pathological conditions has been reported in earlier reports. In the present study, the effects of AEA on contractility, Ca2+ signaling, and action potential (AP) characteristics were investigated in rat ventricular myocytes. Video edge detection was used to measure myocyte shortening. Intracellular Ca2+ was measured in cells loaded with the fluorescent indicator fura-2 AM. AEA (1 ?M) caused a significant decrease in the amplitudes of electrically evoked myocyte shortening and Ca2+ transients. However, the amplitudes of caffeine-evoked Ca2+ transients and the rate of recovery of electrically evoked Ca2+ transients following caffeine application were not altered. Biochemical studies in sarcoplasmic reticulum (SR) vesicles from rat ventricles indicated that AEA affected Ca2+ -uptake and Ca2+ -ATPase activity in a biphasic manner. [3H]-ryanodine binding and passive Ca2+ release from SR vesicles were not altered by 10 ?M AEA. Whole-cell patch-clamp technique was employed to investigate the effect of AEA on the characteristics of APs. AEA (1 ?M) significantly decreased the duration of AP. The effect of AEA on myocyte shortening and AP characteristics was not altered in the presence of pertussis toxin (PTX, 2 ?g/ml for 4 h), AM251 and SR141716 (cannabinoid type 1 receptor antagonists; 0.3 ?M) or AM630 and SR 144528 (cannabinoid type 2 receptor antagonists; 0.3 ?M). The results suggest that AEA depresses ventricular myocyte contractility by decreasing the action potential duration (APD) in a manner independent of CB1 and CB2 receptors. PMID:24472666

Al Kury, Lina T; Voitychuk, Oleg I; Ali, Ramiz M; Galadari, Sehamuddin; Yang, Keun-Hang Susan; Howarth, Frank Christopher; Shuba, Yaroslav M; Oz, Murat

2014-02-01

64

The adult heart responds to increased workload with physiologic hypertrophy, cardiac stem cell activation, and new myocyte formation  

Science.gov (United States)

Aims It is a dogma of cardiovascular pathophysiology that the increased cardiac mass in response to increased workload is produced by the hypertrophy of the pre-existing myocytes. The role, if any, of adult-resident endogenous cardiac stem/progenitor cells (eCSCs) and new cardiomyocyte formation in physiological cardiac remodelling remains unexplored. Methods and results In response to regular, intensity-controlled exercise training, adult rats respond with hypertrophy of the pre-existing myocytes. In addition, a significant number (?7%) of smaller newly formed BrdU-positive cardiomyocytes are produced by the exercised animals. Capillary density significantly increased in exercised animals, balancing cardiomyogenesis with neo-angiogenesis. c-kitpos eCSCs increased their number and activated state in exercising vs. sedentary animals. c-kitpos eCSCs in exercised hearts showed an increased expression of transcription factors, indicative of their commitment to either the cardiomyocyte (Nkx2.5pos) or capillary (Ets-1pos) lineages. These adaptations were dependent on exercise duration and intensity. Insulin-like growth factor-1, transforming growth factor-?1, neuregulin-1, bone morphogenetic protein-10, and periostin were significantly up-regulated in cardiomyocytes of exercised vs. sedentary animals. These factors differentially stimulated c-kitpos eCSC proliferation and commitment in vitro, pointing to a similar role in vivo. Conclusion Intensity-controlled exercise training initiates myocardial remodelling through increased cardiomyocyte growth factor expression leading to cardiomyocyte hypertrophy and to activation and ensuing differentiation of c-kitpos eCSCs. This leads to the generation of new myocardial cells. These findings highlight the endogenous regenerative capacity of the adult heart, represented by the eCSCs, and the fact that the physiological cardiac adaptation to exercise stress is a combination of cardiomyocyte hypertrophy and hyperplasia (cardiomyocytes and capillaries). PMID:23100284

Waring, Cheryl D.; Vicinanza, Carla; Papalamprou, Angela; Smith, Andrew J.; Purushothaman, Saranya; Goldspink, David F.; Nadal-Ginard, Bernardo; Torella, Daniele; Ellison, Georgina M.

2014-01-01

65

Dapagliflozin reduces the amplitude of shortening and Ca(2+) transient in ventricular myocytes from streptozotocin-induced diabetic rats.  

Science.gov (United States)

In the management of type 2 diabetes mellitus, Dapagliflozin (DAPA) is a newly introduced selective sodium-glucose co-transporter 2 inhibitor which promotes renal glucose excretion. Little is known about the effects of DAPA on the electromechanical function of the heart. This study investigated the effects of DAPA on ventricular myocyte shortening and intracellular Ca(2+) transport in streptozotocin (STZ)-induced diabetic rats. Shortening, Ca(2+) transients, myofilament sensitivity to Ca(2+) and sarcoplasmic reticulum Ca(2+), and intracellular Ca(2+) current were measured in isolated rats ventricular myocytes by video edge detection, fluorescence photometry, and whole-cell patch-clamp techniques. Diabetes was characterized in STZ-treated rats by a fourfold increase in blood glucose (440 ± 25 mg/dl, n = 21) compared to Controls (98 ± 2 mg/dl, n = 19). DAPA reduced the amplitude of shortening in Control (76.68 ± 2.28 %, n = 37) and STZ (76.58 ± 1.89 %, n = 42) ventricular myocytes, and reduced the amplitude of the Ca(2+) transients in Control and STZ ventricular myocytes with greater effects in STZ (71.45 ± 5.35 %, n = 16) myocytes compared to Controls (92.01 ± 2.72 %, n = 17). Myofilament sensitivity to Ca(2+) and sarcoplasmic reticulum Ca(2+) were not significantly altered by DAPA in either STZ or Control myocytes. L-type Ca(2+) current was reduced in STZ myocytes compared to Controls and was further reduced by DAPA. In conclusion, alterations in the mechanism(s) of Ca(2+) transport may partly underlie the negative inotropic effects of DAPA in ventricular myocytes from STZ-treated and Control rats. PMID:25351341

Hamouda, N N; Sydorenko, V; Qureshi, M A; Alkaabi, J M; Oz, M; Howarth, F C

2015-02-01

66

Effect of cytoskeleton disruptors on L-type Ca channel distribution in rat ventricular myocytes.  

Science.gov (United States)

The cytoskeleton plays an important role in many aspects of cardiac cell function, including protein trafficking. However, the role of the cytoskeleton in determining Ca channel location in cardiac myocytes is unknown. In the present study we therefore investigated the effect of the cytoskeletal disruptors cytochalasin D, latrunculin, nocadazole and colchicine on the distribution of Ca channels in rat ventricular myocytes during culture for up to 96 h. During culture in the absence of these agents, cell edges became rounded, t-tubule density decreased, and the normal transverse distribution of the alpha1 (pore-forming) subunit of the L-type Ca channel became more punctate and peri-nuclear; these changes were associated with loss of synchronous Ca release in response to electrical stimulation. Disruption of tubulin using nocadazole or colchicine or sequestration of monomeric actin by latrunculin had no effect on these changes. In contrast, cytochalasin D inhibited these changes: cell shape, t-tubule density, transverse Ca channel staining and synchronous Ca release were maintained during culture. The protein synthesis inhibitor cycloheximide had similar effects to cytochalasin. These data suggest that cytochalasin stabilizes actin in adult ventricular myocytes in culture, thus stabilizing cell structure and function, and that actin is important in trafficking L-type Ca channels from the peri-nuclear region to the t-tubules, where they are normally located and provide the trigger for Ca release. PMID:16137761

Leach, R N; Desai, J C; Orchard, C H

2005-11-01

67

Aliskiren limits abdominal aortic aneurysm, ventricular hypertrophy and atherosclerosis in an apolipoprotein-E-deficient mouse model.  

Science.gov (United States)

Aliskiren is a direct renin inhibitor developed to treat hypertension. Several clinical studies have suggested that aliskiren has beneficial effects on cardiovascular diseases beyond its antihypertensive effect. In the present study, we examined whether aliskiren limits the progression of AAA (abdominal aortic aneurysm), VH (ventricular hypertrophy) and atherosclerosis in an AngII (angiotensin II)-infused mouse model. ApoE-/- (apolipoprotein-E-deficient) mice were infused subcutaneously with AngII (1000 ng/kg of body weight per day; 4 weeks) to induce AAA and VH. At the completion of the AngII infusion, mice were randomly allocated to three groups to receive vehicle control, low-dose aliskiren (10 mg/kg of body weight per day) or high-dose aliskiren (50 mg/kg of body weight per day) for 4 weeks. Suprarenal aortic diameter assessed by ultrasound was significantly smaller in mice administered aliskiren at days 42 and 56. Aliskiren also significantly reduced the normalized heart weight, ventricular myocyte cell width and aortic arch atherosclerosis. Aliskiren lowered PRR (pro-renin receptor) expression and MAPK (mitogen-activated protein kinase) activity in the suprarenal aorta and heart. Aortic infiltration of T-lymphocytes and macrophages was reduced by aliskiren. In conclusion, aliskiren limits the progression of AAA, VH and atherosclerosis in an AngII-infused mouse model. PMID:24476071

Seto, Sai-Wang; Krishna, Smriti M; Moran, Corey S; Liu, David; Golledge, Jonathan

2014-07-01

68

Impact of left ventricular geometry on prognosis in hypertensive patients with left ventricular hypertrophy (the LIFE study)  

DEFF Research Database (Denmark)

AIMS: Less is known about the relation between in-treatment left ventricular (LV) geometry and risk of cardiovascular events. We assessed LV geometric patterns on baseline and annual echocardiograms as time-varying predictors of the primary composite endpoint (cardiovascular death, stroke, and myocardial infarction) in 937 hypertensive patients with LV hypertrophy during 4.8 years losartan- or atenolol-based treatment in the Losartan Intervention for Endpoint reduction in hypertension (LIFE) echocardiography substudy. METHODS AND RESULTS: LV geometry was determined from LV mass/body surface area and relative wall thickness in combination. At end of the study, 52% of patients with initial LV hypertrophy had normal geometry (P < 0.001). In particular, concentric remodelling was reduced by 82% and concentric LV hypertrophy by 84%. Development of LV hypertrophy was seen in <5%. In Cox regression analyses including LV geometric patterns as time-varying variables and adjusting for treatment, Framingham risk score, race, and time-varying systolic blood pressure, the patterns independently predicted higher risk of primary composite endpoints [HR 2.99 (1.16-7.71) for concentric remodelling, HR 1.79 (1.17-2.73) for eccentric hypertrophy, and HR 2.71 (1.13-6.45) for concentric hypertrophy; all P < 0.05]. CONCLUSION: In hypertensive patients with ECG LV hypertrophy, in-treatment LV geometry by echocardiography adds information on risk of cardiovascular events Udgivelsesdato: 2008/11

Gerdts, E.; Cramariuc, D.

2008-01-01

69

Genome-wide linkage analysis of electrocardiographic and echocardiographic left ventricular hypertrophy in families with hypertension.  

OpenAIRE

AIMS: To localize chromosomal regions (or quantitative trait loci) that harbour genetic variants influencing the variability of electrocardiographic (ECG) and echocardiographic left ventricular hypertrophy (LVH). METHODS AND RESULTS: We evaluated genetic linkage to ECG Sokolow-Lyon voltage, ECG Cornell voltage product, ECG left ventricular (LV) mass, and to echocardiographic septal wall thickness, LV cavity size, and LV mass in 868 members of 224 white British families. A genome-wide scan was...

Mayosi, Bm; Avery, Pa; Farrall, M.; Keavney, B.; Watkins, H.

2008-01-01

70

Hypertension and hyperparathyroidism are associated with left ventricular hypertrophy in patients on hemodialysis  

OpenAIRE

Conflicting data for association between left ventricular hypertrophy (LVH) and secondary hyperparathyroidism has been reported previously among dialysis patients. The present study was conducted to evaluate the association of hyperparathyroidism and hypertension with LVH. Charts of 130 patients on hemodialysis for at least six months were reviewed. All were subjected to M-mode echocardiography. Left ventricular mass (LVM) was calculated by Devereux's formula. LVM Index (LVMI) was calculated ...

Al-hilali, N.; Hussain, N.; Ataia, A. I.; Al-azmi, M.; Al-helal, B.; Johny, K. V.

2009-01-01

71

Comparison of sarcoplasmic reticulum calcium content in atrial and ventricular myocytes of three fish species.  

Science.gov (United States)

Ryanodine (Ry) sensitivity of cardiac contraction differs between teleost species, between atrium and ventricle, and according to the thermal history of the fish. The hypothesis that variability in Ry sensitivity of contraction is due to species-specific, chamber-specific, and temperature-related differences in the sarcoplasmic reticulum (SR) Ca(2+) content, was tested by comparing steady-state (SS) and maximal (Max) Ca(2+) loads of the SR in three teleost fish, rainbow trout (Oncorhynchus mykiss), burbot (Lota lota), and crucian carp (Carassius carassius), which differ in the extent of SR contribution to excitation-contraction coupling. Fish were acclimated at 4 degrees C (cold-acclimation, CA) or 18 degrees C (warm-acclimation, WA), and SR Ca(2+) content was released by a rapid application of 10 mM caffeine to single cardiac myocytes; its amount was determined from the Na(+)-Ca(2+) exchange current at 18 degrees C. SS Ca(2+) load was larger in atrial (304-915 micromol/l) than ventricular (224-540 micromol/l) myocytes in all fish species (P < 0.05), and the same was true for Max SR Ca(2+) content: 550-1,522 micromol/l and 438-840 micromol/l for atrial and ventricular myocytes, respectively (P < 0.05). Consistent with the hypothesis, acclimation to cold increased Ca(2+) load of the cardiac SR in the burbot heart, but contrary to the hypothesis, temperature acclimation did not affect SR Ca(2+) content in rainbow trout and crucian carp hearts. Furthermore, there was an inverse relation between SR Ca(2+) content and Ry sensitivity of contraction force: the species with the smallest SR Ca(2+) content (burbot) is most sensitive to Ry. Collectively, these findings show that SR Ca(2+) content of fish cardiac myocytes is several times larger than that in mammalian cardiac SR. PMID:19692664

Haverinen, Jaakko; Vornanen, Matti

2009-10-01

72

Abnormal diastolic currents in ventricular myocytes from spontaneous hypertensive heart failure rats.  

Science.gov (United States)

Hypertension is a common cause of heart failure, and ventricular arrhythmias are a major cause of death in heart failure. The spontaneous hypertension heart failure (SHHF) rat model was used to study altered ventricular electrophysiology in hypertension and heart failure. We hypothesized that a reduction in the inward rectifier K(+) current (I(K1)) and expression of pacemaker current (I(f)) would favor abnormal automaticity in the SHHF ventricle. SHHF ventricular myocytes were isolated at 2 and 8 mo of age and during end-stage heart failure (>/=17 mo); myocytes from age-matched rats served as controls. Inward I(K1) was significantly reduced at both 8 and >/=17 mo in SHHF rats compared with controls. There was a reduction in inward I(K1) due to aging in the controls only at >/=17 mo. We found a significant increase in I(f) at all ages in the SHHF rats, compared with young controls. In controls, there was an age-dependent increase in I(f). Action potential recordings in the SHHF rats demonstrated abnormal automaticity, which was abolished by the addition of an I(f) blocker (10 muM zatebradine). Increased I(f) during hypertension alone or combined increases in I(f) with reduced I(K1) during the progression to hypertensive heart failure contribute to a substrate for arrhythmogenesis. PMID:16766638

Sridhar, Arun; Dech, Spencer J; Lacombe, Veronique A; Elton, Terry S; McCune, Sylvia A; Altschuld, Ruth A; Carnes, Cynthia A

2006-11-01

73

Validation of an in vitro contractility assay using canine ventricular myocytes  

Energy Technology Data Exchange (ETDEWEB)

Measurement of cardiac contractility is a logical part of pre-clinical safety assessment in a drug discovery project, particularly if a risk has been identified or is suspected based on the primary- or non-target pharmacology. However, there are limited validated assays available that can be used to screen several compounds in order to identify and eliminate inotropic liability from a chemical series. We have therefore sought to develop an in vitro model with sufficient throughput for this purpose. Dog ventricular myocytes were isolated using a collagenase perfusion technique and placed in a perfused recording chamber on the stage of a microscope at ? 36 °C. Myocytes were stimulated to contract at a pacing frequency of 1 Hz and a digital, cell geometry measurement system (IonOptix™) was used to measure sarcomere shortening in single myocytes. After perfusion with vehicle (0.1% DMSO), concentration–effect curves were constructed for each compound in 4–30 myocytes taken from 1 or 2 dog hearts. The validation test-set was 22 negative and 8 positive inotropes, and 21 inactive compounds, as defined by their effect in dog, cynolomolgous monkey or humans. By comparing the outcome of the assay to the known in vivo contractility effects, the assay sensitivity was 81%, specificity was 75%, and accuracy was 78%. With a throughput of 6–8 compounds/week from 1 cell isolation, this assay may be of value to drug discovery projects to screen for direct contractility effects and, if a hazard is identified, help identify inactive compounds. -- Highlights: ? Cardiac contractility is an important physiological function of the heart. ? Assessment of contractility is a logical part of pre-clinical drug safety testing. ? There are limited validated assays that predict effects of compounds on contractility. ? Using dog myocytes, we have developed an in vitro cardiac contractility assay. ? The assay predicted the in vivo contractility with a good level of accuracy.

Harmer, A.R., E-mail: alex.harmer@astrazeneca.com; Abi-Gerges, N.; Morton, M.J.; Pullen, G.F.; Valentin, J.P.; Pollard, C.E.

2012-04-15

74

Validation of an in vitro contractility assay using canine ventricular myocytes  

International Nuclear Information System (INIS)

Measurement of cardiac contractility is a logical part of pre-clinical safety assessment in a drug discovery project, particularly if a risk has been identified or is suspected based on the primary- or non-target pharmacology. However, there are limited validated assays available that can be used to screen several compounds in order to identify and eliminate inotropic liability from a chemical series. We have therefore sought to develop an in vitro model with sufficient throughput for this purpose. Dog ventricular myocytes were isolated using a collagenase perfusion technique and placed in a perfused recording chamber on the stage of a microscope at ? 36 °C. Myocytes were stimulated to contract at a pacing frequency of 1 Hz and a digital, cell geometry measurement system (IonOptix™) was used to measure sarcomere shortening in single myocytes. After perfusion with vehicle (0.1% DMSO), concentration–effect curves were constructed for each compound in 4–30 myocytes taken from 1 or 2 dog hearts. The validation test-set was 22 negative and 8 positive inotropes, and 21 inactive compounds, as defined by their effect in dog, cynolomolgous monkey or humans. By comparing the outcome of the assay to the known in vivo contractility effects, the assay sensitivity was 81%, specificity was 75%, and accuracy was 78%. With a throughput of 6–8 compounds/week from 1 cell isolation, this assay may be of value to drug discovery projects to screen for direct contractility effects and, if a hazard is identified, help identify inactive compounds. -- Highlights: ? Cardiac contractility is an important physiological function of the heart. ? Assessment of contractility is a logical part of pre-clinical drug safety testing. ? There are limited validated assays that predict effects of compounds on contractility. ? Using dog myocytes, we have developed an in vitro cardiac contractility assay. ? The assay predicted the in vivo contractility with a good level of accuracy.

75

Endogenous Angiogenesis Inhibitors Prevent Adaptive Capillary Growth in Left Ventricular Pressure Overload Hypertrophy  

Science.gov (United States)

Background In left ventricular (LV) pressure-overload hypertrophy, lack of adaptive capillary growth contributes to progression to failure. Remodeling of the hypertrophied myocardium requires proteolysis of the extracellular matrix (ECM) carried out by matrix metalloproteinases (MMPs). MMPs, specifically MMP-9, are known to cleave ECM components to generate angiogenesis inhibitors (angiostatin, endostatin, tumstatin). We hypothesize that MMP-9 releases antiangiogenic factors during compensated and decompensated hypertrophy, which results in lack of adaptive capillary growth. Methods Newborn rabbits underwent aortic banding. Myocardial tissue from age-matched and banded animals at compensated (4 weeks) and decompensated hypertrophy (7 weeks), as identified by serial echocardiography, was analyzed by immunoblotting for angiostatin, endostatin, and tumstatin. MMP-9 activity was determined by zymography. A cell-permeable, potent, selective MMP-9 inhibitor was administered intrapericardially to animals with hypertrophied hearts and tissue was analyzed. Results MMP-9 is activated in hypertrophied myocardium versus in control hearts (22 ± 2 versus 16 ± 1; p = 0.04), which results in significantly increased levels of angiostatin (115 ± 10 versus 86 ± 7; p = 0.02), endostatin (33 ± 1 versus 28 ± 1; p = 0.006), and tumstatin (35 ± 6 versus 17 ± 4; p = 0.04). Zymography confirms inhibition of MMP-9 (hypertrophy + MMP-9 inhibitor, 14 ± 0.6 versus hypertrophy + vehicle, 17 ± 1; p = 0.01) and angiostatin, endostatin, and tumstatin are down-regulated, accompanied by up-regulation of capillary density (hypertrophy + MMP-9 inhibitor, 2.99 ± 0.07 versus hypertrophy + vehicle, 2.7 ± 0.05; p = 0.002). Conclusions Up-regulation of angiogenesis inhibitors prevents adaptive capillary growth in pressure-overload hypertrophied myocardium. Therapeutic interventions aimed at inhibition of angiogenesis inhibitors are useful in maintaining capillary density and thereby preventing heart failure. PMID:22795062

Nikolova, Andriana; Ablasser, Klemens; Wyler von Ballmoos, Moritz C.; Poutias, Dimitrios; Kaza, Elisabeth; McGowan, Francis X.; Moses, Marsha A.; del Nido, Pedro J.; Friehs, Ingeborg

2012-01-01

76

Hypokalaemia induces Ca2+ overload and Ca2+ waves in ventricular myocytes by reducing Na+,K+-ATPase ?2 activity.  

Science.gov (United States)

Hypokalaemia is a risk factor for development of ventricular arrhythmias. The aim of this study was to determine the cellular mechanisms leading to triggering of arrhythmias in ventricular myocytes exposed to low Ko. Low Ko, corresponding to moderate hypokalaemia, increased Ca(2+) transient amplitude, sarcoplasmic reticulum (SR) Ca(2+) load, SR Ca(2+) leak and Ca(2+) wave probability in field stimulated rat ventricular myocytes. The mechanisms leading to Ca(2+) overload were examined. Low Ko reduced Na(+),K(+)-ATPase (NKA) currents, increased cytosolic Na(+) concentration and increased the Na(+) level sensed by the Na(+), Ca(2+) exchanger (NCX). Low Ko also hyperpolarized the resting membrane potential (RMP) without significant alterations in action potential duration. Experiments in voltage clamped and field stimulated ventricular myocytes, along with mathematical modelling, suggested that low Ko increases the Ca(2+) transient amplitude by reducing NKA activity despite hyperpolarization of the RMP. Selective inhibition of the NKA ?2 isoform by low dose ouabain abolished the ability of low Ko to reduce NKA currents, to increase Na(+) levels sensed by NCX and to increase the Ca(2+) transient amplitude. We conclude that low Ko, within the range of moderate hypokalaemia, increases Ca(2+) levels in ventricular myocytes by reducing the pumping rate of the NKA ?2 isoform with subsequent Na(+) accumulation sensed by the NCX. These data highlight reduced NKA ?2-mediated control of NCX activity as a possible mechanism underlying triggered ventricular arrhythmias in patients with hypokalaemia. PMID:25326449

Aronsen, J M; Skogestad, J; Lewalle, A; Louch, W E; Hougen, K; Stokke, M K; Swift, F; Niederer, S; Smith, N P; Sejersted, O M; Sjaastad, I

2014-10-17

77

Alpha 1-adrenergic agonists selectively suppress voltage-dependent K+ current in rat ventricular myocytes.  

OpenAIRE

The effects of alpha 1-adrenergic agonists on the waveforms of action potentials and voltage-gated ionic currents were examined in isolated adult rat ventricular myocytes by the whole-cell patch-clamp recording technique. After "puffer" applications of either of two alpha 1 agonists, phenylephrine and methoxamine, action-potential durations were increased. In voltage-clamped cells, phenylephrine (5-20 microM) or methoxamine (5-10 microM) reduced the amplitudes of Ca2+-independent voltage-acti...

Apkon, M.; Nerbonne, J. M.

1988-01-01

78

Adult ECG criteria for left ventricular hypertrophy in young competitive athletes.  

Science.gov (United States)

Time-tested data indicate that ECG diagnosis of left ventricular hypertrophy in young athletes is challenging due to low sensitivity of the commonly used criteria. We sought to establish whether adult ECG criteria can be appropriate to make diagnosis of both common and uncommon patterns of left ventricular hypertrophy in young trained athletes. A total of 122 athletes, ages 16.2±3.8 years, training at least 5?h per week, were studied with Sokolow-Lyon voltage, Romhilt-Estes, Cornell voltage, Cornell Product, Perugia and Framingham scores. Garson Criteria were also investigated in athletes under 16. Participants were divided into 2 groups based on the presence (group-A, n=56) or absence (group-B, n=66) of at least one positive ECG score. Test performance was calculated with respect to accurate echocardiographic diagnosis of left ventricular hypertrophy. There were no inter-group differences regarding physical characteristics and training burden. 9 athletes from group-A (16%) and 2 from group-B (3%) were found to have left ventricular hypertrophy, likely to be pathological in 2 cases from group-A. Criteria gathering both QRS voltages and ST-T anomalies, like Perugia-score, best identified this subgroup and should be preferred to those based on QRS voltage analysis alone. PMID:23900896

Speranza, G; Magaudda, L; de Gregorio, C

2014-03-01

79

Protective effect of left ventricular hypertrophy in right coronary artery occlusions  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english OBJECTIVE: To test the hypothesis that left ventricular hypertrophy (LVH) reduces the electrocardiographic and functional effects of right coronary artery occlusion. METHODS: We analysed 215 patients (166 males and 49 women,age of 58.9±10.6 years), with occlusion of the right coronary artery without [...] other associated lesions. There was no significant difference (p>0.05) in age and gender distribution between the 78 patients with LVH (left ventricular mass >100g/m²) (Group A) when compared with the 137 patients without LVH (left ventricular mass

Marne de Freitas, Gomes; Carlos Antônio Mascia, Gottschall.

1999-02-01

80

Left ventricular filling patterns in patients with systemic hypertension and left ventricular hypertrophy (the LIFE study). Losartan Intervention For Endpoint  

DEFF Research Database (Denmark)

Abnormal left ventricular (LV) filling may exist in early stages of hypertension. Whether this finding is related to LV hypertrophy is currently controversial. This study was undertaken to assess relations between abnormal diastolic LV filling and LV geometry in a large series of hypertensive patients with electrocardiographic LV hypertrophy. M-mode, 2-dimensional, and pulsed Doppler echocardiographic recordings of mitral inflow velocity and isovolumetric relaxation time (IVRT) were obtained in 750 patients with stage I to III hypertension and LV hypertrophy determined by electrocardiography (sex-adjusted Cornell voltage duration criteria or Sokolow-Lyon voltage criteria) after 14 days of placebo treatment. The patients' mean age was 67+/-7 years and 44% were women. One hundred forty patients (19%) had normal LV geometric pattern, 79 (11%) had concentric remodeling, 342 (45%) had eccentric LV hypertrophy, and 189 (25%) had concentric LV hypertrophy. A normal LV filling pattern was found in 116 patients (16%),abnormal relaxation in 519 (69%), "pseudonormal" filling was found in 83 (11%), and a restrictive filling pattern in 32 (4%). Prolonged IVRT was associated with LV hypertrophy (p

Wachtell, K; Smith, G

2000-01-01

81

Increase in action potential duration and inhibition of the delayed rectifier outward current IK by berberine in cat ventricular myocytes.  

OpenAIRE

1. In the present work, the effects of the antiarrhythmic drug, berberine, on action potential and ionic currents of cat ventricular myocytes were studied. 2. Berberine prolonged action potential duration in cat ventricular myocytes without altering other variables of the action potential. 3. The drug at concentrations of 0.3-30 microM blocked only the delayed rectifier (IK) current with an IC50 = 4.1 microM. Berberine produced a tonic block and a phasic block that was increased with the dura...

Sa?nchez-chapula, J.

1996-01-01

82

Association of Arterial Stiffness and Electrocardiography-Determined Left Ventricular Hypertrophy with Left Ventricular Diastolic Dysfunction  

Science.gov (United States)

Objectives Increased arterial stiffness is associated with left ventricular diastolic dysfunction (LVDD), but this association may be influenced by left ventricular (LV) performance. Left ventricular hypertrophy (LVH) is not only a significant determinant of LV performance, but is also correlated with LVDD. This study is designed to compare LV diastolic function among patients divided by brachial-ankle pulse wave velocity (baPWV) and electrocardiography (ECG)-determined LVH and to assess whether increased baPWV and ECG-determined LVH are independently associated with LVDD. Methods This cross-sectional study enrolled 270 patients and classified them into four groups according to the median value of baPWV and with/without ECG-determined LVH. The baPWV was measured using an ABI-form device. ECG-determined LVH was defined by Sokolow-Lyon criterion. LVDD was defined as impaired relaxation, pseudonormal, and restrictive mitral inflow patterns. Groups 1, 2, 3, and 4 were patients with lower baPWV and without ECG-determined LVH, lower baPWV but with ECG-determined LVH, higher baPWV but without ECG-determined LVH, and higher baPWV and with ECG-determined LVH respectively. Results Early diastolic mitral velocity (Ea) was gradually decreased from group 1 to group 4 (p?0.027). Patients in group 4 had the highest prevalence of LVDD (all p<0.001). After multivariate analysis, both baPWV and ECG-determined LVH were independent determinants of Ea (??=??0.02, P<0.001; ??=??1.77, P<0.001 respectively) and LVDD (odds ratio?=?1.02, P?=?0.011 and odds ratio?=?3.53, P?=?0.013 respectively). Conclusion Our study showed the group with higher baPWV and ECG-determined LVH had the lowest Ea and highest prevalence of LVDD. In addition, both baPWV and ECG-determined LVH were independently associated with Ea and LVDD. Hence, assessment of arterial stiffness by baPWV and LVH by ECG may be useful in identifying the high risk group of LVDD. PMID:23145083

Hsu, Po-Chao; Tsai, Wei-Chung; Lin, Tsung-Hsien; Su, Ho-Ming; Voon, Wen-Chol; Lai, Wen-Ter; Sheu, Sheng-Hsiung

2012-01-01

83

Left atrial systolic force in hypertensive patients with left ventricular hypertrophy: the LIFE study  

DEFF Research Database (Denmark)

In hypertensive patients without prevalent cardiovascular disease, enhanced left atrial systolic force is associated with left ventricular hypertrophy and increased preload. It also predicts cardiovascular events in a population with high prevalence of obesity. Relations between left atrial systolic force and left ventricular geometry and function have not been investigated in high-risk hypertrophic hypertensive patients. Participants in the Losartan Intervention For Endpoint reduction in hypertension echocardiography substudy without prevalent cardiovascular disease or atrial fibrillation (n = 567) underwent standard Doppler echocardiography. Left atrial systolic force was obtained from the mitral orifice area and Doppler mitral peak A velocity. Patients were divided into groups with normal or increased left atrial systolic force (>14.33 kdyn). Left atrial systolic force was high in 297 patients (52.3%), who were older and had higher body mass index and heart rate (all P < 0.01) but similar systolic and diastolic blood pressure, in comparison with patients with normal left atrial systolic force. After controlling for confounders, increased left atrial systolic force was associated with larger left ventricular diameter and higher left ventricular mass index (both P < 0.01). Prevalence of left ventricular hypertrophy was greater (84 vs. 64%; P < 0.001). Participants with increased left atrial systolic force exhibited normal ejection fraction; higher stroke volume, cardiac output, transmitral peak E velocities and peak A velocities; and lower E/A ratio (all P < 0.01). Enhanced left atrial systolic force identifies hypertensive patients with greater left ventricular mass and prevalence of left ventricular hypertrophy, but normal left ventricular chamber systolic function with increased transmitral flow gradient occurring during early filling, consistent with increased preload Udgivelsesdato: 2008/7

Chinali, M.; Simone, G. de

2008-01-01

84

Dipyridamole-thallium tests are predictive of severe cardiac arrhythmias in patients with left ventricular hypertrophy  

International Nuclear Information System (INIS)

In a population of patients with chronic renal failure (CRF) and a high prevalence of left ventricular hypertrophy (LVH) undergoing chronic hemodialysis, the authors investigated the association between the results of dipyridamole-thallium tests (DTTs) and the occurrence of ventricular arrhythmias. They observed a positive significant association between positive DTTs and the occurrence of severe forms of ventricular arrhythmias. A significant association was also observed between the presence of severe LVH and the occurrence of severe ventricular arrhythmias. However, no association was found between the presence of LVH and the positivity of the DTT. As most of their patients with positive DTTs had unimpaired coronary circulations, they conclude that positive DTTs, although falsely indicative of impaired myocardial blood supply, does have an important clinical relevance, indicating increased risk of morbidity (and, possibly, mortality) due to ventricular arrhythmias in a population of CRF patients submitted to chronic renal function replacement program

85

Docosahexaenoic Acid Reduces the Incidence of Early Afterdepolarizations caused by Oxidative Stress in Rabbit Ventricular Myocytes  

Directory of Open Access Journals (Sweden)

Full Text Available Accumulating evidence has suggested that ?3-polyunsaturated fatty acids (?3-PUFAs may have beneficial effects in the prevention/treatment of cardiovascular diseases, while controversies still remain regarding their antiarrhythmic potential. It is not clear yet whether ?-3 PUFAs can suppress early afterdepolarizations (EADs induced by oxidative stress. In the present study, we recorded action potentials (APs using the the patch-clamp technique in ventricular myocytes isolated from rabbit hearts. The treatment of myocytes with H2O2 (200 ?M prolonged AP durations (APDs and induced EADs, which were significantly suppressed by docosahexaenoic acid (DHA, 10 or 25 µM (n = 8. To reveal the ionic mechanisms, we examined the effects of DHA on L-type calcium currents (ICa.L, late sodium (INa, and transient outward potassium currents (Ito in ventricular myocytes pretreated with H2O2. H2O2 (200 ?M increased ICa.L by 46.4% from control (-8.4 ±1.4 pA/pF to a peak level (-12.3±1.8 pA/pF, n=6, p < 0.01 after 6 min of H2O2 perfusion. H2O2-enhanced ICa.L was significantly reduced by DHA (25 ?M (-7.1 ± 0.9 pA/pF, n = 6, p < 0.01. Similarly, H2O2 increased the late INa (-3.2 ± 0.3 pC from control level (-0.7 ± 0.1 pC. DHA (25 ?M completely reversed the H2O2-induced increase in late INa (to -0.8 ± 0.2 pC, n=5. H2O2 also increased the peak amplitude of and the steady state Ito from 8.9 ±1.0 and 2.16 ± 0.25 pA/pF to 12.8 ±1.21 and 3.13 ± 0.47 pA/pF respectively (n=6, p < 0.01, however, treatment with DHA (25 ?M did not produce significant effects on current amplitudes and dynamics of Ito altered by H2O2. In addition, DHA (25 ?M did not affect the increase of intracellular reactive oxygen species (ROS levels induced by H2O2 in rabbit ventricular myocytes. These findings demonstrate that DHA suppresses exogenous H2O2-induced EADs mainly by modulating membrane ion channel functions, while its direct effect on ROS may play less prominent role.

ZhenghangZhao

2012-07-01

86

Effects of astragaloside IV on action potentials and ionic currents in guinea-pig ventricular myocytes.  

Science.gov (United States)

Astragaloside IV (AS-IV) is one of the main active constituents of Astragalus membranaceus, which has various actions on the cardiovascular system. However, its electrophysiological mechanisms are not clear. In the present study, we investigated the effects of AS-IV on action potentials and membrane currents using the whole-cell patch clamp technique in isolated guinea-pig ventricular myocytes. AS-IV prolonged the action potential duration (APD) at all three tested concentrations. The peak effect was achieved with 1×10(-6) M, at which concentration AS-IV significantly prolonged the APD at 95% repolarization from 313.1±38.9 to 785.3±83.7 ms. AS-IV at 1×10(-6) M also enhanced the inward rectifier K(+) currents (I(K1)) and inhibited the delayed rectifier K(+) currents (I(K)). AS-IV (1×10(-6) M) strongly depressed the peak of voltage-dependent Ca(2+) channel current (I(CaL)) from -607.3±37.5 to -321.1±38.3 pA. However, AS-IV was not found to affect the Na(+) currents. Taken together, AS-IV prolonged APD of guinea-pig ventricular myocytes, which might be explained by its inhibition of I(K). AS-IV also influences Ca(2+) signaling through suppressing ICaL. PMID:23546288

Zhao, Meimi; Zhao, Jinsheng; He, Guilin; Sun, Xuefei; Huang, Xueshi; Hao, Liying

2013-01-01

87

Diastolic disease in left ventricular hypertrophy: comparison of M mode and Doppler echocardiography for the assessment of rapid ventricular filling.  

OpenAIRE

OBJECTIVE--To investigate possible discrepancies between M mode and Doppler echocardiography in assessing early diastolic filling. DESIGN--Forty seven patients with left ventricular hypertrophy due to aortic stenosis and 26 healthy controls with a similar age range were studied by M mode, Doppler, apexcardiography, and phonocardiography. The patients also underwent cardiac catheterisation. M mode echograms were digitised by a computer. Early diastolic filling in both groups as assessed by the...

Lee, C. H.; Hogan, J. C.; Gibson, D. G.

1991-01-01

88

Evaluation of myocardial function in the presence of left ventricular hypertrophy in athletes and hypertensive patients  

Directory of Open Access Journals (Sweden)

Full Text Available Introduction Myocardial hypertrophy of the left ventricle may be of physiological or pathological nature. Distinction of these two types of hypertrophy is sometimes not easy and represents a diagnostic challenge. The aim of the study was to assess global diastolic and regional systolic and diastolic myocardial function in the presence of left ventricular hypertrophy in athletes and hypertensive patients. Material and methods In 18 male hypertensive patients and 14 male athletes global diastolic left ventriclar function and regional systolic and diastolic myocardial function of septum and posterior wall were investigated by pulsed wave tissue Doppler imaging. Results Ejection fraction and left ventricle mass index did not differ significantly between two groups. Hypertensive patients were found to have diastolic dysfunction while athletes had normal left ventricular diastolic function (the difference between the groups was P<0.00001. Index of regional diastolic function of septum as well as of the posterior wall was significantly less in hypertensive patients than in athletes (P<0.00001 for both. In spite of the normal global systolic function the regional systolic function of septum and posterior wall was significantly less in hypertensive patients than in athletes (P<0.02for both. Conclusion The present results show significantly less global and regional diastolic function of hypertrophied myocardium in hypertensive patients than in athletes. In the presence of preserved left ventricular systolic function, the quantification of myocardial velocity revealed significantly lower regional systolic function of septum and posterior wall in hypertensive patients than in athletes.

Deljanin-Ili? Marina

2008-01-01

89

Left ventricular remodeling and hypertrophy in patients with aortic stenosis: insights from cardiovascular magnetic resonance  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Cardiovascular magnetic resonance (CMR is the gold standard non-invasive method for determining left ventricular (LV mass and volume but has not been used previously to characterise the LV remodeling response in aortic stenosis. We sought to investigate the degree and patterns of hypertrophy in aortic stenosis using CMR. Methods Patients with moderate or severe aortic stenosis, normal coronary arteries and no other significant valve lesions or cardiomyopathy were scanned by CMR with valve severity assessed by planimetry and velocity mapping. The extent and patterns of hypertrophy were investigated using measurements of the LV mass index, indexed LV volumes and the LV mass/volume ratio. Asymmetric forms of remodeling and hypertrophy were defined by a regional wall thickening ?13 mm and >1.5-fold the thickness of the opposing myocardial segment. Results Ninety-one patients (61±21 years; 57 male with aortic stenosis (aortic valve area 0.93±0.32cm2 were recruited. The severity of aortic stenosis was unrelated to the degree (r2=0.012, P=0.43 and pattern (P=0.22 of hypertrophy. By univariate analysis, only male sex demonstrated an association with LV mass index (P=0.02. Six patterns of LV adaption were observed: normal ventricular geometry (n=11, concentric remodeling (n=11, asymmetric remodeling (n=11, concentric hypertrophy (n=34, asymmetric hypertrophy (n=14 and LV decompensation (n=10. Asymmetric patterns displayed considerable overlap in appearances (wall thickness 17±2mm with hypertrophic cardiomyopathy. Conclusions We have demonstrated that in patients with moderate and severe aortic stenosis, the pattern of LV adaption and degree of hypertrophy do not closely correlate with the severity of valve narrowing and that asymmetric patterns of wall thickening are common. Trial registration ClinicalTrials.gov Reference Number: NCT00930735

Dweck Marc R

2012-07-01

90

Pressure mediated hypertrophy and mechanical stretch up-regulate expression of the long form of leptin receptor (ob-Rb in rat cardiac myocytes  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Hyperleptinemia is known to participate in cardiac hypertrophy and hypertension, but the relationship between pressure overload and leptin is poorly understood. We therefore examined the expression of leptin (ob and the leptin receptor (ob-R in the pressure-overloaded rat heart. We also examined gene expressions in culture cardiac myocytes to clarify which hypertension-related stimulus induces these genes. Results Pressure overload was produced by ligation of the rat abdominal aorta, and ob and ob-R isoform mRNAs were measured using a real-time polymerase chain reaction (PCR. We also measured these gene expressions in neonatal rat cardiac myocytes treated with angiotensin II (ANGII, endothelin-1 (ET-1, or cyclic mechanical stretch. Leptin and the long form of the leptin receptor (ob-Rb gene were significantly increased 4?weeks after banding, but expression of the short form of the leptin receptor (ob-Ra was unchanged. ob-Rb protein expression was also detected by immunohistochemistry in hypertrophied cardiac myocytes after banding. Meanwhile, plasma leptin concentrations were not different between the control and banding groups. In cultured myocytes, ANGII and ET-1 increased only ob mRNA expression. However, mechanical stretch activated both ob and ob-Rb mRNA expression in a time-dependent manner, but ob-Ra mRNA was unchanged by any stress. Conclusions We first demonstrated that both pressure mediated hypertrophy and mechanical stretch up-regulate ob-Rb gene expression in heart and cardiac myocytes, which are thought to be important for leptin action in cardiac myocytes. These results suggest a new local mechanism by which leptin affects cardiac remodeling in pressure-overloaded hearts.

Matsui Hiroki

2012-12-01

91

Derangements in myocardial purine and pyrimidine nucleotide metabolism in patients with coronary artery disease and left ventricular hypertrophy.  

OpenAIRE

Studies in animal models of myocardial ischemia and left ventricular hypertrophy have demonstrated a number of derangements in purine and pyrimidine nucleotide content of myocardium that are postulated to play a role in the pathogenesis of muscle dysfunction in these disorders. The present study examined myocardium of patients with coronary artery disease, left ventricular hypertrophy, or neither of these two abnormalities, to determine whether derangements in purine and pyrimidine nucleotide...

Swain, J. L.; Sabina, R. L.; Peyton, R. B.; Jones, R. N.; Wechsler, A. S.; Holmes, E. W.

1982-01-01

92

Regression of acromegalic left ventricular hypertrophy after lanreotide (a slow-release somatostatin analog).  

Science.gov (United States)

A group of 13 acromegalic patients was treated with lanreotide for 18 months and followed-up echocardiographically; these patients showed significant correlations between the decrease of both growth hormone (GH) and insulin-like growth factor-1 and the decrease of left ventricular mass index. This documents a regression of left ventricular hypertrophy in acromegaly after lanreotide treatment, the degree of which is dependent on the magnitude of the decrease of GH and insulin-like growth factor-1 serum levels. PMID:10335774

Hradec, J; Kral, J; Janota, T; Krsek, M; Hana, V; Marek, J; Malik, M

1999-05-15

93

Economic benefits of left ventricular hypertrophy regression in patients with arterial hypertension  

OpenAIRE

Aim. To evaluate by modelling the economic benefits of left ventricular hypertrophy (LVH) regression in patients with arterial hypertension (HT) due to therapy with fixed combination of valsartan/amlodipine.Material and methods. 20 patients (15 females and 5 males, aged 18 to 70 years) with essential HT accompanied by metabolic syndrome with a history of previous ineffective antihypertensive therapy were included into the study. All patients were treated with fixed combination of amlodipine/v...

Tarlovskaya, E. I.; Maksimchuk, N. S.; Malchicova, S. V.; Avksentieva, M. V.; Sapozhnikova, I. E.; Balandina, Y. A.

2011-01-01

94

Therapeutic inhibition of fatty acid oxidation in right ventricular hypertrophy: exploiting Randle’s cycle  

OpenAIRE

Right ventricular hypertrophy (RVH) and RV failure are major determinants of prognosis in pulmonary hypertension and congenital heart disease. In RVH, there is a metabolic shift from glucose oxidation (GO) to glycolysis. Directly increasing GO improves RV function, demonstrating the susceptibility of RVH to metabolic intervention. However, the effects of RVH on fatty acid oxidation (FAO), the main energy source in adult myocardium, are unknown. We hypothesized that partial inhibitors of FAO (...

Fang, Yong-hu; Piao, Lin; Hong, Zhigang; Toth, Peter T.; Marsboom, Glenn; Bache-wiig, Peter; Rehman, Jalees; Archer, Stephen L.

2011-01-01

95

Prevalence and Determinants of Left Ventricular Hypertrophy in Hypertensive Patients at a Primary Care Clinic  

OpenAIRE

Left ventricular hypertrophy (LVH) has prognostic significance on cardiovascular mortality and morbidity. However, echocardiography screening for LVH is not routinely done for hypertensive patients in a primary care setting. thus, this quantitative study aims to determine the prevalence and factors associated with LVH in hypertensive patients at a primary care setting. this was a cross-sectional study of 359 consecutive patients with uncomplicated essential hypertension attending a hospital-b...

Sm, Ching; Yc, Chia; Wa, Wan Azman

2012-01-01

96

[ECG based diagnosis of right ventricular hypertrophy in patients with chronic obstructive bronchitis].  

Science.gov (United States)

Two mathematical models developed on the basis of a discriminant analysis of the evidence obtained in examination of 84 patients with chronic obstructive bronchitis (COB) are proposed in early diagnosis of right ventricular hypertrophy (RVH) by ECG readings in COB patients. Application of hierarchic classification model is recommended for diagnosis of RVH in screening. The probability model is intended for follow-up of COB patients. PMID:11840803

Fedosova, N B; Kravchenko, A I; Vlasova, I V

2001-01-01

97

Left ventricular diverticulum with marked hypertrophy of the left ventricular apex revealed by thallium-201 myocardial emission CT  

International Nuclear Information System (INIS)

A case of left ventricular apical diverticulum with marked hypertrophy of the left ventricular apical wall revealed by thallium-201 myocardial emission CT is reported. A 23-year-old woman was admitted to our hospital for evaluation of chest oppression. She was known to have had a heart murmur soon after birth, but she grew uneventfully, partaking in normal exercise. At the age of 21, she began to feel chest oppression during exercise. As the attacks became frequent, she was admitted to our hospital. Physical examination revealed an ejection systolic murmur in the second left intercostal space. Electrocardiography showed ST depression and T inversion in leads III, a VF and V4-6. M-mode echocardiography was normal. Two-dimensional echocardiography showed a small diverticulum at the apex of the left ventricle, which was also recognized by left ventriculography. It was about 8 x 12 mm in size. Thallium-201 myocardial emission CT disclosed marked uptake in the apex of the left ventricle, suggesting apical hypertrophy. Stress thallium-201 myocardial emission CT was negative. Coronary angiography was normal. The cause of chest oppression in this patient is uncertain, but the small diverticulum and hypertrophy of the cardiac apex may play a role in its pathogenesis. (author)

98

Ca(2+) homeostasis in sealed t-tubules of mouse ventricular myocytes.  

Science.gov (United States)

We have recently shown that in mouse ventricular myocytes, t-tubules can be quickly and tightly sealed during the resolution of hyposmotic shock of physiologically relevant magnitude. Sealing of t-tubules is associated with trapping extracellular solution inside the myocytes but the ionic homeostasis of sealed t-tubules and the consequences of potential transtubular ion fluxes remain unknown. In this study we investigated the dynamics of Ca(2+) movements associated with sealing of t-tubules. The data show that under normal conditions sealed t-tubules contain Ca(2+) at concentrations below 100?M. However, blockade of voltage-dependent Ca(2+) channels with 10?M nicardipine, or increasing extracellular concentration of K(+) from 5.4mM to 20mM led to several fold increase in concentration of t-tubular Ca(2+). Alternatively, the release of Ca(2+) from sarcoplasmic reticulum using 10mM caffeine led to the restoration of t-tubular Ca(2+) towards extracellular levels within few seconds. Sealing of t-tubules in the presence of extracellular 1.5mM Ca(2+) and 5.4mM extracellular K(+) led to occasional and sporadic intracellular Ca(2+) transients. In contrast, sealing of t-tubules in the presence of 10mM caffeine was characterized by a significant long lasting increase in intracellular Ca(2+). The effect was completely abolished in the absence of extracellular Ca(2+) and significantly reduced in pre-detubulated myocytes but was essentially preserved in the presence of mitochondrial decoupler dinitrophenol. This study shows that sealed t-tubules are capable of highly regulated transport of Ca(2+) and present a major route for Ca(2+) influx into the cytosol during sealing process. PMID:24787472

Moench, I; Lopatin, A N

2014-07-01

99

Alloxan-induced diabetes reduces sarcolemmal Na+-K+ pump function in rabbit ventricular myocytes.  

Science.gov (United States)

The effect of diabetes on sarcolemmal Na(+)-K(+) pump function is important for our understanding of heart disease associated with diabetes and design of its treatment. We induced diabetes characterized by hyperglycemia but no other major metabolic disturbances in rabbits. Ventricular myocytes isolated from diabetic rabbits and controls were voltage clamped and internally perfused with the whole cell patch-clamp technique. Electrogenic Na(+)-K(+) pump current (I(p), arising from the 3:2 Na(+)-to-K(+) exchange ratio) was identified as the shift in holding current induced by Na(+)-K(+) pump blockade with 100 micromol/l ouabain in most experiments. There was no effect of diabetes on I(p) recorded when myocytes were perfused with pipette solutions containing 80 mmol/l Na(+) to nearly saturate intracellular Na(+)-K(+) pump sites. However, diabetes was associated with a significant decrease in I(p) measured when pipette solutions contained 10 mmol/l Na(+). The decrease was independent of membrane voltage but dependent on the intracellular concentration of K(+). There was no effect of diabetes on the sensitivity of I(p) to extracellular K(+). Pump inhibition was abolished by restoration of euglycemia or by in vivo angiotensin II receptor blockade with losartan. We conclude that diabetes induces sarcolemmal Na(+)-K(+) pump inhibition that can be reversed with pharmacological intervention. PMID:17020934

Hansen, Peter S; Clarke, Ronald J; Buhagiar, Kerrie A; Hamilton, Elisha; Garcia, Alvaro; White, Caroline; Rasmussen, Helge H

2007-03-01

100

Accumulation of slowly activating delayed rectifier potassium current (IKs) in canine ventricular myocytes  

DEFF Research Database (Denmark)

In guinea-pig ventricular myocytes, in which the deactivation of slowly activating delayed rectifier potassium current (IKs) is slow, IKs can be increased by rapid pacing as a result of incomplete deactivation and subsequent current accumulation. Whether accumulation of IKs occurs in dogs, in which the deactivation is much faster, is still unclear. In this study the conditions under which accumulation occurs in canine ventricular myocytes were studied with regard to its physiological relevance in controlling action potential duration (APD). At baseline, square pulse voltage clamp experiments revealed that the accumulation of canine IKs could occur, but only at rather short interpulse intervals (<100 ms). With action potential (AP) clamp commands of constant duration (originally recorded at rate of 2 Hz), an accumulation was only found at interpulse intervals close to 0 ms. Transmembrane potential recordings with high-resistance microelectrodes revealed, however, that at the fastest stimulation rates with normally captured APs (5 Hz) the interpulse interval exceeded 50 ms. This suggested that no IKs accumulation occurs, which was supported by the lack of effect of an IKs blocker, HMR 1556 (500 nM), on APD. In the presence of the beta-adrenergic receptor agonist isoproterenol (isoprenaline, 100 nM) the accumulation with AP clamp commands of constant duration was much more pronounced and a significant accumulating current was found at a relevant interpulse interval of 100 ms. HMR 1556 prolonged APD, but this lengthening was reverse rate dependent. AP clamp experiments in a physiologically relevant setting (short, high rate APs delivered at a corresponding rate) revealed a limited accumulation of IKs in the presence of isoproterenol. In conclusion, a physiologically relevant accumulation of IKs was only observed in the presence of isoproterenol. Block of IKs, however, led to a reverse rate-dependent prolongation of APD indicating that IKs does not have a dominant role at short cycle lengths.

Stengl, Milan; Volders, Paul G A

2003-01-01

101

Study of Huoxue Qianyang Granules in revising the left ventricular hypertrophy of spontaneous hypertension rats  

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Full Text Available Objective: To study the mechanism of Huoxue Qianyang Granule (HXQYG, a traditional Chinese compound medicine, in revising the left ventricular hypertrophy of hypertension. Methods: Spontaneous hypertension rats (SHR were randomly divided into seven groups: untreated group, Songling Xuemaikang (SLXMK-treated group, captopril-treated group, high-, medium- and low-dose HXQYG-treated groups, and normal control group. The systolic blood pressure (SBP and left ventricular mass index (LVMI were measured. The content of angiotensin ? (Ang? in left ventricular tissue was determined by radioimmunoassay. The expressions of angiotensin converting enzyme (ACE protein and mRNA in left ventricular tissue were analyzed separately by immunohistochemical method and RT-PCR. Results: (1 SBP and LVMI were higher in the untreated group than those in the normal control group, and they were lower in the high- and medium-dose HXQYG-treated groups than those in the untreated group, but higher than those in the captopril-treated group, and without significant difference as compared to those in the SLXMK-treated group. (2 The content of Ang? and expressions of ACE protein and mRNA in the left ventricular tissue in the untreated group were higher than those in the normal control group, and they were lower in the HXQYG-treated groups than those in the untreated group, but higher than those in the captopril-treated group, and without significant difference as compared to those in the SLXMK-treated group. Conclusion: HXQYG can reverse the left ventricular hypertrophy of SHR, which may be due to decreasing the amount of Ang? and expressions of ACE protein and mRNA in the left ventricular tissue.

Duan ZHOU

2006-11-01

102

Anti-hypertensive drugs have different effects on ventricular hypertrophy regression  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english OBJECTIVES: There is a direct relationship between the regression of left ventricular hypertrophy (LVH) and a decreased risk of mortality. This investigation aimed to describe the effects of anti-hypertensive drugs on cardiac hypertrophy through a meta-analysis of the literature. METHODS: The Medlin [...] e (via PubMed), Lilacs and Scielo databases were searched using the subject keywords cardiac hypertrophy, antihypertensive and mortality. We aimed to analyze the effect of anti-hypertensive drugs on ventricle hypertrophy. RESULTS: The main drugs we described were enalapril, verapamil, nifedipine, indapamina, losartan, angiotensin-converting enzyme inhibitors and atenolol. These drugs are usually used in follow up programs, however, the studies we investigated used different protocols. Enalapril (angiotensin-converting enzyme inhibitor) and verapamil (Ca++ channel blocker) caused hypertrophy to regress in LVH rats. The effects of enalapril and nifedipine (Ca++ channel blocker) were similar. Indapamina (diuretic) had a stronger effect than enalapril, and losartan (angiotensin II receptor type 1 (AT1) receptor antagonist) produced better results than atenolol (selective ?1 receptor antagonist) with respect to LVH regression. CONCLUSION: The anti-hypertensive drugs induced various degrees of hypertrophic regression.

Celso, Ferreira Filho; Luiz Carlos de, Abreu; Vitor E., Valenti; Marcelo, Ferreira; Adriano, Meneghini; José Alexandre, Silveira; Andrés R. Pérez, Riera; Eduardo, Colombari; Neif, Murad; Paulo Roberto, Santos-Silva; Lovian José Henrique Pereira da, Silva; Luiz Carlos Marques, Vanderlei; Tatiana D., Carvalho; Celso, Ferreira.

103

Anti-hypertensive drugs have different effects on ventricular hypertrophy regression  

Directory of Open Access Journals (Sweden)

Full Text Available OBJECTIVES: There is a direct relationship between the regression of left ventricular hypertrophy (LVH and a decreased risk of mortality. This investigation aimed to describe the effects of anti-hypertensive drugs on cardiac hypertrophy through a meta-analysis of the literature. METHODS: The Medline (via PubMed, Lilacs and Scielo databases were searched using the subject keywords cardiac hypertrophy, antihypertensive and mortality. We aimed to analyze the effect of anti-hypertensive drugs on ventricle hypertrophy. RESULTS: The main drugs we described were enalapril, verapamil, nifedipine, indapamina, losartan, angiotensin-converting enzyme inhibitors and atenolol. These drugs are usually used in follow up programs, however, the studies we investigated used different protocols. Enalapril (angiotensin-converting enzyme inhibitor and verapamil (Ca++ channel blocker caused hypertrophy to regress in LVH rats. The effects of enalapril and nifedipine (Ca++ channel blocker were similar. Indapamina (diuretic had a stronger effect than enalapril, and losartan (angiotensin II receptor type 1 (AT1 receptor antagonist produced better results than atenolol (selective ?1 receptor antagonist with respect to LVH regression. CONCLUSION: The anti-hypertensive drugs induced various degrees of hypertrophic regression.

Celso Ferreira Filho

2010-01-01

104

Digoxin- and monensin-induced changes of intracellular Ca2+ concentration in isolated guinea-pig ventricular myocyte.  

Science.gov (United States)

This study was undertaken to determine the possible mechanisms of actions of monensin and digoxin by using isolated guinea-pig ventricular myocytes. Since Ca2+ is the major signal for triggering contraction of cardiac muscle, the objective of this study was to determine whether monensin and digoxin affect the [Ca2+]i of cardiac myocytes and if so is this effect due to an increase in [Na+]i. Three different concentrations of digoxin (0.3, 1 and 3 micromol/l) and three different concentrations of monensin (0.3, 1 and 3 micromol/l) were used. Each treatment was monitored for two hours by using computerized fluoroscopy. Both digoxin and monensin increased the [Ca2+]i and accelerated the onset time of [Ca2+]i increase in a dose-dependent manner. Normal myocytes (loaded with fura-2 for 30 min before the treatment) were also compared with 'weakened' myocytes (loaded with fura-2 for 3 h before the treatment to create a 'weakened' condition). It was found that although 0.3 micromol/l monensin and digoxin did not change the [Ca2+]i in normal myocytes, they increased the [Ca2 +]i in 'weakened' myocytes. Finally, a Na+-free medium was used to demonstrate the effect of [Na+]o on both monensin- and digoxin-induced increases in [Ca2+]i. It was found that digoxin did not increase the [Ca2+]i in the Na+-free medium. Although monensin increased the [Ca2+]i in the Na+-free solution, this increase was not as large as in the Na+-containing medium. The results of the study led to the conclusion that the positive inotropic effect of digoxin depends on [Na+]o. However, monensin increases [Ca2+]i in Na+-dependent and -independent ways. An addition conclusion was that 'weakened' myocytes are more sensitive to the monensin and digoxin treatment than normal myocytes. PMID:12227477

Meral, I; Hsu, W; Hembrough, F B

2002-08-01

105

Left Ventricular Hypertrophy: An allometric comparative analysis of different ECG markers  

International Nuclear Information System (INIS)

Allometry, in general biology, measures the relative growth of a part in relation to the whole living organism. Left ventricular hypertrophy (LVH) is the heart adaptation to excessive load (systolic or diastolic). The increase in left ventricular mass leads to an increase in the electrocardiographic voltages. Based on clinical data, we compared the allometric behavior of three different ECG markers of LVH. To do this, the allometric fit AECG ? + ? (VM) relating left ventricular mass (estimated from ecocardiographic data) and ECG amplitudes (expressed as the Cornell-Voltage, Sokolow and the ECG overall voltage indexes) were compared. Besides, sensitivity and specificity for each index were analyzed. The more sensitive the ECG criteria, the better the allometric fit. In conclusion: The allometric paradigm should be regarded as the way to design new and more sensitive ECG-based LVH markers.

106

Left Ventricular Hypertrophy: An allometric comparative analysis of different ECG markers  

Science.gov (United States)

Allometry, in general biology, measures the relative growth of a part in relation to the whole living organism. Left ventricular hypertrophy (LVH) is the heart adaptation to excessive load (systolic or diastolic). The increase in left ventricular mass leads to an increase in the electrocardiographic voltages. Based on clinical data, we compared the allometric behavior of three different ECG markers of LVH. To do this, the allometric fit AECG = ? + ? (VM) relating left ventricular mass (estimated from ecocardiographic data) and ECG amplitudes (expressed as the Cornell-Voltage, Sokolow and the ECG overall voltage indexes) were compared. Besides, sensitivity and specifity for each index were analyzed. The more sensitive the ECG criteria, the better the allometric fit. In conclusion: The allometric paradigm should be regarded as the way to design new and more sensitive ECG-based LVH markers.

Bonomini, M. P.; Ingallina, F.; Barone, V.; Valentinuzzi, M. E.; Arini, P. D.

2011-12-01

107

Increased insulin-like growth factor-I gene expression precedes left ventricular cardiomyocyte hypertrophy in a rapidly-hypertrophying rat model system.  

Science.gov (United States)

Chronic pressure overload leads to an increase in the size, i.e. hypertrophy, of cardiomyocytes in the heart. However, the molecular mechanisms underlying this hypertrophy are not understood. Insulin-like growth factor-I (IGF-I) synthesized locally in the heart is known to be associated with the hypertrophic process. So far, however, cardiac IGF-I gene expression in the widely used rat model system has only been shown to be increased when the hypertrophy induced by pressure-overload was already established. Therefore, the question of whether IGF-I serves as an initiating or early-enhancing factor for the cardiac hypertrophy remains unanswered. Here, cardiac hypertension and hypertrophy were rapidly induced in the rat by complete constriction of the abdominal aorta between the origins of the renal arteries. Carotid arterial systolic blood pressure remained unchanged in sham rats but increased rapidly in the pressure-overloaded constricted rats with a sustained hypertension established by 3 days. Hypertrophy of left ventricular (LV) cardiomyocytes in constricted rats also occurred by 3 days. However, this hypertrophy was preceded by increases in LV IGF-I mRNA and protein which occurred within 1 day. These results support the hypothesis that cardiac-synthesized IGF-I is an initiating or early-enhancing factor for hypertrophy of LV cardiomyocytes. PMID:14624474

Huang, Chi-Yang; Buchanan, David L; Gordon, Robert L; Sherman, Matthew J; Razzaq, Jamil; White, Karen; Buetow, Dennis E

2003-12-01

108

Apoptosis in severe, compensated pressure overload predominates in nonmyocytes and is related to the hypertrophy but not function  

OpenAIRE

It is widely held that myocyte apoptosis in left ventricular hypertrophy (LVH) contributes to left ventricle (LV) dysfunction and heart failure. The main goal of this investigation was to determine if there is a statistical relationship among LV hypertrophy, apoptosis and LV function, and importantly whether the apoptosis occurs in myocytes or nonmyocytes in the heart. We used both rat and canine models of severe LVH induced by chronic thoracic aortic banding with resultant LV-aortic pressure...

Gelpi, Ricardo J.; Park, Misun; Gao, Shumin; Dhar, Sunil; Vatner, Dorothy E.; Vatner, Stephen F.

2010-01-01

109

Loss of T-tubules and other changes to surface topography in ventricular myocytes from failing human and rat heart.  

Science.gov (United States)

T-tubular invaginations of the sarcolemma of ventricular cardiomyocytes contain junctional structures functionally coupling L-type calcium channels to the sarcoplasmic reticulum calcium-release channels (the ryanodine receptors), and therefore their configuration controls the gain of calcium-induced calcium release (CICR). Studies primarily in rodent myocardium have shown the importance of T-tubular structures for calcium transient kinetics and have linked T-tubule disruption to delayed CICR. However, there is disagreement as to the nature of T-tubule changes in human heart failure. We studied isolated ventricular myocytes from patients with ischemic heart disease, idiopathic dilated cardiomyopathy, and hypertrophic obstructive cardiomyopathy and determined T-tubule structure with either the fluorescent membrane dye di-8-ANNEPs or the scanning ion conductance microscope (SICM). The SICM uses a scanning pipette to produce a topographic representation of the surface of the live cell by a non-optical method. We have also compared ventricular myocytes from a rat model of chronic heart failure after myocardial infarction. T-tubule loss, shown by both ANNEPs staining and SICM imaging, was pronounced in human myocytes from all etiologies of disease. SICM imaging showed additional changes in surface structure, with flattening and loss of Z-groove definition common to all etiologies. Rat myocytes from the chronic heart failure model also showed both T-tubule and Z-groove loss, as well as increased spark frequency and greater spark amplitude. This study confirms the loss of T-tubules as part of the phenotypic change in the failing human myocyte, but it also shows that this is part of a wider spectrum of alterations in surface morphology. PMID:19342485

Lyon, Alexander R; MacLeod, Ken T; Zhang, Yanjun; Garcia, Edwin; Kanda, Gaelle Kikonda; Lab, Max J; Korchev, Yuri E; Harding, Sian E; Gorelik, Julia

2009-04-21

110

Evaluation of left ventricular eccentric hypertrophy by /sup 201/Tl-myocardial scintigraphy  

Energy Technology Data Exchange (ETDEWEB)

In order to elucidate the mechanism of left ventricular eccentric hypertrophy in conditions of volume overload, Tl-201 myocardial scintigraphy was performed in patients with aortic valve regurgitation and mitral valve regurgitation. There was a good relationship between the severity of Tl-defects, as determined by Tl-201 myocardial scintigraphy, and the changes in the T wave on the ECG on the one hand and the NYHA functional classification of heart diseases. In 17 of 18 patients where LVDd increased with increasing severity of Tl-defects and the defects were moderate to severe, LVDd was 65 mm or larger. There was a significant negative correlation between the washout rate for the whole circumference of the left ventricle, as determined by exercise Tl-201 SPECT, and LVDd (r=-0.603, p<0.01). The phenomenon of redistribution as determined by exercise Tl-201 myocardial scintigraphy was observed relatively early. Our results suggest that mechanical volume overload and ischemic changes are involved in left ventricular wall damage in left ventricular eccentric hypertrophy. For patients with moderate to severe Tl-defects valve replacement is indicated, no matter whether they may have heart failure or arrhythmia.

Yamazaki, Junichi; Kawamura, Yasuaki; Okuzumi, Ichio; Morishita, Takeshi; Koyama, Nobuya; Komatsu, Hisashi; Ohsawa, Hidefumi; Yabe, Yoshimasa

1989-03-01

111

Hypothermia increases the gain of excitation-contraction coupling in guinea pig ventricular myocytes.  

Science.gov (United States)

Components of excitation-contraction (EC)-coupling were compared at 37 degrees C and 22 degrees C to determine whether hypothermia altered the gain of EC coupling in guinea pig ventricular myocytes. Ca(2+) concentration (fura-2) and cell shortening (edge detector) were measured simultaneously. Hypothermia increased fractional shortening (8.3+/-1.7 vs. 2.6+/-0.3% at 37 degrees C), Ca(2+) transients (157+/-33 vs. 35+/-5 nM at 37 degrees C), and diastolic Ca(2+) (100+/-9 vs. 60+/-6 nM at 37 degrees C) in field-stimulated myocytes (2 Hz). In experiments with high-resistance microelectrodes, the increase in contractions and Ca(2+) transients was accompanied by a twofold increase in action potential duration (APD). When voltage-clamp steps eliminated changes in APD, cooling still increased contractions and Ca(2+) transients. Hypothermia increased sarcoplasmic reticulum (SR) Ca(2+) stores (83+/-17 at 37 degrees C to 212+/-50 nM, assessed with caffeine) and increased fractional SR Ca(2+) release twofold. In contrast, peak Ca(2+) current was much smaller at 22 degrees C than at 37 degrees C (1.3+/-0.4 and 3.5+/-0.7 pA/pF, respectively). In cells dialyzed with sodium-free pipette solutions to inhibit Ca(2+) influx via reverse-mode Na(+)/Ca(2+) exchange, hypothermia still increased contractions, Ca(2+) transients, SR stores, and fractional release but decreased the amplitude of Ca(2+) current. The rate of SR Ca(2+) release per unit Ca(2+) current, a measure of EC-coupling gain, was increased sixfold by hypothermia. This increase in gain occurred regardless of whether cells were dialyzed with sodium-free solutions. Thus an increase in EC-coupling gain contributes importantly to positive inotropic effects of hypothermia in the heart. PMID:18614812

Shutt, Robin H; Howlett, Susan E

2008-09-01

112

Ca Sparks Do Not Explain all Ryanodine Receptor-Mediated SR Ca Leak in Mouse Ventricular Myocytes  

OpenAIRE

Diastolic Ca leak from the sarcoplasmic reticulum (SR) of ventricular myocytes reduces the SR Ca content, stabilizing the activity of the SR Ca release channel ryanodine receptor for the next beat. SR Ca leak has been visualized globally using whole-cell fluorescence, or locally using confocal microscopy, but never both ways. When using confocal microscopy, leak is imaged as “Ca sparks,” which are fluorescent objects generated by the local reaction-diffusion of released Ca and cytosolic i...

Santiago, Demetrio J.; Curran, Jerald W.; Bers, Donald M.; Lederer, W. J.; Stern, Michael D.; Ri?os, Eduardo; Shannon, Thomas R.

2010-01-01

113

Cardiotoxicity of emetine dihydrochloride by calcium channel blockade in isolated preparations and ventricular myocytes of guinea-pig hearts.  

OpenAIRE

1. The cardiotoxic effects of emetine dihydrochloride on mechanical and electrical activity were studied in isolated preparations (papillary muscles, sinoatrial and atrioventricular nodes, ventricular myocytes) of the guinea-pig heart. 2. Force of contraction was measured isometrically, action potentials and maximum rate of rise of the action potential were recorded by means of the intracellular microelectrode technique. Single channel L-type calcium current (Ba2+ ions as charge carrier) was ...

Lemmens-gruber, R.; Karkhaneh, A.; Studenik, C.; Heistracher, P.

1996-01-01

114

Pattern of left ventricular hypertrophy seen on transthoracic echo in patients with hypertensive cardiomyopathy when compared with idiopathic hypertrophic cardiomyopathy  

International Nuclear Information System (INIS)

Objective: To explore the pattern of left ventricular hypertrophy caused by hypertension and to compare it with idiopathic hypertrophic cardiomyopathy. Methods: The retrospective study was conducted at the echocardiography lab of Rashid Hospital, Dubai, from January 2009 to January 2010. Cases of 11 patients with significant left ventricular hypertrophy (septum >15mm) due to underlying hypertension were analysed and compared with 11 cases of idiopathic hypertrophic cardiography (septum >15mm) to assess the two groups with similar baseline echocardiographic features. Minitab software was used for statistical analysis. Results: Although the pattern of hypertrophy in hypertensive patients was more concentric (n=5; 45%), there was also asymmetrical septal hypertrophy in 4 (36%) cases, particularly the elderly with sigmoid shape septum. There was evidence of resting mid-cavity gradient due to reduced left ventricular end-systolic diameter in 4 (36%) cases. Conclusion: Although the equation between hypertension and left ventricular hypertrophy is more concentric, but it can be associated with left ventricular outflow tract obstruction and significant mid-cavity gradients similar to that seen in idiopathic hypertrophic cardiomyopathy. (author)

115

What is the role of silent coronary artery disease and left ventricular hypertrophy in the genesis of ventricular arrhythmias in men with essential hypertension?  

Science.gov (United States)

Ventricular arrhythmias are not uncommon in patients with hypertension, are often attributed to left ventricular hypertrophy and are thought to be associated with an increased risk of sudden death. However, underlying silent coronary artery disease, another potential cause of ventricular arrhythmias, is often present in the same patient group. Therefore, the prevalence of ventricular arrhythmias was prospectively examined in 183 consecutive asymptomatic men with hypertension with neither clinical nor electrocardiographic (ECG) evidence of coronary artery disease in whom technically adequate echocardiograms could be obtained. After previous therapy had been withdrawn for greater than or equal to 4 days, each patient underwent exercise or dipyridamole thallium-201 scintigraphy, 48-h Holter ambulatory ECG monitoring and echocardiography for measurement of the left ventricular mass index. Forty patients (22%) had frequent ventricular ectopic activity, defined on the basis of greater than 10 premature ventricular complexes/h (38 patients) or ventricular tachycardia (11 patients), or both. A higher proportion of patients with than without a reversible thallium-201 defect had frequent premature ventricular complexes (33% vs. 18%, p less than 0.02) or ventricular tachycardia (14% vs. 4%, p less than 0.02). Similarly, more patients with than without left ventricular hypertrophy (defined as left ventricular mass index greater than or equal to 134 g/m2) had frequent premature ventricular complexes (29% vs. 15%, p less than 0.05) and ventricular tachycardia (12% vs. 2%, p less than 0.01). By stepwise logistic regression analysis, both findings were independent predictors of ventricular arrhythmia, which was present in 53% of patients with both abnormalities, but in only 12% of those with neither abnormality.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1531991

Szlachcic, J; Tubau, J F; O'Kelly, B; Ammon, S; Daiss, K; Massie, B M

1992-03-15

116

Vitamin D Receptor Gene Polymorphism and Left Ventricular Hypertrophy in Chronic Kidney Disease  

OpenAIRE

FokI and BsmI polymorphisms of vitamin D receptor (VDR) gene are regarded as reliable markers of disturbed vitamin D signaling pathway. Left ventricular hypertrophy (LVH) is a strong cardiovascular risk marker in end stage renal disease (ESRD) patients. Since BsmI polymorphism has been associated with LVH in ESRD patients, we addressed this study in patients with chronic kidney disease (CKD) not yet on dialysis. One hundred and forty five patients with CKD stage 3 were genotyped for FokI and ...

Domenico Santoro; Giorgia Gagliostro; Angela Alibrandi; Riccardo Ientile; Guido Bellinghieri; Vincenzo Savica; Michele Buemi; Daniela Caccamo

2014-01-01

117

QRS Voltage-Duration Product in the Identification of Left Ventricular Hypertrophy in Spontaneously Hypertensive Rats  

OpenAIRE

OBJECTIVE - Evaluation of the performance of the QRS voltage-duration product (VDP) for detection of left ventricular hypertrophy (LVH) in spontaneously hypertensive rats (SHR). METHODS - Orthogonal electrocardiograms (ECG) were recorded in male SHR at the age of 12 and 20 weeks, when systolic blood pressure (sBP) reached the average values of 165±3 mmHg and 195±12 mmHg, respectively. Age- and sex- matched normotensive Wistar Kyoto (WKY) rats were used as controls. VDP was calculated as a p...

Ljuba Bacharova; Jan Kyselovic; Jan Klimas

2002-01-01

118

Adiponectin as an independent predictor of left ventricular hypertrophy in nondiabetic patients with hypertension.  

Science.gov (United States)

We evaluated novel and traditional biomarkers as well as hemodynamic parameters associated with the development of left ventricular hypertrophy (LVH) in nondiabetic patients with hypertension. Nondiabetic patients with hypertension (n = 86) were evaluated for lipids, glucose, insulin, homeostasis model assessment-insulin resistance (HOMA-IR), adiponectin, aldosterone, renin, matrix metalloproteinase 2, and endothelin. Arterial elasticity was evaluated using pulse wave contour. The LVH parameters were assessed echographically. Adiponectin was significantly and inversely associated with left ventricular mass (LVM; P = .032). The aldosterone-renin ratio (ARR) was significantly, positively associated with LVM (P = .031). Fasting insulin as well as HOMA-IR was significantly, positively associated with LVM (P = .036 and P = .025, respectively). In multiple linear regression analysis, adiponectin and ARR remained a significant predictor of LVM. The present study found that adiponectin and ARR are important independent determinants of LVH in nondiabetic patients with hypertension. PMID:24576986

Peer, Maya; Mashavi, Margarita; Matas, Zipora; Harpaz, David; Shargorodsky, Marina

2015-03-01

119

Asociación de la hipertrofía ventricular izquierda con eventos cardiacos posteriores a intervencionismo coronario percutáneo. Association of left ventricular hypertrophy with cardiac events after percutaneous coronary intervention.  

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Full Text Available Introduction: Left ventricular hypertrophy is not included in the prognostic models of cardiacevents after percutaneous coronary intervention.Objective To determine the association of left ventricular hypertrophy with the presenceof cardiac events during 4 years follow-up after percutaneous coronary intervention.Method 80 hypertensive patients without prior revascularization, undergoing successfulpercutaneous coronary intervention with bare-metal stents at the NationalCardiology and Cardiovascular Surgery Institute between December 2002 andApril 2004, were prospectively included. The demographic, clinical and angiographiccharacteristics were included in our database during the procedure.We made a 4 years follow-up.Results Restenosis (p<0.02 was more frequent in the group of hypertensive patientswith hypertrophy of both anterior and posterior left ventricle walls. Univariateregression analysis showed that left ventricular hypertrophy associates with ahigher restenosis incidence (OR 3.12; CI 95% 1.20-8.14.Conclusions Left ventricular hypertrophy is a risk marker of restenosis after percutaneouscoronary intervention. There was no association with any other cardiac eventduring the long follow-up of hypertensive patients.

Luis R. Llerena Rojas

2011-01-01

120

Sex differences in SR Ca(2+) release in murine ventricular myocytes are regulated by the cAMP/PKA pathway.  

Science.gov (United States)

Previous studies have shown that ventricular myocytes from female rats have smaller contractions and Ca(2+) transients than males. As cardiac contraction is regulated by the cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) pathway, we hypothesized that sex differences in cAMP contribute to differences in Ca(2+) handling. Ca(2+) transients (fura-2) and ionic currents were measured simultaneously (37°C, 2Hz) in ventricular myocytes from adult male and female C57BL/6 mice. Under basal conditions, diastolic Ca(2+), sarcoplasmic reticulum (SR) Ca(2+) stores, and L-type Ca(2+) current did not differ between the sexes. However, female myocytes had smaller Ca(2+) transients (26% smaller), Ca(2+) sparks (6% smaller), and excitation-contraction coupling gain in comparison to males (23% smaller). Interestingly, basal levels of intracellular cAMP were lower in female myocytes (0.7±0.1 vs. 1.7±0.2fmol/?g protein; pforskolin abolished sex differences in cAMP levels, as well as differences in Ca(2+) transients, sparks, and gain. To determine if the breakdown of cAMP differed between the sexes, phosphodiesterase (PDE) mRNA levels were measured. PDE3 expression was similar in males and females, but PDE4B expression was higher in female ventricles. The inhibition of cAMP breakdown by PDE4 (10?M rolipram) abolished differences in Ca(2+) transients and gain. These findings suggest that female myocytes have lower levels of basal cAMP due, in part, to higher expression of PDE4B. Lower cAMP levels in females may attenuate PKA phosphorylation of Ca(2+) handling proteins in females, and may limit positive inotropic responses to stimulation of the cAMP/PKA pathway in female hearts. PMID:25066697

Parks, Randi J; Ray, Gibanananda; Bienvenu, Laura A; Rose, Robert A; Howlett, Susan E

2014-10-01

121

Cell-volume regulation by swelling-activated chloride current in guinea-pig ventricular myocytes.  

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The cell-volume regulation by swelling-activated Cl- current (I(Cl,swell)) was studied in guinea pig ventricular myocytes, using a microscopic video-image analysis. We have previously shown that in ventricular cells depolarized in high-K+ ([K+]o>45 mM) solution, an activation of the cyclic AMP-dependent Cl- current (I(Cl,cAMP)) leads to cell swelling. We first investigated the mechanism underlying the I(Cl,cAMP)-independent recovery (shrinkage) of the swollen cells. They shrank when the membrane potential (Vm) was made negative to the equilibrium potential of Cl- (ECl) by lowering [K+]o or [Cl-]o in the high-K+ solution. This shrinkage was attenuated by the inhibitors (DIDS, glibenclamide, furosemide) of swelling-activated Cl- current (I(Cl,swell)). These findings suggested an involvement of I(Cl,swell) in the observed isosmotic cell shrinkage. On the other hand, an application of hyposmotic (70% of control) solution to the cells at normal [K+]o (ECl>Vm) induced a cell swelling, and the swollen cells underwent a slight but definite spontaneous cell shrinkage during hyposmotic challenge, indicating the operation of the mechanism of regulatory volume decrease (RVD). This RVD was pronounced at low [Cl-]o, at which ECl was much more positive than Vm. On the contrary, when the hyposmotic solution was applied to the cells at high [K+]o, at which ECl was negative to Vm, the cells swelled vigorously and monotonically without showing RVD, the swelling being much greater than that seen at normal [K+]o. Both the RVD at normal [K+]o and the extra cell swelling at high [K+]o were suppressed by DIDS. These results suggest that I(Cl,swell) activated by cell swelling can shrink or inflate the cardiac cells under hyposmotic as well as isosmotic conditions, depending on Vm and ECl. PMID:15040846

Yamamoto, Shintaro; Ishihara, Keiko; Ehara, Tsuguhisa; Shioya, Takao

2004-02-01

122

Effects of hypertrophy on left atrial and ventricular compliance and plasma ANF levels in conscious dogs.  

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Alterations in left atrial (LA) and left ventricular (LV) compliance and arterial and coronary sinus atrial natriuretic factor (ANF) concentrations at baseline and in response to both volume depletion and expansion were investigated in 15 conscious dogs with aortic banding-induced LV hypertrophy (LVH) (LV/body wt increased by 64%), which also induced LAH (LA/body wt increased by 61%). With volume expansion coronary sinus ANF increased more (P < 0.05) in dogs with LVH (+427 +/- 88 pg/ml) compared with control dogs (+146 +/- 45 pg/ml). Arterial ANF levels also rose more with volume expansion in LVH. In dogs with LVH, the LV end-diastolic pressure-diameter relationship was shifted to the left with a steeper slope with volume expansion, such that at any given diastolic dimension, diastolic pressure was higher. In contrast, the pressure-dimension relationship for the LA appendage was shifted in the opposite direction during both atrial systolic and diastolic phases, with a more shallow slope in hypertrophy compared with control dogs, resulting in an augmented pressure-dimension product during volume loading in LAH. In conclusion, in dogs with LVH and LAH, enhanced ANF was revealed in the coronary sinus and systemic circulation during volume expansion, which could be due, in part, to a more compliant, but hypertrophied, LA, which responded to equivalent volume loading with an augmented pressure-dimension product. PMID:7864205

Hasebe, N; Hittinger, L; Kohin, S; Shen, Y T; Graham, R M; Vatner, S F

1995-02-01

123

Beneficial effect of isradipine on the development of left ventricular hypertrophy in mild hypertension  

DEFF Research Database (Denmark)

The objective of this study was to analyze the long-term hemodynamic effects of the calcium antagonist isradipine in mild hypertension compared with those of the beta 1-selective adrenoceptor antagonist atenolol, focusing in particular on the development of cardiac hypertrophy. Ten male patients with mild essential hypertension were entered into a double-blind crossover study. Examinations were carried out after 2 weeks of placebo run-in, and after 6 and 12 months of active treatment. Mean resting blood pressure was reduced from 115 +/- 12 mm Hg to 106 +/- 12 mm Hg with atenolol, and to 107 +/- 8 mm Hg with isradipine. The increase in the product of heart rate times blood pressure was significantly greater during isradipine treatment, as was the maximum exercise capacity. Left ventricular mass was increased from 228 +/- 36 g to 305 +/- 68 g with atenolol whereas it remained unchanged with isradipine (254 +/- 55 g). The results indicate that antihypertensive treatment with isradipine as monotherapy may preventthe development of left ventricular hypertrophy whereas treatment with atenolol as monotherapy does not appear to offer this possibility.

Mehlsen, J; Fornitz, Gitte Gleerup

1993-01-01

124

Baroreceptor sensitivity, cardiovascular responses and ECG left ventricular hypertrophy in men: the SABPA study.  

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AIM. Research has shown a significant relationship between hypertension and attenuated baroreceptor sensitivity (BRS), which in turn reflects alterations of autonomic control of the cardiovascular system. The objective of this study was to compare the BRS of African and Caucasian men and determine possible associations with blood pressure and left ventricular hypertrophy. MATERIALS AND METHODS. Participants included African (n = 82) and Caucasian (n = 100) male teachers, aged between 20 and 65 years, recruited in the North-West Province, South Africa. Ambulatory blood pressure monitoring was conducted for a 22-23-h period and, thereafter, cardiovascular parameters were recorded with a Finometer and 12-lead ECG during rest and while challenging the cardiovascular system with the cold pressor and Stroop color?word conflict tests. Spontaneous BRS was calculated as well as the Cornell product [marker of left ventricular hypertrophy (LVH)]. RESULTS. The African men had significantly lower BRS stress responses. Attenuated BRS coupled to an ?-adrenergic response pattern predicted elevation of blood pressure in the African men. BRS reduction did not prove to be a significant predictor of LVH. CONCLUSION. Lower BRS, especially during stress, may pose a significant health threat for African men regarding earlier development or promotion of ? -adrenergic-driven hypertension and greater risk for cardiovascular disease. PMID:21545353

van Lill, Lisa; Malan, Leon; van Rooyen, Johannes; Steyn, Faans; Reimann, Manja; Ziemssen, Tjalf

2011-12-01

125

Carotid intima-media thickness and left ventricular hypertrophy in hemodialysis patients  

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Introduction: Two principal findings of cardiovascular disease in end-stage renal disease patients undergoing regular hemodialysis are left ventricular hypertrophy (LVH) and arterial disease due to rapidly progressive atherosclerotic vascular disease that can be characterized by an enlargement and hypertrophy of arteries (intima-media complex thickening; IMT).Objectives: In this study, we sought to evaluate the relationship between left ventricular hypertrophy with intima-media complex thickening in end-stage renal disease patients undergoing regular hemodialysis. Patients and Methods: Sixty-one patients with end-stage renal disease (ESRD) who were undergoing regular and maintenance hemodialysis treatment (F=23, M=38) were studied. The subjects consisted of 50 non-diabetic hemodialysis patients (F=20, M=30) and 11 diabetic hemodialysis patients (F=3, M=8). For all the subjects, echocardiography and carotid intima-media thickness measuring by B-mode ultrasonography were performed. Results: In this study, there was a positive correlation between stages of LVH with duration of hemodialysis treatment, stages of hypertension (HTN), and with carotid-IMT. A positive correlation was also seen between stages of LVH and presence of chest pain, and more thickening of the intima-media complex was seen in the diabetic group. Diabetes mellitus was associated with the presence of chest pain, as was positive correlation between stages of HTN with IMT, and a reverse correlation was observed between IMT with the percent of cardiac ejection fraction. Conclusion: Prevalence of thickening in intima-media complex is more evident in hemodialysis subjects with LVH. When there is LVH, IMT is similar in severity to the LVH. PMID:25340151

Rafieian-Kopaei, Mahmoud; Nasri, Hamid

2013-01-01

126

Carotid intima-media thickness and left ventricular hypertrophy in hemodialysis patients  

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Full Text Available Introduction: Two principal findings of cardiovascular disease in end-stage renal disease patients undergoing regular hemodialysis are left ventricular hypertrophy (LVH and arterial disease due to rapidly progressive atherosclerotic vascular disease that can be characterized by an enlargement and hypertrophy of arteries (intima-media complex thickening; IMT.Objectives: In this study, we sought to evaluate the relationship between left ventricular hypertrophy with intima-media complex thickening in end-stage renal disease patients undergoing regular hemodialysis.Patients and Methods: Sixty-one patients with end-stage renal disease (ESRD who were undergoing regular and maintenance hemodialysis treatment (F=23, M=38 were studied. The subjects consisted of 50 non-diabetic hemodialysis patients (F=20, M=30 and 11 diabetic hemodialysis patients (F=3, M=8. For all the subjects, echocardiography and carotid intima-media thickness measuring by B-mode ultrasonography were performed.Results: In this study, there was a positive correlation between stages of LVH with duration of hemodialysis treatment, stages of hypertension (HTN, and with carotid-IMT. A positive correlation was also seen between stages of LVH and presence of chest pain, and more thickening of the intima-media complex was seen in the diabetic group. Diabetes mellitus was associated with the presence of chest pain, as was positive correlation between stages of HTN with IMT, and a reverse correlation was observed between IMT with the percent of cardiac ejection fraction.Conclusion: Prevalence of thickening in intima-media complex is more evident in hemodialysis subjects with LVH. When there is LVH, IMT is similar in severity to the LVH.

Rafieian-Kopaei Mahmoud

2013-10-01

127

Prognostic significance of left ventricular diastolic dysfunction in patients with left ventricular hypertrophy and systemic hypertension (the LIFE Study)  

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Patients with hypertension and left ventricular (LV) hypertrophy commonly have impaired diastolic filling. However, it remains unknown whether changes in LV diastolic filling variables are associated with cardiovascular morbidity and mortality. In this study, 778 patients with hypertension with electrocardiographic LV hypertrophy who underwent echocardiography at baseline and annually thereafter during randomized losartan- or atenolol-based antihypertensive treatment were followed for a mean of 4.6 years. The composite cardiovascular end point was the first occurrence of fatal or nonfatal myocardial infarction, fatal or nonfatal stroke, and cardiovascular mortality. Antihypertensive therapy resulted in an increase in the prevalence of normal transmitral flow pattern from 28% to 46% of patients. Although antihypertensive treatment often resulted in a marked increase in the prevalence of normal mitral valve flow pattern, this was not associated with reduced cardiovascular morbidity and mortality when adjusting for blood pressure, left atrial diameter, LV mass index, and treatment in time-varying Cox analyses. In contrast, lower in-treatment E/A ratios and shorter mitral valve deceleration times were associated with less risk for heart failure. Similarly, normal in-treatment transmitral flow pattern was strongly associated with less risk for heart failure (hazard ratio 0.22, 95% confidence interval 0.05 to 0.98, p = 0.048), even when taking in-treatment left atrial diameter and blood pressure into account. In conclusion, antihypertensive treatment in patients with hypertension with electrocardiographic LV hypertrophy resulted in significant improvement in transmitral flow patterns; this was not associated with reduced cardiovascular morbidity and mortality. However, normal in-treatment LV filling was strongly associated with a reduced risk for hospitalization for heart failure.

Wachtell, Kristian; Palmieri, Vittorio

2010-01-01

128

Effects of levosimendan in patients with left ventricular hypertrophy undergoing aortic valve replacement  

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BACKGROUND: Left ventricular hypertrophy is associated with adverse outcomes, including death, during cardiac surgery. This may be facilitated by an increased oxygen demand and diastolic dysfunction. Levosimendan augments haemodynamics without further oxygen consumption and improves echocardiographic indices of diastolic dysfunction. This study aimed to describe the haemodynamic effects of short-term pre- and intra-operative levosimendan infusion including advanced echocardiographic measures of diastolic and systolic heart function. METHODS: The study was randomised, double-blinded and placebo-controlled performed at a single-centre university hospital. Patients with left ventricular hypertrophy and ejection fraction >?45% scheduled for single procedure aortic valve replacement were included and randomised to infusion of either levosimendan 0.1??g/kg/min or placebo from 4?h before anaesthesia to the end of surgery. Outcome measures were echocardiographic indices of left ventricular diastolic function: E/e' (primary endpoint), e', e'/a' and indices of systolic function: longitudinal strain, ejection fraction and s'. Patients were followed until 6 months after surgery. In addition, invasive haemodynamic measures were obtained perioperatively. RESULTS: The trial was prematurely terminated due to an overall high incidence of post-operative atrial fibrillation (15/20, P?=?0.002) after inclusion of 20 patients. The relative decrease in perioperative cardiac index was lower (P?=?0.016) in the levosimendan group. There was no difference in E/e', and similar results were found for all measures of systolic function. CONCLUSION: Short-term levosimendan caused a transient relative increase in cardiac index, but no effect was seen on the first post-operative day and up to 6 months post-operatively with indices of systolic and diastolic heart function.

Juhl-Olsen, P; Jakobsen, C-J

2014-01-01

129

The effects of implanted valve sizes on ventricular hypertrophy in aortic stenosis  

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Full Text Available Objective: We aimed to study the effects of the valve sizes according to body surface area on aortic gradient and ventricular hypertrophy in the cases of aortic valve replacement due to isolated aortic stenosis.Methods: Between January 2006 and April 2007, patients (12 men, 15 women; totally 27 followed up prospectively with echocardiography fourth and sixth month postoperatively. The patients were divided into two groups according to the prosthetic aortic valve diameters (19-21 mm vs 23-25 mm. The primary endpoints between the two groups (aortic regurgitation, left ventricular mass index and transvalvular gradient measured by color and continuous wave Doppler were compared. Fischer exact test and Mann-Whitney U test were used for intergroup comparison whereas intragroup analysis was done with Freidman test.Results: Mean systolic gradient and left ventricular mass index were significantly reduced in 23 mm and 25 mm valves (p<0.01 in the postoperative follow-up. In addition, especially, decline in the values of left ventricular mass, left ventricular mass index, peak systolic gradient and the mean systolic gradient were found to be significant. These values associated with regression were detectable at the postoperative 4th month, but actual significant regression was observed at the postoperative 6th month (p<0.01. On the other hand, the values obtained for 19 mm and 21 mm valves also showed significant progress (p<0.05.Conclusion: Factors such as age, gender and activity are important in the selection of appropriate valve sizes in aortic valve replacement. However, the patient's body surface is the most important prognostic factor compared to others.

Hikmet Selçuk Gedik

2012-02-01

130

Ventricular hypertrophy blocked delayed anesthetic cardioprotection in rats by alteration of iNOS/COX-2 signaling.  

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The aim of the current study was to determine whether ventricular hypertrophy affects the delayed isoflurane preconditioning against myocardial ischemia-reperfusion (IR) injury. Transverse aortic constriction (TAC) was performed on male Sprague-Dawley rats to induce left ventricular (LV) hypertrophy, then sham-operated or hypertrophied rat hearts were subjected to isoflurane preconditioning (2.1% v/v, 1?h). 24?h after exposure, the hearts were isolated and perfused retrogradely by the Langendorff for 30?min (equilibration) followed by 40?min of ischemia and then 120?min of reperfusion. The hemodynamics, infarct size, apoptosis, nitric oxide synthase (NOS), cyclooxygenase-2 (COX-2), Cleaved Caspase-3 and production of NO were determined. We found that the hemodynamic parameters were all markedly improved during the reperfusion period and the myocardial infarct size and apoptosis was significantly reduced by delayed isoflurane preconditioning in sham-operated rats. However, such cardiac improvement induced by delayed isoflurane preconditioning was not observed in hypertrophied hearts. The expression of iNOS, COX-2 and NO was markedly enhanced, whereas Cleaved Caspase-3 activity was inhibited by delayed isoflurane preconditioning in sham-operated rats, a phenomenon was not found in TAC-control groups pretreated with isoflurane. Our results demonstrated that ventricular hypertrophy abrogated isoflurane-induced delayed cardioprotection by alteration of iNOS/COX-2 pathway. PMID:25400168

Ma, Leilei; Kong, Feijuan; Ge, Hongwei; Liu, Jingquan; Gong, Fangxiao; Xu, Liang; Hu, Bangchuan; Sun, Renhua

2014-01-01

131

Changes in electrocardiographic left ventricular hypertrophy and risk of major cardiovascular events in isolated systolic hypertension: the LIFE study  

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The predictive value of changes in the severity of electrocardiographic left ventricular hypertrophy (ECG-LVH) during antihypertensive therapy remains unclear in isolated systolic hypertension (ISH). In a Losartan Intervention For Endpoint reduction in hypertension substudy, we included 1320 patients aged 54-83 years with systolic blood pressure (BP) of 160-200?mm?Hg, diastolic BP

Larstorp, A C K; Okin, P M

2011-01-01

132

Iodine-123 phenylpentadecanoic acid myocardial scintigraphy in patients with left ventricular hypertrophy: Alterations in left ventricular distribution and utilization  

International Nuclear Information System (INIS)

Regional alterations in myocardial substrate uptake and/or utilization have been demonstrated in rats with hypertension. To determine whether alterations in left ventricular fatty acid uptake and/or utilization are present in patients with left ventricular hypertrophy (LVH), we compared the results of rest and exercise iodine-123 phenylpentadecanoic acid (IPPA) myocardial scintigraphy in 10 patients with hypertension who had concentric LVH without evidence of coronary artery disease and in 15 normal subjects. Patients with LVH had more heterogeneous left ventricular activity of IPPA compared to normal subjects after exercise but not at rest. Although IPPA clearance was similar in both patients with LVH and normal subjects, postexercise washout in segments showing decreased initial IPPA uptake was reduced compared to washout at rest in patients with LVH (11.7 +/- 7.5% versus 21.5 +/- 8.4% at 20 minutes after injection, n = 15; p = 0.005). Exercise thallium-201 (TI-201) scintigraphy was normal in all seven patients with LVH tested. Patients with LVH showed significantly greater heterogeneity in IPPA uptake compared to TI-201 uptake immediately after exercise (25 +/- 5% versus 16 +/- 6%; p = 0.013). We conclude that (1) compared to normal subjects, patients with LVH show heterogeneous myocardial IPPA activity after exercise but not at rest; (2) postexercise washout of IPPA was decreased in segments with reduced uptake after exercise in patients with LVH; and (3) the distise in patients with LVH; and (3) the distribution of IPPA is more heterogeneous than that of TI-201 immediately after exercise in patients with concentric LVH. The postexercise heterogeneity in IPPA uptake and delayed washout in segments with reduced initial uptake is consistent with exercise-induced myocardial ischemia in patients with LVH

133

Metformin attenuates ventricular hypertrophy by activating the AMP-activated protein kinase-endothelial nitric oxide synthase pathway in rats.  

Science.gov (United States)

1. Metformin is an activator of AMP-activated protein kinase (AMPK). Recent studies suggest that pharmacological activation of AMPK inhibits cardiac hypertrophy. In the present study, we examined whether long-term treatment with metformin could attenuate ventricular hypertrophy in a rat model. The potential involvement of nitric oxide (NO) in the effects of metformin was also investigated. 2. Ventricular hypertrophy was established in rats by transaortic constriction (TAC). Starting 1 week after the TAC procedure, rats were treated with metformin (300 mg/kg per day, p.o.), N(G)-nitro-L-arginine methyl ester (L-NAME; 50 mg/kg per day, p.o.) or both for 8 weeks prior to the assessment of haemodynamic function and cardiac hypertrophy. 3. Cultured cardiomyocytes were used to examine the effects of metformin on the AMPK-endothelial NO synthase (eNOS) pathway. Cells were exposed to angiotensin (Ang) II (10?? mol/L) for 24 h under serum-free conditions in the presence or absence of metformin (10?³ mol/L), compound C (10?? mol/L), L-NAME (10?? mol/L) or their combination. The rate of incorporation of [³H]-leucine was determined, western blotting analyses of AMPK-eNOS, neuronal nitric oxide synthase (nNOS) and inducible nitric oxide synthase (iNOS) were undertaken and the concentration of NO in culture media was determined. 4. Transaortic constriction resulted in significant haemodynamic dysfunction and ventricular hypertrophy. Myocardial fibrosis was also evident. Treatment with metformin improved haemodynamic function and significantly attenuated ventricular hypertrophy. Most of the effects of metformin were abolished by concomitant L-NAME treatment. L-NAME on its own had no effect on haemodynamic function and ventricular hypertrophy in TAC rats. 5. In cardiomyocytes, metformin inhibited AngII-induced protein synthesis, an effect that was suppressed by the AMPK inhibitor compound C or the eNOS inhibitor L-NAME. The improvement in cardiac structure and function following metformin treatment was associated with enhanced phosphorylation of AMPK and eNOS and increased NO production. 6. The findings of the present study indicate that long-term treatment with metformin could attenuate ventricular hypertrophy induced by pressure overload via activation of AMPK and a downstream signalling pathway involving eNOS-NO. PMID:21083698

Zhang, Cheng-Xi; Pan, Si-Nian; Meng, Rong-Sen; Peng, Chao-Quan; Xiong, Zhao-Jun; Chen, Bao-Lin; Chen, Guang-Qin; Yao, Feng-Juan; Chen, Yi-Li; Ma, Yue-Dong; Dong, Yu-Gang

2011-01-01

134

Cross-signaling between L-type Ca2+ channels and ryanodine receptors in rat ventricular myocytes  

OpenAIRE

Calcium-mediated cross-signaling between the dihydropyridine (DHP) receptor, ryanodine receptor, and Na(+)-Ca2+ exchanger was examined in single rat ventricular myocytes where the diffusion distance of Ca2+ was limited to < 50 nm by dialysis with high concentrations of Ca2+ buffers. Dialysis of the cell with 2 mM Ca(2+)- indicator dye, Fura-2, or 2 mM Fura-2 plus 14 mM EGTA decreased the magnitude of ICa-triggered intracellular Ca2+ transients (Cai-transients) from 500 to 20-100 nM and comple...

1996-01-01

135

Block of the delayed rectifier current (IK) by the 5-HT3 antagonists ondansetron and granisetron in feline ventricular myocytes.  

OpenAIRE

1. We investigated the effects of two 5-HT3 antagonists, ondansetron and granisetron, on the action potential duration (APD) and the delayed rectifier current (IK) of feline isolated ventricular myocytes. Whole-cell current and action potential recordings were performed at 37 degrees C with the patch clamp technique. 2. Ondansetron and granisetron blocked IK with a KD of 1.7 +/- 1.0 and 4.3 +/- 1.7 microM, respectively. At a higher concentration (30 microM), both drugs blocked the inward rect...

Lorenzi, F. G.; Bridal, T. R.; Spinelli, W.

1994-01-01

136

Epinephrine enhances Ca2+ current-regulated Ca2+ release and Ca2+ reuptake in rat ventricular myocytes.  

OpenAIRE

The voltage dependence of the intracellular Ca2+ transients was measured in single rat ventricular myocytes with the fluorescent Ca2+ indicator dye fura-2. The whole-cell voltage clamp technique was used to measure the membrane current, and 0.9 mM fura-2 was loaded into the cell by including it in the dialyzing solution of the patch electrode. A mechanical light chopper operating at 1200 Hz was used to obtain simultaneous measurements of the intracellular Ca2+ activity with fluorescence excit...

Callewaert, G.; Cleemann, L.; Morad, M.

1988-01-01

137

Frequent left ventricular hypertrophy independent of blood pressure in 1851 pre-western Inuit  

DEFF Research Database (Denmark)

BACKGROUND: Elevated blood pressure is a risk factor for cardiovascular disease and may be detected by left ventricular hypertrophy (LVH) in electrocardiogram (ECG). Pre-western Inuit had frequent signs of LVH in ECG predominantly in the 3rd decade while a low occurrence of ischemic heart disease. METHODS: We evaluated the association between blood pressures and ECG signs of LVH, cardiac auscultation, and symptoms related to heart disease in the recently recovered data from the survey of 1851 Inuit conducted in 1962-1964 in East Greenland. RESULTS: The participation rate was 97%. Among the 812 Inuit aged 18years or above blood pressure was unaltered until the age of 39years (systolic, p=76; diastolic, p=0.36) and increased subsequently (both, p140mmHg was more frequent when aged >40years (p90mmHg was more common in men (p40years (p

Andersen, Stig; Kjærgaard, Marie

2011-01-01

138

Postnatal developmental decline in IK1 in mouse ventricular myocytes isolated by the Langendorff perfusion method: comparison with the chunk method.  

Science.gov (United States)

Expression and function of cardiac ion channels exhibit postnatal developmental changes, which, however, has not yet been proven in ventricular myocytes isolated using similar techniques. In this study, ventricular myocytes were enzymatically dissociated from mouse heart at different postnatal ages (including postnatal day 0) by similar techniques using Langendorff perfusion. Whole-cell patch-clamp experiments were performed to record action potentials, I (K1), I (Kr), I (Kur), I (ss), and I (Ca,L), in ventricular myocytes freshly isolated from postnatal days 0, 7, and 14 and adult mice. Viable ventricular myocytes of day-0 mouse heart exhibited spindle-shaped appearance having cell length of approximately 50 ?m, which gradually developed to a rod-shaped one having clear cross striation with cell length of approximately 120 ?m (adult). The action potential duration markedly shortened, while the resting membrane potential depolarized to a small but significant extent during postnatal development. I (K1) density was maximal in postnatal day-0 ventricular myocytes and gradually decreased during development, which was accompanied by postnatal depolarization of resting membrane potential. However, I (K1) density was markedly decreased by approximately 80% in postnatal day-0 ventricular myocytes, when isolated by the chunk method. Quantitative real-time polymerase chain reaction (PCR) and western blot analyses demonstrated higher Kir2.3 expression but lower expression levels of Kir2.1 and Kir2.2 in day-0 mouse ventricles, compared with those of day-14 and adult mouse ventricles. Whereas I (Kr) exhibited marked decrease during postnatal development, I (Kur), I (ss), and I (Ca,L) exhibited postnatal developmental increase. The present cell isolation method using the Langendorff perfusion thus found that, in mouse ventricles, I (K1) exhibited postnatal developmental decrease, associated with depolarization of resting potential. PMID:22415213

Hoshino, Shinsuke; Omatsu-Kanbe, Mariko; Nakagawa, Masao; Matsuura, Hiroshi

2012-04-01

139

Cardiac morphology in left ventricular hypertrophy using thallium-201 myocardial scintigraphy  

International Nuclear Information System (INIS)

To evaluate cardiac morphology in the patients with various cases of hypertrophy, we measured left ventricular (LV) size using thallium-201 myocardial scintigraphy in 29 normal subjects and in 90 patients. Cardiac shape and dimension were assessed by measuring the wall thickness and external length in the short and long axis of LV image in LAO projection. In aortic stenosis and hypertensive heart disease the shape was spherical and the wall was thickened. In both mitral (MR) and aortic (AR) regurgitations, LV dilatation were shown; spherical shape in chronic MR but ellipsoid shape in acute MR and AR. Decreased LV size but normal shape was observed in mitral stenosis and cor pulmonale. In hypertrophic cardiomyopathy the LV wall was asymmetrically hypertrophied, while in congestive cardiomyopathy the wall is thin with marked LV dilatation and the shape was spherical. We concluded that the heart had characteristic configuration which might reflect cardiac performance or compensate for the load to the heart, and that thallium-201 myocardial scintigraphy is useful in the evaluation of cardiac morphology as well as in diagnosis of myocardial ischemia. (author)

140

Rapamycin attenuates hypoxia-induced pulmonary vascular remodeling and right ventricular hypertrophy in mice  

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Full Text Available Abstract Background Chronic hypoxia induces pulmonary arterial hypertension (PAH. Smooth muscle cell (SMC proliferation and hypertrophy are important contributors to the remodeling that occurs in chronic hypoxic pulmonary vasculature. We hypothesized that rapamycin (RAPA, a potent cell cycle inhibitor, prevents pulmonary hypertension in chronic hypoxic mice. Methods Mice were held either at normoxia (N; 21% O2 or at hypobaric hypoxia (H; 0.5 atm; ~10% O2. RAPA-treated animals (3 mg/kg*d, i.p. were compared to animals injected with vehicle alone. Proliferative activity within the pulmonary arteries was quantified by staining for Ki67 (positive nuclei/vessel and media area was quantified by computer-aided planimetry after immune-labeling for ?-smooth muscle actin (pixel/vessel. The ratio of right ventricle to left ventricle plus septum (RV/[LV+S] was used to determine right ventricular hypertrophy. Results Proliferative activity increased by 34% at day 4 in mice held under H (median: 0.38 compared to N (median: 0.28, p = 0.028 which was completely blocked by RAPA (median HO+RAPA: 0.23, p = 0.003. H-induced proliferation had leveled off within 3 weeks. At this time point media area had, however, increased by 53% from 91 (N to 139 (H, p Conclusion Therapy with rapamycin may represent a new strategy for the treatment of pulmonary hypertension.

Tillmanns Harald H

2007-02-01

141

(/sup 3/H)-8-cyclopentyl-1,3-dipropylxanthine binding to A1 adenosine receptors of intact rat ventricular myocytes  

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The purpose of the present study was the identification of A1 adenosine receptors in intact rat ventricular myocytes, which are thought to mediate the negative inotropic effects of adenosine. The adenosine receptor antagonist (/sup 3/H)-8-cyclopentyl-1,3-dipropylxanthine was used as radioligand. Binding of the radioligand to intact myocytes was rapid, reversible, and saturable with a binding capacity of 40,000 binding sites per cell. The dissociation constant of the radioligand was 0.48 nM. The adenosine receptor antagonists 8-cyclopentyl-1,3-dipropylxanthine, xanthine amine congener, and theophylline were competitive inhibitors with affinities in agreement with results obtained for A1 receptors in other tissues. Competition experiments using the adenosine receptor agonists R-N(6)-phenylisopropyladenosine, 5'-N-ethylcarboxamidoadenosine, and S-N(6)-phenylisopropyladenosine gave monophasic displacement curves with Ki values of 50 nM, 440 nM, and 4,300 nM, which agreed well with the GTP-inducible low affinity state in cardiac membranes. The low affinity for agonists was not due to agonist-induced desensitization, and correlated well with the corresponding IC50 values for the inhibition of cyclic AMP accumulation by isoprenaline. It is suggested that only a low affinity state of A1 receptors can be detected in intact rat myocytes due to the presence of high concentrations of guanine nucleotides in intact cells.

Martens, D.; Lohse, M.J.; Schwabe, U.

1988-09-01

142

[3H]-8-cyclopentyl-1,3-dipropylxanthine binding to A1 adenosine receptors of intact rat ventricular myocytes  

International Nuclear Information System (INIS)

The purpose of the present study was the identification of A1 adenosine receptors in intact rat ventricular myocytes, which are thought to mediate the negative inotropic effects of adenosine. The adenosine receptor antagonist [3H]-8-cyclopentyl-1,3-dipropylxanthine was used as radioligand. Binding of the radioligand to intact myocytes was rapid, reversible, and saturable with a binding capacity of 40,000 binding sites per cell. The dissociation constant of the radioligand was 0.48 nM. The adenosine receptor antagonists 8-cyclopentyl-1,3-dipropylxanthine, xanthine amine congener, and theophylline were competitive inhibitors with affinities in agreement with results obtained for A1 receptors in other tissues. Competition experiments using the adenosine receptor agonists R-N(6)-phenylisopropyladenosine, 5'-N-ethylcarboxamidoadenosine, and S-N(6)-phenylisopropyladenosine gave monophasic displacement curves with Ki values of 50 nM, 440 nM, and 4,300 nM, which agreed well with the GTP-inducible low affinity state in cardiac membranes. The low affinity for agonists was not due to agonist-induced desensitization, and correlated well with the corresponding IC50 values for the inhibition of cyclic AMP accumulation by isoprenaline. It is suggested that only a low affinity state of A1 receptors can be detected in intact rat myocytes due to the presence of high concentrations of guanine nucleotides in intact cells

143

Reduction of left ventricular ejection fraction on isometric hand grip and cold pressor in hypertensive patients with left ventricular hypertrophy  

International Nuclear Information System (INIS)

Sustained isometric handgrip (SIHG) and cold pressor (CP) tests are used to assess patients suspected of having coronary artery disease (CAD). The normal response to SIHG and CP is that the blood pressure (BP) increases and left ventricular (LV) ejection fraction (EF) either increases or remains unchanged. Both SIHG and CP tests have been shown to reduce LVEF in patients with CAD. We have assessed the effects of SIHG and CP using radionuclide angiography (RA) in hypertensive patients out of which 10 had left ventricular hypertrophy (LVH group) and 8 had no evidence of LVH (non-LVH group). All patients underwent exercice Thallium-201 (201Tl) imaging in order to rule out CAD. In the LVH group, the mean resting systolic BP (SBP) (210.5 +- 4.7 SE) and diastolic BP (DBP) (119.5 +- 2.3) < mean SBP (237 +- 7.3) and DBP (126 +- 3.1) on SIHG (P<0.0001 and <0.001, respectively). The mean resting EF in LVH group (67 +- 4.3) and the non-LVH group (70 +- 4.3) were similar (P=NS). However, on SIHG and CP the mean EF in LVH group decreased (54 +- 4.6) (P<0.0001) and (62 +- 4.3) (P<0.025) respectively. There were no significant changes in EF on SIHG and CP in the non-LVH group. This finding suggests that while screening patients for CAD using RA, reduction of EF on SIHG and CP may also be due to LVH, resulting in false positive tests for CAD, thus reducing specificity for detection of CAD by these tests

144

The role of secondary hyperparathyroidism in left ventricular hypertrophy of patients under chronic hemodialysis  

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Full Text Available End-stage renal disease (ESRD patients frequently develop structural cardiac abnormalities, particularly left ventricular hypertrophy (LVH. The mechanisms involved in these processes are not completely understood. In the present study, we evaluated a possible association between parathyroid hormone (PTH levels and left ventricular mass (LVM in patients with ESRD. Stable uremic patients on intermittent hemodialysis treatment were evaluated by standard two-dimensional echocardiography and their sera were analyzed for intact PTH. Forty-one patients (mean age 45 years, range 18 to 61 years, 61% males, who had been on hemodialysis for 3 to 186 months, were evaluated. Patients were stratified into 3 groups according to serum PTH: low levels (280 pg/ml; group III = 21 patients. A positive statistically significant association between LVM index and PTH was identified (r = 0.34; P = 0.03, Pearson's correlation coefficient in the sample as a whole. In subgroup analyses, we did not observe significant associations in the low and intermediate PTH groups; nevertheless, PTH and LVM index were correlated in patients with high PTH levels (r = 0.62; P = 0.003. LVM index was also inversely associated with hemoglobin (r = -0.34; P = 0.03. In multivariate analysis, after adjustment for age, hemoglobin, body mass index, and blood pressure, the only independent predictor of LVM index was PTH level. Therefore, PTH is an independent predictor of LVH in patients undergoing chronic hemodialysis. Secondary hyperparathyroidism may contribute to the elevated cardiovascular morbidity associated with LVH in ESRD.

R.B. Randon

2005-09-01

145

Impact of electrocardiographic findings for diagnosis of left ventricular hypertrophy in patients with primary aldosteronism.  

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BACKGROUND: Compared to patients with similar levels of hypertension, patients with primary aldosteronism have a greater left ventricular hypertrophy (LVH). The presence of LVH should be detected as early as possible to prevent cardiovascular complications associated with the condition. We evaluated comparative diagnostic value of electrocardiographic (ECG) indexes for LVH in patients with primary aldosteronism. METHODS: ECG and echocardiographic data were obtained in 88 patients with primary aldosteronism. We analyzed the four most commonly used ECG indexes, including Sokolow-Lyon index, Cornell voltage index, Cornell product index, and Gubner index. RESULTS: Echocardiographic LVH was found in 35 patients (40%). Sensitivity ranged from 0% for Gubner index to 49% for Cornell product index. Specificity ranged from 81% for Sokolow-Lyon index to 100% for Gubner index. Sokolow-Lyon index (r=0.43, p<0.001), Cornell voltage index (r=0.55, p<0.001) and Cornell product index (r=0.52, p<0.001) correlated significantly with left ventricular mass (LVM) index. No significant correlation was found between Gubner index and LVM index. CONCLUSIONS: ECG indexes had a reasonably high specificity, but a low sensitivity for LVH in patients with primary aldosteronism. Cornell voltage index and Cornell product index had a better diagnostic value of LVH, and had a better correlation with LVM index in these patients. PMID:23535447

Kurisu, Satoshi; Iwasaki, Toshitaka; Mitsuba, Naoya; Ishibashi, Ken; Dohi, Yoshihiro; Kihara, Yasuki

2013-03-27

146

Evaluation of myocardial disorders in patients with dilated cardiomyopathy and left ventricular eccentric hypertrophy  

International Nuclear Information System (INIS)

201Tl myocardial SPECT was performed in cases of dilated cardiomyopathy and valvular heart disease with left ventricular eccentric hypertrophy, and the two groups were compared from the standpoint of the mechanism of onset of myocardial disorders. Significant coefficients of correlation were seen between the Tl score and LVDd (r=0.792, r=0.785) and Tl score and LVEF (r=-0.634, r=-0.555) in both dilated cardiomyopathy and valvular heart disease. In cases of valvular heart disease, significant correlation coefficients (r=-0.756, r=-0.720) between LVDd and r-WR (relative-washout rate), and Tl score and r-WR were observed, but no such correlation was seen in dilated cardiomyopathy. In valvular heart disease, a decrease in myocardial perfusion associated with enlargement of the left ventricle appeared, while in dilated cardiomyopathy, there was a marked decrease in LVEF in proportion to the thallium defect. Therefore, it was assumed that left ventricular wall disorders occur due to myocardial metabolic disorders and coronary microcirculation disorders. (author)

147

QRS Voltage-Duration Product in the Identification of Left Ventricular Hypertrophy in Spontaneously Hypertensive Rats  

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Full Text Available SciELO Brazil | Language: English Abstract in english OBJECTIVE - Evaluation of the performance of the QRS voltage-duration product (VDP) for detection of left ventricular hypertrophy (LVH) in spontaneously hypertensive rats (SHR). METHODS - Orthogonal electrocardiograms (ECG) were recorded in male SHR at the age of 12 and 20 weeks, when systolic blood [...] pressure (sBP) reached the average values of 165±3 mmHg and 195±12 mmHg, respectively. Age- and sex- matched normotensive Wistar Kyoto (WKY) rats were used as controls. VDP was calculated as a product of maximum QRS spatial vector magnitude and QRS duration. Left ventricular mass (LVM) was weighed after rats were sacrificed. RESULTS - LVM in SHR at 12 and 20 weeks of age (0.86±0.05 g and 1.05±0.07 g, respectively) was significantly higher as compared with that in WKY (0.65±0.07 g and 0.70±0.02 g). The increase in LVM closely correlated with the sBP increase. VDP did not reflect the increase in LVM in SHR. VDP was lower in SHR as compared with that in WKY, and the difference was significant at the age of 20 weeks (18.2mVms compared with 10.7mVms, p

Ljuba, Bacharova; Jan, Kyselovic; Jan, Klimas.

2002-08-01

148

Rebound stimulation of the cAMP-regulated Cl- current by acetylcholine in guinea-pig ventricular myocytes.  

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1. Acetylcholine (ACh)-induced rebound stimulation of the cAMP-regulated Cl- current was studied in isolated guinea-pig ventricular myocytes using dialysing and dialysis-limiting configurations of the whole-cell patch-clamp technique. 2. Exposure to and subsequent washout of ACh produced a transient rebound stimulation of the Cl- current. However, this rebound response was only observed in the presence of submaximally stimulating concentrations of the cAMP-producing agonists isoprenaline (Iso) or histamine. ACh-induced rebound stimulation was not observed in the presence of maximally stimulating concentrations of Iso, nor was it observed in the absence of Iso. 3. To prevent saturation of responses during rebound, the effects of ACh were studied in the presence of a subthreshold concentration of Iso (0.001 microM). Varying the duration of exposure to ACh before washout demonstrated that the stimulatory effect of 1 microM ACh approaches steady state with a time constant of 34 s. Exposing myocytes to varying concentrations of ACh for 90 s demonstrated that the EC50 for the stimulatory effect of ACh was 0.15 microM with a maximum response equal to 67% of that obtained by a maximally stimulating concentration of Iso alone. 4. Rebound stimulation of the Cl- current could also be elicited by washing in 2 microM atropine during exposure to ACh, instead of washing out ACh. Furthermore, ACh-induced rebound was blocked by the M2 muscarinic receptor antagonist methoctramine but not by the M1 receptor antagonist pirenzepine. Rebound was also blocked in pertussis toxin (PTX)-treated myocytes. 5. ACh-induced rebound stimulation was not blocked by: (a) L-NMMA, an inhibitor of nitric oxide synthase activity; (b) Methylene Blue, LY-83583, and ODQ, inhibitors of cGMP production; or (c) milrinone, an inhibitor of cGMP-dependent phosphodiesterase activity. 6. These results indicate that ACh can stimulate cAMP-regulated ion channel activity in cardiac ventricular myocytes by facilitating beta-adrenergic and histaminergic responses. This is opposite to the inhibitory actions more typically associated with muscarinic receptor stimulation in ventricular myocardium. This stimulatory effect of ACh is mediated through M2 muscarinic receptors and a PTX-sensitive G-protein, but it does not appear to involve the production of nitric oxide or cGMP. PMID:9061643

Zakharov, S I; Harvey, R D

1997-01-01

149

Hipertrofia ventricular izquierda y factores de riesgo cardiovascular en niños y adolescentes hipertensos / Left ventricular hypertrophy and cardiovascular risk factors present in hypertensive children and adolescents  

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Full Text Available SciELO Cuba | Language: Spanish Abstract in spanish INTRODUCCIÓN. La hipertrofia ventricular izquierda es la más prominente evidencia de afectación de los órganos diana, causada por la hipertensión en los niños y adolescentes. El ecocardiograma es la herramienta fundamental para su diagnóstico. El principal objetivo de esta investigación fue determin [...] ar la presencia de hipertrofia ventricular izquierda mediante ecocardiograma, en niños y adolescentes con hipertensión arterial esencial y relacionarla con algunos factores de riesgo. MÉTODOS. Se estudiaron 140 niños y adolescentes con hipertensión arterial esencial. Se evaluaron variables demográficas, antropométricas, antecedentes personales y familiares de factores de riesgo cardiovascular y la presencia o no de hipertrofia ventricular izquierda. RESULTADOS. Más de la cuarta parte del total presentó hipertrofia ventricular izquierda. De ellos, la mayor frecuencia correspondió al sexo masculino y al grupo etario de 10 a 14 años, en ambos sexos. Hubo un mayor porcentaje en los menores de 5 años y se estableció una relación estadística significativa con el antecedente personal de bajo peso y alto peso al nacer, y con el antecedente familiar de cardiopatía isquémica. CONCLUSIONES. La hipertrofia ventricular izquierda no es una complicación infrecuente de la hipertensión arterial en la infancia. Abstract in english INTRODUCTION: Left ventricular hypertrophy is the more significant evidence of target organs provoked by hypertension in children and adolescents. Echocardiogram is the main tool for its diagnosis. The main objective of present research was to determine presence of left ventricular hypertrophy be ec [...] hocardiogram in children and adolescents presenting with essential high blood pressure and to relate it with risk factors. METHODS: More of the quarter of total had left ventricular hypertrophy. From them, the great frequency was for male sex and for the age-group from 10 to 14 years in both sexes. There was a greater percentage in those under 5 years and we established a significant statistic relation with the personal low and high birth weight and with the family background of ischemic heart disease. CONCLUSIONS: Left ventricular hypertrophy is a frequent complication of hypertension in childhood.

Juan René, Llapur Milián; Raquel, González Sánchez; Acelia, Betancourt Pérez; Doris Yisell, Rubio Olivares.

2009-06-01

150

P-1075 exerts diverse modulatory effects on mitochondrial ATP-sensitive K+ channels in rabbit ventricular myocytes.  

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P-1075 was reported to be selective for sarcolemmal ATP-sensitive K (sarcKATP) channels because of its lack of mitochondria-oxidizing effect in isolated adult rabbit myocytes. Conflicting results however have been reported on the action of P-1075 on mitochondrial KATP (mitoKATP) channels. The aim of the present study was to reevaluate the effect of P-1075 on mitoKATP channels. Endogenous flavoprotein autofluorescence in isolated rabbit ventricular myocytes was measured to assay mitoKATP channel activity. The mitoKATP channel opener diazoxide (100 microM) oxidized the flavoprotein. P-1075 at a concentration of 30 microM significantly inhibited the oxidative effect of diazoxide from 48.6 +/- 7.1% to 28.2 +/- 5.2% of the maximum value induced by 2,4-dinitrophenol (DNP, 100 microM) (n = 4, P < 0.05). Additionally, P-1075 (30 microM) significantly inhibited the pinacidil (100 microM)-induced flavoprotein oxidation by 48.4 +/- 3.9% (n = 4, P < 0.05). The inhibitory effects of P-1075 on diazoxide-induced flavoprotein oxidation were observed in the micromolar range in a concentration dependent manner. P-1075 alone oxidized flavoprotein in the range 30 nM to 5 microM, and was nearly maximal at 150 nM (11.1 +/- 1.9% of the DN P value, n = 5). These results indicate that P-1075 exerts diverse effects on mitoKATP channel in rabbit ventricular myocytes: P-1075 has a partial agonist effect and weakly activates mitoKATP channels at low concentrations, whereas P-1075 rather inhibits the opening of mitoKATP channels in the micromolar concentration range. PMID:16495751

Sato, Toshiaki; Nakaya, Haruaki

2006-02-01

151

Inhibitory effect of cinobufagin on L-type Ca2+ currents, contractility, and Ca2+ homeostasis of isolated adult rat ventricular myocytes.  

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Cinobufagin (CBG), a major bioactive ingredient of the bufanolide steroid compounds of Chan Su, has been widely used to treat coronary heart disease. At present, the effect of CBG on the L-type Ca(2+) current (I Ca-L) of ventricular myocytes remains undefined. The aim of the present study was to characterize the effect of CBG on intracellular Ca(2+) ([Ca(2+)]i) handling and cell contractility in rat ventricular myocytes. CBG was investigated by determining its influence on I Ca-L, Ca(2+) transient, and contractility in rat ventricular myocytes using the whole-cell patch-clamp technique and video-based edge-detection and dual-excitation fluorescence photomultiplier systems. The dose of CBG (10(-8) M) decreased the maximal inhibition of CBG by 47.93%. CBG reduced I Ca-L in a concentration-dependent manner with an IC50 of 4 × 10(-10) M, upshifted the current-voltage curve of I Ca-L, and shifted the activation and inactivation curves of I Ca-L leftward. Moreover, CBG diminished the amplitude of the cell shortening and Ca(2+) transients with a decrease in the time to peak (Tp) and the time to 50% of the baseline (Tr). CBG inhibited L-type Ca(2+) channels, and reduced [Ca(2+)]i and contractility in adult rat ventricular myocytes. These findings contribute to the understanding of the cardioprotective efficacy of CBG. PMID:24977199

Li, Pinya; Song, Qiongtao; Liu, Tao; Wu, Zhonglin; Chu, Xi; Zhang, Xuan; Zhang, Ying; Gao, Yonggang; Zhang, Jianping; Chu, Li

2014-01-01

152

Left Ventricular Hypertrophy and Ejection Fraction in Association with C-Reactive Protein (CRP) in Regular Hemodialysis Patients  

OpenAIRE

To study the associations of serum C-reactive protein (CRP) as a marker of inflammation, with left ventricular hypertrophy (LVH) as an independent risk factor for mortality in hemodialysis (HD) patients, a cross sectional study was conducted on maintenance hemodialysis patients. On the basis of septal thickness, the patients stratified into no LVH, mild, moderate and severe LVH. For patients levels of serum albumin (Alb) and C-reactive protein (CRP) were measured using standard kits. T...

Hamid Nasri M.D.; Shahin Shirani M.D.

2006-01-01

153

LONG-TERM EFFECTS OF CHLORTHALIDONE VS HYDROCHLOROTHIAZIDE ON ELECTROCARDIOGRAPHIC LEFT VENTRICULAR HYPERTROPHY IN THE MULTIPLE RISK FACTOR INTERVENTION TRIAL  

OpenAIRE

Chlorthalidone (CTD) reduces 24-hour blood pressure more effectively than hydrochlorothiazide (HCTZ), but whether this influences electrocardiographic left ventricular hypertrophy (LVH) is uncertain. One source of comparative data is the Multiple Risk Factor Intervention Trial (MRFIT), which randomly assigned 8,012 hypertensive men to special intervention (SI) or usual care (UC). SI participants could use CTD or HCTZ initially; previous analyses have grouped clinics by their main diuretic use...

Ernst, Michael E.; Neaton, James D.; Grimm, Richard H.; Collins, Gary; Thomas, William; Soliman, Elsayed Z.; Prineas, Ronald J.

2011-01-01

154

DIFFERENTIATION BETWEEN HYPERTROPHIC CARDIOMYOPATHY AND HYPERTENSIVE LEFT VENTRICULAR HYPERTROPHY: THE ROLE OF STRAIN RATE IMAGING STUDY AND INTEGRATED BACKSCATTER ANALYSIS  

OpenAIRE

Background: To date, any non-invasive technique is satisfactory to differentiate Hypertrophic Cardiomyopathy (HCM) from hypertensive left ventricular hypertrophy (H-LVH). We hypothesized that in HCM the presence of local peculiar tissue abnormalities results in the significant impairment of the regional systolic deformation and myocardial reflectivity, even if global function appears normal. Methods: Twenty non-obstructive HCM patients, 20 age- and gender-matched hypertensive patients (HT...

Orlando, Silvia

2010-01-01

155

Effect of microalbuminuria-lowering on regression of left ventricular hypertrophy in children and adolescents with essential hypertension  

OpenAIRE

Background: Microalbuminuria (MA) is associated with increased cardiovascular risk in hypertensive patients, but not many studies have specifically examined the effects of MA-lowering on regression of left ventricular hypertrophy (LVH) among pediatric patients with hypertension. Methods: Fifty-five patients with essential hypertension, 11 to 19 years old were prospectively studied. All patients received concomitant therapy of hydrochlorothiazide and angiotensin-converting-enzyme inhibitor. Fi...

Assadi F ; Translated by: Akbari Asbagh P; Hajizadeh N.

2007-01-01

156

Angiotensin II receptor blockers and cardiovascular protection: Focus on left ventricular hypertrophy regression and atrial fibrillation prevention  

OpenAIRE

Cesare Cuspidi1,2, Francesca Negri2, Alberto Zanchetti31Department of Clinical Medicine and Prevention, University of Milano-Bicocca, Milan, Italy; 2Policlinico di Monza; 3Centro Interuniversitario di Fisiologia Clinica e Ipertensione, Università di Milano, and Istituto Auxologico Italiano, Milan, ItalyAbstract: Left ventricular hypertrophy (LVH) and atrial fibrillation (AF) are strong predictors of cardiovascular (CV) morbidity and mortality, independently of blood pressure levels...

Cesare Cuspidi; Francesca Negri; Alberto Zanchetti

2008-01-01

157

Cardiac Steatosis and Left Ventricular Hypertrophy in Patients with Generalized Lipodystrophy as Determined by Magnetic Resonance Spectroscopy and Imaging  

OpenAIRE

Generalized lipodystrophy is a rare disorder characterized by marked loss of adipose tissue with reduced triglyceride storage capacity leading to a severe form of metabolic syndrome including, hypertriglyceridemia, insulin resistance, type 2 diabetes mellitus, and hepatic steatosis. Recent echocardiographic studies suggest that concentric left ventricular (LV) hypertrophy is another characteristic feature of this syndrome but the mechanism remains unknown. It has recently been hypothesized th...

Nelson, Michael D.; Victor, Ronald G.; Szczepaniak, Edward W.; Simha, Vinaya; Garg, Abhimanyu; Szczepaniak, Lidia S.

2013-01-01

158

The role of secondary hyperparathyroidism in left ventricular hypertrophy of patients under chronic hemodialysis  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english End-stage renal disease (ESRD) patients frequently develop structural cardiac abnormalities, particularly left ventricular hypertrophy (LVH). The mechanisms involved in these processes are not completely understood. In the present study, we evaluated a possible association between parathyroid hormon [...] e (PTH) levels and left ventricular mass (LVM) in patients with ESRD. Stable uremic patients on intermittent hemodialysis treatment were evaluated by standard two-dimensional echocardiography and their sera were analyzed for intact PTH. Forty-one patients (mean age 45 years, range 18 to 61 years), 61% males, who had been on hemodialysis for 3 to 186 months, were evaluated. Patients were stratified into 3 groups according to serum PTH: low levels (280 pg/ml; group III = 21 patients). A positive statistically significant association between LVM index and PTH was identified (r = 0.34; P = 0.03, Pearson's correlation coefficient) in the sample as a whole. In subgroup analyses, we did not observe significant associations in the low and intermediate PTH groups; nevertheless, PTH and LVM index were correlated in patients with high PTH levels (r = 0.62; P = 0.003). LVM index was also inversely associated with hemoglobin (r = -0.34; P = 0.03). In multivariate analysis, after adjustment for age, hemoglobin, body mass index, and blood pressure, the only independent predictor of LVM index was PTH level. Therefore, PTH is an independent predictor of LVH in patients undergoing chronic hemodialysis. Secondary hyperparathyroidism may contribute to the elevated cardiovascular morbidity associated with LVH in ESRD.

R.B., Randon; L.E., Rohde; L., Comerlato; J.P., Ribeiro; R.C., Manfro.

1409-14-01

159

Economic benefits of left ventricular hypertrophy regression in patients with arterial hypertension  

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Full Text Available Aim. To evaluate by modelling the economic benefits of left ventricular hypertrophy (LVH regression in patients with arterial hypertension (HT due to therapy with fixed combination of valsartan/amlodipine.Material and methods. 20 patients (15 females and 5 males, aged 18 to 70 years with essential HT accompanied by metabolic syndrome with a history of previous ineffective antihypertensive therapy were included into the study. All patients were treated with fixed combination of amlodipine/valsartan in doses of 5/160 and 10/160 mg depending on blood pressure (BP level. Treatment duration was 24 weeks. Changes in BP level, LVH regression were assessed. Economic evaluation was performed on the basis of modelling with the specialized software Decision Tree 4.xla.Results. Effect of fixed amlodipine/valsartan combination therapy on LVH was used to estimate treatment effectiveness and to build the model. Patients were distributed according to left ventricular (LV mass (at baseline and after 24 weeks of therapy. Significant decrease in LV mass from 205.8±50.4 to 181.9±45.1 g (p<0.05 was revealed. The model took into account economic and frequency factors for 10 year prognosis: this therapy prevents 36 deaths, 6 strokes, 24 myocardial infarction per 1000 patients. Absence of need in treatment of these prevented events can save 2 516 772.42 RUR for every 1 000 patients. It would reduce the total costs per patient during 10 years.Conclusion. Treatment with amlodipine/valsartan single pill combination has not only clinical advantages, but also pharmacoeconomic benefits. This combination reduces risk of acute myocardial infarction and death more effectively. Treatment with fixed valsartan/amlodipine combination saves maximum years of life with less cost during 10 years. Despite of higher pharmacotherapy costs, fixed valsartan/amlodipine combination reduces total costs due to prevention of fatal and nonfatal cardiovascular events.

E.I. Tarlovskaya

2011-01-01

160

Electrocardiographic assessment of left ventricular hypertrophy with time-voltage QRS and QRST-wave areas.  

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The sum of time-voltage QRS areas in the 12-lead electrocardiogram (ECG) has outperformed other 12-lead ECG indices for detection of left ventricular hypertrophy (LVH). We assessed indices of time-voltage QRS and T-wave (QRST) areas from body surface potential mapping (BSPM) for detection of and quantitation of the degree of LVH. We studied 42 patients with echocardiographic LVH (LVH group) and 11 healthy controls (controls). QRST area sums were calculated from 123-lead BSPM and from the 12-lead ECG for comparison. Leadwise discriminant indices and correlation coefficients were used to identify optimal recording locations for QRST area-based LVH assessment. BSPM QRS area sum was greater in the LVH group than in controls (3752 +/- 1259 vs 2278 +/- 627 microV s, respectively; P<0.001) and at 91% specificity showed 74% sensitivity for LVH detection. The 12-lead QRS area sum performed similarly. Taking T-wave areas into account did not improve the results. QRS area sum from two most informative leads (located in the upper and lower right precordium) also separated the LVH group from controls (61.1 +/- 23.5 vs 27.8 +/- 6.5 microV s, respectively; P<0.00001). This 2-lead QRS area sum showed 90% sensitivity with 100% specificity for LVH detection and maintained high correlation to indexed left ventricular mass (r=0.732; P<0.001). In conclusion, the BSPM QRS area sum compared to 12-lead QRS area sum does not substantially improve LVH assessment. The 2-lead QRS area sum may improve ECG QRS area-based LVH assessment. PMID:14688808

Oikarinen, L; Karvonen, M; Viitasalo, M; Takala, P; Kaartinen, M; Rossinen, J; Tierala, I; Hänninen, H; Katila, T; Nieminen, M S; Toivonen, L

2004-01-01

161

Screening for left ventricular hypertrophy in patients with type 2 diabetes mellitus in the community  

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Full Text Available Abstract Background Left ventricular hypertrophy (LVH is a strong predictor of cardiovascular disease and is common among patients with type 2 diabetes. However, no systematic screening for LVH is currently recommended for patients with type 2 diabetes. The purpose of this study was to determine whether NT-proBNP was superior to 12-lead electrocardiography (ECG for detection of LVH in patients with type 2 diabetes. Methods Prospective cross-sectional study comparing diagnostic accuracy of ECG and NT-proBNP for the detection of LVH among patients with type 2 diabetes. Inclusion criteria included having been diagnosed for > 5 years and/or on treatment for type 2 diabetes; patients with Stage 3/4 chronic kidney disease and known cardiovascular disease were excluded. ECG LVH was defined as either the Sokolow-Lyon or Cornell voltage criteria. NT-proBNP level was measured using the Roche Diagnostics Elecsys assay. Left ventricular mass was assessed from echocardiography. Receiver operating characteristic curve analysis was carried out and area under the curve (AUC was calculated. Results 294 patients with type 2 diabetes were recruited, mean age 58 (SD 11 years, BP 134/81 ± 18/11 mmHg, HbA1c 7.3 ± 1.5%. LVH was present in 164 patients (56%. In a logistic regression model age, gender, BMI and a history of hypertension were important determinants of LVH (p Conclusions LVH was highly prevalent in asymptomatic patients with type 2 diabetes. ECG was an inadequate test to identify LVH and while NT-proBNP was superior to ECG it remained unsuitable for detecting LVH. Thus, there remains a need for a screening tool to detect LVH in primary care patients with type 2 diabetes to enhance risk stratification and management.

Bagg Warwick

2011-04-01

162

QRS Voltage-Duration Product in the Identification of Left Ventricular Hypertrophy in Spontaneously Hypertensive Rats  

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Full Text Available OBJECTIVE - Evaluation of the performance of the QRS voltage-duration product (VDP for detection of left ventricular hypertrophy (LVH in spontaneously hypertensive rats (SHR. METHODS - Orthogonal electrocardiograms (ECG were recorded in male SHR at the age of 12 and 20 weeks, when systolic blood pressure (sBP reached the average values of 165±3 mmHg and 195±12 mmHg, respectively. Age- and sex- matched normotensive Wistar Kyoto (WKY rats were used as controls. VDP was calculated as a product of maximum QRS spatial vector magnitude and QRS duration. Left ventricular mass (LVM was weighed after rats were sacrificed. RESULTS - LVM in SHR at 12 and 20 weeks of age (0.86±0.05 g and 1.05±0.07 g, respectively was significantly higher as compared with that in WKY (0.65±0.07 g and 0.70±0.02 g. The increase in LVM closely correlated with the sBP increase. VDP did not reflect the increase in LVM in SHR. VDP was lower in SHR as compared with that in WKY, and the difference was significant at the age of 20 weeks (18.2mVms compared with 10.7mVms, p<0.01. On the contrary, a significant increase in the VDP was observed in the control WKY at the age of 20 weeks without changes in LVM. The changes in VDP were influenced mainly by the changes in QRSmax. CONCLUSION - LVM was not the major determinant of QRS voltage changes and consequently of the VDP. These data point to the importance of the nonspatial determinants of the recorded QRS voltage in terms of the solid angle theory.

Ljuba Bacharova

2002-08-01

163

Improvement of diastolic function after regression of left ventricular hypertrophy / Mejora de la función diastólica tras regresión de la hipertrofia ventricular izquierda  

Scientific Electronic Library Online (English)

Full Text Available SciELO Mexico | Language: English Abstract in spanish Objetivo: Evaluar la función diastólica después de revertir la hipertrofia ventricular izquierda, en hipertensión leve a moderada tratada con inhibidores de la enzima convertidora angiotensina (ECA) y, si era necesario, con un diurético. Métodos: Noventa y ocho pacientes hipertensos con hipertrofia [...] ventricular izquierda e índices de función diastólica anormal del ventrículo izquierdo recibieron captopril 50 a 200 mg/día (Capotena®) más clortalidona durante 12 meses para lograr el control de la presión arterial, definido como presión diastólica Abstract in english Objective: To evaluate the diastolic function after regression of left ventricular hypertrophy, in mild to moderate hypertension treated with angiotensin converting enzyme(ACE) inhibitor and, if necessary, with a diuretic. Methods: Ninety-eight hypertensive patients with left ventricular hypertrophy [...] (LVH) and abnormal left ventricle diastolic function indexes received captopril (Capotena® ) 50 to 200 mg/day plus chlortalidone during 12 months to reach blood pressure control, defined as a diastolic blood pressure

Raúl, Teniente-Valente; Sergio, Solorio; Enrique, Vargas-Salado; Carlos, Aguirre-Vázquez; Martha A, Hernández-González; José Antonio, Olvera-Lopez; Leticia, Rodríguez-Mariscal; Miguel Angel, Luna-Ruiz; José Manuel, Guillén Contreras; Blanca Olivia, Murillo Ortiz.

2008-12-01

164

Fibroblast Growth Factor 23 and Left Ventricular Hypertrophy in Hemodialysis Patients  

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Full Text Available Background: Left ventricular hypertrophy (LVH is a common cardiovascular complication and an independent risk factor for cardiovascular death in hemodialysis (HD patients. Previous studies have shown that fibroblast growth factor 23 (FGF23, which has an important role in phosphate metabolism, is elevated in HD patients. Objectives: The aim of this study was to determine the association of FGF23 and LVH and the prognostic value of serum FGF23 level in HD patients. One hundred seven HD patients were evaluated for LVH by echocardiography. Serum FGF23 levels were measured using a commercial enzyme-linked immunosorbent assay kit. Results: Patients with LVH were more likely to have higher systolic blood pressure (BP and LVH was significantly associated with female gender and higher serum levels of phosphate and calcium ×phosphate products. LVH was also associated with higher serum FGF23 level. Multivariate analysis indicated that serum FGF23 level, systolic BP, and serum phosphate level remained correlated with LVH. This suggested that serum FGF23 level is independently associated with LVH in our HD patients. Cox analysis indicated no significant difference in risk of death for patients with elevated serum FGF23 level. Conclusion: LVH has a high prevalence in HD patients, and FGF23 is independently associated with LVH but is not a predictor for prognosis during a 4-year follow-up period.

Ayaka Saito

2014-09-01

165

Vitamin D Receptor Gene Polymorphism and Left Ventricular Hypertrophy in Chronic Kidney Disease  

Directory of Open Access Journals (Sweden)

Full Text Available FokI and BsmI polymorphisms of vitamin D receptor (VDR gene are regarded as reliable markers of disturbed vitamin D signaling pathway. Left ventricular hypertrophy (LVH is a strong cardiovascular risk marker in end stage renal disease (ESRD patients. Since BsmI polymorphism has been associated with LVH in ESRD patients, we addressed this study in patients with chronic kidney disease (CKD not yet on dialysis. One hundred and forty five patients with CKD stage 3 were genotyped for FokI and BsmI VDR polymorphisms, in order to assess the relationships between these VDR polymorphisms, some markers of mineral bone disorders, and LVH measured by echocardiography. Patients bearing either the Ff heterozygous or FF homozygous genotype had significantly higher PTH values than those bearing the ff genotype. The relationships between VDR genotypes and LVH revealed a highly significant association of the BsmI Bb heterozygous genotype with LVH. In patients with CKD stage 3 BsmI B allele was independently related to LVH. Since LVH is a frequent finding in dialysis population due to several mechanisms, the presence of the same relationship in patients with CKD strengthens the hypothesis that alterations of vitamin D signaling are implicated in LVH development in patients with renal diseases.

Domenico Santoro

2014-03-01

166

Vitamin D receptor gene polymorphism and left ventricular hypertrophy in chronic kidney disease.  

Science.gov (United States)

FokI and BsmI polymorphisms of vitamin D receptor (VDR) gene are regarded as reliable markers of disturbed vitamin D signaling pathway. Left ventricular hypertrophy (LVH) is a strong cardiovascular risk marker in end stage renal disease (ESRD) patients. Since BsmI polymorphism has been associated with LVH in ESRD patients, we addressed this study in patients with chronic kidney disease (CKD) not yet on dialysis. One hundred and forty five patients with CKD stage 3 were genotyped for FokI and BsmI VDR polymorphisms, in order to assess the relationships between these VDR polymorphisms, some markers of mineral bone disorders, and LVH measured by echocardiography. Patients bearing either the Ff heterozygous or FF homozygous genotype had significantly higher PTH values than those bearing the ff genotype. The relationships between VDR genotypes and LVH revealed a highly significant association of the BsmI Bb heterozygous genotype with LVH. In patients with CKD stage 3 BsmI B allele was independently related to LVH. Since LVH is a frequent finding in dialysis population due to several mechanisms, the presence of the same relationship in patients with CKD strengthens the hypothesis that alterations of vitamin D signaling are implicated in LVH development in patients with renal diseases. PMID:24618509

Santoro, Domenico; Gagliostro, Giorgia; Alibrandi, Angela; Ientile, Riccardo; Bellinghieri, Guido; Savica, Vincenzo; Buemi, Michele; Caccamo, Daniela

2014-01-01

167

Simulation of the effect of rogue ryanodine receptors on a calcium wave in ventricular myocytes with heart failure.  

Science.gov (United States)

Calcium homeostasis is considered to be one of the most important factors for the contraction and relaxation of the heart muscle. However, under some pathological conditions, such as heart failure (HF), calcium homeostasis is disordered, and spontaneous waves may occur. In this study, we developed a mathematical model of formation and propagation of a calcium wave based upon a governing system of diffusion-reaction equations presented by Izu et al (2001 Biophys. J. 80 103-20) and integrated non-clustered or 'rogue' ryanodine receptors (rogue RyRs) into a two-dimensional (2D) model of ventricular myocytes isolated from failing hearts in which sarcoplasmic reticulum (SR) Ca(2+) pools are partially unloaded. The model was then used to simulate the effect of rogue RyRs on initiation and propagation of the calcium wave in ventricular myocytes with HF. Our simulation results show that rogue RyRs can amplify the diastolic SR Ca(2+) leak in the form of Ca(2+) quarks, increase the probability of occurrence of spontaneous Ca(2+) waves even with smaller SR Ca(2+) stores, accelerate Ca(2+) wave propagation, and hence lead to delayed afterdepolarizations (DADs) and cardiac arrhythmia in the diseased heart. This investigation suggests that incorporating rogue RyRs in the Ca(2+) wave model under HF conditions provides a new view of Ca(2+) dynamics that could not be mimicked by adjusting traditional parameters involved in Ca(2+) release units and other ion channels, and contributes to understanding the underlying mechanism of HF. PMID:20505230

Lu, Luyao; Xia, Ling; Ye, Xuesong; Cheng, Heping

2010-01-01

168

Simulation of the effect of rogue ryanodine receptors on a calcium wave in ventricular myocytes with heart failure  

Science.gov (United States)

Calcium homeostasis is considered to be one of the most important factors for the contraction and relaxation of the heart muscle. However, under some pathological conditions, such as heart failure (HF), calcium homeostasis is disordered, and spontaneous waves may occur. In this study, we developed a mathematical model of formation and propagation of a calcium wave based upon a governing system of diffusion-reaction equations presented by Izu et al (2001 Biophys. J. 80 103-20) and integrated non-clustered or 'rogue' ryanodine receptors (rogue RyRs) into a two-dimensional (2D) model of ventricular myocytes isolated from failing hearts in which sarcoplasmic reticulum (SR) Ca2+ pools are partially unloaded. The model was then used to simulate the effect of rogue RyRs on initiation and propagation of the calcium wave in ventricular myocytes with HF. Our simulation results show that rogue RyRs can amplify the diastolic SR Ca2+ leak in the form of Ca2+ quarks, increase the probability of occurrence of spontaneous Ca2+ waves even with smaller SR Ca2+ stores, accelerate Ca2+ wave propagation, and hence lead to delayed afterdepolarizations (DADs) and cardiac arrhythmia in the diseased heart. This investigation suggests that incorporating rogue RyRs in the Ca2+ wave model under HF conditions provides a new view of Ca2+ dynamics that could not be mimicked by adjusting traditional parameters involved in Ca2+ release units and other ion channels, and contributes to understanding the underlying mechanism of HF.

Lu, Luyao; Xia, Ling; Ye, Xuesong; Cheng, Heping

2010-06-01

169

Effects of the venom of the spider Ornithoctonus hainana on neonatal rat ventricular myocytes cellular and ionic electrophysiology.  

Science.gov (United States)

Cardiac ion channels are membrane-spanning proteins that allow the passive movement of ions across the cell membrane along its electrochemical gradient, which regulates the resting membrane potential as well as the shape and duration of the cardiac action potential. Additionally, they have been recognized as potential targets for the actions of neurotransmitters, hormones and drugs of cardiac diseases. Spider venoms contain high abundant of toxins that target diverse ion channels and have been considered as a potential resource of new constituents with speci?c pharmacological properties. However, few peptides from spider venoms were detected as cardiac channel antagonists. In order to explore the effects of the venom of Ornithoctonus hainana on the action potential and ionic currents of neonatal rat ventricular myocytes (NRVMs), whole cell patch clamp technique was used to record action potential duration (APD), sodium current (INa), L calcium current (ICaL), rapidly activating and inactivating transient outward currents (Ito1), rapid (IKr) and slow (IKs) components of the delayed rectifier currents and the inward rectifier currents (IK1). Our results showed that 100 ?g/mL venom obviously prolonged APDs. Signi?cantly, the venom could inhibit INa and ICaL effectively, while no evident inhibitory effects on cardiac K(+) channels (Ito1, Iks, Ikr and Ik1) were observed, suggesting that the venom represented a multifaceted pharmacological profile. The effect of venom on Na(+) and Ca(2+) currents of ventricular myocytes revealed that the hainan venom as a rich resource of cardiac channel antagonists might be valuable tools for the investigation of both channels and drug development. PMID:24930961

Zhang, Yiya; Liu, Jinyan; Liu, Zhonghua; Wang, Meichi; Wang, Jing; Lu, Shanshan; Zhu, Li; Zeng, Xiongzhi; Liang, Songping

2014-09-01

170

Simulation of the effect of rogue ryanodine receptors on a calcium wave in ventricular myocytes with heart failure  

International Nuclear Information System (INIS)

Calcium homeostasis is considered to be one of the most important factors for the contraction and relaxation of the heart muscle. However, under some pathological conditions, such as heart failure (HF), calcium homeostasis is disordered, and spontaneous waves may occur. In this study, we developed a mathematical model of formation and propagation of a calcium wave based upon a governing system of diffusion–reaction equations presented by Izu et al (2001 Biophys. J. 80 103–20) and integrated non-clustered or 'rogue' ryanodine receptors (rogue RyRs) into a two-dimensional (2D) model of ventricular myocytes isolated from failing hearts in which sarcoplasmic reticulum (SR) Ca2+ pools are partially unloaded. The model was then used to simulate the effect of rogue RyRs on initiation and propagation of the calcium wave in ventricular myocytes with HF. Our simulation results show that rogue RyRs can amplify the diastolic SR Ca2+ leak in the form of Ca2+ quarks, increase the probability of occurrence of spontaneous Ca2+ waves even with smaller SR Ca2+ stores, accelerate Ca2+ wave propagation, and hence lead to delayed afterdepolarizations (DADs) and cardiac arrhythmia in the diseased heart. This investigation suggests that incorporating rogue RyRs in the Ca2+ wave model under HF conditions provides a new view of Ca2+ dynamics that could not be mimicked by adjusting traditional parameterked by adjusting traditional parameters involved in Ca2+ release units and other ion channels, and contributes to understanding the underlying mechanism of HF

171

Alterations of contractions and L-type Ca2+ currents by murrayafoline-A in rat ventricular myocytes.  

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We examined the effects of murrayafoline-A (1-methoxy-3-methylcarbazole, Mu-A), which is isolated from the dried roots of Glycosmis stenocarpa, on cell shortenings and L-type Ca2+ currents (ICa,L) in rat ventricular myocytes. Cell shortenings and ICa,L were measured using the video edge detection method and patch-clamp techniques, respectively. Mu-A transiently increased cell shortenings in a concentration-dependent manner with an EC50 of ~20 ?M. The maximal effect of Mu-A, approximately 175% of the control, was observed at ?100 ?M. The positive inotropic effect of Mu-A (25 ?M) reached a maximum after ~2-min exposures, and then decayed after a ~1-min steady-state. During the Mu-A-induced positive inotropy, the rate of contraction was accelerated, whereas the rate of relaxation was not significantly altered. To understand the possible mechanism for the Mu-A-induced positive inotropy, the ICa,L was assessed. Mu-A transiently enhanced the ICa,L. Concentration-dependence of the increase in ICa,L by Mu-A was similar to that of positive inotropic effect of Mu-A. The maximal effect of Mu-A (25 ?M) on ICa,L was observed at 2-3 min after the application of Mu-A. A partial inhibition of ICa,L using verapamil (1 ?M) induced a right shift of concentration-response curve of the positive inotropic effect of Mu-A and significantly attenuated the effect. These results suggest that Mu-A may transiently enhance contractility, at least in part, by increasing the Ca2+ influx through the L-type Ca2+ channels in rat ventricular myocytes. PMID:25016086

Son, Min-Jeong; Chidipi, Bojjibabu; Kim, Joon-Chul; Huong, Tran Thu; Tai, Bui Huu; Kim, Young Ho; Ahn, Joung Real; Cuong, Nguyen Manh; Woo, Sun-Hee

2014-10-01

172

Pressure overload-induced mild cardiac hypertrophy reduces left ventricular transmural differences in mitochondrial respiratory chain activity and increases oxidative stress  

OpenAIRE

Objective: Increased mechanical stress and contractility characterizes normal left ventricular subendocardium (Endo) but whether Endo mitochondrial respiratory chain complex activities is reduced as compared to subepicardium (Epi) and whether pressure overload-induced left ventricular hypertrophy (LVH) might modulate transmural gradients through increased reactive oxygen species (ROS) production is unknown. Methods: LVH was induced by 6 weeks abdominal aortic banding and cardiac structure...

BernardGENY; MichelKINDO; LaurentMONASSIER; FabriceFAVRET

2012-01-01

173

A Dynamic Model of Excitation-Contraction Coupling during Acidosis in Cardiac Ventricular Myocytes  

OpenAIRE

Acidosis in cardiac myocytes is a major factor in the reduced inotropy that occurs in the ischemic heart. During acidosis, diastolic calcium concentration and the amplitude of the calcium transient increase, while the strength of contraction decreases. This has been attributed to the inhibition by protons of calcium uptake and release by the sarcoplasmic reticulum, to a rise of intracellular sodium caused by activation of sodium-hydrogen exchange, decreased calcium binding affinity to Troponi...

Crampin, Edmund J.; Smith, Nicolas P.

2006-01-01

174

A Localized Meshless Approach for Modeling Spatial-temporal Calcium Dynamics in Ventricular Myocytes  

OpenAIRE

Spatial-temporal calcium dynamics due to calcium release, buffering and re-uptaking plays a central role in studying excitation-contraction (E-C) coupling in both normal and diseased cardiac myocytes. In this paper, we employ a meshless method, namely, the local radial basis function collocation method (LRBFCM) to model such calcium behaviors by solving a nonlinear system of reaction-diffusion partial differential equations. In particular, a simplified structural unit containing a single tran...

Yao, Guangming; Yu, Zeyun

2012-01-01

175

Enalaprilato na prevenção da hipertrofia ventricular esquerda induzida pelo isoproterenol / Enalaprilat prevents the left ventricular hypertrophy induced by isoproterenol  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese OBJETIVO: Avaliar se o enalaprilato, droga inibidora da enzima de conversão da angiotensina I, previne a hipertrofia ventricular esquerda (HVE) induzida pelo isoproterenol. MÉTODOS: Foram divididos em 4 grupos, 72 ratos Wistar-EPM: CON controle; ENA, tratados com enalaprilato (1mg/kg via subcutânea [...] (sc) por 8 dias); ISO, tratados com isoproterenol (0,3mg/kg via sc/8 dias) e ENA+ISO, tratados simultaneamente com ambas as drogas. Em 10 animais de cada grupo foram determinadas a freqüência cardíaca (FC) e a pressão arterial (PA) e verificado o peso de ventrículo esquerdo (VE). Em 8 animais de cada grupo, fragmento do VE foi corado com hematoxilina-eosina e picro-sírius e preparado para estudo morfométrico e ultra-estrutural, respectivamente, com microscópio de luz e eletrônico. RESULTADOS: Nos grupos estudados (CON, ENA, ISO e ISO+ENA) não ocorreram variações na PA. Os grupos ISO e ISO+ENA exibiram aumentos significantes na FC. O grupo ISO apresentou aumento significativo do peso do VE (PU= 0,821g e PS= 0,204g), quando comparado ao grupo CON. O grupo ENA não exibiu modificação de peso do VE quando comparado ao grupo CON (PU= 0,590g e PS= 0,139g). No grupo ENA+ISO (PU= 0,737g e PS= 0,177g) constatou-se diferença de peso ao ser comparado aos grupos ISO e CON. A análise morfométrica e ultra-estrutural mostraram que o ISO induziu hipertrofia dos cardiomiócitos e aumento do tecido conjuntivo com depósito de fibras colágenas do tipo I. O enalaprilato associado com isoproterenol atenuou importantemente aquela manifestação. CONCLUSÃO: O enalaprilato inibiu a ação do isoproterenol sobre os cardiomiócitos, evitando parcialmente, na dose utilizada, a HVE e diminuindo também a quantidade de fibras colágenas. Abstract in english PURPOSE: To evaluate whether the enalaprilat, angiotensin I enzyme conversion inhibitor, could prevent the left ventricular hypertrophy (LVH) induced by isoproterenol. METHODS: Seventy two adult Wistar-EPM rats were divided into four groups: CON, control; ENA, treated with enalaprilat (1mg/kg via su [...] bcutaneous (sc) for 8 days); ISO, treated with isoproterenol (0.3mg via sc for 8 days) e ENA+ISO, treated with both drugs simultaneously. Each group had the arterial blood pressure, cardiac rate and the left ventricle (LV) weight determined in 10 animals. In 8 animals from each group a small sample was taken from the LV and stained with hematoxyline-eosine and picrosirius for morphometric and ultra-structural studies with optic and transmission electronic microscopy. RESULTS: The ISO group showed that the LV weight increased 47% in comparison with control. On the other hand the ENA+ISO group showed only 22.1% increase (p

Eduardo A. S., Costa; Bráulio, Luna Fº; Rui, Póvoa; Celso, Ferreira Fº; Neif, Murad; Marcelo, Ferreira; Celso, Ferreira.

1997-07-01

176

Exercise-induced subendocardial dysfunction in dogs with left ventricular hypertrophy.  

Science.gov (United States)

The effects of treadmill exercise on regional myocardial blood flow and function were examined in 10 adult, conscious dogs with left ventricular hypertrophy (LVH) induced by aortic banding in puppies, which resulted in a left ventricular (LV) weight/body weight ratio of 8.5 +/- 0.3. Data were compared with results from eight control dogs with an LV weight/body weight ratio of 4.9 +/- 0.2. At rest, LV systolic and end-diastolic pressures were significantly greater (p less than 0.01), and mean arterial pressure was significantly less (p less than 0.05) in LVH dogs. Mean myocardial blood flow (control dogs, 0.98 +/- 0.11 ml/min/g; LVH dogs, 1.16 +/- 0.06 ml/min/g) and the transmural blood flow distribution at baseline, as assessed by endocardial/epicardial blood flow ratio (control, 1.35 +/- 0.12; LVH, 1.21 +/- 0.09), were similar in the two groups. During exercise to a target heart rate (240 beats/min), LVH dogs demonstrated greater (p less than 0.01) increases in LV systolic and end-diastolic pressures. In control dogs, as expected, exercise augmented velocity of circumferential fiber shortening (16 +/- 9%) and shortening fraction (15 +/- 5%), but in LVH dogs, exercise reduced the velocity of circumferential fiber shortening (-14 +/- 6%) and shortening fraction (-17 +/- 5%). Exercise also increased full wall thickening (35 +/- 5%), subendocardial wall thickening (66 +/- 10%), and subepicardial wall thickening (44 +/- 9%) in control dogs. In LVH dogs, exercise increased subepicardial wall thickening (31 +/- 9%) and reduced subendocardial wall thickening (-40 +/- 7%); full wall thickening did not change (-11 +/- 9%). This was associated with a fall in endocardial/epicardial flow ratio to 0.72 +/- 0.05 (p less than 0.01) in LVH dogs. The subendocardial dysfunction persisted late into recovery, at a time when the transmural blood flow distribution had returned to baseline; this occurrence suggested myocardial stunning. Thus, in dogs with LVH, selective subendocardial hypoperfusion and profound selective depression in subendocardial wall thickening are observed during exercise. The subendocardial dysfunction persisted into recovery despite resolution of the perfusion abnormality. PMID:2137037

Hittinger, L; Shannon, R P; Kohin, S; Manders, W T; Kelly, P; Vatner, S F

1990-02-01

177

Left ventricular hypertrophy: The relationship between the electrocardiogram and cardiovascular magnetic resonance imaging.  

Science.gov (United States)

Conventional assessment of left ventricular hypertrophy (LVH) using the electrocardiogram (ECG), for example, by the Sokolow-Lyon, Romhilt-Estes or Cornell criteria, have relied on assessing changes in the amplitude and/or duration of the QRS complex of the ECG to quantify LV mass. ECG measures of LV mass have typically been validated by imaging with echocardiography or cardiovascular magnetic resonance imaging (CMR). However, LVH can be the result of diverse etiologies, and LVH is also characterized by pathological changes in myocardial tissue characteristics on the genetic, molecular, cellular, and tissue level beyond a pure increase in the number of otherwise normal cardiomyocytes. For example, slowed conduction velocity through the myocardium, which can be due to diffuse myocardial fibrosis, has been shown to be an important determinant of conventional ECG LVH criteria regardless of LV mass. Myocardial tissue characterization by CMR has emerged to not only quantify LV mass, but also detect and quantify the extent and severity of focal or diffuse myocardial fibrosis, edema, inflammation, myocarditis, fatty replacement, myocardial disarray, and myocardial deposition of amyloid proteins (amyloidosis), glycolipids (Fabry disease), or iron (siderosis). This can be undertaken using CMR techniques including late gadolinium enhancement (LGE), T1 mapping, T2 mapping, T2* mapping, extracellular volume fraction (ECV) mapping, fat/water-weighted imaging, and diffusion tensor CMR. This review presents an overview of current and emerging concepts regarding the diagnostic possibilities of both ECG and CMR for LVH in an attempt to narrow gaps in our knowledge regarding the ECG diagnosis of LVH. PMID:25367364

Bacharova, Ljuba; Ugander, Martin

2014-11-01

178

T-wave axis deviation and left ventricular hypertrophy interaction in diabetes and hypertension.  

Science.gov (United States)

Electrocardiographic signs of left ventricular hypertrophy (ECG-LVH) and T-wave axis (TA) deviation are independent predictors of fatal and non fatal events. We assessed the prevalence of ECG-LVH, TA abnormalities and their combination according to the presence or absence of diabetes and/or hypertension in a large sample of the adult general Italian population. Data from 10,184 women (54 ± 11 years) and 8775 men (54 ± 11 years) were analyzed from the Moli-sani cohort, a database of randomly recruited adults (age >35) from the general population of Molise, a central region of Italy that includes collection of standard 12-lead resting ECG. Subjects with previous myocardial infarction, angina, cerebrovascular disease or left bundle brunch block or missing values for TA or ECG-LVH have been excluded. TA was measured from the standard 12-lead ECG and it was defined as the rotation of the T wave in the frontal plane as computed by a proprietary algorithm (CalECG/Bravo, AMPS-LLC, NY). ECG-LVH was defined as Sokolow Lyon voltage (SLv) >35 mm or Cornell voltage duration Product (CP) >= 2440 mm*ms. Among subjects with ECG-LVH, prevalence of hypertension was 59.0% and 49.7%, respectively for men and women, whereas that of diabetes was 10.7% and 5.7%. In hypertensives, TA was normal in 72.3% of subjects, borderline in 24.8% and abnormal in 2.9%. In diabetics, TA was normal in 70.4% of subjects, borderline in 26.5% and abnormal in 3.1%. In both hypertensive and diabetic subjects, the prevalence of ECG-LVH, was significantly greater in subjects with borderline or abnormal TA. Hypertension was an independent predictor of abnormal TA (odd ratio: 1.38, P = .025). These results suggest that hypertension might play a relevant role in the pathogenesis of TA deviation. PMID:24011993

Assanelli, Deodato; Di Castelnuovo, Augusto; Rago, Livia; Badilini, Fabio; Vinetti, Giovanni; Gianfagna, Francesco; Salvetti, Massimo; Zito, Francesco; Donati, Maria Benedetta; de Gaetano, Giovanni; Iacoviello, Licia

2013-01-01

179

Gender differences in factors influencing electrocardiographic findings of left ventricular hypertrophy in severe aortic stenosis.  

Science.gov (United States)

We investigated gender differences in factors influencing the electrocardiographic (ECG) findings of left ventricular hypertrophy (LVH) in patients with severe aortic stenosis (AS). The functional and geometric responses of the left ventricle to chronic pressure overload, such as hypertension and AS, have been reported to be different between men and women. However, gender differences in the factors influencing the ECG findings of LVH in pressure overload remain unknown. We conducted a retrospective observational study in consecutive patients with severe AS (aortic valve area (AVA) assessed by cardiac catheterization Sokolow-Lyon index associated with ST-T wave changes (with no digitalis therapy); (2) high voltage alone; and (3) normal. Groups 1 and 2 were defined as LVH on ECG. We compared the ECG findings in relation to the AS severity between genders. Women were older, but there were no significant differences in the prevalence of hypertension, AVA index (AVAI), mean pressure gradient or peak velocity across the AV, LV mass index (LVMI) derived from echocardiography or the distribution of ECG categories between genders. A multiple logistic regression analysis including age, gender, hypertension, AVAI, mean pressure gradient, and LVMI revealed that the LVMI (P = 0.001) and AVAI (P = 0.0434) were significantly related to the distribution of ECG categories. LVMI significantly predicted LVH on ECG in both genders, but AVAI was a predictive factor in only women. ECG LVH in patients with severe AS may be mainly reflected by LVMI in men and by both LVMI and AVAI in women. Factors other than AVA, such as end-stage disease and/or complicating factors such as hypertension, may underlie the observed differences in ECG findings of LVH between men and women. PMID:23979264

Satoh, Shinji; Omura, Soichiro; Inoue, Hiroko; Ejima, Emiko; Shimozono, Koutatsu; Hayashi, Makiko; Mori, Takahiro; Takenaka, Katsuhiko; Kawamura, Natsumi; Numaguchi, Kotaro; Mori, Etsuo; Asoh, Akemi; Nakamura, Toshihiro; Hiyamuta, Koji

2014-09-01

180

Intercoronary connection with bidirectional blood flow and concentric left ventricular hypertrophy  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Homem de cor branca, 54 anos, com histórias de dor esternal atípica para insuficiência coronária, iniciada há 6 meses. Antecedentes: HAS e tabagismo. O exame do aparelho cardiovascular era normal. PA = 140/100mmHg (ambos os braços). O E.C.G. de repouso revelou onda T negativa em D2, D3 e AVF. O ecoc [...] ardiograma bidimensional demonstrou hipertrofia concêntrica do VE de grau moderado. No TE, protocolo de Ellestad, a frequência cardíaca não atingiu os níveis preconizados e ocorreu aumento acentuado da PA (230/140 mm Hg). Não apresentou alterações expressivas do segmento ST em relação ao repouso. No cateterismo cardíaco, a pressão do VE foi de 170/20 mm HG. O VE apresentava aspecto hipertrófico. Cinecoronariografia esquerda e direita não revelaram lesões obstrutivas. Injeção seletiva de contraste na ACD demonstrou enchimento retrógrado da porção distal da ACX até sua porção média através de conexões intercoronárias. Da mesma forma injeção seletiva na ACE demonstrou enchimento retrógrado da porção distal da ACD por conexões intercoronárias da ACX para a ACD. Revisão da literatura e possíveis mecanismos foram apresentados. Abstract in english Cardiac catheterization in a 55-year-old man, with a 6-month history of atypical chest pain and Q-waves in D1, Dili and AVF, showed concentric left ventricular (LV) hypertrophy and a large intercoronary connection between right coronary artery (RCA) and circumflex artery (CX), with bidirectional blo [...] od flow. Although the RCA and CX were normal, selective injection of CX filled RCA retrogradely and in the same way selective injection of RCA filled CX. Possible mechanisms and literature are reviewed.

George César Ximenes, Meireles; Luciano Mauricio, Abreu Filho.

1994-12-01

181

Electrocardiographic left ventricular hypertrophy in GUSTO IV ACS: an important risk marker of mortality in women.  

DEFF Research Database (Denmark)

AIM: To examine the association of left ventricular hypertrophy (LVH) on admission electrocardiography with adverse outcomes in acute coronary syndrome (ACS) patients. METHODS AND RESULTS: A total of 7443 non-ST-elevation ACS patients in Global Utilization of STrategies to Open occluded arteries (GUSTO) IV ACS trial had admission electrocardiograms analysed at a core laboratory. LVH [>or=20 mm Cornell voltage (LV voltage) (women) or >or=28 mm (men) plus strain patterns] was observed in 586 (7.9%) patients, and women accounted for 74%. LVH patients were also older and had more co-morbidities, ST-depression >or= 0.5 mm, elevated C-reactive protein and N-terminal pro-brain naturetic peptide (NT-proBNP), and lower troponin T. Invasive procedures occurred less often in LVH patients (cardiac catheterization: 31 vs. 38%, P = 0.001; percutaneous coronary intervention: 12 vs. 20%, P < 0.001). Mortality was significantly higher in patients with LVH (30 day: 5 vs. 3%, P = 0.046; 1 year: 14 vs. 7%, P < 0.001), whereas 30day myocardial infarction (MI) and death/MI did not differ. After baseline adjustment including NT-proBNP, LVH remained associated with increased hazard of 1 year mortality in women, but not in men [P-interaction = 0.033; women: adjusted hazard ratio (LVH vs. no LVH): 1.42 (1.04-1.94), P = 0.029]. CONCLUSION: Electrocardiographic-LVH identifies an important subset of ACS patients with a higher risk of long-term mortality, particularly among women. These novel findings highlight opportunities to improve treatment and outcome among similar ACS patients. Udgivelsesdato: 2007-Sep

Westerhout, Cynthia M; Lauer, Michael S

2007-01-01

182

Natakalim improves post-infarction left ventricular remodeling by restoring the coordinated balance between endothelial function and cardiac hypertrophy.  

Science.gov (United States)

Endothelial dysfunction can lead to congestive heart failure and the activation of endothelial ATP-sensitive potassium (K(ATP)) channels may contribute to endothelial protection. Therefore, the present study was carried out to investigate the hypothesis that natakalim, a novel K(ATP) channel opener, ameliorates post-infarction left ventricular remodeling and failure by correcting endothelial dysfunction. The effects of myocardial infarction were assessed 8 weeks following left anterior descending coronary artery occlusion in male Wistar rats. Depressed blood pressure, cardiac dysfunction, evidence of left ventricular remodeling and congestive heart failure were observed in the rats with myocardial infarction. Treatment with natakalim at daily oral doses of 1, 3 or 9 mg/kg/day for 8 weeks prevented these changes. Natakalim also prevented the progression to cardiac failure, which was demonstrated by the increase in right ventricular weight/body weight (RVW/BW) and relative lung weight, signs of cardiac dysfunction, as well as the overexpression of atrial and brain natriuretic peptide mRNAs. Our results also demonstrated that natakalim enhanced the downregulation of endothelium-derived nitric oxide, attenuated the upregulation of inducible nitric oxide synthase-derived nitric oxide (NO), inhibited the upregulated endothelin system and corrected the imbalance between prostacyclin and thromboxane A(2). Overall, our findings suggest that natakalim prevents post-infarction hypertrophy and cardiac failure by restoring the coordinated balance between endothelial function and cardiac hypertrophy. PMID:25215478

Zhou, Hong-Min; Zhong, Ming-Li; Zhang, Yan-Fang; Cui, Wen-Yu; Long, Chao-Liang; Wang, Hai

2014-11-01

183

The left atrium, atrial fibrillation, and the risk of stroke in hypertensive patients with left ventricular hypertrophy  

DEFF Research Database (Denmark)

The Losartan Intervention For Endpoint reduction in hypertension (LIFE) study provided extensive data on predisposing factors, consequences, and prevention of atrial fibrillation (AF) in patients with hypertension and left ventricular (LV) hypertrophy. Randomized losartan-based treatment was superior to atenolol-based treatment for reducing new-onset AF and complications, especially stroke, associated with new-onset or pre-existing AF. Potential mechanisms of AF prevention by angiotensin receptor blockade supported by LIFE results include greater reduction in left atrial size and LV hypertrophy. Differential effects of antihypertensive treatment on the left atrium and left ventricle may help prevent AF and reduce risk of stroke associated with hypertensive heart disease Udgivelsesdato: 2008/12

Wachtell, K.; Devereux, R.B.

2008-01-01

184

The H1–H2 domain of the ?1 isoform of Na+–K+–ATPase is involved in ouabain toxicity in rat ventricular myocytes  

International Nuclear Information System (INIS)

The composition of different isoforms of Na+-K+-ATPase (NKA, Na/K pump) in ventricular myocytes is an important factor in determining the therapeutic effect and toxicity of cardiac glycosides (CGs) on heart failure. The mechanism whereby CGs cause these effects is still not completely clear. In the present study, we prepared two site-specific antibodies (SSA78 and WJS) against the H1–H2 domain of ?1 and ?2 isoforms of NKA in rat heart, respectively, and compared their influences on the effect of ouabain (OUA) in isolated rat ventricular myocytes. SSA78 or WJS, which can specifically bind with the ?1 or ?2 isoform, were assessed with enzyme linked immunosorbent assay (ELISA), Western blot and immunofluorescent staining methods. Preincubation of myocytes with SSA78 inhibited low OUA affinity pump current but not high OUA affinity pump current, reduced the rise in cytosolic calcium concentration ([Ca2+]i), attenuated mitochondrial Ca2+ overload, restored mitochondrial membrane potential reduction, and delayed the decrease of the myocardial contractile force as well as the occurrence of arrhythmic contraction induced by high concentrations (1 mM) but not low concentrations (1 ?M) of OUA. Similarly, preincubation of myocytes with WJS inhibited high OUA affinity pump current, reduced the increase of [Ca2+]i and the contractility induced by 1 ?M but not that induced by 1 mM OUA. These results indicate that the H1–H2 domain of the NKA ?1 isoform mediates OUA-induced cardiac toxicity in rat ventricular myocytes, and inhibitors for this binding site may be used as an adjunct to CGs treatment for cardiovascular disease. -- Highlights: ? We prepared two antibodies against the H1-H2 domain of ?1 and ?2 isoforms of NKA. ? The H1-H2 domain of the NKA ?1 isoform mediates OUA-induced cardiac toxicity. ? The H1-H2 domain of the NKA ?2 isoform mediates OUA-induced positive inotropic.

185

Cyclic AMP-mediated increase in L-type calcium current (ICa,L) by nitroglycerin in guinea-pig ventricular myocytes.  

Science.gov (United States)

The effects of nitroglycerin (NG) on the L-type Ca2+ current (ICa,L) were investigated in guinea-pig ventricular myocytes. NG did not affect the basal ICa,L significantly. The ICa,L was increased by NG when the ICa,L was augmented by the pre-treatment with isoproterenol (Iso), and this increase was abolished by the pretreatment with methylene blue (MB), a guanylate cyclase inhibitor. NG also increased ICa,L in the myocytes undergoing the pretreatment with isobutylmethylxanthine (IBMX). The NG-induced increase in ICa,L was also observed in the myocytes intracellularly dialyzed with cyclic adenosine monophosphate (cAMP). The order of the Iso-induced increase in ICa,L was Iso, IBMX and cAMP. Relatively a lower concentration of the extracellularly applied 8bromo-cyclic guanosine monophosphate (8Br-cGMP) increased ICa,L in the myocytes dialyzed with cAMP, whereas the higher concentration of 8Br-cGMP decreased ICa,L. NG produced a marked increase in cGMP levels, and a slight increase in cAMP levels in the ventricular tissues. These results suggest that the stimulatory effect of NG on the ICa,L is due to an inhibition of cGMP-inhibitable cAMP-phosphodiesterase (PDE) and a possible activation of cGMP-dependent protein kinase via the NG-induced increase in cGMP levels in guinea-pig ventricular myocytes. PMID:11990453

Tsuchida, Katsuharu; Watajima, Hiroshi

2002-03-01

186

Strict fluid volume control and left ventricular hypertrophy in hypertensive patients on chronic haemodialysis: a cross-sectional study.  

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Left ventricular hypertrophy (LVH) is very common in haemodialysis patients. We measured left ventricular mass in three groups of haemodialysis patients: group A (n = 40) were normotensive and receiving a strict salt-restricted diet; group B (n = 23) were normotensive and receiving anti-hypertensive drugs; and group C (n = 43) were hypertensive despite anti-hypertensive drug treatment. The interdialytic weight gain in group B and group C was significantly higher than in group A; the mean left atrial index and left ventricular end-systolic and end-diastolic diameter indices were all higher in group B than in group A. The interventricular septum and posterior wall were significantly thicker in group B and group C than group A, resulting in a higher left ventricular mass index. Left ventricular systolic and diastolic function parameters were slightly better in group A than in the other groups. These results show that strict fluid volume control decreases blood pressure, reduces dilated cardiac compartments and corrects LVH more effectively than lowering blood pressure without correcting the volume overload. PMID:14997710

Gunal, A I; Karaca, I; Aygen, B; Yavuzkir, M; Dogukan, A; Celiker, H

2004-01-01

187

Left ventricular hypertrophy, abnormal ventricular geometry and relative wall thickness are associated with increased risk of stroke in hypertensive patients among the Han Chinese.  

Science.gov (United States)

Our study aimed to explore whether left ventricular hypertrophy (LVH), abnormal LV geometry and relative wall thickness (RWT) are associated with an increased risk of stroke in a hypertensive Chinese population. This study included 462 stroke patients and 3808 non-stroke hypertensive patients. LVH was diagnosed using the criteria of LV mass ?49.2?g?m(-2.7) for men and 46.7?g?m(-2.7) for women. A partition value of 0.43 was used for RWT. LV geometric patterns (normal, concentric remodeling, concentric or eccentric hypertrophy) were calculated according to LVH and RWT. Logistic regression analyses were used to determine the odds ratio (OR) and 95% confidence intervals (CI) of LVH, LV geometry abnormality and RWT for stroke. Our study suggested that LVH was associated with increased stroke risk (adjusted OR, 1.52; 95% CI, 1.25-1.85; multivariate-adjusted OR, 1.43; 95% CI, 1.16-1.75) and that concentric hypertrophy carried the highest risk of stroke (adjusted OR, 1.62; 95% CI, 1.21-2.17), followed by eccentric hypertrophy (adjusted OR, 1.51; 95% CI, 1.12-2.03), with concentric remodeling ranked third (adjusted OR, 1.34; 95% CI, 1.01-1.80). RWT was associated with an increased risk of stroke and was independent of LVMI and other risk factors for stroke (adjusted OR, 3.97; 95% CI, 1.10-14.34). Our observations in Chinese patients with hypertension indicated that LVH was an important risk factor for stroke, LV geometry abnormality was related to the presence of stroke, concentric hypertrophy carried the highest risk of stroke in cases of abnormal LV geometry and that RWT was also a risk factor for stroke and was independent of LVMI and other stroke risk factors. PMID:24830536

Wang, Shuxia; Xue, Hao; Zou, Yubao; Sun, Kai; Fu, Chunyan; Wang, Hu; Hui, Rutai

2014-09-01

188

Comparison of Echocardiographic and Cardiac Magnetic Resonance Imaging in Hypertrophic Cardiomyopathy Sarcomere Mutation Carriers Without Left Ventricular Hypertrophy  

Science.gov (United States)

Background Left ventricular hypertrophy (LVH) typically manifests during or after adolescence in sarcomere mutation carriers at risk for developing hypertrophic cardiomyopathy. Guidelines recommend serial imaging of mutation carriers without LVH (G+/LVH?) to monitor for phenotypic evolution, but the optimal strategy is undefined. Compared with echocardiography (echo), cardiac MRI (CMR) offers improved endocardial visualization and potential to assess scar. However, the incremental advantage offered by CMR for early diagnosis of hypertrophic cardiomyopathy is unclear. Therefore, we systematically compared echo and CMR in G+/LVH? subjects. Methods and Results A total of 40 sarcomere mutation carriers with normal echo wall thickness (<12 mm or z score <2.5 in children) underwent concurrent CMR. Mean age was 21.7±11.1 years, 55% were female. If left ventricular wall thickness seemed nonuniform, the size and location of relatively thickened segments were noted. Late gadolinium enhancement was assessed with CMR. Diagnostic agreement between echo and CMR was good (90%), although CMR measurements of left ventricular wall thickness were ?19% lower than echo. Four subjects had mild hypertrophy (12.6–14 mm; ?2 segments) appreciated by CMR but not echo. No subjects had late gadolinium enhancement. During median 35-month follow-up, 2 subjects developed overt hypertrophic cardiomyopathy, including 1 with mild LVH by CMR at baseline. Conclusions Echo is unlikely to miss substantial LVH; however, CMR identified mild hypertrophy in ?10% of mutation carriers with normal echo wall thickness. CMR may be a useful adjunct in hypertrophic cardiomyopathy family screening, particularly in higher risk situations, or if echocardiographic images are suboptimal or suggest borderline LVH. PMID:23690394

Valente, Anne Marie; Lakdawala, Neal K.; Powell, Andrew J.; Evans, Sarah P.; Cirino, Allison L.; Orav, E. John.; MacRae, Calum A.; Colan, Steven D.; Ho, Carolyn Y.

2014-01-01

189

Effects of monocarboxylic acid-derived Cl- channel blockers on depolarization-activated potassium currents in rat ventricular myocytes.  

Science.gov (United States)

The effects of monocarboxylic acid-derived Cl(-) channel blockers on cardiac depolarization-activated K(+) currents were investigated. Membrane currents in rat ventricular myocytes were recorded using the whole-cell configuration of the patch-clamp technique. 5-Nitro-2-(3-phenylpropylamino)-benzoic acid (NPPB) and niflumic acid (NFA) induced an outward current at 0 mV. Both NPPB and NFA failed to induce any current when used intracellularly or after K(+) in the bath and pipette solutions was replaced by equimolar Cs(+). Voltage pulse protocols revealed that NPPB and NFA enhanced the steady-state K(+) current but inhibited the transient outward K(+) current. Genistein, a tyrosine kinase (PTK) inhibitor, inhibited NPPB- and NFA-induced outward current. Another PTK inhibitor, lavendustin A, produced a comparable effect. In contrast, the inactive analogue of genistein, daidzein, was ineffective. Orthovanadate, a tyrosine phosphatase inhibitor, markedly slowed the deactivation of the outward current induced by NPPB and NFA. The protein kinase A (PKA) inhibitor H-89 inhibited NPPB-induced outward current at 0 mV. In contrast, the protein kinase C (PKC) inhibitor H-7 was without significant effect on the action of NPPB. Pretreatment of the myocytes with genistein or H-89 prevented the enhancing effect of NPPB. Increasing intracellular Cl(-) from 22 to 132 mm slightly reduced NPPB-induced outward current at 0 mV. These results demonstrate that the monocarboxylic acid-derived Cl(-) channel blockers NPPB and NFA enhance cardiac steady-state K(+) current, and suggest that the enhancing effect of the Cl(-) channel blockers is mediated by stimulation of PKA and PTK signalling pathways. PMID:17303647

Zhou, Shi-Sheng; Zhang, Li-Bin; Sun, Wu-Ping; Xiao, Fu-Cheng; Zhou, Yi-Ming; Li, Ya-Jie; Li, Dong-Liang

2007-05-01

190

Tribulosin suppresses apoptosis via PKC epsilon and ERK1/2 signaling pathway during hypoxia/reoxygenation in neonatal rat ventricular cardiac myocytes.  

Science.gov (United States)

Tribulosin (tigogenin 3-O-?-D-xylopyranosyl(1-2)-[?-D-xylopyranosyl (1-3)]-?-D-glucopyranosyl (1-4)-[a-L-rhamnopyranosyl(1-2)]-?-D-galactopyranoside), a component of gross saponins of Tribulus terrestris, has been shown to produce cytoprotective effects in heart. Yet, the precise mechanisms are not fully understood. We examined the mechanisms of tribulosin on myocardial protection. Ventricular myocytes were isolated from the heart of neonatal rats and were exposed to 3 h of hypoxia followed by 2 h reoxygenation. Apoptosis was induced by hypoxia/reoxygenation (H/R), and the expression of protein kinase C epsilon (PKC?) and extracellular signal-regulated kinase 1 and 2 (ERK1/2) in cultured neonatal rat cardiac myocytes was detected. The results indicated that treatment with tribulosin in the culture medium protected cardiac myocytes against apoptosis induced by H/R. PKC? and ERK1/2 expression increased after pretreated with tribulosin. In the presence of PKC? inhibitor co-treated with tribulosin, the expression of ERK1/2 was decreased in H/R cardiac myocytes. While preconditioned with PD98059, ERK1/2 inhibitor, no effects on the expression of PKC? were detected. Tribulosin has protective effects on cardiac myocytes against apoptosis induced by H/R injury via PKC? and ERK1/2 signaling pathway. PMID:22115037

Zhang, Shuang; Li, Hong; Yang, Shi-Jie

2011-12-01

191

Comparison of guinea-pig ventricular myocytes and dog Purkinje fibres for in vitro assessment of drug-induced delayed repolarization.  

OpenAIRE

INTRODUCTION: QT interval prolongation and Torsade de Pointes (TdP) arrhythmias are recognised as a potential risk with many drugs, most of which delay cardiac repolarization by inhibiting the rapidly activating K(+) current (I(Kr)). The objective of this study was to compare the effects of compounds on cardiac action potentials recorded from guinea-pig ventricular myocytes and dog Purkinje fibres. METHODS AND RESULTS: Effects of dofetilide, sotalol, cisapride, terfenadine, haloperidol and sp...

Terrar, Da; Wilson, Cm; Graham, Sg; Bryant, Sm; Heath, Bm

2007-01-01

192

The calcium-independent transient outward potassium current in isolated ferret right ventricular myocytes. II. Closed state reverse use- dependent block by 4-aminopyridine  

OpenAIRE

Block of the calcium-independent transient outward K+ current, I(to), by 4-aminopyridine (4-AP) was studied in ferret right ventricular myocytes using the whole cell patch clamp technique. 4-AP reduces I(to) through a closed state blocking mechanism displaying "reverse use- dependent" behavior that was inferred from: (a) development of tonic block at hyperpolarized potentials; (b) inhibition of development of tonic block at depolarized potentials; (c) appearance of "crossover phenomena" in wh...

1993-01-01

193

Protein kinase C enhances the rapidly activating delayed rectifier potassium current, IKr, through a reduction in C-type inactivation in guinea-pig ventricular myocytes.  

OpenAIRE

1. The rapidly activating delayed rectifier potassium current, IKr, was studied in guinea-pig ventricular myocytes in the presence of thiopentone, which blocks the more slowly activating component of the delayed rectifier potassium current, IKs, and using whole cell perforated patch clamp or switched voltage clamp with sharp electrodes to minimise intracellular dialysis. 2. Activation of protein kinase A (PKA) by isoprenaline or forskolin caused an increase in IKr tail currents. Following a 3...

Heath, Bm; Terrar, Da

2000-01-01

194

Endothelin downregulates SERCA2 gene and protein expression in adult rat ventricular myocytes: regulation by pertussis toxin-sensitive Gi protein and cAMP  

OpenAIRE

Downregulation of the sarcoplasmic reticulum calcium ATPase (SERCA2) is associated with diastolic dysfunction in the failing heart. Elevated plasma endothelin-1 (ET) levels are correlated with congestive heart failure suggesting that ET may play a pathophysiological role. We have investigated the ability of ET to regulate SERCA2 gene expression in isolated adult rat ventricular myocytes. We find that ET enhances net protein synthesis by ?40% but significantly downregulates SERCA2 mRNA expre...

Hilal-dandan, Randa; He, Huaping; Martin, Jody L.; Brunton, Laurence L.; Dillmann, Wolfgang H.

2009-01-01

195

Computational modeling and numerical methods for spatiotemporal calcium cycling in ventricular myocytes  

Directory of Open Access Journals (Sweden)

Full Text Available Intracellular calcium (Ca cycling dynamics in cardiac myocytes is regulated by a complex network of spatially distributed organelles, such as sarcoplasmic reticulum (SR, mitochondria, and myofibrils. In this study, we present a mathematical model of intracellular Ca cycling and numerical and computational methods for computer simulations. The model consists of a coupled Ca release unit (CRU network, which includes a SR domain and a myoplasm domain. Each CRU contains 10 L-type Ca channels and 100 ryanodine receptor channels, with individual channels simulated stochastically using a varient of Gillespie’s method, modified here to handle time-dependent transition rates. Both the SR domain and the myoplasm domain in each CRU are modeled by 5x5x5 voxels to maintain proper Ca diffusion. Advanced numerical algorithms implemented on graphical processing units were used for fast computational simulations. For a myocyte containing 100x20x10 CRUs, a one-second heart time simulation takes about 10 minutes of machine time on a single NVIDIA Tesla C2050. Examples of simulated Ca cycling dynamics, such as Ca sparks, Ca waves, and Ca alternans, are shown.

MichaelNivala

2012-05-01

196

Influences from physical activity and gender on the metabolic syndrome and left ventricular hypertrophy : cross-sectional and longitudinal studies  

OpenAIRE

Aims: The overall aim was to investigate influences from physical activity (PA) and gender on the metabolic syndrome (MetS) and left ventricular hypertrophy (LVH). Specific aims: Study 1: To examine the prevalence of the MetS and its association to PA and other lifestyle factors. Study 2: To evaluate plausible links between the MetS and its components and LVH. Study 3: To investigate potential influences from insulin-like growth factor-1 (IGF-1) and IGF binding protein-1 (IGFBP-1) on th...

Halldin, Mats

2014-01-01

197

Effects of valsartan and nebivolol on blood pressure, QT dispersion and left ventricular hypertrophy in hypertensive patients  

OpenAIRE

Objectives: The aim of this study was to analyze the antihypertensiveeffect of Valsartan and Nebivolol and their effects on QT dispersion and left ventricular hypertrophy (LVH) in the treatment of naive hypertensive patients.Methods: A prospective study with a six-month follow-up was conducted on hypertensive patients with LVH and mild/ moderate essential hypertension. The patients were randomly assigned to Valsartan (80 to 160 mg/day) or Nebivolol (5 to 10 mg/day) groups. The study group con...

Luminita L??ea; Negrea, S?tefania L.; Bolboaca?, Sorana D.

2010-01-01

198

Characterization of the endothelin-1-induced regulation of L-type Ca2+ current in rabbit ventricular myocytes.  

Science.gov (United States)

The effects of endothelin-1 (ET-1) on the L-type Ca2+ current (I(Ca)) and the interaction of ET-1 with beta-adrenoceptor stimulation were investigated in rabbit ventricular myocytes by the whole-cell patch-clamp technique. ET-1 (10(-8) M) had a biphasic effect on I(Ca) (direct effect), causing a transient decrease that was followed by a long-lasting increase which is much smaller than the increase induced by isoprenaline (ISO). The effect of ET-1 on I(Ca) was abolished by a selective ET(A) receptor antagonist, FR139317 (10(-6) M). The increase in I(Ca) induced by ET-1 (10(-8) M) was enhanced by a selective ET(B) receptor antagonist, BQ-788 (10(-6) M), as the transient decrease but not the increase in I(Ca) induced by ET-1 (10(-8) M) was suppressed by BQ-788. In the presence of ISO (10(-6) M), ET-1 elicited a more pronounced inhibitory effect: at 10(-9)-10(-7) M ET-1 inhibited the ISO-induced increase in I(Ca) in a concentration-dependent manner (anti-adrenergic effect). The maximum inhibition induced by ET-1 at 10(-7) M was approximately 80% of the ISO-induced response, and the IC50 value for anti-adrenergic effect of ET-1 was 4.2x10(-9) M. The anti-adrenergic effect of ET-1 (10(-8) M) was antagonized by the ET(A) antagonist FR139317 (10(-9)-10(-6) M) in a concentration-dependent manner and was partially inhibited by the ET(B) antagonist BQ-788 (10(-6) M). The anti-adrenergic effect of ET-1 was markedly attenuated by pretreatment of ventricular myocytes with pertussis toxin. The increases in I(Ca) induced by forskolin (10(-6) M), 3-isobutyl-1-methylxanthine (10(-4) M), and 8-bromo-cyclic AMP (3x10(-4) M) were also suppressed by ET-1 (10(-8) M). In summary, ET-1 has a differential effect on I(Ca) in the absence and in the presence of ISO: ET- I has a feeble biphasic action on the baseline I(Ca) and, in addition, it elicits a pronounced anti-adrenergic effect on the ISO-induced increase in I(Ca). Pertussis toxin-sensitive G protein is responsible for the anti-adrenergic effect of ET-1 on I(Ca), but the anti-adrenergic effect of ET-1 may involve also the regulation at the level of signaling process beyond the cyclic AMP generation. Anti-adrenergic effect of ET-1 on I(Ca) is mainly due to activation of ET(A) receptors but ET(B) receptors are also involved partially in the anti-adrenergic effect of ET-1 on I(Ca) in rabbit ventricular myocytes. PMID:10619182

Watanabe, T; Endoh, M

1999-12-01

199

Effect of exercise training on Ca2+ release units of left ventricular myocytes of spontaneously hypertensive rats  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english In cardiomyocytes, calcium (Ca2+) release units comprise clusters of intracellular Ca2+ release channels located on the sarcoplasmic reticulum, and hypertension is well established as a cause of defects in calcium release unit function. Our objective was to determine whether endurance exercise train [...] ing could attenuate the deleterious effects of hypertension on calcium release unit components and Ca2+ sparks in left ventricular myocytes of spontaneously hypertensive rats. Male Wistar and spontaneously hypertensive rats (4 months of age) were divided into 4 groups: normotensive (NC) and hypertensive control (HC), and normotensive (NT) and hypertensive trained (HT) animals (7 rats per group). NC and HC rats were submitted to a low-intensity treadmill running protocol (5 days/week, 1 h/day, 0% grade, and 50-60% of maximal running speed) for 8 weeks. Gene expression of the ryanodine receptor type 2 (RyR2) and FK506 binding protein (FKBP12.6) increased (270%) and decreased (88%), respectively, in HC compared to NC rats. Endurance exercise training reversed these changes by reducing RyR2 (230%) and normalizing FKBP12.6 gene expression (112%). Hypertension also increased the frequency of Ca2+ sparks (HC=7.61±0.26 vs NC=4.79±0.19 per 100 µm/s) and decreased its amplitude (HC=0.260±0.08 vs NC=0.324±0.10 ?F/F0), full width at half-maximum amplitude (HC=1.05±0.08 vs NC=1.26±0.01 µm), total duration (HC=11.51±0.12 vs NC=14.97±0.24 ms), time to peak (HC=4.84±0.06 vs NC=6.31±0.14 ms), and time constant of decay (HC=8.68±0.12 vs NC=10.21±0.22 ms). These changes were partially reversed in HT rats (frequency of Ca2+ sparks=6.26±0.19 µm/s, amplitude=0.282±0.10 ?F/F0, full width at half-maximum amplitude=1.14±0.01 µm, total duration=13.34±0.17 ms, time to peak=5.43±0.08 ms, and time constant of decay=9.43±0.15 ms). Endurance exercise training attenuated the deleterious effects of hypertension on calcium release units of left ventricular myocytes.

M.A., Carneiro-Júnior; J.F., Quintão-Júnior; L.R., Drummond; V.N., Lavorato; F.R., Drummond; M.A., Amadeu; E.M., Oliveira; L.B., Felix; J.S., Cruz; J.G., Mill; A.J., Natali; T.N., Prímola-Gomes.

2014-08-29

200

Effect of exercise training on Ca2+ release units of left ventricular myocytes of spontaneously hypertensive rats  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english In cardiomyocytes, calcium (Ca2+) release units comprise clusters of intracellular Ca2+ release channels located on the sarcoplasmic reticulum, and hypertension is well established as a cause of defects in calcium release unit function. Our objective was to determine whether endurance exercise train [...] ing could attenuate the deleterious effects of hypertension on calcium release unit components and Ca2+ sparks in left ventricular myocytes of spontaneously hypertensive rats. Male Wistar and spontaneously hypertensive rats (4 months of age) were divided into 4 groups: normotensive (NC) and hypertensive control (HC), and normotensive (NT) and hypertensive trained (HT) animals (7 rats per group). NC and HC rats were submitted to a low-intensity treadmill running protocol (5 days/week, 1 h/day, 0% grade, and 50-60% of maximal running speed) for 8 weeks. Gene expression of the ryanodine receptor type 2 (RyR2) and FK506 binding protein (FKBP12.6) increased (270%) and decreased (88%), respectively, in HC compared to NC rats. Endurance exercise training reversed these changes by reducing RyR2 (230%) and normalizing FKBP12.6 gene expression (112%). Hypertension also increased the frequency of Ca2+ sparks (HC=7.61±0.26 vs NC=4.79±0.19 per 100 µm/s) and decreased its amplitude (HC=0.260±0.08 vs NC=0.324±0.10 ?F/F0), full width at half-maximum amplitude (HC=1.05±0.08 vs NC=1.26±0.01 µm), total duration (HC=11.51±0.12 vs NC=14.97±0.24 ms), time to peak (HC=4.84±0.06 vs NC=6.31±0.14 ms), and time constant of decay (HC=8.68±0.12 vs NC=10.21±0.22 ms). These changes were partially reversed in HT rats (frequency of Ca2+ sparks=6.26±0.19 µm/s, amplitude=0.282±0.10 ?F/F0, full width at half-maximum amplitude=1.14±0.01 µm, total duration=13.34±0.17 ms, time to peak=5.43±0.08 ms, and time constant of decay=9.43±0.15 ms). Endurance exercise training attenuated the deleterious effects of hypertension on calcium release units of left ventricular myocytes.

M.A., Carneiro-Júnior; J.F., Quintão-Júnior; L.R., Drummond; V.N., Lavorato; F.R., Drummond; M.A., Amadeu; E.M., Oliveira; L.B., Felix; J.S., Cruz; J.G., Mill; A.J., Natali; T.N., Prímola-Gomes.

2014-11-01

201

Hipertrofia cardíaca esquerda e direita em necropsias de hipertensos / Left and right ventricular hypertrophy at autopsy of hypertensive individuals  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese OBJETIVO: Medir a espessura ventricular direita e esquerda em falecidos com história de hipertensão arterial, submetidos a necropsias clínicas. MÉTODOS: Foram selecionados 90 casos do Serviço de Verificação de Óbitos de Recife -PE, de ambos os sexos, com história de hipertensão arterial essencial, c [...] om relação à espessura das paredes cardíacas, além da correlação com outros achados de necropsia e informes clínicos. RESULTADOS: Observouse associação significativa entre a presença de hipertrofia ventricular esquerda (HVE) e direita (HVD), e de cardiopatia hipertensiva grave e HVD. Houve predomínio da HVD e HVE em homens, na faixa etária dos 60-79 anos, com maior prevalência nas etnias parda e negra, e naqueles com estado nutricional adequado ou com sobrepeso e em obesos. CONCLUSÃO: Observou-se que a presença de HVD relaciona-se com HVE, sugerindo que há fatores patogênicos semelhantes envolvidos no desenvolvimento da hipertrofia bilateral. A HVD parece associar-se à doença cardíaca mais grave, podendo, a partir de outros estudos, ser considerada novo fator prognóstico na avaliação dos pacientes hipertensos. Abstract in english OBJECTIVE: To measure the right and left ventricular thickness in deceased individuals with a history of hypertension submitted to clinical autopsies. METHODS: We selected 90 cases from the Death Verification Service of the city of Recife, state of Pernambuco, Brazil, of both sexes, with a history o [...] f essential arterial hypertension related to heart wall thickness, in addition to correlation with autopsy findings and other clinical reports. RESULTS: There was a significant association between the presence of left ventricular hypertrophy (LVH) and right ventricular hypertrophy (RVH) and between severe hypertensive cardiomyopathy and RVH. There was a predominance of RVH and LVH in men aged 60-79 years and a higher prevalence in the Brazilian mulatto and Black ethnic groups and in those with adequate nutritional status or overweight and obese individuals. CONCLUSION: It was observed that the presence of RVH was related to LVH, suggesting that there are similar pathogenic factors involved in the development of bilateral hypertrophy. The RVH seems to be associated with more severe heart disease and may, based on other studies, be considered as a new prognostic factor in the evaluation of hypertensive patients.

Mirella Pessoa, Sant' Anna; Roberto José Vieira de, Mello; Luciano Tavares, Montenegro; Mônica Modesto, Araújo.

2012-02-01

202

Left Ventricular Hypertrophy and Ejection Fraction in Association with C-Reactive Protein (CRP in Regular Hemodialysis Patients  

Directory of Open Access Journals (Sweden)

Full Text Available To study the associations of serum C-reactive protein (CRP as a marker of inflammation, with left ventricular hypertrophy (LVH as an independent risk factor for mortality in hemodialysis (HD patients, a cross sectional study was conducted on maintenance hemodialysis patients. On the basis of septal thickness, the patients stratified into no LVH, mild, moderate and severe LVH. For patients levels of serum albumin (Alb and C-reactive protein (CRP were measured using standard kits. Thirty-six HD patients consisting of 25 non diabetic and 11 diabetic HD patients enrolled in this study. Mean?SD of age of patients were 46±17 years. The median duration of hemodialysis were 19 months. Mean±SD of CRP of total patients were 8.7±6.7 mg/l (median:8 mg/l. Mean±SD of LV ejection fraction of all patients were 48±11.5 percent (median = 52%. In this study an inverse association between serum CRP and LV ejection fraction which is more significant in non diabetic dialysis patients and a positive correlation of serum CRP with stages of LVH were found. This study showed the positive association between inflammation and left ventricular hypertrophy and ejection fraction. More attention to treatment of malnutrition of hemodialysis patients to diminish the inflammatory state of hemodialysis procedure needs.

Hamid Nasri M.D.

2006-01-01

203

Coronary artery calcification and ECG pattern of left ventricular hypertrophy or strain identify different healthy individuals at risk  

DEFF Research Database (Denmark)

PURPOSE:: To improve risk stratification for development of ischaemic heart disease, several markers have been proposed. Both the presence of coronary artery calcification (CAC) and ECG pattern of left ventricular hypertrophy/strain have been shown to provide independent prognostic information. In this study, we investigated the association between established risk factors, ECG measurements and the presence of coronary artery calcification. METHOD:: A random sample of healthy men and women aged 50 or 60 years were invited to the screening study. Established risk factors were measured. A noncontrast computed tomographic (CT) scan was performed to assess the CAC score. ECG analysis included left ventricular hypertrophy (LVH) using the Sokolow-Lyon criteria and the Cornell voltage?×?QRS duration product, and strain pattern based on ST segment depression and T-wave abnormalities. The association between the presence of CAC, clinical variables and ECG findings was evaluated by means of multivariate logistic regression. RESULTS:: Of 1825 invited individuals, 1226 accepted the screening. The prevalence of hypertension was 50%. Hypertensive patients frequently had LVH and/or strain when compared with nonhypertensive individuals (21 vs. 14%, P?

Diederichsen, SØren Zöga; Gerke, Oke

2013-01-01

204

Angiotensin II receptor blockers and cardiovascular protection: Focus on left ventricular hypertrophy regression and atrial fibrillation prevention  

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Full Text Available Cesare Cuspidi1,2, Francesca Negri2, Alberto Zanchetti31Department of Clinical Medicine and Prevention, University of Milano-Bicocca, Milan, Italy; 2Policlinico di Monza; 3Centro Interuniversitario di Fisiologia Clinica e Ipertensione, Università di Milano, and Istituto Auxologico Italiano, Milan, ItalyAbstract: Left ventricular hypertrophy (LVH and atrial fibrillation (AF are strong predictors of cardiovascular (CV morbidity and mortality, independently of blood pressure levels and other modifiable and nonmodifiable risk factors. The actions of circulating and tissue angiotensin II, mediated by AT1 receptors, play an important role in the development of a wide spectrum of cardiovascular alterations, including LVH, atrial enlargement and AF. Growing experimental and clinical evidence suggests that antihypertensive drugs may exert different effects on LVH regression and new onset AF in the setting of arterial hypertension. Since a number of large and adequately designed studies have found angiotensin II receptor blockers (ARBs to be more effective in reducing LVH than beta-blockers and data are also available showing their effectiveness in preventing new or recurrent AF, it is reasonable to consider this class of drugs among first line therapies in patients with hypertension and LVH (a very high risk phenotype predisposing to AF and as adjunctive therapy to antiarrhythmic agents in patients undergoing pharmacological or electrical cardioversion of AF.Keywords: angiotensin II receptor blockers, left ventricular hypertrophy, atrial fibrillation

Cesare Cuspidi

2008-03-01

205

Myocyte necrosis underlies progressive myocardial dystrophy in mouse dsg2-related arrhythmogenic right ventricular cardiomyopathy  

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Mutations in the cardiac desmosomal protein desmoglein-2 (DSG2) are associated with arrhythmogenic right ventricular cardiomyopathy (ARVC). We studied the explanted heart of a proband carrying the DSG2-N266S mutation as well as transgenic mice (Tg-NS) with cardiac overexpression of the mouse equivalent of this mutation, N271S-dsg2, with the aim of investigating the pathophysiological mechanisms involved. Transgenic mice recapitulated the clinical features of ARVC, including sudden death at yo...

Pilichou, K.; Remme, C. A.; Basso, C.; Campian, M. E.; Rizzo, S.; Barnett, P.; Scicluna, B. P.; Bauce, B.; Hoff, M. J. B. Den; Bakker, J. M. T.; Tan, H. L.; Valente, M.; Nava, A.; Wilde, A. A. M.; Moorman, A. F. M.

2009-01-01

206

Role of oxidative stress in the aortic constriction-induced ventricular hypertrophy in rat  

OpenAIRE

Introduction:Severe abdominal aortic constriction above the renal arteries induces arterial hypertension above the stenotic site that is the cause of cardiac hypertrophy. Previous studies have shown that high blood pressure induces myocardial oxidative stress with conflicting results. In the present study, we assessed the effects of acute hypertension on the myocardial oxidative stress and its relation with cardiac hypertrophy. Methods:Experiments were performed on two groups of rats, sham an...

Zahra Jahanbakhsh; Mohammad Taghi Mohammadi; Mahvash Jafari2; Ali Khoshbaten; Maryam Salehi5

2012-01-01

207

Hydrogen sulfide endothelin-induced myocardial hypertrophy in rats and the mechanism involved.  

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The aim of the study was to evaluate the clinical efficacy of hydrogen sulfide (H2S) treatment on the endothelin-induced cardiac hypertrophy. Sixty-four adult male rats, weighing from 180 to 200 g, were randomly divided into four groups: ten in normal group, ten in sham group, 44 in model group established by inducing the myocardial hypertrophy with endothelin. The myocardial hypertrophy model rats were randomly divided into two groups: 22 in the simple myocardial hypertrophy model group and 22 in the H2S treatment group. Rats in normal group were given 2 ml pure water by gavage per day, those in the sham group and simple cardiac hypertrophy model group were given 2 ml of saline by gavage per day, and rats in the pure cardiac hypertrophy with H2S treatment were given intraperitoneal injections of 2 ml NaHS saline per day for a period of 4 weeks. Left ventricular mass index, myocyte hypertrophy, volume fraction of myocardial interstitial collagen, myocardial hydroxyproline content and other indicators of cardiac hypertrophy were observed after 4 weeks. (1) There were significant differences on the ventricular mass between the treatment group and the cardiac hypertrophy group: The left ventricular mass decreased 21.4 % and the left ventricular mass index decreased 5.97 % (P hydroxyproline content decreased 22.3 and 31.3 % in treatment group compared with the cardiac hypertrophy group, respectively (P < 0.05). H2S had a good clinical efficacy in reducing left ventricular mass fraction and myocardial collagen levels, improving myocardial hypertrophy and decrease myocardial fibrosis. It is worthy for further clinical studies. PMID:24980860

Yang, Fengyong; Liu, Zhen; Wang, Yajing; Li, Zhaoxin; Yu, Haichu; Wang, Qixin

2014-12-01

208

Tissue Doppler Imaging can be useful to distinguish pathological from physiological left ventricular hypertrophy: a study in master athletes and mild hypertensive subjects  

OpenAIRE

Abstract Background Transthoracic echocardiography left ventricular wall thickness is often increased in master athletes and it results by intense physical training. Left Ventricular Hypertrophy can also be due to a constant pressure overload. Conventional Pulsed Wave (PW) Doppler analysis of diastolic function sometimes fails to distinguish physiological from pathological LVH. The aim of this study is to evaluate the role of Pulsed Wave Tissue Doppler Imaging in diffe...

De Luca Alessio; Cappelli Brunello; Stefani Laura; Del Furia Francesca; Toncelli Loira; Galanti Giorgio; Vono Maria

2009-01-01

209

Galphaq-protein carboxyl terminus imitation polypeptide (GCIP)-27 inhibits right ventricular hypertrophy induced by monocrotaline in rats.  

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This study was to investigate the probable inhibitory effect of Galphaq-protein carboxyl terminus imitation polypeptide-27 (GCIP-27), the optimized form of GCIP, which is a competition candidate of the activated binding sites on Galphaq, on the right ventricular (RV) hypertrophy induced by monocrotaline (MCT) in rats. We have previously shown that GCIP-27, can prevent the hypertrophyc responses in cultured rat cardiomyocytes induced by noradrenaline and angiotensin II. Male Sprague-Dawley rats were given a single dose (50 mg/kg) of MCT subcutaneouly to induce pulmonary hypertension (PH) and RV hypertrophy. GCIP-27 (30, 90 microg/kg) or vehicle was administered (twice daily, intraperitoneally) from day 1 to day 21. GCIP-27 (90 microg/kg) inhibited the elevated pulmonary arteria systolic pressure (PASP) and mean pulmonary arteria pressure induced by MCT, but its dose at 30 microg/kg only reduced the elevated PASP. And no effect could be seen on the pulmonary arteria diastolic pressure at both two doses. On the other hand, the two doses of GCIP-27 improved significantly the weight ratio of RV to left ventricle plus septum, the RV free wall thickness and pulmonary arteria acceleration time (PAAT). In morphometric observation, GCIP-27 (30, 90g/kg) could attenuate cardiomyocytes hypertrophy, interstitium fibrosis, mitochondria swelling and malformation markedly in RVs of MCT-treated rats. Furthermore, GCIP-27 (30, 90 mug/kg) significantly reduced the overexpression of the proliferating cell nuclear antigen (PCNA) induced by MCT in RV cardiocytes. The results suggest that GCIP-27 can effectively attenuate the RV hypertrophy induced by MCT in rats, which may be mediated by both the direct effect on cardiomyocyte and the secondary effect by reducing PH, and may be involved in its influence on the Gq signal pathway. PMID:19252281

Yang, Dan-Li; Zhang, Hai-Gang; Xu, Ya-Li; Gao, Yun-Hua; Yang, Xiao-Jiao; Hao, Xue-Qin; Su, Min; Wang, Xiu-Qin; Li, Xiao-Hui

2009-03-01

210

Fragmented QRS and Left Ventricular Geometry in Hypertensive Patients  

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Full Text Available Introduction: Fragmented QRS is a depolarization abnormality detected with routin ECG recording. It is related with conduction defect which occurs after myocardial fibrosis. In the left ventricular hypertrophy, an excessive amount of collagen accumulates in the interstitium when the myocytes became hypertrophied, resulting in myocardial fibrosis. In this study, we aimed to investigate the relationship of fragmented QRS which was detected on ECG recordings of the hypertensive patients with the left ventricular geometry.Patients and Methods: Essential hypertension patients referred to our hospital on outpatient bases were included in the study. 12-lead resting ECG was taken in all the patients. Left ventricular geometry defined using left ventricular mass index and relative wall thickness with transthorasic echocardiography.Results: Sixy seven patients with fragmented QRS and 63 patients without fragmented QRS included the study. We found that patients in the group with fragmented QRS detected have a wider mean left atrium diameter, greater left ventricular mass and left ventricular mass index compared with the group without fragmented QRS. Concentric and eccentric hypertrophy were more common in fragmented QRS group, while normal geometry and concentric remodelling have greater rates in the normal group.Conclusion: Left ventricular hypertrophy is observed more frequently in the patients with fragmented QRS than without fragmented QRS. This may be associated with the increased myocardial fibrosis in the left ventricular hypertrophy. Existence of fragmented QRS can be used for risk stratification in the hypertensive patients.

Lütfü Bekar

2013-08-01

211

Long-Chain Fatty Acids Activate Calcium Channels in Ventricular Myocytes  

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Nonesterified fatty acids accumulate at sites of tissue injury and necrosis. In cardiac tissue the concentrations of oleic acid, arachidonic acid, leukotrienes, and other fatty acids increase greatly during ischemia due to receptor or nonreceptor-mediated activation of phospholipases and/or diminished reacylation. In ischemic myocardium, the time course of increase in fatty acids and tissue calcium closely parallels irreversible cardiac damage. We postulated that fatty acids released from membrane phospholipids may be involved in the increase of intracellular calcium. We report here that low concentrations (3-30 ?M) of each long-chain unsaturated (oleic, linoleic, linolenic, and arachidonic) and saturated (palmitic, stearic, and arachidic) fatty acid tested induced multifold increases in voltage-dependent calcium currents (ICa) in cardiac myocytes. In contrast, neither short-chain fatty acids (calcium channels depended on chain length and required a free carboxyl group. Inhibition of protein kinases C and A, G proteins, eicosanoid production, or nonenzymatic oxidation did not block the fatty acid-induced increase in ICa. Thus, long-chain fatty acids appear to directly activate ICa, possibly by acting at some lipid sites near the channels or directly on the channel protein itself. We suggest that the combined effects of fatty acids released during ischemia on ICa may contribute to ischemia-induced pathogenic events on the heart that involve calcium, such as arrhythmias, conduction disturbances, and myocardial damage due to cytotoxic calcium overload.

Huang, James Min-Che; Xian, Hu; Bacaner, Marvin

1992-07-01

212

Increased reactive oxygen species, metabolic maladaptation, and autophagy contribute to pulmonary arterial hypertension-induced ventricular hypertrophy and diastolic heart failure.  

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Pulmonary arterial hypertension (PAH) is a debilitating and deadly disease with no known cure. Heart failure is a major comorbidity and a common cause of the premature death of patients with PAH. Increased asymmetrical right ventricular hypertrophy and septal wall thickening compress the left ventricular cavity and elicit diastolic heart failure. In this study, we used the Sugen5416/hypoxia/normoxia-induced PAH rat to determine whether altered pyridine nucleotide signaling in the failing heart contributes to 1) increased oxidative stress, 2) changes in metabolic phenotype, 3) autophagy, and 4) the PAH-induced failure. We found that increased reactive oxygen species, metabolic maladaptation, and autophagy contributed to the pathogenesis of right ventricular remodeling and hypertrophy that lead to left ventricular diastolic dysfunction. In addition, arterial elastance increased in PAH rats. Glucose-6-phosphate dehydrogenase is a major source of pyridine molecule (nicotinamide adenine dinucleotide phosphate), which is a substrate for nicotinamide adenine dinucleotide phosphate oxidases in the heart. Dehydroepiandrosterone, a 17-ketosteroid that reduces pulmonary hypertension and right ventricular hypertrophy, inhibited glucose-6-phosphate dehydrogenase, decreased oxidative stress, increased glucose oxidation and acetyl-coA, and reduced autophagy in the hearts of PAH rats. It also decreased arterial stiffness and improved left ventricular diastolic function. These findings demonstrate that pyridine nucleotide signaling, at least partly, mediates PAH-induced diastolic heart failure, and that reduction of glucose-6-phosphate dehydrogenase-derived nicotinamide adenine dinucleotide phosphate is beneficial to improve left ventricle diastolic function. PMID:25267798

Rawat, Dhawjbahadur K; Alzoubi, Abdallah; Gupte, Rakhee; Chettimada, Sukrutha; Watanabe, Makino; Kahn, Andrea G; Okada, Takao; McMurtry, Ivan F; Gupte, Sachin A

2014-12-01

213

Modulation by histamine of the delayed outward potassium current in guinea-pig ventricular myocytes.  

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1. Histamine receptor-mediated modulation of the delayed outward potassium current (IK) was investigated in guinea-pig single ventricular cells by the whole-cell voltage clamp. 2. Histamine increased IK in a dose- dependent manner with a half-maximum dose of 3.8 x 10(-8) M. Histamine (10(-6) M) increased IK by a factor of 3.02 without a significant change in the current kinetics. The threshold dose of histamine for increasing IK was 10(-9) M and this value was similar to that for calcium curr...

Yazawa, K.; Abiko, Y.

1993-01-01

214

QRS duration and QT interval predict mortality in hypertensive patients with left ventricular hypertrophy: the Losartan Intervention for Endpoint Reduction in Hypertension Study.  

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Left ventricular hypertrophy is a risk factor for cardiovascular mortality, including sudden cardiac death. Experimentally, left ventricular hypertrophy delays ventricular conduction and prolongs action potential duration. Electrocardiographic QRS duration and QT interval measures reflect these changes, but whether these measures can further stratify risk in patients with electrocardiographic left ventricular hypertrophy is unknown. We measured the QRS duration and QT intervals from the baseline 12-lead electrocardiograms in the Losartan Intervention For Endpoint Reduction in Hypertension (LIFE) study, which included hypertensive patients with electrocardiographic evidence of left ventricular hypertrophy randomized to either losartan-based or atenolol-based treatment to lower blood pressure. In the present study, we related study baseline electrocardiographic measures to cardiovascular and all-cause mortality. There were 5429 patients (male 45.8%; mean age 66+/-7 years) included in the present analyses. After a mean follow-up of 4.9+/-0.8 years, there were 417 deaths from all causes, including 214 cardiovascular deaths. In separate univariate Cox regression analyses, QRS duration and several QT measures were significant predictors of cardiovascular mortality and all-cause mortality. However, in multivariate Cox analyses including all electrocardiographic measures and adjusting for other risk factors as well as treatment strategy, only QRS duration and maximum rate-adjusted QT(apex) interval remained as significant independent predictors of cardiovascular (P=0.022 and P=0.037, respectively) and all-cause mortality (P=0.038 and P=0.002, respectively). In conclusion, in a hypertensive risk population identified by electrocardiographic left ventricular hypertrophy, increased QRS duration and maximum QT(apex) interval can further stratify mortality risk even in the setting of effective blood pressure-lowering treatment. PMID:15037560

Oikarinen, Lasse; Nieminen, Markku S; Viitasalo, Matti; Toivonen, Lauri; Jern, Sverker; Dahlöf, Björn; Devereux, Richard B; Okin, Peter M

2004-05-01

215

Clinical impact of ' in-treatment' wall motion abnormalities in hypertensive patients with left ventricular hypertrophy: the LIFE study  

DEFF Research Database (Denmark)

Objectives Left ventricular systolic wall motion abnormalities have prognostic value. Whether wall motion detected by serial echocardiographic examinations predicts prognosis in hypertensive patients with left ventricular hypertrophy ( LVH) without clinically recognized atherosclerotic disease has, however, never been investigated. We examined whether 'in- treatment' wall motion abnormalities predicted outcome in the Losartan Intervention For Endpoint ( LIFE) reduction in hypertension echocardiographic substudy. Methods We studied 749 patients without coronary artery disease, myocardial infarction ( MI), or stroke history. Echocardiographic segmental wall motion abnormalities at baseline and annual re-evaluations (' as time- varying covariate') were examined in relation to endpoints ( cardiovascular mortality, MI, stroke, and hospitalized heart failure). Adjusted Cox regression was used to analyze the primary composite endpoint of cardiovascular death, MI, or stroke and, separately, for fatal and nonfatal MI and hospitalized heart failure. Results During a mean follow-up of 4.8 years, an event was recorded in 67 ( 9%) patients. In Cox models after adjusting for age, gender, treatment, blood pressure lowering, and serial change of left ventricular mass index, ' in-treatment' segmental wall motion abnormalities were associated with subsequent composite endpoint [ hazard ratio =2.1, 95% confidence interval ( CI) 1.1-3.8; P=0.019] and MI [ hazard ratio =3.7 ( 1.5 - 8.9); P=0.004]. Conclusion In hypertensive patients with LVH and no history of cardiovascular disease, ' in- treatment' left ventricular wall motion abnormalities are associated with increased likelihood of subsequent cardiovascular events independent of age, gender, blood pressure lowering, treatment modality, and in- treatment left ventricular mass index Udgivelsesdato: 2008/4

Cicala, S.; Simone, G. de

2008-01-01

216

BET acetyl-lysine binding proteins control pathological cardiac hypertrophy.  

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Cardiac hypertrophy is an independent predictor of adverse outcomes in patients with heart failure, and thus represents an attractive target for novel therapeutic intervention. JQ1, a small molecule inhibitor of bromodomain and extraterminal (BET) acetyl-lysine reader proteins, was identified in a high throughput screen designed to discover novel small molecule regulators of cardiomyocyte hypertrophy. JQ1 dose-dependently blocked agonist-dependent hypertrophy of cultured neonatal rat ventricular myocytes (NRVMs) and reversed the prototypical gene program associated with pathological cardiac hypertrophy. JQ1 also blocked left ventricular hypertrophy (LVH) and improved cardiac function in adult mice subjected to transverse aortic constriction (TAC). The BET family consists of BRD2, BRD3, BRD4 and BRDT. BRD4 protein expression was increased during cardiac hypertrophy, and hypertrophic stimuli promoted recruitment of BRD4 to the transcriptional start site (TSS) of the gene encoding atrial natriuretic factor (ANF). Binding of BRD4 to the ANF TSS was associated with increased phosphorylation of local RNA polymerase II. These findings define a novel function for BET proteins as signal-responsive regulators of cardiac hypertrophy, and suggest that small molecule inhibitors of these epigenetic reader proteins have potential as therapeutics for heart failure. PMID:23939492

Spiltoir, Jessica I; Stratton, Matthew S; Cavasin, Maria A; Demos-Davies, Kim; Reid, Brian G; Qi, Jun; Bradner, James E; McKinsey, Timothy A

2013-10-01

217

The strain pattern, and not Sokolow-Lyon electrocardiographic voltage criteria, is independently associated with anatomic left ventricular hypertrophy.  

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Although obesity and chest-wall thickness influence the Sokolow-Lyon electrocardiographic (ECG) voltage criteria and strain pattern, these factors have not been taken into account in previous studies that evaluate the relationship between the ECG criteria and anatomic left ventricular hypertrophy (LVH). The introduction of multislice computed tomography (MSCT) has enabled assessment of not only coronary artery stenoses but also left ventricular volume and mass, left atrial volume, and chest-wall thickness. We hypothesized that evaluating the relation between the ECG voltage criteria or strain pattern and the aforementioned factors using MSCT would be highly valuable. The study population consisted of 93 patients who required MSCT angiography. The Sokolow-Lyon voltage and strain patterns were determined to detect anatomic LVH, which was defined as increased left ventricular mass. The Sokolow-Lyon voltage criteria, as an indicator of anatomic LVH, had a sensitivity of 57 %, specificity of 67 %, positive predictive value of 36 %, and negative predictive value of 82 %. By contrast, the strain pattern had a sensitivity of 65 %, specificity of 87 %, positive predictive value of 63 %, and negative predictive value of 88 %. Multivariate analysis revealed that the strain pattern was associated with the presence of anatomic LVH, whereas the Sokolow-Lyon voltage was not. This MSCT study demonstrated that even after removing the effects of various factors, the strain pattern remained associated with the presence of anatomic LVH, in contrast to the Sokolow-Lyon voltage. PMID:24048761

Ehara, Shoichi; Hasegawa, Takao; Matsumoto, Kenji; Otsuka, Kenichiro; Yamazaki, Takanori; Iguchi, Tomokazu; Izumi, Yasukatsu; Shimada, Kenei; Yoshiyama, Minoru

2014-09-01

218

Cardiac MRI assessed left ventricular hypertrophy in differentiating hypertensive heart disease from hypertrophic cardiomyopathy attributable to a sarcomeric gene mutation  

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To evaluate the value of cardiac magnetic resonance imaging (CMRI)-assessed left ventricular hypertrophy (LVH) in differentiating between hypertensive heart disease and hypertrophic cardiomyopathy (HCM). 95 unselected subjects with mild-to-moderate hypertension, 24 patients with HCM attributable to the D175N mutation of the {alpha}-tropomyosin gene and 17 control subjects were studied by cine CMRI. Left ventricular (LV) quantitative and qualitative characteristics were evaluated. LV maximal end-diastolic wall thickness, wall thickness-to-LV volume ratio, end-diastolic septum thickness and septum-to-lateral wall thickness ratio were useful measures for differentiating between LVH due to hypertension and HCM. The most accurate measure for identifying patients with HCM was the LV maximal wall thickness {>=}17 mm, with a sensitivity, specificity, negative predictive value, positive predictive value, and accuracy of 90%, 93%, 86%, 95% and 91%, respectively. LV maximal wall thickness in the anterior wall, or regional bulging in left ventricular wall was found only in patients with HCM. LV mass index was not discriminant between patients with HCM and those with LVH due to hypertension. LV maximal thickness measured by CMRI is the best anatomical parameter in differentiating between LVH due to mild-to-moderate hypertension and HCM attributable to a sarcomeric mutation. CMRI assessment of location and quality of LVH is also of value in differential diagnosis. (orig.)

Sipola, Petri [Kuopio University Hospital, Department of Clinical Radiology, Kuopio (Finland); University of Eastern Finland, Institute of Clinical Medicine, Faculty of Health Sciences, Kuopio (Finland); Magga, Jarkko; Peuhkurinen, Keijo [Kuopio University Hospital, Department of Medicine, Kuopio (Finland); Husso, Minna [Kuopio University Hospital, Department of Clinical Radiology, Kuopio (Finland); Jaeaeskelaeinen, Pertti; Kuusisto, Johanna [Kuopio University Hospital, Department of Medicine, Kuopio (Finland); Kuopio University Hospital, Heart Center, P.O. Box 1777, Kuopio (Finland)

2011-07-15

219

Cardiac MRI assessed left ventricular hypertrophy in differentiating hypertensive heart disease from hypertrophic cardiomyopathy attributable to a sarcomeric gene mutation  

International Nuclear Information System (INIS)

To evaluate the value of cardiac magnetic resonance imaging (CMRI)-assessed left ventricular hypertrophy (LVH) in differentiating between hypertensive heart disease and hypertrophic cardiomyopathy (HCM). 95 unselected subjects with mild-to-moderate hypertension, 24 patients with HCM attributable to the D175N mutation of the ?-tropomyosin gene and 17 control subjects were studied by cine CMRI. Left ventricular (LV) quantitative and qualitative characteristics were evaluated. LV maximal end-diastolic wall thickness, wall thickness-to-LV volume ratio, end-diastolic septum thickness and septum-to-lateral wall thickness ratio were useful measures for differentiating between LVH due to hypertension and HCM. The most accurate measure for identifying patients with HCM was the LV maximal wall thickness ?17 mm, with a sensitivity, specificity, negative predictive value, positive predictive value, and accuracy of 90%, 93%, 86%, 95% and 91%, respectively. LV maximal wall thickness in the anterior wall, or regional bulging in left ventricular wall was found only in patients with HCM. LV mass index was not discriminant between patients with HCM and those with LVH due to hypertension. LV maximal thickness measured by CMRI is the best anatomical parameter in differentiating between LVH due to mild-to-moderate hypertension and HCM attributable to a sarcomeric mutation. CMRI assessment of location and quality of LVH is also of value in differential diagnosis. (orig.)tial diagnosis. (orig.)

220

The Neuron-Restrictive Silencer Element–Neuron-Restrictive Silencer Factor System Regulates Basal and Endothelin 1-Inducible Atrial Natriuretic Peptide Gene Expression in Ventricular Myocytes  

OpenAIRE

Induction of the atrial natriuretic peptide (ANP) gene is a common feature of ventricular hypertrophy. A number of cis-acting enhancer elements for several transcriptional activators have been shown to play central roles in the regulation of ANP gene expression, but much less is known about contributions made by transcriptional repressors. The neuron-restrictive silencer element (NRSE), also known as repressor element 1, mediates repression of neuronal gene expression in nonneuronal cells. We...

Kuwahara, Koichiro; Saito, Yoshihiko; Ogawa, Emiko; Takahashi, Nobuki; Nakagawa, Yasuaki; Naruse, Yoshihisa; Harada, Masaki; Hamanaka, Ichiro; Izumi, Takehiko; Miyamoto, Yoshihiro; Kishimoto, Ichiro; Kawakami, Rika; Nakanishi, Michio; Mori, Nozomu; Nakao, Kazuwa

2001-01-01

221

Endothelial cells contribute to generation of adult ventricular myocytes during cardiac homeostasis.  

Science.gov (United States)

Cardiac tissue undergoes renewal with low rates. Although resident stem cell populations have been identified to support cardiomyocyte turnover, the source of the cardiac stem cells and their niche remain elusive. Using Cre/Lox-based cell lineage tracing strategies, we discovered that labeling of endothelial cells in the adult heart yields progeny that have cardiac stem cell characteristics and express Gata4 and Sca1. Endothelial-derived cardiac progenitor cells were localized in the arterial coronary walls with quiescent and proliferative cells in the media and adventitia layers, respectively. Within the myocardium, we identified labeled cardiomyocytes organized in clusters of single-cell origin. Pulse-chase experiments showed that generation of individual clusters was rapid but confined to specific regions of the heart, primarily in the right anterior and left posterior ventricular walls and the junctions between the two ventricles. Our data demonstrate that endothelial cells are an intrinsic component of the cardiac renewal process. PMID:25001281

Fioret, Bryan A; Heimfeld, Jeremy D; Paik, David T; Hatzopoulos, Antonis K

2014-07-10

222

Endothelial Cells Contribute to Generation of Adult Ventricular Myocytes during Cardiac Homeostasis  

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Full Text Available Cardiac tissue undergoes renewal with low rates. Although resident stem cell populations have been identified to support cardiomyocyte turnover, the source of the cardiac stem cells and their niche remain elusive. Using Cre/Lox-based cell lineage tracing strategies, we discovered that labeling of endothelial cells in the adult heart yields progeny that have cardiac stem cell characteristics and express Gata4 and Sca1. Endothelial-derived cardiac progenitor cells were localized in the arterial coronary walls with quiescent and proliferative cells in the media and adventitia layers, respectively. Within the myocardium, we identified labeled cardiomyocytes organized in clusters of single-cell origin. Pulse-chase experiments showed that generation of individual clusters was rapid but confined to specific regions of the heart, primarily in the right anterior and left posterior ventricular walls and the junctions between the two ventricles. Our data demonstrate that endothelial cells are an intrinsic component of the cardiac renewal process.

Bryan A. Fioret

2014-07-01

223

Asynchronous activation of calcium and potassium currents by isoproterenol in canine ventricular myocytes.  

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Adrenergic activation of L-type Ca(2+) and various K(+) currents is a crucial mechanism of cardiac adaptation; however, it may carry a substantial proarrhythmic risk as well. The aim of the present work was to study the timing of activation of Ca(2+) and K(+) currents in isolated canine ventricular cells in response to exposure to isoproterenol (ISO). Whole cell configuration of the patch-clamp technique in either conventional voltage clamp or action potential voltage clamp modes were used to monitor I(Ca), I(Ks), and I(Kr), while action potentials were recorded using sharp microelectrodes. ISO (10 nM) elevated the plateau potential and shortened action potential duration (APD) in subepicardial and mid-myocardial cells, which effects were associated with multifold enhancement of I(Ca) and I(Ks) and moderate stimulation of I(Kr). The ISO-induced plateau shift and I(Ca) increase developed faster than the shortening of APD and stimulation of I(Ks) and I(Kr). Blockade of ?1-adrenoceptors (using 300 nM CGP-20712A) converted the ISO-induced shortening of APD to lengthening, decreased its latency, and reduced the plateau shift. In contrast, blockade of ?2-adrenoceptors (by 50 nM ICI 118,551) augmented the APD-shortening effect and increased the latency of plateau shift without altering its magnitude. All effects of ISO were prevented by simultaneous blockade of both receptor types. Inhibition of phosphodiesterases decreased the differences observed in the turn on of the ISO-induced plateau shift and APD shortening. ISO-induced activation of I(Ca) is turned on faster than the stimulation of I(Ks) and I(Kr) in canine ventricular cells due to the involvement of different adrenergic pathways and compartmentalization. PMID:24566722

Ruzsnavszky, Ferenc; Hegyi, Bence; Kistamás, Kornél; Váczi, Krisztina; Horváth, Balázs; Szentandrássy, Norbert; Bányász, Tamás; Nánási, Péter P; Magyar, János

2014-05-01

224

Sensibilidade do eletrocardiograma na hipertrofia ventricular de acordo com gênero e massa cardíaca / Electrocardiogram sensitivity in left ventricular hypertrophy according to gender and cardiac mass  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese FUNDAMENTO: Sabe-se que vários fatores interferem na sensibilidade do Eletrocardiograma (ECG) no diagnóstico da Hipertrofia Ventricular Esquerda (HVE), sendo o gênero e a massa cardíaca alguns dos principais. OBJETIVO: Avaliar a influência do sexo na sensibilidade de alguns dos critérios utilizados [...] para a detecção de HVE, de acordo com a progressão do grau de hipertrofia ventricular. MÉTODOS: De acordo com o gênero e com o grau de HVE ao ecocardiograma, os pacientes foram divididos em três grupos: HVE leve, moderada e severa. Avaliou-se a sensibilidade do ECG para detectar HVE entre homens e mulheres, conforme o grau de HVE. RESULTADOS: Dos 874 pacientes, 265 eram homens (30,3%) e 609, mulheres (69,7%). Os critérios [(S + R) X QRS], Sokolow-Lyon, Romhilt-Estes, Perúgia e padrão strain mostraram alto poder discriminatório no diagnóstico de HVE entre homens e mulheres nos três grupos de HVE, com desempenho superior na população masculina e destaque para os escores [(S + R) X QRS] e Perúgia. CONCLUSÃO: A sensibilidade diagnóstica do ECG é maior com o aumento da massa cardíaca. O exame é mais sensível entre homens, destacando-se os escores [(S + R) X QRS] e Perúgia. Abstract in english BACKGROUND: Several factors are known to interfere with electrocardiogram (ECG) sensitivity when diagnosing Left Ventricular Hypertrophy (LVH), with gender and cardiac mass being two of the most important ones OBJECTIVE: To evaluate the influence of gender on the sensitivity of some of the criteria [...] used to detect LVH, according to the progression of ventricular hypertrophy degree. METHODS: According to gender and the degree of LVH at the echocardiogram, the patients were divided in three groups: mild, moderate and severe LVH. ECG sensitivity to detect LVH was assessed between men and women, according to the LVH degree. RESULTS: Of the 874 patients, 265 were males (30.3%) and 609, females (69.7%). The [(S + R) X QRS], Sokolow-Lyon, Romhilt-Estes, Perugia and strain criteria showed high discriminatory power in the diagnosis of LVH between men and women in the three groups with LVH, with a superior performance in the male population and highlighting the importance of the [(S + R) X QRS] and Perugia scores. Conclusion: The diagnostic sensitivity of the ECG increases with the cardiac mass. The examination is more sensitive in men, highlighting the importance of the [(S + R) X QRS] and Perugia scores. CONCLUSION: The diagnostic sensitivity of the ECG increases with the cardiac mass. The examination is more sensitive in men, highlighting the importance of the [(S + R) X QRS] and Perugia scores.

Ana P., Colossimo; Francisco de Assis, Costa; Andrés R. P., Riera; Maria T. N., Bombig; Valter C., Lima; Francisco A. H., Fonseca; Maria C. O., Izar; Bráulio, L. Filho; Dilma, Souza; Rui M. S., Povoa.

2011-09-01

225

Sensibilidade do eletrocardiograma na hipertrofia ventricular de acordo com gênero e massa cardíaca Electrocardiogram sensitivity in left ventricular hypertrophy according to gender and cardiac mass  

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Full Text Available FUNDAMENTO: Sabe-se que vários fatores interferem na sensibilidade do Eletrocardiograma (ECG no diagnóstico da Hipertrofia Ventricular Esquerda (HVE, sendo o gênero e a massa cardíaca alguns dos principais. OBJETIVO: Avaliar a influência do sexo na sensibilidade de alguns dos critérios utilizados para a detecção de HVE, de acordo com a progressão do grau de hipertrofia ventricular. MÉTODOS: De acordo com o gênero e com o grau de HVE ao ecocardiograma, os pacientes foram divididos em três grupos: HVE leve, moderada e severa. Avaliou-se a sensibilidade do ECG para detectar HVE entre homens e mulheres, conforme o grau de HVE. RESULTADOS: Dos 874 pacientes, 265 eram homens (30,3% e 609, mulheres (69,7%. Os critérios [(S + R X QRS], Sokolow-Lyon, Romhilt-Estes, Perúgia e padrão strain mostraram alto poder discriminatório no diagnóstico de HVE entre homens e mulheres nos três grupos de HVE, com desempenho superior na população masculina e destaque para os escores [(S + R X QRS] e Perúgia. CONCLUSÃO: A sensibilidade diagnóstica do ECG é maior com o aumento da massa cardíaca. O exame é mais sensível entre homens, destacando-se os escores [(S + R X QRS] e Perúgia.BACKGROUND: Several factors are known to interfere with electrocardiogram (ECG sensitivity when diagnosing Left Ventricular Hypertrophy (LVH, with gender and cardiac mass being two of the most important ones OBJECTIVE: To evaluate the influence of gender on the sensitivity of some of the criteria used to detect LVH, according to the progression of ventricular hypertrophy degree. METHODS: According to gender and the degree of LVH at the echocardiogram, the patients were divided in three groups: mild, moderate and severe LVH. ECG sensitivity to detect LVH was assessed between men and women, according to the LVH degree. RESULTS: Of the 874 patients, 265 were males (30.3% and 609, females (69.7%. The [(S + R X QRS], Sokolow-Lyon, Romhilt-Estes, Perugia and strain criteria showed high discriminatory power in the diagnosis of LVH between men and women in the three groups with LVH, with a superior performance in the male population and highlighting the importance of the [(S + R X QRS] and Perugia scores. Conclusion: The diagnostic sensitivity of the ECG increases with the cardiac mass. The examination is more sensitive in men, highlighting the importance of the [(S + R X QRS] and Perugia scores. CONCLUSION: The diagnostic sensitivity of the ECG increases with the cardiac mass. The examination is more sensitive in men, highlighting the importance of the [(S + R X QRS] and Perugia scores.

Ana P. Colossimo

2011-09-01

226

Hipertrofia ventricular e mortalidade cardiovascular em pacientes de hemodiálise de baixo nível educacional Hipertrofia ventricular y mortalidad cardiovascular en pacientes de hemodiálisis de bajo nivel educativo Ventricular hypertrophy and cardiovascular mortality in hemodialysis patients with low educational level  

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Full Text Available FUNDAMENTO: A hipertrofia ventricular esquerda é potente preditor de mortalidade em renais crônicos. Estudo prévio de nosso grupo mostrou que renais crônicos com menor escolaridade têm hipertrofia ventricular mais intensa. OBJETIVO: Ampliar estudo prévio e verificar se a hipertrofia ventricular esquerda pode justificar a associação entre escolaridade e mortalidade cardiovascular de pacientes em hemodiálise. MÉTODOS: Foram avaliados 113 pacientes entre janeiro de 2005 e março de 2008 e seguidos até outubro de 2010. Foram traçadas curvas de sobrevida comparando a mortalidade cardiovascular, e por todas as causas dos pacientes com escolaridade de até três anos (mediana da escolaridade e pacientes com escolaridade igual ou superior a quatro anos. Foram construídos modelos múltiplos de Cox ajustados para as variáveis de confusão. RESULTADOS: Observou-se associação entre nível de escolaridade e hipertrofia ventricular. A diferença estatística de mortalidade de origem cardiovascular e por todas as causas entre os diferentes níveis de escolaridade ocorreu aos cinco anos e meio de seguimento. No modelo de Cox, a hipertrofia ventricular e a proteína-C reativa associaram-se à mortalidade por todas as causas e de origem cardiovascular. A etiologia da insuficiência renal associou-se à mortalidade por todas as causas e a creatinina associou-se à mortalidade de origem cardiovascular. A associação entre escolaridade e mortalidade perdeu significância estatística no modelo ajustado. CONCLUSÃO: Os resultados do presente trabalho confirmam estudo prévio e demonstram, ademais, que a maior mortalidade cardiovascular observada nos pacientes com menor escolaridade pôde ser explicada por fatores de risco de ordem bioquímica e de morfologia cardíaca.FUNDAMENTO: La hipertrofia ventricular izquierda es potente predictor de mortalidad en renales crónicos. Estudio previo de nuestro grupo mostró que renales crónicos con menor escolaridad tienen hipertrofia ventricular más intensa. OBJETIVO: Ampliar estudio previo y verificar si la hipertrofia ventricular izquierda puede justificar la asociación entre escolaridad y mortalidad cardiovascular de pacientes en hemodiálisis. MÉTODOS: Fueron evaluados 113 pacientes entre enero de 2005 y marzo de 2008 y seguidos hasta octubre de 2010. Fueron trazadas curvas de sobrevida comparando la mortalidad cardiovascular, y por todas las causas de los pacientes con escolaridad de hasta tres años (mediana de la escolaridad y pacientes con escolaridad igual o superior a cuatro años. Fueron construidos modelos múltiples de Cox ajustados para las variables de confusión. RESULTADOS: Se observó asociación entre nivel de escolaridad e hipertrofia ventricular. La diferencia estadística de mortalidad de origen cardiovascular y por todas las causas entre los diferentes niveles de escolaridad ocurrió a los cinco años y medio de seguimiento. En el modelo de Cox, la hipertrofia ventricular y la proteína-C reactiva se asociaron a la mortalidad por todas las causas y de origen cardiovascular. La etiología de la insuficiencia renal se asoció a la mortalidad por todas las causas y la creatinina se asoció a la mortalidad de origen cardiovascular. La asociación entre escolaridad y mortalidad perdió significación estadística en el modelo ajustado. CONCLUSÓN: Los resultados del presente trabajo confirman estudio previo y demuestran, además, que la mayor mortalidad cardiovascular observada en los pacientes con menor escolaridad puede ser explicada por factores de riesgo de orden bioquímico y de morfología cardíaca.BACKGROUND: Left ventricular hypertrophy is a strong predictor of mortality in chronic kidney patients. A previous study of our group has shown that chronic kidney patients with low educational level has more severe ventricular hypertrophy. OBJECTIVE: To extend a previous study and to assess whether left ventricular hypertrophy can explain the association between schooling and cardiovascular mortality in hemodialysis patients. METHODS: This stud

Rosana dos Santos e Silva Martin

2012-01-01

227

p21-Activated kinase1 (Pak1) is a negative regulator of NADPH-oxidase 2 in ventricular myocytes.  

Science.gov (United States)

Ischemic conditions reduce the activity of the p21-activated kinase (Pak1) resulting in increased arrhythmic activity. Triggered arrhythmic activity during ischemia is based on changes in cellular ionic balance and the cells Ca(2+) handling properties. In the current study we used isolated mouse ventricular myocytes (VMs) deficient for the expression of Pak1 (Pak1(-/-)) to determine the mechanism by which Pak1 influences the generation of arrhythmic activity during simulated ischemia. The Ca(2+) transient amplitude and kinetics did not significantly change in wild type (WT) and Pak1(-/-) VMs during 15 min of simulated ischemia. However, Pak1(-/-) VMs exhibited an exaggerated increase in [Ca(2+)]i, which resulted in spontaneous Ca(2+) release events and waves. The Ca(2+) overload in Pak1(-/-) VMs could be suppressed with a reverse mode blocker (KB-R7943) of the sodium calcium exchanger (NCX), a cytoplasmic scavenger of reactive oxygen species (ROS; TEMPOL) or a RAC1 inhibitor (NSC23766). Measurements of the cytoplasmic ROS levels revealed that decreased Pak1 activity in Pak1(-/-) VMs or VMs treated with the Pak1 inhibitor (IPA3) enhanced cellular ROS production. The Pak1 dependent increase in ROS was attenuated in VMs deficient for NADPH oxidase 2 (NOX2; p47(phox-/-)) or in VMs where NOX2 was inhibited (gp91ds-tat). Voltage clamp recordings showed increased NCX activity in Pak1(-/-) VMs that depended on enhanced NOX2 induced ROS production. The exaggerated Ca(2+) overload in Pak1(-/-) VMs could be mimicked by low concentrations of ouabain. Overall our data show that Pak1 is a critical negative regulator of NOX2 dependent ROS production and that a latent ROS dependent stimulation of NCX activity can predispose VMs to Ca(2+) overload under conditions where no significant changes in excitation-contraction coupling are yet evident. PMID:24380729

DeSantiago, Jaime; Bare, Dan J; Xiao, Lei; Ke, Yunbo; Solaro, R John; Banach, Kathrin

2014-02-01

228

Saturated but not mono-unsaturated fatty acids induce apoptotic cell death in neonatal rat ventricular myocytes.  

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The energy need of cardiac muscle cells in vivo is largely covered by the oxidation of saturated and mono-unsaturated fatty acids (FA). However, in vitro studies have shown that the saturated FA C16:0 at physiological concentrations exerts detrimental effects on primary cultures of neonatal rat ventricular myocytes by, as yet, unknown mechanisms. To evaluate the noxious effects of FA in more detail, neonatal cardiomyocytes were exposed to saturated (C16:0; C18:0) or mono-unsaturated (C16:1; cis-C18:1; trans-C18:1) FA, or combinations thereof for up to 48 h. FA (0.5 mM) complexed to bovine serum albumin (BSA) (0.15 mM) were added to a glucose-containing defined medium. Irrespective of the length and degree of unsaturation of the aliphatic chain, FA supplied to the cells were readily incorporated in the phospholipid pool. In the presence of mono-unsaturated FA, cardiomyocytes remained healthy and accumulated substantial amounts of triacylglycerol. In contrast, within 24 h after application of the saturated FA C16:0 or C18:0, cells had become irreversibly damaged, as evidenced by the presence of pyknotic nuclei and massive release of the cytosolic markers lactate dehydrogenase (LDH) and fatty acid-binding protein (FABP). Moreover, the occurrence of DNA-laddering indicated that apoptosis was involved. Induction of apoptotic cell death by C16:0 was counteracted by the co-administration of equimolar amounts of cis-C18:1, whereas trans-C18:1 delayed, but did not prevent, loss of cardiomyocyte viability. The present findings suggest that the incorporation of saturated, but not mono-unsaturated, fatty acids induces alterations in the phospholipid membrane, which initiate apoptotic cell death in neonatal cardiomyocytes. PMID:9254064

de Vries, J E; Vork, M M; Roemen, T H; de Jong, Y F; Cleutjens, J P; van der Vusse, G J; van Bilsen, M

1997-07-01

229

Characteristics of left ventricular hypertrophy estimated by MIBG and BMIPP cardiac scintigraphy in patients undergoing peritoneal dialysis  

International Nuclear Information System (INIS)

Left ventricular hypertrophy (LVH) has been reported as a major factor in morbidity and mortality in chronic dialysis patients. However, cardiovascular mortality in peritoneal dialysis (PD) patients with LVH is substantially similar to that in hemodialysis (HD) patients. The present study sought to study whether sympathetic nerve activity and fatty acid metabolism of the myocardium estimated by 123I metaiodobenzylguanidine (MIBG) and 123I ?-methyl-p-iodophenyl-pentadecanoic acid (BMIPP) myocardial scintigraphy are impaired or not in PD patients with LVH. The underlying disease of 45 PD patients enrolled in this study was chronic glomerulonephritis in all cases. Serum levels of natriuretic peptides (arterial natriuretic peptide (ANP), brain natriuretic peptide (BNP)) and free carnitine and MIBG, BMIPP myocardial scintigraphy and 2-dimensional echocardiography were measured in these 45 PD patients. The following results were obtained. The prevalence of increased left ventricular mass index (LVMI) was 84.4%. LVMI correlated with age, and serum levels of ANP and BNP, and inversely correlated with a heart-to-mediastinum ratio (H/M) estimated by MIBG and BMIPP myocardial scintigraphy. Percentages of the normal image of MIBG and BMIPP measured with a single photon emission computed tomography (SPECT) were 37.8% and 62.2%, respectively. The PD patients showing the diffuse defect of MIBG or BMIPP imaging had the decrease in left ventricular ejection fracecrease in left ventricular ejection fraction (LVEF). Especially, the serum level of free carnitine was reduced in the PD patients with diffuse defect of BMIPP SPECT. From these results, we concluded that PD patients with LVH showed impaired sympathetic nerve activity and fatty acid metabolism of the myocardium. Metabolic and functional disturbances of the myocardium may influence mortality in PD patients. (author)

230

Comparison of usefulness of Sokolow and Cornell criteria for left ventricular hypertrophy in subjects aged 30 years.  

Science.gov (United States)

The use of electrocardiography in sports or military screening is considered an effective tool for diagnosing potentially fatal conditions. The present study was designed to compare the yield of electrocardiographic criteria for left ventricular hypertrophy (LVH) criteria for the diagnosis of LVH and hypertrophic obstructive cardiomyopathy in subjects aged 30 years. The association between the electrocardiographic (ECG) criteria for LVH (ECG-LVH) and echocardiographic findings was compared in 4 groups of air force academy candidates: (1) young candidates undergoing echocardiography because of ECG-LVH findings (n = 666); (2) young candidates without ECG-LVH findings undergoing routine echocardiography (n = 4,043); (3) older designated aviators undergoing echocardiography because of ECG-LVH findings (n = 196); and (4) older designated aviators undergoing routine echocardiography without ECG-LVH findings (n = 1,098). The predictive value of ECG-LVH findings for echocardiographic LVH, left ventricular mass, posterior wall thickness, and interventricular septal thickness were compared among the 4 groups. The ECG criteria in young subjects correlated with the left ventricular mass and posterior wall thickness but not with the interventricular septal thickness. In older subjects, these criteria correlated with left ventricular mass, interventricular septal, and posterior wall thickness. The positive and negative predictive value of ECG-LVH findings for the echocardiographic diagnosis of LVH in young subjects was 6.0% and 99.0%, respectively. In older subjects the positive and negative predictive value of ECG-LVH findings was 34% and 93%, respectively. In conclusion, ECG criteria are probably a useful tool for exclusion of LVH in young and older subjects; however, their low positive predictive value would probably lead to unnecessary echocardiographic tests, particularly in young subjects. PMID:22534054

Grossman, Alon; Prokupetz, Alex; Koren-Morag, Nira; Grossman, Ehud; Shamiss, Ari

2012-08-01

231

Isolation and study of cardiac nuclei from canine myocardium and adult ventricular myocytes.  

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The nuclear envelope encloses the genome as well as the molecular machinery responsible for both the replication and transcription of DNA as well as the maturation of nascent RNA. Recent studies ascribe a growing number of functions to the nuclear membrane, in addition to sequestering the DNA, through receptors and their effectors, ion channels, as well as ion pumps and transporters located within the nuclear membrane itself. Despite the obvious structural and functional importance of the nucleus, certain aspects remain poorly understood due to the challenges associated with its accessibility in vivo, as well as isolating nuclei intact and with sufficient purity from cardiac cells to permit studies in vitro. Here, we present a detailed protocol for isolation of intact nuclei from both myocardial tissue and freshly isolated adult ventricular cardiomyocytes. These methods are based on partial permeabilization of plasma membrane with digitonin and cell disruption, followed by differential and discontinuous sucrose density centrifugation. These preparations provide for rapid separation of nonnuclear membranes and cytosol from nuclei. PMID:25304349

Tadevosyan, Artavazd; Allen, Bruce G; Nattel, Stanley

2015-01-01

232

Histopathological study of time course changes in inter-renal aortic banding-induced left ventricular hypertrophy of mice  

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The left ventricular hypertrophy (LVH) in response to pressure overload is an important risk factor in cardiac morbidity and mortality. To investigate the time course of histopathological alterations in the LVH in response to pressure overload, histopathological and immunohistochemical examination was performed using the aortic banding-induced mouse LVH model. Five-week-old male CD-1 mice were subjected to the inter-renal aortic banding. Major organs were sampled on 3, 10, 14, 21, 28 or 42 days after banding. Haematoxylin and eosin (H&E) staining, Masson's trichrome staining and immunohistochemistry for proliferating cell nuclear antigen (PCNA), alpha-smooth muscle actin (aSMA), ICAM-1, type I collagen and CD31 was performed and microscopically examined. Three days after aortic banding, acute inflammatory changes, such as macrophages/neutrophil infiltration and vascular wall injury were observed on/around the coronary arteries/arterioles of both ventricles. Intense ICAM-1 immunostaining was observed on the endothelium of the coronary arteries/arterioles. After day 10, vascular wall thickening and perivascular fibrosis was induced on the coronary arteries/arterioles. Immunohistochemistry for aSMA and PCNA demonstrated the proliferation of vascular smooth muscle cells in the media. After day 28, minimal cardiomyocyte hypertrophy was observed at the light microscope level. In the inter-renal aortic banding LVH model, histopathological alterations in early phase were mainly observed on coronary arteries/arterioles. These early phase alterations were thought to be hypertension-related changes in the coronary vasculatures. The cardiomyocyte hypertrophy observed in later phase was minimal at the light microscope level. These evidences would facilitate the understanding of pathophysiology of pressure overload LVH. PMID:17244336

Higashiyama, Hiroyuki; Sugai, Masaki; Inoue, Hirotaka; Mizuyachi, Kaori; Kushida, Hiroshi; Asano, Satoshi; Kinoshita, Mine

2007-01-01

233

Sildenafil attenuates pulmonary inflammation and fibrin deposition, mortality and right ventricular hypertrophy in neonatal hyperoxic lung injury  

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Full Text Available Abstract Background Phosphodiesterase-5 inhibition with sildenafil has been used to treat severe pulmonary hypertension and bronchopulmonary dysplasia (BPD, a chronic lung disease in very preterm infants who were mechanically ventilated for respiratory distress syndrome. Methods Sildenafil treatment was investigated in 2 models of experimental BPD: a lethal neonatal model, in which rat pups were continuously exposed to hyperoxia and treated daily with sildenafil (50–150 mg/kg body weight/day; injected subcutaneously and a neonatal lung injury-recovery model in which rat pups were exposed to hyperoxia for 9 days, followed by 9 days of recovery in room air and started sildenafil treatment on day 6 of hyperoxia exposure. Parameters investigated include survival, histopathology, fibrin deposition, alveolar vascular leakage, right ventricular hypertrophy, and differential mRNA expression in lung and heart tissue. Results Prophylactic treatment with an optimal dose of sildenafil (2 × 50 mg/kg/day significantly increased lung cGMP levels, prolonged median survival, reduced fibrin deposition, total protein content in bronchoalveolar lavage fluid, inflammation and septum thickness. Treatment with sildenafil partially corrected the differential mRNA expression of amphiregulin, plasminogen activator inhibitor-1, fibroblast growth factor receptor-4 and vascular endothelial growth factor receptor-2 in the lung and of brain and c-type natriuretic peptides and the natriuretic peptide receptors NPR-A, -B, and -C in the right ventricle. In the lethal and injury-recovery model we demonstrated improved alveolarization and angiogenesis by attenuating mean linear intercept and arteriolar wall thickness and increasing pulmonary blood vessel density, and right ventricular hypertrophy (RVH. Conclusion Sildenafil treatment, started simultaneously with exposure to hyperoxia after birth, prolongs survival, increases pulmonary cGMP levels, reduces the pulmonary inflammatory response, fibrin deposition and RVH, and stimulates alveolarization. Initiation of sildenafil treatment after hyperoxic lung injury and continued during room air recovery improves alveolarization and restores pulmonary angiogenesis and RVH in experimental BPD.

Boersma Hester

2009-04-01

234

Left Ventricular Hypertrophy Is Associated with Diastolic Filling Alterations in Normotensive Offspring of Hypertensive Nigerians  

OpenAIRE

Contribution of left ventricular diastolic dysfunction to adverse events in patients with cardiovascular diseases is increasingly being recognized and individuals with pedigree for hypertension are thought to exhibit anatomic and or functional changes in their left ventricle before they become hypertensive. This study aimed at characterizing left ventricular diastolic function in normotensive offspring of hypertensive Nigerians. Sixty-five offspring of hypertensive parents aged 15–25 years ...

Ogunmodede, J. A.; Soladoye, A.; Omotoso, A. B.; Sanya, E. O.; Kolo, P. M.

2012-01-01

235

Fendiline inhibits L-type calcium channels in guinea-pig ventricular myocytes: a whole-cell patch-clamp study.  

OpenAIRE

1. Fendiline, a diphenylalkylamine type of antianginal drug, was examined for its effects on L-type calcium channels in guinea-pig ventricular myocytes by the whole-cell patch-clamp technique. 2. Fendiline (0.3-100 microM) applied extracellularly inhibited the calcium channel current (ICa) in a concentration- and time-dependent manner. The IC50 of fendiline was 17.0 +/- 2.43 microM and the Hill slope was 1.39 +/- 0.23. 3. Inhibition of ICa by fendiline appeared with an onset of less than 3 s....

Tripathi, O.; Schreibmayer, W.; Tritthart, H. A.

1993-01-01

236

Accuracy of advanced versus strictly conventional 12-lead ECG for detection and screening of coronary artery disease, left ventricular hypertrophy and left ventricular systolic dysfunction  

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Full Text Available Abstract Background Resting conventional 12-lead ECG has low sensitivity for detection of coronary artery disease (CAD and left ventricular hypertrophy (LVH and low positive predictive value (PPV for prediction of left ventricular systolic dysfunction (LVSD. We hypothesized that a ~5-min resting 12-lead advanced ECG test ("A-ECG" that combined results from both the advanced and conventional ECG could more accurately screen for these conditions than strictly conventional ECG. Methods Results from nearly every conventional and advanced resting ECG parameter known from the literature to have diagnostic or predictive value were first retrospectively evaluated in 418 healthy controls and 290 patients with imaging-proven CAD, LVH and/or LVSD. Each ECG parameter was examined for potential inclusion within multi-parameter A-ECG scores derived from multivariate regression models that were designed to optimally screen for disease in general or LVSD in particular. The performance of the best retrospectively-validated A-ECG scores was then compared against that of optimized pooled criteria from the strictly conventional ECG in a test set of 315 additional individuals. Results Compared to optimized pooled criteria from the strictly conventional ECG, a 7-parameter A-ECG score validated in the training set increased the sensitivity of resting ECG for identifying disease in the test set from 78% (72-84% to 92% (88-96% (P Conclusion Resting 12-lead A-ECG scoring is more accurate than strictly conventional ECG in screening for CAD, LVH and LVSD.

Warren Stafford G

2010-06-01

237

Diverse effects of renal denervation on ventricular hypertrophy and blood pressure in DOCA-salt hypertensive rats  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Cardiac hypertrophy that accompanies hypertension seems to be a phenomenon of multifactorial origin whose development does not seem to depend on an increased pressure load alone, but also on local growth factors and cardioadrenergic activity. The aim of the present study was to determine if sympathe [...] tic renal denervation and its effects on arterial pressure level can prevent cardiac hypertrophy and if it can also delay the onset and attenuate the severity of deoxycorticosterone acetate (DOCA)-salt hypertension. DOCA-salt treatment was initiated in rats seven days after uninephrectomy and contralateral renal denervation or sham renal denervation. DOCA (15 mg/kg, sc) or vehicle (soybean oil, 0.25 ml per animal) was administered twice a week for two weeks. Rats treated with DOCA or vehicle (control) were provided drinking water containing 1% NaCl and 0.03% KCl. At the end of the treatment period, mean arterial pressure (MAP) and heart rate measurements were made in conscious animals. Under ether anesthesia, the heart was removed and the right and left ventricles (including the septum) were separated and weighed. DOCA-salt treatment produced a significant increase in left ventricular weight/body weight (LVW/BW) ratio (2.44 ± 0.09 mg/g) and right ventricular weight/body weight (RVW/BW) ratio (0.53 ± 0.01 mg/g) compared to control (1.92 ± 0.04 and 0.48 ± 0.01 mg/g, respectively) rats. MAP was significantly higher (39%) in DOCA-salt rats. Renal denervation prevented (P>0.05) the development of hypertension in DOCA-salt rats but did not prevent the increase in LVW/BW (2.27 ± 0.03 mg/g) and RVW/BW (0.52 ± 0.01 mg/g). We have shown that the increase in arterial pressure level is not responsible for cardiac hypertrophy, which may be more related to other events associated with DOCA-salt hypertension, such as an increase in cardiac sympathetic activity

A.M., Cabral; I.F., Silva; C.R., Gardioli; H., Mauad; E.C., Vasquez.

1998-04-01

238

Characteristics of left ventricular hypertrophy estimated by MIBG and BMIPP cardiac scintigraphy in patients undergoing peritoneal dialysis  

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Left ventricular hypertrophy (LVH) has been reported as a major factor in morbidity and mortality in chronic dialysis patients. However, cardiovascular mortality in peritoneal dialysis (PD) patients with LVH is substantially similar to that in hemodialysis (HD) patients. The present study sought to study whether sympathetic nerve activity and fatty acid metabolism of the myocardium estimated by {sup 123}I metaiodobenzylguanidine (MIBG) and {sup 123}I {beta}-methyl-p-iodophenyl-pentadecanoic acid (BMIPP) myocardial scintigraphy are impaired or not in PD patients with LVH. The underlying disease of 45 PD patients enrolled in this study was chronic glomerulonephritis in all cases. Serum levels of natriuretic peptides (arterial natriuretic peptide (ANP), brain natriuretic peptide (BNP)) and free carnitine and MIBG, BMIPP myocardial scintigraphy and 2-dimensional echocardiography were measured in these 45 PD patients. The following results were obtained. The prevalence of increased left ventricular mass index (LVMI) was 84.4%. LVMI correlated with age, and serum levels of ANP and BNP, and inversely correlated with a heart-to-mediastinum ratio (H/M) estimated by MIBG and BMIPP myocardial scintigraphy. Percentages of the normal image of MIBG and BMIPP measured with a single photon emission computed tomography (SPECT) were 37.8% and 62.2%, respectively. The PD patients showing the diffuse defect of MIBG or BMIPP imaging had the decrease in left ventricular ejection fraction (LVEF). Especially, the serum level of free carnitine was reduced in the PD patients with diffuse defect of BMIPP SPECT. From these results, we concluded that PD patients with LVH showed impaired sympathetic nerve activity and fatty acid metabolism of the myocardium. Metabolic and functional disturbances of the myocardium may influence mortality in PD patients. (author)

Ohashi, Hiroshige; Oda, Hiroshi; Ohno, Michiya; Watanabe, Sachirow; Kotoo, Yasunori; Matsuno, Yukihiko [Gifu Prefectural Hospital (Japan)

2002-12-01

239

Sarcolemmal ion currents and sarcoplasmic reticulum Ca2+ content in ventricular myocytes from the cold stenothermic fish, the burbot (Lota lota).  

Science.gov (United States)

The burbot (Lota lota) is a cold stenothermic fish species whose heart is adapted to function in the cold. In this study we use whole-cell voltage-clamp techniques to characterize the electrophysiological properties of burbot ventricular myocytes and to test the hypothesis that changes in membrane currents and intracellular Ca2+ cycling associated cold-acclimation in other fish species are routine for stenothermic cold-adapted species. Experiments were performed at 4 degrees C, which is the body temperature of burbot for most of the year, and after myocytes were acutely warmed to 11 degrees C, which is in the upper range of temperatures experienced by burbot in nature. Results on K+ channels support our hypothesis as the relative density of K-channel conductances in the burbot heart are similar to those found for cold-acclimated cold-active fish species. I(K1) conductance was small (39.2+/-5.4 pS pF(-1) at 4 degrees C and 71.4+/-1.7 pS pF(-1) at 11 degrees C) and I(Kr) was large (199+/-27 pS pF(-1) at 4 degrees C and 320.3+/-8 pS pF(-1) at 11 degrees C) in burbot ventricular myocytes. We found high Na+-Ca2+ exchange (NCX) activity (35.9+/-6.3 pS pF(-1) at 4 degrees C and 58.6+/-8.4 pS pF(-1) at 11 degrees C between -40 and 20 mV), suggesting that it may be the primary pathway for sarcolemmal (SL) Ca2+ influx in this species. In contrast, the density (I(Ca), 0.81+/-0.13 pA pF(-1) at 4 degrees C, and 1.35+/-0.18 pA pF(-1) at 11 degrees C) and the charge (Q(Ca), 0.24+/-0.043 pC pF(-1) at 4 degrees C and 0.21+/-0.034 pC pF(-1) at 11 degrees C) carried by the L-type Ca2+ current was small. Our results on sarcolemmal ion currents in burbot ventricular myocytes suggest that cold stenothermy and compensative cold-acclimation involve many of the same subcellular adaptations that culminate in enhanced excitability in the cold. PMID:16888058

Shiels, Holly A; Paajanen, Vesa; Vornanen, Matti

2006-08-01

240

Usefulness of QRS voltage correction by body mass index to improve electrocardiographic detection of left ventricular hypertrophy in patients with systemic hypertension.  

Science.gov (United States)

Obesity reduces the accuracy of voltage-based electrocardiographic (ECG) criteria for diagnosis of left ventricular (LV) hypertrophy. We developed a new ECG score for diagnosis of LV hypertrophy, defined either by a typical strain pattern or a product of the Cornell voltage (R wave height in lead aVL plus S wave depth in lead V3) by body mass index >604 mm?kg/m(2). We examined a population of 2,747 untreated hypertensive subjects (mean age 49 ± 11 years) with good quality ECG and echocardiographic tracings. Several traditional ECG criteria for LV hypertrophy were compared with the new score, with echocardiographic LV mass taken as reference. Among the tested criteria, the highest sensitivity combined with specificity was yielded by the new score (sensitivity 36.1%, 95% confidence interval [CI] 32.9 to 39.4; specificity 90.5%, 95% CI 89.1 to 91.8; and accuracy 73.1%, 95% CI 71.5 to 74.8). Prevalence of ECG LV hypertrophy with the new score was 18%. On the basis of comparisons between areas under the receiver operating characteristic curves, the best performance was achieved by the new score with respect to other ECG criteria for LV hypertrophy (all p <0.0001). In conclusion, correction of Cornell voltage by body mass index as a marker of obesity improves the performance of traditional electrocardiography for diagnosis of LV hypertrophy in patients with hypertension. PMID:24934758

Angeli, Fabio; Verdecchia, Paolo; Iacobellis, Gianluca; Reboldi, Gianpaolo

2014-08-01

241

Relationship between L-type Ca2+ current and unitary sarcoplasmic reticulum Ca2+ release events in rat ventricular myocytes.  

Science.gov (United States)

1. The time courses of Ca2+ current and Ca2+ spark occurrence were determined in single rat ventricular myocytes voltage clamped with patch pipettes containing 0.1 microM fluo-3. Acquisition of line-scan images on a laser scanning confocal microscope was synchronized with measurement of Cd2+-sensitive Ca2+ currents. In most cells, individual Ca2+ sparks were observed by reducing Ca2+ current density with nifedipine (0.1-8 microM). 2. Ca2+ sparks elicited by depolarizing voltage-clamp pulses had a peak [Ca2+] amplitude of 289 +/- 3 nM with a decay half-time of 20.8 +/- 0.2 ms and a full width at half-maximum of 1.40 +/- 0.03 microm (mean +/- s. e.m., n = 345), independent of the membrane potential. 3. The time between the beginning of a depolarization and the initiation of each Ca2+ spark was calculated and data were pooled to construct waiting time histograms. Exponential functions were fitted to these histograms and to the decaying phase of the Ca2+ current. This analysis showed that the time constants describing Ca2+ current and Ca2+ spark occurrence at membrane potentials between -30 mV and +30 mV were not significantly different. At +50 mV, in the absence of nifedipine, the time constant describing Ca2+ spark occurrence was significantly larger than the time constant of the Ca2+ current. 4. A simple model is developed using Poisson statistics to relate macroscopic Ca2+ current to the opening of single L-type Ca2+ channels at the dyad junction and to the time course of Ca2+ spark occurrence. The model suggests that the time courses of macroscopic Ca2+ current and Ca2+ spark occurrence should be closely related when opening of a single L-type Ca2+ channel initiates a Ca2+ spark. By comparison with the data, the model suggests that Ca2+ sparks are initiated by the opening of a single L-type Ca2+ channel at all membrane potentials encountered during an action potential. PMID:10066927

Collier, M L; Thomas, A P; Berlin, J R

1999-04-01

242

Statistical analysis of the angle of intrusion of porcine ventricular myocytes from epicardium to endocardium using diffusion tensor magnetic resonance imaging.  

Science.gov (United States)

Pairs of cylindrical knives were used to punch semicircular slices from the left basal, sub-basal, equatorial, and apical ventricular wall of porcine hearts. The sections extended from the epicardium to the endocardium. Their semicircular shape compensated for the depth-related changing orientation of the myocytes relative to the equatorial plane. The slices were analyzed by diffusion tensor magnetic resonance imaging. The primary eigenvector of the diffusion tensor was determined in each pixel to calculate the number and angle of intrusion of the long axis of the aggregated myocytes relative to the epicardial surface. Arrays of axially sectioned aggregates were found in which 53% of the approximately two million segments evaluated intruded up to +/-15 degrees , 40% exhibited an angle of intrusion between +/-15 degrees and +/-45 degrees , and 7% exceeded an angle of +/-45 degrees , the positive sign thereby denoting an epi- to endocardial spiral in clockwise direction seen from the apex, while a negative sign denotes an anticlockwise spiral from the epicardium to the endocardium. In the basal and apical slices, the greater number of segments intruded in positive direction, while in the sub-basal and equatorial slices, negative angles of intrusion prevailed. The sampling of the primary eigenvectors was insensitive to postmortem decomposition of the tissue. In a previous histological study, we also documented the presence of large numbers of myocytes aggregated with their long axis intruding obliquely from the epicardial to the endocardial ventricular surfaces. We used magnetic resonance diffusion tensor imaging in this study to provide a comprehensive statistical analysis. PMID:17929275

Schmid, Peter; Lunkenheimer, Paul P; Redmann, Klaus; Rothaus, Kai; Jiang, Xiaoyi; Cryer, Colin W; Jaermann, Thomas; Niederer, Peter; Boesiger, Peter; Anderson, Robert H

2007-11-01

243

Extracellular Superoxide Dismutase Deficiency Exacerbates Pressure Overload–Induced Left Ventricular Hypertrophy and Dysfunction  

OpenAIRE

Extracellular superoxide dismutase (SOD) contributes only a small fraction to total SOD activity in the normal heart but is strategically located to scavenge free radicals in the extracellular compartment. To examine the physiological significance of extracellular SOD in the response of the heart to hemodynamic stress, we studied the effect of extracellular SOD deficiency on transverse aortic constriction (TAC)-induced left ventricular remodeling. Under unstressed conditions extracellular SOD...

Lu, Z.; Xu, X.; Hu, X.; Zhu, G.; Zhang, P.; Deel, E. D.; French, J. P.; Fassett, J. T.; Oury, T. D.; Bache, R. J.; Chen, Y. J.

2007-01-01

244

Structural and functional consequences of minoxidil-induced cardiac hypertrophy.  

Science.gov (United States)

Minoxidil, a potent arteriolar vasodilator, is used clinically as an antihypertensive agent, providing blood pressure control in patients who are resistant to conventional drug therapy. In spite of its antihypertensive effects, however, minoxidil treatment does not result in regression of cardiac hypertrophy. Laboratory studies have shown that minoxidil treatment actually causes cardiac enlargement when administered to normotensive animals. The mechanism of minoxidil-induced cardiac hypertrophy and its consequences for the myocardium have not been determined. Because cardiac hypertrophy is a significant independent risk factor for cardiovascular morbidity and mortality, it is important to understand this dissociation between blood pressure and cardiac enlargement and also to consider the possible impact of such findings on the clinical use of minoxidil. In the investigation presented here, we examined the structure and function of cardiac muscle from normotensive rats who developed myocardial hypertrophy after minoxidil treatment. Data demonstrate that minoxidil produces enlargement of the left ventricle, right ventricle and interventricular septum. The right ventricular enlargement produced by minoxidil treatment is due to an increase in myocyte cross-sectional area, a finding which may suggest pressure overload of the right ventricle. Left ventricular and septal enlargement in this model cannot be totally accounted for by an increase in myocyte cross-sectional area, suggesting that minoxidil causes enlargement by a mechanism other than pressure overload in these areas of the heart. Functionally, left ventricular papillary muscles from hearts with minoxidil-induced hypertrophy develop force which is equal to that developed by control muscles, but contract and relax more slowly than muscles from control hearts.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8169836

Moravec, C S; Ruhe, T; Cifani, J R; Milovanovic, M; Khairallah, P A

1994-04-01

245

Whole-exome Sequencing and an iPSC-Derived Cardiomyocyte Model Provides a Powerful Platform for Gene Discovery in Left Ventricular Hypertrophy  

OpenAIRE

Rationale: Left ventricular hypertrophy (LVH) is a heritable predictor of cardiovascular disease, particularly in blacks. Objective: Determine the feasibility of combining evidence from two distinct but complementary experimental approaches to identify novel genetic predictors of increased LV mass. Methods: Whole-exome sequencing (WES) was conducted in seven African-American sibling trios ascertained on high average familial LV mass indexed to height (LVMHT) using Illumina HiSeq technology. I...

Zhi, D.; Irvin, M. R.; Gu, C. C.; Stoddard, A. J.; Lorier, R.; Matter, A.; Rao, D. C.; Srinivasasainagendra, V.; Tiwari, H. K.; Turner, A.; Broeckel, U.; Arnett, D. K.

2012-01-01

246

Detection of incipient left ventricular hypertrophy in mild to moderate arterial hypertension with normal electrocardiogram and echocardiogram: a new use for signal-averaged electrocardiography  

OpenAIRE

OBJECTIVE: To assess signal-averaged electrocardiogram (SAECG) for diagnosing incipient left ventricular hypertrophy (LVH). METHODS: A study with 115 individuals was carried out. The individuals were divided as follows: GI - 38 healthy individuals; GII - 47 individuals with mild to moderate hypertension and normal findings on echocardiogram and ECG; and GIII - 30 individuals with hypertension and documented LVH. The magnitude vector of the SAECG was analyzed with the high-pass cutoff frequenc...

Paulo Ginefra; Barbosa, Eduardo C.; Benchimol-barbosa, P. R.; Bomfim, Alfredo S.; Boghossian, Si?lvia H.; Salgado, Angelo A.; Brasil, Fla?via G.; Freitas, Elizabete A.; Albanesi Filho, Francisco M.

2003-01-01

247

Fixed combination of valsartan and amlodipine: effects on the left ventricular hypertrophy regression, albuminuria reduction and endothelium function in hypertensive patients with metabolic syndrome  

OpenAIRE

Aim. To study effects of fixed combination of valsartan and amlodipine on of left ventricular hypertrophy (LVH) regression, microalbuminuria reduction and endothelium function in hypertensive patients with metabolic syndrome (MS).Materials and methods. 20 hypertensive patients (15 females and 5 males) with metabolic syndrome and a history of previous ineffective antihypertensive therapy were studied. Combined antihypertensive therapy was applied during 12-24 weeks. Amlodipine and valsartan do...

Tarlovskaya, Ye I.; Maksimchuk, N. S.; Ye Sapozhnikova, I.; Malchikova, S. V.

2010-01-01

248

Mutation of the Protein Kinase I Alpha Leucine Zipper Domain Produces Hypertension and Progressive Left Ventricular Hypertrophy: A Novel Mouse Model of Age-Dependent Hypertensive Heart Disease  

OpenAIRE

Hypertensive heart disease causes significant mortality in older patients, yet there is an incomplete understanding of molecular mechanisms that regulate age-dependent hypertensive left ventricular hypertrophy (LVH). Therefore, we tested the hypothesis that the cGMP-dependent protein kinase G I alpha (PKGI?) attenuates hypertensive LVH by evaluating the cardiac phenotype in mice with selective mutations of the PKGI? leucine zipper domain. These leucine zipper mutant (LZM) mice develop basal...

Blanton, Robert M.; Takimoto, Eiki; Aronovitz, Mark; Thoonen, Robrecht; Kass, David A.; Karas, Richard H.; Mendelsohn, Michael E.

2013-01-01

249

Negative association of endothelial nitric oxide gene polymorphism with hypertension in Turkish patients: effect of ecNOS polymorphism on left ventricular hypertrophy  

OpenAIRE

Abstract Background Endothelial nitric oxide synthase produces nitric oxide which is involved in many physiologic regulatory functions. Variable number of tandem repeats in intron 4 of endothelial nitric oxide synthase gene are reported to be associated with blood pressure regulation. Nitric oxide is involved in regulation of cardiomyocyte genes but it is not known If endothelial nitric oxide synthase 4 gene polymorphisms are related with left ventricular hypertrophy. We stud...

Arslan Erol; Barcin Cem; Sezer Murat; Ozbek Ugur; Gokhan, Ekmekci C.; Olcay Ayhan; Boztosun Bilal; Nisanci Yilmaz

2006-01-01

250

The Effects of Cyclic Guanylate Cyclase Stimulation on Right Ventricular Hypertrophy and Failure Alone and in Combination with Phosphodiesterase-5 Inhibition  

DEFF Research Database (Denmark)

BACKGROUND:: We investigated if soluble guanylate cyclase stimulation either alone or in combination with PDE5 inhibition could prevent pressure overload induced right ventricular hypertrophy and failure. METHODS AND RESULTS:: The soluble guanylate cyclase stimulator BAY 41-2272 (BAY, 10 mg/kg/day) either alone or in combination (BAY+SIL) with a PDE5 inhibitor sildenafil (SIL, 100 mg/kg/day) was examined for prevention of right ventricular hypertrophy and failure in Wistar rats (n=73) operated by pulmonary trunk banding (PTB).All treatments failed to inhibit the development of RV hypertrophy and failure. In the BAY and BAY+SIL groups there were an increased mortality. Mean arterial blood pressure was lowered and cardiac output increased in the BAY+SIL group. Systolic RV pressure was increased in the BAY and BAY+SIL group possibly due to an inotropic response and/or increased venous return. CONCLUSIONS:: Stimulation of sGC by BAY 41-2272 alone or in combination with sildenafil failed to prevent the developmentof RV hypertrophy and failure in rats subjected to pulmonary trunk banding. An increased mortality was observed in animals treated by BAY 41-2272 alone and in combination with sildenafil.

Andersen, Asger; Nielsen, Jan MØller

2013-01-01

251

Obesidad central y regresión de hipertrofia ventricular izquierda / Central obesity and left ventricular hypertrophy regression / Obesidade central e regressão da hipertrofia esquerda  

Scientific Electronic Library Online (English)

Full Text Available SciELO Argentina | Language: Spanish Abstract in portuguese Em sujeitos hipertensos, os níveis de pressão arterial per se seriam a principal determinante do desenvolvimento de hiperetrofia ventricular esquerda. Por outra parte, o índice de massa corporal e o perímetro de cintura se associaram em forma lineal, contínua e positiva com o índice de massa ventric [...] ular esquerdo ainda em não hipertensos. Um tratamento insuficiente seria a principal causa da falta de regressão do dano no órgão branco. O objetivo do presente trabalho é determinar o impacto da obesidade central sobre a regressão do índice de massa ventricular esquerdo. Material e métodos: incluíram-se 102 pacientes (p) HTA que concorreram por primeira vez a um consultório especializado em forma consecutiva, mediulhes o índice de massa ventricular esquerdo (IMVE) pelo método de Devereux ao início e logo de pelo menos 1 ano de tratamento. Foram divididos em dois grupos: GA: perímetro cintura (PC) esses valores. Para a análise de estatística se aplicou test t de Students para diferenças de médias e proporções, e se considerou significação estatístico p Abstract in spanish En sujetos hipertensos, los niveles de presión arterial per se serían el principal determinante del desarrollo de hipertrofia ventricular izquierda. Por otra parte, el índice de masa corporal y el perímetro de cintura se han asociado en forma lineal, continua y positiva con elíndice de masa ventricu [...] lar izquierdo aún en no hipertensos. Un tratamiento insuficiente sería la principal causa de falta de regresión del daño en órgano blanco. El objetivo del presente trabajo es determinar el impacto de la obesidad central sobre la regresión del índice de masa ventricular izquierdo. Material y métodos: se incluyeron 102 pacientes (p) HTA que concurrieron por primera vez a un consultorio especializado en forma consecutiva, se les midió el índice de masa ventricular izquierdo (IMVI) por método de Devereux al inicio y luego de al menos 1 año de tratamiento. Fueron divididos en dos grupos: GA: perímetro cintura (PC) esos valores. Para el análisis estadístico se aplicó test t de Students para diferencias de medias y proporciones, y se consideró significación estadística p Abstract in english Blood pressure per se may be the main determinant of left ventricle hypertrophy development in hypertensive subjects. On the other side, body mass index and waist circumference are related to left ventricle mass index (LVMI) positively, continuously and linearly even in non hypertensive patients. An [...] insufficient treatment may be the main reason of not achieving regression of target organ damage. The objective of this trial is to establish the impact of central obesity on LVMI regression. Material and methods: 102 consecutive hypertensive patients (p) wich attended for the first time to a specialized consultory room were included. LVMI was measured with the Devereux method at the begining and after at least one year of treatment. The patients were divided into two groups: GA: waist circumference (WC) of those values. The statistic analysis was done with the Students t test for differences in proportions and means and a p value

Daniel, Piskorz; Luciano, Citta; Norberto, Citta; Marcelo, Lanzotti; Roberto, Lanzotti; Horacio, Locatelli; Alicia, Tommasi.

2007-12-01

252

Effect of microalbuminuria-lowering on regression of left ventricular hypertrophy in children and adolescents with essential hypertension  

Directory of Open Access Journals (Sweden)

Full Text Available Background: Microalbuminuria (MA is associated with increased cardiovascular risk in hypertensive patients, but not many studies have specifically examined the effects of MA-lowering on regression of left ventricular hypertrophy (LVH among pediatric patients with hypertension. Methods: Fifty-five patients with essential hypertension, 11 to 19 years old were prospectively studied. All patients received concomitant therapy of hydrochlorothiazide and angiotensin-converting-enzyme inhibitor. Five patients also required angiotensin-receptor blocker to achieve the blood pressure goal. Baseline and 12-month follow-up measures of left ventricular mass index (LVMI determined by echocardiography and urine microalbumin/creatinine ratio (MA/Cr were collected. MA was defined as MA/Cr>30. LVH was defined as LVMI>38.6 g/m2. The primary end points were 25% or more reductions in MA and the LVMI. Results: Weight (r=0.83, body surface area (r=0.85, body mass index (BMI (r=0.86, systolic blood pressure (SBP (r=0.57, diastolic blood pressure (DBP (r=0.49, mean arterial pressure (r=0.53 and MA (r=0.87 were all univariate correlates of LVMI. In a multiple regression analysis, MA, BMI and SBP were significant correlates of LVMI. MA alone explained 76% of the variance of LVMI, whereas BMI and SBP explained only 1.6% and 0.4% of the variance, respectively. MA was the most significant correlate of follow-up LVMI after BMI and SBP were included in the overall multiple regression models. Conclusion: MA is a strong predictor of LVH in hypertensive children and adolescents. MA-lowering halts the progression of LVH or induces its regression.

Assadi F ; Translated by: Akbari Asbagh P

2007-04-01

253

Relation between abdominal obesity, insulin resistance and left ventricular hypertrophy diagnosed by electrocardiogram and magnetic resonance imaging in hypertensive patients.  

Science.gov (United States)

Obesity is related to left ventricular hypertrophy (LVH). Whether LVH on electrocardiography (ECG-LVH) is a result of increased cardiac electrical activity or due to increased left ventricular mass (LVM) remains to be determined. The aims of the present study were to investigate the relation between obesity and ECG-LVH and LVM by magnetic resonance imaging (MRI-LVM) in patients with hypertension and to investigate the relation of insulin resistance (IR) and LVH. Patients with hypertension (n = 421) were evaluated using Sokolow-Lyon voltage, Cornell voltage, and cardiac magnetic resonance imaging. Waist circumference was used as a measure of abdominal obesity. Linear regression analysis revealed an inverse relation (adjusted ? = -0.02, 95% confidence interval -0.02 to -0.01) between waist circumference and Sokolow-Lyon voltage, indicating a decrease of 0.02 mV per 1-cm increase in waist circumference. There was a positive relation between waist circumference and MRI-LVM (? = 0.49, 95% confidence interval 0.32 to 0.67). Patients in the highest quartile of LVM had a worse metabolic profile than patients with the Sokolow-Lyon voltage criterion. The relations of IR with ECG-LVH and MRI-LVM were similar to those of waist circumference in relation to ECG-LVH and MRI-LVM. In conclusion, there is an inverse relation between waist circumference and ECG-LVH and a positive relation between waist circumference and MRI-LVM. This study indicates that obesity has a different relation to voltage criteria for LVH compared to anatomic criteria for LVH, supporting the hypothesis that IR decreases electrocardiographic voltages, despite an increase in MRI-LVM. The clinical implication is that especially in patients with IR, Sokolow-Lyon voltage is low in contrast to high MRI-LVM. PMID:22483385

Vernooij, Joris W P; Cramer, Maarten J M; Visseren, Frank L J; Korndewal, Marjolein J; Bots, Michiel L; Meijs, Matthijs F L; Doevendans, Pieter A F M; Spiering, Wilko

2012-07-15

254

Left ventricular diastolic dysfunction is associated with impaired baroreflex at rest and during orthostatic stress in hypertensive patients with left ventricular hypertrophy.  

Science.gov (United States)

The study aimed to determine the relationship between left ventricular (LV) diastolic function and the heart's spontaneous baroreflex at rest and in response to orthostatic stress during a prospective follow-up of hypertensive patients with LV hypertrophy (LVH+). LV structure and function and baroreflex sensitivity (BRS) during tilt testing were evaluated in 24 LVH+ patients and compared with 25 age-matched healthy controls and 25 hypertensive patients without LVH (LVH-). Clinical status, diastolic function and BRS were then assessed in LVH+ patients during treatment with telmisartan (monotherapy or combined with hydrochlorothiazide and/or amlodipine) at 6- and 18-month follow-ups. LVH+ patients had significantly altered diastolic function indices and decreased BRS as compared with healthy controls and LVH- patients. During the 18-month follow-up, favorable changes in diastolic function were associated with improvement in BRS at rest and during tilting. In multivariate regression models, an index reflecting rate of LV myocardial relaxation (E'sept) where E'sept denotes peak early diastolic velocity at the septal mitral annulus and a surrogate for LV filling pressure (E/E'sept), independently from other clinical and echocardiographic variables related to the low-frequency component of BRS during tilting. In conclusion, the LV diastolic function indices have independent associations with BRS parameters obtained at rest and during orthostatic stress in LVH+ patients receiving long-term pharmacological intervention. PMID:23426068

Makowski, K; Gielerak, G; Kramarz, E; Wierzcho?, S; Kami?ski, G; Kowal, J; Krzesi?ski, P; Zegad?o, A; Skrobowski, A

2013-08-01

255

Relations among impaired coronary flow reserve, left ventricular hypertrophy and thallium perfusion defects in hypertensive patients without obstructive coronary artery disease  

International Nuclear Information System (INIS)

Invasive Doppler catheter-derived coronary flow reserve, echocardiographic measurements of left ventricular hypertrophy and intravenous dipyridamole-limited stress thallium-201 scintigraphy were compared in 48 patients (40 were hypertensive or diabetic) with clinical ischemic heart disease and no or minor coronary artery disease. Abnormal vasodilator reserve (ratio less than 3:1) occurred in 50% of the study group and markedly abnormal reserve (less than or equal to 2:1) occurred in 27%. Coronary vasodilator reserve was significantly lower (2.2 +/- 0.8 versus 3.5 +/- 1.3, p = 0.003) and indexed left ventricular mass significantly higher (152.6 +/- 42.2 versus 113.6 +/- 24.0 g, p = 0.0007) in patients with a positive (n = 11) versus a negative (n = 32) thallium perfusion scan. Coronary flow reserve was linearly related in coronary basal flow velocity as follows: y = -0.17x + 4.59; r = -0.57; p = 0.00002. The decrement in flow reserve was not linearly related to the degree of left ventricular hypertrophy. Abnormal vasodilator reserve subsets found in hypertensive patients were defined on the basis of basal flow velocity, indexed left ventricular mass and clinical factors. In this series, diabetes did not cause a detectable additional decrement in flow reserve above that found with hypertension alone. These findings demonstrate that thallium perfusion defects are associated with depressed coronary vasodilator reserve in hypertensive patients without obstructive coronary ive patients without obstructive coronary artery disease. Left ventricular hypertrophy by indexed mass criteria is predictive of which hypertensive patients are likely to have thallium defects

256

Ischemic preconditioning effect of prodromal angina is attenuated in acute myocardial infarction patients with hypertensive left ventricular hypertrophy  

International Nuclear Information System (INIS)

Several animal experiments on acute myocardial infarction (AMI) have shown that the cardioprotective effects of ischemic preconditioning are more significant in hypertensive subjects. However, because there are no clinical data on the impact of hypertension on ischemic preconditioning in patients with AMI, whether clinical ischemic preconditioning of prodromal angina was beneficial in AMI patients with hypertension was investigated in the present study. 125 patients with a first anterior AMI who had undergone successful reperfusion therapy were divided into 2 groups, with or without hypertension, and into 2 further subgroups based on the presence or absence of prodromal angina. Dual-isotope (thallium-201(TL)/Tc-99m pyrophosphate) single-photon emission computed tomography (SPECT) was performed within 1 week of reperfusion therapy. Left ventricular (LV) function and LV mass index (LVMI) were measured by left ventriculography and echocardiography, respectively. In patients without hypertension, prodromal angina resulted in significantly less myocardial damage on TL-SPECT, better LV ejection fraction and a greater myocardial blush grade compared to patients without prodromal angina. However, these cardioprotective effects of prodromal angina were significantly diminished in hypertensive patients. Importantly, the myocardial salvage effects of prodromal angina showed a significant negative correlation with LVMI, which was significantly greater in hypertensive patients. Thantly greater in hypertensive patients. The cardioprotective effects of prodromal angina were attenuated in patients with hypertension. Hypertensive LV hypertrophy may crucially limit the effects of ischemic preconditioning in AMI. (author)

257

Effect of antihypertensive therapy based on new method of individual choice of drugs on left ventricular hypertrophy in elderly patients  

Directory of Open Access Journals (Sweden)

Full Text Available Aim. To study the effects of antihypertensive therapy based on consideration of individual heart rhythm variability (HRV on left ventricular hypertrophy (LVH in hypertensive elderly patients.Material and methods. 60 hypertensive elderly patients with LVH were included in the study. They were split in two groups (30 people in each one.Patients of the group-I had common antihypertensive therapy. Patients of group-II received medications prescribed with consideration of individual heart rate variability. Holter monitoring with analysis of HRV, 24-hour blood pressure monitoring and ultra sonography were conducted initially and 18 months after treatment beginning.Results. BP control was reached in the majority of patients of both groups. The patients of group-II in comparison with patients of group-I had reduction of low- high frequency power ratio (LF/HF and higher rate of LVH reduction. Relationship between LVH dynamics and ratio LF/HF was found.Conclusion. Arterial hypertension therapy considering individual HRV contributes in LVH reduction in elderly patients.

K.I. Pshenichkin

2007-01-01

258

Electrocardiographic diagnosis of left ventricular hypertrophy in aortic valve disease: evaluation of ECG criteria by cardiovascular magnetic resonance  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Left ventricular hypertrophy (LVH is a hallmark of chronic pressure or volume overload of the left ventricle and is associated with risk of cardiovascular morbidity and mortality. The purpose was to evaluate different electrocardiographic criteria for LVH as determined by cardiovascular magnetic resonance (CMR. Additionally, the effects of concentric and eccentric LVH on depolarization and repolarization were assessed. Methods 120 patients with aortic valve disease and 30 healthy volunteers were analysed. As ECG criteria for LVH, we assessed the Sokolow-Lyon voltage/product, Gubner-Ungerleider voltage, Cornell voltage/product, Perugia-score and Romhilt-Estes score. Results All ECG criteria demonstrated a significant correlation with LV mass and chamber size. The highest predictive values were achieved by the Romhilt-Estes score 4 points with a sensitivity of 86% and specificity of 81%. There was no difference in all ECG criteria between concentric and eccentric LVH. However, the intrinsicoid deflection (V6 37 ± 1.0 ms vs. 43 ± 1.6 ms, p Conclusion By calibration with CMR, a wide range of predictive values was found for the various ECG criteria for LVH with the most favourable results for the Romhilt-Estes score. As electrocardiographic correlate for concentric LVH as compared with eccentric LVH, a shorter intrinsicoid deflection and a significant ST-segment and T-wave depression in the anterolateral leads was noted.

Feuerbach Stefan

2009-06-01

259

Telomere length is associated with ACE I/D polymorphism in hypertensive patients with left ventricular hypertrophy  

DEFF Research Database (Denmark)

INTRODUCTION: Short telomeres are often associated with cardiovascular risk factors and age-related diseases, while the angiotensin converting enzyme (ACE) gene insertion/deletion polymorphism (DD, ID, II) has shown such associations less consistently. We hypothesized that telomere length and association of telomere length with cardiovascular risk is affected by ACE (I/D) genotype. METHODS: We measured leucocyte telomere length (LTL) by Southern blot and analysed ACE I/D genotypes in 1249 subjects with hypertension and left ventricular hypertrophy (LVH). We examined interactions of ACE I/D genotype with LTL and cardiovascular risk. RESULTS: Mean LTL in DD or ID genotype was shorter (8.15 and 8.14 kb, respectively), than in II genotype (8.27 kb, p=0.0005). This difference was significant in the younger subjects (55-64 years, p=0.02) but not in the older group (65-80 years, p=0.56 ). In DD but not I/D or II genotype, proportion of short telomeres (

Fyhrquist, Frej; Eriksson, Anders

2013-01-01

260

Papel del estrés oxidativo y nitrosativo en la hipertrofia cardiaca y remodelación ventricular / Role of oxidative and nitrosative stress in cardiac hypertrophy and ventricular remodeling  

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: Spanish Abstract in spanish Objetivo: hacer una revisión de los mecanismos moleculares del estrés oxidativo y nitrosativo en la fisiopatología de la falla cardiaca. Metodología: se hizo una búsqueda en Medline (Pubmed) con las palabras clave: oxidative stress, ventricular remodeling, heart failure y nitrosative stress. Se cons [...] ultó además bibliografía citada por autores de reconocida trayectoria en investigación en este tema. Resultados: se seleccionaron los 112 artículos más relevantes en el tema de estrés oxidativo/ nitrosativo que se relacionarán con falla cardiaca. Conclusiones: las respuestas de estrés de los cardiomiocitos y del tejido miocárdico es muy probable que constituyan un aspecto significativo del desarrollo de patologías cardiacas que desencadenan como evento final su progresión hacia falla cardiaca. El estrés oxidativo es un tema común en la fisiopatología de la cardiomiopatía isquémica y no isquémica. Patologías cardiacas como la falla cardiaca son usualmente precedidas de hipertrofia cardiaca secundaria, al menos en parte, a la generación de especies reactivas del oxígeno en los cardiomiocitos. Varios son los mecanismos implicados en la remodelación ventricular y progresión de la falla cardiaca que dependen de alteraciones homeostáticas en los sistemas que generan estrés oxidativo y/o nitrosativo. La discusión se centra en la reciente evidencia derivada de investigaciones llevadas a cabo tanto in vitro en cardiomiocitos cultivados como in vivo en modelos experimentales de patologías cardiacas. Las implicaciones clínicas de los recientes descubrimientos aunque son muy prometedoras para la terapéutica de la falla cardiaca, aun no han logrado trasladarse con total éxito a la práctica clínica en los ensayos clínicos realizados hasta el momento (Acta Med Colomb 2010; 2010; 35: 82-95). Abstract in english Objective: to review the molecular mechanisms of oxidative and nitrosative stress in the process of ventricular remodeling and the pathophysiology of heart failure. Metodology: a Medline (PubMed) search was performed using the keywords: oxidative stress, ventricular remodeling, heart failure, nitros [...] ative stress. Cited bibliography in key papers from renowned authors in this field of research was also examined. Results: 112 articles were selected as the most relevant regarding the several systems of oxidative stress production in the cardiovascular system in addition to their relevance to the pathophysiology of heart failure. Conclusions: the stress responses of cardiomyocytes and the myocardial tissue as a whole are likely to constitute a significant aspect of the development of cardiac pathologies. Oxidative stress is a common theme in the pathophysiology of ischemic and non-ischemic cardiomyopathy. Cardiac pathologies such as heart failure are usually preceded by cardiac hypertrophy secondary, at least in part, to the generation of reactive oxygen species in cardiomyocytes. Several mechanisms have been implicated in ventricular remodeling during heart failure progression which depends on homeostatic alterations in oxidative and nitrosative stress. The discussion is centered in the exposition of recent evidence from research carried out either in vitro in cultured cardiomyocytes as well as from in vivo models of experimental cardiac pathologies. The clinical implications of this novel understanding, although very promising for the therapeutic treatment of heart failure, up until now, have failed to translate with total success to the clinical practice in several clinical trials (Acta Med Colomb 2010; 2010; 35: 82-95).

Alejandro, Giraldo.

2010-06-01

261

La hipertrofia ventricular izquierda no siempre revierte con el descenso de la presión arterial / Left ventricular hypertrophy not always reverts with the decrease in blood pressure / A hipertrofia ventricular esquerda nem sempre reverte com a diminuição da pressão arterial  

Scientific Electronic Library Online (English)

Full Text Available SciELO Argentina | Language: Spanish Abstract in portuguese Introdução. Em pacientes hipertensos considera-se que uma queda nos valores da pressão arterial é necessária para atingir a regressão da lesão em órgãos-alvo. O objetivo deste estudo é determinar o efeito obtido com a diminuição da pressão arterial em pacientes hipertensos arteriais na hipertrofia v [...] entricular esquerda em uma clínica especializada. Material e métodos. Os pacientes hipertensos na primeira consulta, segundo definição da IV Guias da Federação Argentina de Cardiologia, com hipertrofia ventricular esquerda diagnosticada pelo método ecocardiográfico de Devereux, considerando sua presença com um índice de massa ventricular esquerda igual ou superior a 110 g/m² em mulheres e 125 g/m², em homens, divididos em dois grupos: 1) a pressão arterial controlada: menos de 140 - 90 mm Hg ou inferior a 130 - 80 mm Hg em pacientes de alto risco, os pacientes com nefropatia diabética ou portadores de doença isquêmica do coração no final do seguimento, 2) pressão arterial não controlada: acima dos valores estabelecidos no final do seguimento. Aplicou-se na análise estadística o teste t de Student, considerando-se significância estatística p Abstract in spanish Introducción. En pacientes hipertensos se considera que el descenso de las cifras de presión arterial logra la regresión del daño en órgano blanco. El objetivo del presente estudio es determinar el efecto que se obtiene con el descenso de la presión arterial en pacientes hipertensos arteriales sobre [...] la hipertrofia ventricular izquierda en un consultorio especializado. Material y métodos. Pacientes hipertensos en primera consulta según definición de las IV Guías de la Federación Argentina de Cardiología, con hipertrofia ventricular izquierda diagnosticada en ecocardiografía por método de Devereux, considerándose su presencia con un índice de masa ventricular izquierda mayor o igual a 110 gramos/m² en las mujeres y 125 gramos/m² en los hombres; divididos en dos grupos: 1) presión arterial controlada: menor a 140-90 mm Hg o menor a 130-80 mm Hg en pacientes de alto riesgo, diabéticos, nefrópatas o portadores de cardiopatía isquémica al final del seguimiento; 2) presión arterial no controlada: por encima de las cifras enunciadas al final del seguimiento. En el análisis estadístico, se aplicó test t de students, considerándose significación estadística p Abstract in english Background. In hypertensive patients it is considered that a fall in blood pressure values is necessary to achieve the regression of target organ damage. The aim of this study is to determine the effect obtained with decreasing blood pressure in hypertensive patients on left ventricular hypertrophy [...] in a specialized clinic. Methods. Hypertensive patients at first consultation as defined by Argentina Cardiology Federation Guides IV, with left ventricular hypertrophy diagnosed by echocardiographic method of Devereux, considering its presence with a left ventricular mass index equal or greater than 110 g/m² in women and 125 g/m² in men, divided into two groups: 1) controlled blood pressure: less than 140 - 90 mm Hg or lower than 130 - 80 mm Hg in high risk patients, patients with diabetic nephropathy or ischemic heart disease carriers at end of follow up, 2) uncontrolled blood pressure: above the values set out at the end of follow up. In statistical analysis t students test was applied, considering statistical significance p

Daniel, Piskorz; Alicia, Tommasi.

2010-03-01

262

Thallium myocardial perfusion scans for the assessment of right ventricular hypertrophy in patients with cystic fibrosis. A comparison with other noninvasive techniques  

International Nuclear Information System (INIS)

The incidence of right ventricular hypertrophy in 32 patients with cystic fibrosis was studied using thallium 201 (TI-201) myocardial perfusion scans, and compared with other noninvasive techniques including electrocardiography, vectorcardiography, and M-mode echocardiography. The patients (mean age, 17.3 yr; range, 7 to 33) had a wide range of clinical and pulmonary abnormalities (mean Shwachman-Kulczycki score, 66.6). In the total study group, TI-201 scans, like the vectorcardiograms and the M-mode echocardiograms, gave a surprisingly high proportion of positive predictions for right ventricular hypertrophy (RVH) (44%). The correlations with all other noninvasive methods were uniformly poor, so caution must be exercised in using this technique to predict early RVH in order to follow the natural history of cor pulmonale in cystic fibrosis. At the time of the study, 6 patients had clinical evidence of right ventricular failure, and in this disease setting must have had RVH. In 3 patients, RVH was confirmed at autopsy, and it was successfully predicted by TI-201 scans in 5 of the 6 patients. The false negative scan may have been due to regional myocardial ischemia secondary to severe right ventricular failure. In contrast, the vectorcardiogram, using Fowler's new criteria, made a successful prediction of RVH in all 6 patients, and the electro cardiogram in only 3. Although the M-mode echocardiogram was abnormal in all patients, it would have predicted RVH (with increas it would have predicted RVH (with increased right ventricular anterior wall thickness) in only 1 patient. We concluded that TI-201 myocardial perfusion cans are good at confirming RVH in cases with established right ventricular failure, but have no advantage over vectorcardiographic assessments, which are logistically easier to perform and carry no radiation risks

263

Hipertrofia ventricular esquerda do atleta: resposta adaptativa fisiológica do coração / Left ventricular hypertrophy of athletes: adaptative physiologic response of the heart  

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Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese OBJETIVO: Verificar se a hipertrofia ventricular esquerda (HVE) de atletas competitivos de resistência (maratonistas) representa processo adaptativo, puramente fisiológico, ou se pode envolver aspectos patológicos em suas características anatômicas e funcionais. MÉTODOS: De novembro de 1999 a dezemb [...] ro de 2000, foram separados consecutivamente de 30 maratonistas em atividade esportiva plena, idade inferior a 50 anos, com HVE, previamente documentada, e sem cardiopatia subjacente. Foram submetidos aos exames: clínico, eletrocardiograma, ecodopplercardiograma, e teste ergométrico (TE). Quinze foram sorteados para realizar, também, teste ergoespirométrico e ressonância magnética (RM) do coração. RESULTADOS: Nos TE, todos apresentavam boa capacidade física cardiopulmonar, sem evidências de resposta isquêmica ao exercício, sintomas ou arritmias. No ecodopplercardiograma, os valores do diâmetro e espessura diastólica da parede posterior do ventrículo esquerdo (VE), do septo interventricular, massa do VE e diâmetro do átrio esquerdo, foram significativamente maiores que os do grupo de não atletas, com idades e medidas antropométricas semelhantes. A média da massa do VE dos atletas indexada à superfície corpórea (126 g/m2) foi significativamente maior que a do grupo controle (70 g/m2) (p Abstract in english OBJECTIVE: To verify whether left ventricular hypertrophy (LVH) of elite competition athletes (marathoners) represents a purely physiological, adaptative process, or it may involve pathological aspects in its anatomical and functional characteristics. METHODS: From November 1999 to December 2000, co [...] nsecutive samples from 30 under 50-year-old marathoners in full sportive activity, with previously documented LVH and absence of cardiopathy were selected. They were submitted to clinical exams, electrocardiogram, color Doppler echocardiogram and exercise treadmill test (ETT). Fifteen were assorted to be also submitted to ergoespirometric test and heart magnetic resonance imaging (MRI). RESULTS: In ETT, all of them showed good physical pulmonary capacity, with no evidences of ischemic response to exercise, symptoms or arrhythmias. In Doppler echocardiogram, values of diameter and diastolic thickness of LV posterior wall, interventricular septum, LV mass and left atrium diameter, were significantly higher when compared to non-athlete control group, with similar ages and anthropometric measurements. The mean of LV mass of athletes indexed to body surface (126 g/m2) was significantly greater than the one in control group (70 g/m2) (p

Nabil, Ghorayeb; Michel, Batlouni; Ibraim M. F, Pinto; Giuseppe S, Dioguardi.

2005-09-01

264

Myocardial perfusion in type 2 diabetes with left ventricular hypertrophy: normalisation by acute angiotensin-converting enzyme inhibition  

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The purpose of this study was to assess whether acute angiotensin-converting enzyme (ACE) inhibition would improve myocardial perfusion and perfusion reserve in a subpopulation of normotensive patients with diabetes and left ventricular hypertrophy (LVH), both independent risk factors of coronary disease. Using positron emission tomography (PET), we investigated the response of regional myocardial perfusion to acute ACE inhibition with i.v. infusion of perindoprilat (vs saline infusion as control, minimum interval 3 days) in 12 diabetic patients with LVH. Myocardial perfusion was quantified with PET using nitrogen-13 ammonia infused at rest and during dipyridamole hyperaemia. Twelve healthy control subjects were included in the study, five of whom were also studied with perindoprilat. Mean blood pressure in normo-albuminuric, asymptomatic patients was 123{+-}7/65{+-}9 mmHg. Compared with controls, maximal perfusion was reduced in patients (1.8{+-}0.6 vs 2.5{+-}1.0 ml min{sup -1} g{sup -1}; P<0.05), and perfusion reserve was also lower, at borderline significance (2.7{+-}1.0 vs 3.6{+-}1.3; P=0.059). During perindoprilat infusion, myocardial perfusion reserve in patients increased to 3.9{+-}0.9 (P<0.001) due to normalisation of maximal perfusion (2.3{+-}0.5 ml min{sup -1} g{sup -1}, P<0.01). In the five control subjects both resting and hyperaemic perfusion remained unchanged during perindoprilat infusion. It is concluded that acute ACE inhibition with perindoprilat improves maximal achieved myocardial perfusion in non-hypertensive patients with diabetes and LVH. (orig.)

Hesse, Birger; Meyer, Christian; Hove, Jens D.; Holm, Soeren; Kofoed, Klaus F. [Department of Clinical Physiology and Nuclear Medicine, KF 4011, Rigshospitalet, University of Copenhagen, Blegdamsvej 9, 2100, Copenhagen (Denmark); Nielsen, Flemming S.; Sato, Asako; Parving, Hans-Henrik [Steno Diabetes Center, Gentofte (Denmark); Bang, Lia E.; Svendsen, Tage L. [Department of Internal Medicine, Naestved County Hospital (Denmark); Opie, Lionel H. [Department of Medicine, Cape Heart Center, University of Cape Town (South Africa)

2004-03-01

265

The Metabolic Syndrome and ECG Detected Left Ventricular Hypertrophy – Influences from IGF-1 and IGF-Binding Protein-1  

Science.gov (United States)

Background and Aims The metabolic syndrome (MetS) is associated with an increased risk for left ventricular hypertrophy (LVH) and cardiovascular mortality. The aim of this study was to investigate potential influences from insulin-like growth factor-1 (IGF-1) and IGF binding protein-1 (IGFBP-1) on the relationship between the MetS and LVH, also taking into account the role of physical activity (PA), use of oestrogen and gender. Methods and Results In a population-based cross-sectional study of 60-year-old men (n?=?1822) and women (n?=?2049) participants underwent physical examination and laboratory tests, including electrocardiography (ECG), and completed an extensive questionnaire. Women showed higher levels of IGFBP-1 than men (37.0 vs. 28.0 µg/l, p<0.001), and women with LVH had lower levels of IGFBP-1 than women without LVH (31.0 µg/l vs. 37.0 µg/l, p<0.001). Furthermore, women with low levels of IGFBP-1 had a significantly increased risk of having LVH (crude OR?2.5). When stratifying for PA and oestrogen, respectively, a weaker association between IGFBP-1 and LVH was demonstrated in physically active men and women, compared to inactive individuals, as well as in women using oestrogen, compared to non-users. Conclusion In a representative sample of 60-year-old Swedish men and women, the main findings were higher levels of IGFBP-1 in women than in men; lower levels of IGFBP-1 in women with LVH, compared to women without LVH; and an increased risk of having LVH in women with low levels of IGFBP-1. The association between IGFBP-1 and LVH was diminished in physically active men and women, as well as in women using oestrogen. PMID:25461385

Halldin, Mats; Brismar, Kerstin; Fahlstadius, Per; Vikström, Max; de Faire, Ulf; Hellénius, Mai-Lis

2014-01-01

266

Tc-99m sestaMIBI SPECT imaging in angina patients with echocardiographic left ventricular hypertrophy (LVH)  

International Nuclear Information System (INIS)

Left ventricular hypertrophy (LVH) is relatively common, occurring in 15-20% of the general population. LVH were known to exert an adverse influence on the accuracy of myocardial perfusion scintigraphy. However, most studies were done in the patients having hypertension. The diagnostic accuracy of the stress myocardial perfusion scan in the normotensive patients with LVH for the detection of significant coronary artery disease has not been separately examined. This study was prepared to determine the diagnostic accuracy of Tc-99m myocardial perfusion scan in patients with echocardiographic LVH. Tc-99m sestaMIBI myocardial scan was performed with either exercise (n=40) or adenosine (n=44) stress in 84 consecutive anginal patients with normal ECG. Fifty nine patients had significant coronary artery disease (>50%) in coronary angiogram. Overall sensitivity and specificity of the SPECT imaging were 88%, and 84% respectively. The patients were divided into two groups ; 1) LVH= patients with echocardiographic LVH(n=29) and 2) No LVH =patients without echocardiographic LVH(n=55). Sensitivities were 88% in both groups. Specificities were 67% in LVH and 100% in No LVH group ( p < 0.05). Fifty seven patients were normotensive and analyzed separately (LVH group =20, No LVH group = 37). Exercise stress was done in 29 and adenosine in 28 patients. Sensitivities and specificities were not significantly different in LVH and No LVH groups (83% vs 86%, p=NS and 88% vs 100%, p= NS) for% vs 86%, p=NS and 88% vs 100%, p= NS) for the detection of coronary artery disease. Echocardiographic LVH does not appear to affect the diagnostic value of the Tc-99m sestaMIBI SPECT imaging in the normotensive angima patients

267

Effects of valsartan and nebivolol on blood pressure, QT dispersion and left ventricular hypertrophy in hypertensive patients  

Directory of Open Access Journals (Sweden)

Full Text Available Objectives: The aim of this study was to analyze the antihypertensiveeffect of Valsartan and Nebivolol and their effects on QT dispersion and left ventricular hypertrophy (LVH in the treatment of naive hypertensive patients.Methods: A prospective study with a six-month follow-up was conducted on hypertensive patients with LVH and mild/ moderate essential hypertension. The patients were randomly assigned to Valsartan (80 to 160 mg/day or Nebivolol (5 to 10 mg/day groups. The study group consistedof 108 patients, 55 in the Valsartan group and 53 in the Nebivolol group.Results: The range of mean systolic blood pressure (SBP varied from 152±17 (baseline to 132±17 mmHg (follow-up in the Valsartan group (p<0.001; from 146±13 to 125±14 mmHg in the Nebivolol group (p<0.001. The decrease in mean diastolic blood pressure (DBP was 9.5±2.5 mmHg in the Valsartan group and 12.3±5.0 mmHg in the Nebivolol group. A significant reduction in QT and corrected QT (Bazett’s formula dispersion was observed in both groups, with a slightly higher reduction in the Valsartan group. Echocardiography showed a decreasein the left ventricle mass (LVM indices (p<0.05 in both groups with a greater reduction in the Valsartan group.Conclusion: Valsartan treatment was as effective as Nebivolol in reducing the 24 hour- SBP after a 6 month treatment. Nebivolol treatment proved to be superior to Valsartan in reducing DBP. Both therapies were effective in reducing the LVH; Valsartan proved to be superior to Nebivolol in reducing the QT interval indexes in relation to blood pressure and LVM reduction.

Luminita L??ea

2010-06-01

268

[Evaluation of electrocardiographic left ventricular hypertrophy with both QRS voltage and ST-T change using echocardiography].  

Science.gov (United States)

The purpose of the present study is to determine whether electrocardiographic QRS voltage criteria with ST-T change is useful in the diagnosis of left ventricular hypertrophy (LVH) using echocardiography. One hundred men including 59 with hypertension (HT), 9 with hypertrophic cardiomyopathy (HCM), and 32 without any cardiovascular disease were enrolled in this study. All of them had the electrocardiographic evidence of LVH by Sokolow-Lyon voltage criteria (RV5 or RV6 > 2.6 mV, SV1+RV5 or SV1+RV6 > or = 3.5 mV). They were classified into three groups based on ST-T pattern as follows: Normal ST-T (group N): normal ST-T in twelve leads; Early strain ST-T (group ES): ST depression, flat T (T/R or = 12 mm was present. According to this echocardiographic evidence, 31.7%(20/63) of group N, 75.0% (12/16) of group ES, and 100% (21/21) of group S were diagnosed. There were significant correlations between QRS voltage indices (RV5, RV6, SV1+RV5 and SV1+RV6) and IVST, (IVST+LVPWT)/2, and LV mass in group S(r = 0.650 to 0.858, p < 0.05) but not in group N. Values for IVST and LV mass were significantly greater in group S than in group ES or N. The electrocardiographic diagnosis of LVH with both QRS voltage and ST-T change thus appeared to be more useful than that with QRS voltage criteria alone. PMID:9283227

Yagi, T; Noda, A; Itoh, R; Yamada, H; Nakashima, N; Yokota, M

1997-08-01

269

Uncontrolled hypertension is associated with coronary artery calcification and electrocardiographic left ventricular hypertrophy: a case-control study.  

Science.gov (United States)

We conducted a 1:2 matched case-control study in order to evaluate whether the prevalence of coronary artery calcium (CAC) and electrocardiographic left ventricular hypertrophy (LVH) or strain was higher in patients with uncontrolled hypertension than in subjects from the general population, and evaluate the association between CAC and LVH in patients with uncontrolled hypertension. Cases were patients with uncontrolled hypertension, whereas the controls were random individuals from the general population without cardiovascular disease. CAC score was assessed using a non-contrast computed tomographic scan. LVH was evaluated using the Sokolow-Lyon voltage combination and Cornell voltage-duration product, respectively. Associations between CAC, LVH and traditional cardiovascular risk factors were tested by means of ordinal, conditional and classic binary logistic regression models. We found that uncontrolled hypertension was independently associated with both an ordinal CAC score category (odds ratio (OR) 3.9 (95% CI, 1.6-9.1), P=0.002), the presence of CAC score>99 (OR 4.5 (95% CI, 1.4-14.7), P=0.01) and electrocardiographic LVH (OR 10.1 (95% CI, 3.4-30.2), P<0.001) on both univariate and multivariable analyses. There was, however, no correlation between CAC and LVH. The lack of an association between CAC and LVH suggests that they are markers of different complications of hypertension and may have independent predictive values. Patients with both CAC and LVH may be at higher risk than those in whom only one of these markers is present.Journal of Human Hypertension advance online publication, 2 October 2014; doi:10.1038/jhh.2014.88. PMID:25273860

Nielsen, M L; Pareek, M; Gerke, O; Diederichsen, S Z; Greve, S V; Blicher, M K; Sand, N P R; Mickley, H; Diederichsen, A C P; Olsen, M H

2014-10-01

270

Plasma levels of nitric oxide metabolites are markedly reduced in normotensive men with electrocardiographically determined left ventricular hypertrophy.  

Science.gov (United States)

Recent studies have revealed that electrocardiographically determined left ventricular hypertrophy (ECG-LVH) is a risk factor for cardiovascular death not only in hypertensive patients but also in normotensive subjects. However, the underlying mechanisms remain to be elucidated. In this study, we tested our hypothesis that normotensive subjects with ECG-LVH have reduced nitric oxide production. A total of 840 Japanese male workers were enrolled, and 579 eligible subjects were studied. ECG-LVH was assessed according to the Sokolow-Lyon voltage criteria and the Cornell voltage-duration product. The median level of plasma NOx (nitrite plus nitrate), a marker of systemic nitric oxide production, was markedly lower in the normotensive subjects with ECG-LVH (n=73) than in those without (n=506), and the clinical characteristics were significantly different between the 2 groups (each P<0.05). Importantly, a one-to-one propensity score matching analysis showed similar markedly lower median plasma NOx level in the normotensive subjects with ECG-LVH compared with that observed in the matched normotensive subjects without ECG-LVH (P<0.05). Furthermore, the tertiles of the plasma NOx levels were inversely correlated with the prevalence and severity of ECG-LVH (both P<0.05). The lower plasma NOx levels were associated with significantly higher plasma 8-isoprostane levels, a marker of systemic lipid peroxidation (P<0.05). These results provide the first evidence that normotensive subjects with ECG-LVH exhibit defective nitric oxide production, along with increased oxidative stress. Our findings may thus explain, at least in part, a potential mechanism underlying the increased risk of cardiovascular death in normotensive individuals with ECG-LVH. PMID:24914203

Kamezaki, Fumihiko; Tsutsui, Masato; Takahashi, Masao; Sonoda, Shinjo; Kubo, Tatsuhiko; Fujino, Yoshihisa; Adachi, Tetsuo; Abe, Haruhiko; Takeuchi, Masaaki; Mayumi, Toshihiko; Otsuji, Yutaka

2014-09-01

271

The occurrence of left ventricular hypertrophy in normotensive individuals in a community setting in North-East Trinidad  

Directory of Open Access Journals (Sweden)

Full Text Available Romel Bacchus, Kristianna Singh, Ijaz Ogeer, Kameel MungrueDepartment Paraclinical Sciences, Public Health and Primary Care Unit, Faculty of Medical Sciences, University of the West Indies, EWMSC, Mt Hope TrinidadObjective: The purpose of this study is to determine primarily the occurrence of left ventricular hypertrophy (LVH in normotensive Trinidadians.Design and methods: Enrolment into the study required participants to have normal blood pressure (?140/90 using the JNC 7 (The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure classification, free of type 2 diabetes, as well as no existing LVH. Upon entry into the study, participants were first screened for LVH using a standard 12-lead electrocardiogram (ECG, using the Sokolow–Lyon index and the Cornell index. ECHO was used to confirm or refute the diagnosis of LVH.Results: A total of 209 patients met the criteria for entry into the study. Of these, 63.6% had LVH using Cornell criteria and 68.2% using LVH by Sokolow–Lyon criteria. Subsequently, ECHO confirmed the diagnosis in 2.9% using American Society of Echocardiography criteria and 1.5% using World Health Organization criteria. Thus the estimated prevalence of LVH in normotensive individuals was approximately 3%.Conclusion: The estimated prevalence of LVH in normotensive individuals appears to be relatively high if an ECG is the single investigation performed, which is common in our setting and may also be common in the developing world. However, using ECHO, the prevalence of LVH approaches a value similarly reported in the literature. Therefore, these findings raise two important issues: 1 the use of criteria such as the Cornell and Sokolow–Lyon voltage criteria established in the developed world from populations of vastly different ethnic backgrounds may not be widely applicable, and 2 all individuals suspected of having LVH should have an ECHO.Keywords: hypertension, normotensive, echocardiography, Sokolow–Lyon

Bacchus R

2011-07-01

272

Prolonged Corrected QT Interval Is Predictive of Future Stroke Events Even in Subjects Without ECG-Diagnosed Left Ventricular Hypertrophy.  

Science.gov (United States)

We attempted to evaluate whether subjects who exhibit prolonged corrected QT (QTc) interval (?440 ms in men and ?460 ms in women) on ECG, with and without ECG-diagnosed left ventricular hypertrophy (ECG-LVH; Cornell product, ?244 mV×ms), are at increased risk of stroke. Among the 10 643 subjects, there were a total of 375 stroke events during the follow-up period (128.7±28.1 months; 114 142 person-years). The subjects with prolonged QTc interval (hazard ratio, 2.13; 95% confidence interval, 1.22-3.73) had an increased risk of stroke even after adjustment for ECG-LVH (hazard ratio, 1.71; 95% confidence interval, 1.22-2.40). When we stratified the subjects into those with neither a prolonged QTc interval nor ECG-LVH, those with a prolonged QTc interval but without ECG-LVH, and those with ECG-LVH, multivariate-adjusted Cox proportional hazards analysis demonstrated that the subjects with prolonged QTc intervals but not ECG-LVH (1.2% of all subjects; incidence, 10.7%; hazard ratio, 2.70, 95% confidence interval, 1.48-4.94) and those with ECG-LVH (incidence, 7.9%; hazard ratio, 1.83; 95% confidence interval, 1.31-2.57) had an increased risk of stroke events, compared with those with neither a prolonged QTc interval nor ECG-LVH. In conclusion, prolonged QTc interval was associated with stroke risk even among patients without ECG-LVH in the general population. PMID:25534703

Ishikawa, Joji; Ishikawa, Shizukiyo; Kario, Kazuomi

2015-03-01

273

Aortic remodelling following the treatment and regression of hypertensive left ventricular hypertrophy: a cardiovascular magnetic resonance study.  

Science.gov (United States)

Abstract Background: Increased arterial stiffness independently predicts adverse prognosis. While different antihypertensive strategies produce different magnitudes of left ventricular hypertrophy (LVH) regression, there are no comparative data on how these strategies affect arterial stiffness. The aim was to determine the longitudinal change in aortic stiffness following the treatment of essential hypertension with two mechanistically different antihypertensive treatment strategies. Methods and results: Forty-two patients with essential hypertension and CMR confirmed with LVH were randomly assigned to antihypertensive regimes for 6 months. Treatment strategies were designed either to inhibit the renin-angiotensin-aldosterone system (RAAS) and the sympathetic nervous system (SNS) (valsartan and moxonidine, group VM) or to have neutral effect on these systems (bendroflumethiazide and amlodipine, group BA). Both treatment groups underwent identical baseline and a 6-month follow-up CMR and were compared with a healthy age-matched control group. Baseline aortic distensibility (AD) was lower in both hypertensive groups compared with controls (2.8?×?10(-3?)mmHg(-1) in group VM (p?=?0.001) and 3.3?×?10(-3?)mmHg(-1) group BA (p?=?0.039) compared with 4.5?×?10(-3?)mmHg(-1) in the control group). AD increased after antihypertensive therapy (VM: 2.8?×?10(-3?)mmHg(-1)-4.2?×?10(-3?)mmHg(-1) (p?=?0.001); BA 3.3?×?10(-3?)mmHg(-1)-4.6?×?10(-3?)mmHg(-1) (p?

Ripley, David P; Negrou, Kalliopi; Oliver, James J; Worthy, Gill; Struthers, Allan D; Plein, Sven; Greenwood, John P

2014-10-01

274

Uncontrolled hypertension is associated with coronary artery calcification and electrocardiographic left ventricular hypertrophy : a case-control study  

DEFF Research Database (Denmark)

We conducted a 1:2 matched case-control study in order to evaluate whether the prevalence of coronary artery calcium (CAC) and electrocardiographic left ventricular hypertrophy (LVH) or strain was higher in patients with uncontrolled hypertension than in subjects from the general population, and evaluate the association between CAC and LVH in patients with uncontrolled hypertension. Cases were patients with uncontrolled hypertension, whereas the controls were random individuals from the general population without cardiovascular disease. CAC score was assessed using a non-contrast computed tomographic scan. LVH was evaluated using the Sokolow-Lyon voltage combination and Cornell voltage-duration product, respectively. Associations between CAC, LVH and traditional cardiovascular risk factors were tested by means of ordinal, conditional and classic binary logistic regression models. We found that uncontrolled hypertension was independently associated with both an ordinal CAC score category (odds ratio (OR) 3.9 (95% CI, 1.6-9.1), P=0.002), the presence of CAC score>99 (OR 4.5 (95% CI, 1.4-14.7), P=0.01) and electrocardiographic LVH (OR 10.1 (95% CI, 3.4-30.2), P<0.001) on both univariate and multivariable analyses. There was, however, no correlation between CAC and LVH. The lack of an association between CAC and LVH suggests that they are markers of different complications of hypertension and may have independent predictive values. Patients with both CAC and LVH may be at higher risk than those in whom only one of these markers is present.Journal of Human Hypertension advance online publication, 2 October 2014; doi:10.1038/jhh.2014.88.

Nielsen, M L; Pareek, Manan

2015-01-01

275

The influence of cell dimensions on the vulnerability of ventricular myocytes to lethal injury by high-intensity electrical fields / Influência das dimensões celulares sobre a vulnerabilidade de miócitos ventriculares ao efeito letal de campos elétricos de alta intensidade  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Campos elétricos de alta intensidade (HIEF) são aplicados ao miocárdio durante desfibrilação e cardioversão. Embora eficazes na reversão de arritmias potencialmente letais, HIEF podem lesar cardiomiócitos por eletropermeabilização da membrana. Neste estudo, a influência das dimensões celulares sobre [...] o efeito letal de HIEF foi estudada em cardiomiócitos isolados de rato alinhados paralelamente ao campo. A máxima variação do potencial de membrana induzida pelo campo (?Vmax) foi calculada com o modelo de Klee-Plonsey. As células estudadas foram distribuídas em dois pares de grupos de acordo com seu comprimento e largura. A intensidade limiar do campo não dependeu da largura celular, mas sim do comprimento (menor nas células mais longas, p Abstract in english Application of high intensity electric fields (HIEF) to the myocardium is commonly used for cardiac defibrillation/cardioversion. Although effective at reversing life-threatening arrhythmias, HIEF may cause myocyte damage due to membrane electropermeabilization. In this study, the influence of cell [...] length and width on HIEF-induced lethal injury was analyzed in isolated rat cardiomyocytes in parallel alignment with the field. The field-induced maximum variation of membrane potential (?Vmax) was estimated with the Klee-Plonsey model. The studied myocyte population was arranged in two group pairs for comparison: the longest vs. the shortest cells, and the widest vs. narrowest cells. Threshold field intensity was significantly lower in the longest vs. shortest myocytes, whereas cell width influence was not significant. The threshold ?Vmax was comparable in all groups. Likewise, a significant leftward shift of the lethality curve (i.e., relationship of the probability of lethality vs. field intensity) of the longest cells was observed, evidencing greater sensitivity to HIEF-induced damage. However, the lethality curve as a function of ?Vmax was similar in all groups, confirming a prediction of the Klee-Plonsey model. The similar results for excitation and injury at threshold and HIEF stimulation, respectively, indicate that: a) the effect of cell length on the sensitivity to the field would be attributable to differences in field-induced membrane polarization that lead to excitation or lethal electroporation; b) the Klee-Plonsey model seems to be reliable for analysis of cell interaction with HIEF; c) it is possible that increased cell length in hypertrophied hearts enhances myocyte fragility upon defibrillation/cardioversion.

Jair Trapé, Goulart; Pedro Xavier de, Oliveira; José Wilson Magalhães, Bassani; Rosana Almada, Bassani.

2012-12-01

276

The novel regulations of MEF2A, CAMKK2, CALM3, and TNNI3 in ventricular hypertrophy induced by arsenic exposure in rats.  

Science.gov (United States)

Arsenic is a ubiquitous toxic compound that exists naturally in many sources such as soil, groundwater, and food; in which vast majority forms are arsenite (As(3+)) or arsenate (As(5+)). The mechanism of arsenic detoxification in humans still remains obscured. Epidemiologic studies documented that arsenic pollution caused black foot disease, cardiovascular diseases (hypertension, hypotension, cardiomyopathy), bladder cancer and skin cancer in many countries in which Taiwan is considered as high arsenic exposure country for long time ago. However, the effects of arsenic to cardiac functions still lacked of investigation while some studies mainly focus on inflammatory and cancer mechanisms. In the present study, we found cardiac hypertrophy signaling may be the most significant pathway for up regulated genes in arsenic exposed patients via bioinformatics approach. To verify our bioinformatics prediction, arsenic was fed orally to rats at different concentration based on previous studies in Taiwan. Using hemodynamic method as the main tool to measure the changes in blood pressure, left ventricular pressure and left ventricular contractility index, the findings suggest that highly exposure to arsenic lead to hypertension; elevated left ventricular diastolic pressure and alteration in cardiac contractility which are supposed to be the interaction between arsenic and cardiac nerves activity via the changing in calcium homeostasis. Collectively, based on our real-time PCR and western blot data strongly suggest that calcium homeostasis may also go through MEF2A, TNNI3, CAMKK2, CALM3 and cardiac hypertrophy relative signaling pathway. PMID:25089838

Phan, Nam Nhut; Wang, Chih-Yang; Lin, Yen-Chang

2014-10-01

277

Massa ventricular e critérios eletrocardiográficos de hipertrofia: avaliação de um novo escore Ventricular mass and electrocardiographic criteria of hypertrophy: evaluation of new score  

Directory of Open Access Journals (Sweden)

Full Text Available FUNDAMENTO: A hipertrofia ventricular esquerda (HVE é um importante e independente fator de risco cardiovascular. Inexistem, no Brasil, estudos desenhados para testar a eficácia do eletrocardiograma (ECG no diagnóstico desse grave processo patológico. OBJETIVO: Avaliar um novo escore eletrocardiográfico para diagnóstico de HVE pelo ECG: soma da maior amplitude da onda S com a maior da onda R no plano horizontal, multiplicando-se o resultado pela duração do QRS [(S+R X QRS] e comparando-o com os critérios eletrocardiográficos clássicos. MÉTODOS: Foram analisados os ecocardiogramas e ECG de 1.204 pacientes hipertensos em tratamento ambulatorial. Avaliou-se o índice de massa do ventrículo esquerdo (IMVE pelo ecocardiograma, firmando-se o diagnóstico de HVE quando > 96 g/m² para mulheres e > 116 g/m² para homens. No ECG analisaram-se quatro critérios clássicos de HVE, além do novo escore a ser testado. RESULTADOS: Todos os índices estudados tiveram correlação estatisticamente significativa com a massa calculada do ventrículo esquerdo (VE. Porém, o novo escore foi o que apresentou maior correlação (r = 0,564. Os outros critérios apresentaram as seguintes correlações: Romhilt-Estes (r = 0,464; Sokolow-Lyon (r = 0,419; Cornell voltagem (r = 0,377; Cornell duração (r = 0,444. Para avaliação da acurácia do índice testado, utilizou-se o ponto de corte de 2,80 mm.s. Com esse valor foram obtidas as seguintes cifras para sensibilidade e especificidade: 35,2% e 88,7%, respectivamente. CONCLUSÃO: Todos os critérios eletrocardiográficos para avaliação da massa do VE apresentaram baixa sensibilidade. O novo escore foi o que apresentou melhor correlação com o IMVE em relação aos outros avaliados.BACKGROUND: The left ventricular hypertrophy (LVH is an important and independent cardiovascular risk factor. There is a scarcity of studies in Brazil designed to test the efficacy of the electrocardiogram (ECG in the diagnosis of this important pathological process. OBJECTIVE: To evaluate a new electrocardiographic score for the diagnosis of LVH by ECG: the sum of the highest amplitude of the S wave and the highest amplitude of the R wave on the horizontal plane, multiplied by the result of the QRS duration [(S+R X QRS] and comparing it with the classic electrocardiographic criteria. METHODS: The echocardiograms and ECG of 1,204 hypertensive patients receiving outpatient care were evaluated. The left ventricular mass index (LVMI was assessed by the echocardiogram, with a diagnosis of LVH when the LVMI was > 96 g/m² for women and > 116 g/m² for men. Four classic criteria of LVH were analyzed at the ECG, in addition to the new score to be tested. RESULTS: In general, the studied ECG-LVH criteria showed significant statistical correlation to the echocardiographic LVMI. The (R+S X QRS index, using 2.80 mm.s as the cutoff value, provided test accuracy regarding sensibility and specificity of 35.2% and 88.71%, respectively, representing the best correlation to LVMI (r=0.564 when compared to the other indexes: Romhilt-Estes (r=0.464; Sokolow-Lyon (r=0.419; Cornell voltage (r=0.377; Cornell product r=0.444. CONCLUSION: All the electrocardiographic criteria used for the assessment of the LV mass presented low sensitivity. The new score presented the best correlation with LVMI when compared to the other indexes.

Cléber do Lago Mazzaro

2008-04-01

278

Massa ventricular e critérios eletrocardiográficos de hipertrofia: avaliação de um novo escore / Ventricular mass and electrocardiographic criteria of hypertrophy: evaluation of new score  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese FUNDAMENTO: A hipertrofia ventricular esquerda (HVE) é um importante e independente fator de risco cardiovascular. Inexistem, no Brasil, estudos desenhados para testar a eficácia do eletrocardiograma (ECG) no diagnóstico desse grave processo patológico. OBJETIVO: Avaliar um novo escore eletrocardiog [...] ráfico para diagnóstico de HVE pelo ECG: soma da maior amplitude da onda S com a maior da onda R no plano horizontal, multiplicando-se o resultado pela duração do QRS [(S+R) X QRS)] e comparando-o com os critérios eletrocardiográficos clássicos. MÉTODOS: Foram analisados os ecocardiogramas e ECG de 1.204 pacientes hipertensos em tratamento ambulatorial. Avaliou-se o índice de massa do ventrículo esquerdo (IMVE) pelo ecocardiograma, firmando-se o diagnóstico de HVE quando > 96 g/m² para mulheres e > 116 g/m² para homens. No ECG analisaram-se quatro critérios clássicos de HVE, além do novo escore a ser testado. RESULTADOS: Todos os índices estudados tiveram correlação estatisticamente significativa com a massa calculada do ventrículo esquerdo (VE). Porém, o novo escore foi o que apresentou maior correlação (r = 0,564). Os outros critérios apresentaram as seguintes correlações: Romhilt-Estes (r = 0,464); Sokolow-Lyon (r = 0,419); Cornell voltagem (r = 0,377); Cornell duração (r = 0,444). Para avaliação da acurácia do índice testado, utilizou-se o ponto de corte de 2,80 mm.s. Com esse valor foram obtidas as seguintes cifras para sensibilidade e especificidade: 35,2% e 88,7%, respectivamente. CONCLUSÃO: Todos os critérios eletrocardiográficos para avaliação da massa do VE apresentaram baixa sensibilidade. O novo escore foi o que apresentou melhor correlação com o IMVE em relação aos outros avaliados. Abstract in english BACKGROUND: The left ventricular hypertrophy (LVH) is an important and independent cardiovascular risk factor. There is a scarcity of studies in Brazil designed to test the efficacy of the electrocardiogram (ECG) in the diagnosis of this important pathological process. OBJECTIVE: To evaluate a new e [...] lectrocardiographic score for the diagnosis of LVH by ECG: the sum of the highest amplitude of the S wave and the highest amplitude of the R wave on the horizontal plane, multiplied by the result of the QRS duration [(S+R) X QRS)] and comparing it with the classic electrocardiographic criteria. METHODS: The echocardiograms and ECG of 1,204 hypertensive patients receiving outpatient care were evaluated. The left ventricular mass index (LVMI) was assessed by the echocardiogram, with a diagnosis of LVH when the LVMI was > 96 g/m² for women and > 116 g/m² for men. Four classic criteria of LVH were analyzed at the ECG, in addition to the new score to be tested. RESULTS: In general, the studied ECG-LVH criteria showed significant statistical correlation to the echocardiographic LVMI. The (R+S) X QRS index, using 2.80 mm.s as the cutoff value, provided test accuracy regarding sensibility and specificity of 35.2% and 88.71%, respectively, representing the best correlation to LVMI (r=0.564) when compared to the other indexes: Romhilt-Estes (r=0.464); Sokolow-Lyon (r=0.419); Cornell voltage (r=0.377); Cornell product r=0.444). CONCLUSION: All the electrocardiographic criteria used for the assessment of the LV mass presented low sensitivity. The new score presented the best correlation with LVMI when compared to the other indexes.

Cléber do Lago, Mazzaro; Francisco de Assis, Costa; Maria Teresa Nogueira, Bombig; Bráulio, Luna Filho; Ângelo Amato Vincenzo de, Paola; Antonio Carlos de Camargo, Carvalho; William da, Costa; Francisco Antonio Helfenstein, Fonseca; Rui Manoel dos Santos, Póvoa.

2008-04-01

279

TRPC1, CaN and NFATC3 signaling pathway in the pathogenesis and progression of left ventricular hypertrophy in spontaneously hypertensive rats.  

Science.gov (United States)

Abstract Spontaneously hypertensive rats (SHR) was used to study left ventricular hypertrophy (LVH) and its dynamic change after the interventions with Telmisartan and Amlodipine. The results showed that the expression of TRPC1, CaN and NFATC3 increased gradually with the pathogenesis and progression of LVH. Telmisartan reduced blood pressure and LVH, and down-regulated the expression of TRPC1, CaN and NFATC3 in left ventricle of SHR. Amlodipine reduced the blood pressure in SHR but had no impact on the hypertrophy and expression of above factors. Our data suggest that the pathogenesis and progression of LVH in SHR are related to upregulation of TRPC1, CaN and NFATC3 signaling pathway. PMID:25271479

Zou, Guangrong; Hong, Huashan; Lin, Xiaohong; Shi, Xiaoyun; Wu, Ying; Chen, Lianglong

2014-10-01

280

Calcium homeostasis in a local/global whole cell model of permeabilized ventricular myocytes with a Langevin description of stochastic calcium release.  

Science.gov (United States)

Population density approaches to modeling local control of Ca(2+) -induced Ca(2+) release in cardiac myocytes can be used to construct minimal whole cell models that accurately represent heterogeneous local Ca(2+) signals. Unfortunately, the computational complexity of such "local/global" whole cell models scales with the number of Ca(2+) release unit (CaRU) states, which is a rapidly increasing function of the number of ryanodine receptors (RyRs) per CaRU. Here we present an alternative approach based on a Langevin description of the collective gating of RyRs coupled by local [Ca(2+)]. The computational efficiency of this approach no longer depends on the number of RyRs per CaRU. When the RyR model is minimal, Langevin equations may be replaced by a single Fokker-Planck equation, yielding an extremely compact and efficient local/global whole cell model that reproduces and helps interpret recent experiments that investigate Ca(2+) homeostasis in permeabilized ventricular myocytes. Our calculations show that elevated myoplasmic [Ca(2+)] promotes elevated network SR [Ca(2+)] via SERCA-mediated Ca(2+) uptake. However, elevated myoplasmic [Ca(2+)] may also activate RyRs and promote stochastic SR Ca(2+) release, which can in turn decrease SR [Ca(2+)]. Increasing myoplasmic [Ca(2+)] results in an exponential increase in spark-mediated release and a linear increase in non-spark-mediated release, consistent with recent experiments. The model exhibits two steady-state release fluxes for the same network SR [Ca(2+)] depending on whether myoplasmic [Ca(2+)] is low or high. In the later case, spontaneous release decreases SR [Ca(2+)] in a manner that maintains robust Ca(2+) sparks. PMID:25485896

Wang, Xiao; Weinberg, Seth H; Hao, Yan; Sobie, Eric A; Smith, Gregory Douglas

2014-12-01

281

Correlação eletro-ecocardiográfica no diagnóstico da hipertrofia ventricular esquerda / Electro-echocardiographic correlation in the diagnosis of left ventricular hypertrophy  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese OBJETIVO: Comparar a eficácia diagnóstica de 4 critérios eletrocardiográficos: índices de Sokolov, Gubner, Cornell e Romhilt, na detecção da hipertrofia ventricular esquerda (HVE) em pacientes hipertensos. MÉTODOS: Foram avaliados 30 pacientes ambulatoriais, com hipertensão arterial sistêmica leve, [...] moderada ou grave, sendo considerado o diagnóstico de HVE quando os índices eram: Sokolov >35mm, Gubner >22mm, Romhilt >5 pontos e Cornell >20mm para mulheres e 28mm para homens. Determinaram-se, então, a sensibilidade, especificidade, eficácia diagnóstica e outras variáveis diagnósticas para cada um dos critérios, isoladamente, e para os 4 considerados simultaneamente, utilizando-se como padrão ouro para HVE o índice de massa do ventrículo esquerdo >98g/m² para mulheres e >120g/m² para homens, obtido ao ecocardiograma. RESULTADOS: Considerando cada critério eletrocardiográfico isolado, o índice de Sokolov apresentou a melhor eficácia, com sensibilidade = 40%, eficácia diagnóstica de 50% e especificidade 100%; o 2º critério mais eficaz foi o índice de Gubner e, em 3º lugar, empatados, os índices de Romhilt e Cornell. Quando considerados, simultaneamente, ou seja, a presença de pelo menos um dos quatro critérios, a sensibilidade foi 52% e a eficácia diagnóstica 57%. CONCLUSÃO: Os quatro critérios eletrocardiográficos considerados individualmente ou em conjunto foram pouco eficazes na detecção da HVE e, considerando a importância desta entidade patológica, concluímos que é imprescindível a utilização de método propedêutico mais sensível para tal diagnóstico. Abstract in english PURPOSE: To compare the efficacy of four electrocardiographic criteria: Sokolov, Gubner, Cornell and Romhilt indexes, in the diagnosis of left ventricular hypertrophy (LVH) in hypertensive patients. METHODS: LVH was analyzed in the eletrocardiogram of 30 ambulatory patients presenting with systemic [...] arterial hypertension, classified as mild, moderate and severe, according to the following indexes: Sokolov >35mm, Gubner >22mm, Romhilt >5 points and Cornell >20mm for women and 28mm for men. Sensitivity, specificity, diagnostic accuracy and other diagnostic variables were determined. Mass index of the left ventricle, >98g/m² for women and >120g/m² for men, obtained by echocardiography, was considered the gold standard for the diagnosis of LVH. RESULTS: When electrocardiographic criteria were considered separately, the Sokolov index showed the highest accuracy, with a sensitivity of 40%, diagnostic accuracy of 50% and specificity of 100%; the second most accurate index was Gubner, and Romhilt and Cornell indexes followed. When at least one of the indexes was positive, the sensitivity was 52% and diagnostic accuracy was 57%. CONCLUSION: The four electrocardiographic indexes were not diagnostic of LVH, when analyzed either separately or together. Considering the high prevalence of this pathological condition, we conclude that a more accurate diagnostic method should be used in this diagnosis.

Hamilton, Domingos; Josane Couto Elias, Luzio; Gualberto Nogueira de, Leles; Leandro, Sauer; Luiz Alberto, Ovando.

1998-07-01

282

Association of pulse pressure with new-onset atrial fibrillation in patients with hypertension and left ventricular hypertrophy : the Losartan Intervention For Endpoint (LIFE) reduction in hypertension study  

DEFF Research Database (Denmark)

Previous studies have found pulse pressure (PP), a marker of arterial stiffness, to be an independent predictor of atrial fibrillation (AF) in general and hypertensive populations. We examined whether PP predicted new-onset AF in comparison with other blood pressure components in the Losartan Intervention For Endpoint reduction in hypertension study, a double-blind, randomized (losartan versus atenolol), parallel-group study, including 9193 patients with hypertension and electrocardiographic left ventricular hypertrophy. In 8810 patients with neither a history of AF nor AF at baseline, Minnesota coding of electrocardiograms confirmed new-onset AF in 353 patients (4.0%) during mean 4.9 years of follow-up. In multivariate Cox regression analyses, baseline and in-treatment PP and baseline and in-treatment systolic blood pressure predicted new-onset AF, independent of baseline age, height, weight, and Framingham Risk Score; sex, race, and treatment allocation; and in-treatment heart rate and Cornell product. PP was the strongest single blood pressure predictor of new-onset AF determined by the decrease in the -2 Log likelihood statistic, in comparison with systolic blood pressure, diastolic blood pressure, and mean arterial pressure. When evaluated in the same model, the predictive effect of systolic and diastolic blood pressures together was similar to that of PP. In this population of patients with hypertension and left ventricular hypertrophy, PP was the strongest single blood pressure predictor of new-onset AF, independent of other risk factors.

Larstorp, Anne Cecilie K; Ariansen, Inger

2012-01-01

283

Endomyocardial biopsies in patients with left ventricular hypertrophy and a common Chinese later-onset fabry mutation (IVS4?+?919G?>?A)  

Science.gov (United States)

Background In Taiwan, DNA-based newborn screening showed a surprisingly high incidence of a cardiac Fabry mutation (IVS4?+?919G?>?A). The prevalence of this mutation is too high to be believed that it is a real pathogenic mutation. The purpose of this study is to identify the cardiac pathologic characteristics in patients with left ventricular hypertrophy and this mutation Methods and results Endomyocardial biopsies were obtained in 22 patients (Median age: 61, males: 17; females: 5) with left ventricular hypertrophy and the IVS4?+?919G?>?A mutation; five patients had not received enzyme replacement therapy (ERT) before biopsy, while the other 17 patients had received ERT from 8 months to 51 months. Except for three patients who had received ERT for more than 3 years, all other patients showed significant pathological change and globotriaosylceramide (Gb3) accumulation in their cardiomyocytes. In contrast to classical Fabry patients, no Gb3 accumulation was found in the capillary endothelial cells of any of our patients. Fourteen patients (63.6%) were found to have myofibrillolysis. Conclusions All of the untreated and most of the treated IVS4?+?919G?>?A patients showed typical pathological changes of Fabry disease in their cardiomyocytes. No endothelial accumulation of Gb3 was found, which is similar to the findings of several previous reports regarding later-onset Fabry disease. This result highly suggests that the IVS4?+?919G?>?A is a real pathogenic later-onset Fabry mutation. PMID:24980630

2014-01-01

284

Calcium-sensing receptor activation contributed to apoptosis stimulates TRPC6 channel in rat neonatal ventricular myocytes  

International Nuclear Information System (INIS)

Capacitative calcium entry (CCE) refers to the influx of calcium through plasma membrane channels activated on depletion of endoplasmic sarcoplasmic/reticulum (ER/SR) Ca2+ stores, which is performed mainly by the transient receptor potential (TRP) channels. TRP channels are expressed in cardiomyocytes. Calcium-sensing receptor (CaR) is also expressed in rat cardiac tissue and plays an important role in mediating cardiomyocyte apoptosis. However, there are no data regarding the link between CaR and TRP channels in rat heart. In this study, in rat neonatal myocytes, by Ca2+ imaging, we found that the depletion of ER/SR Ca2+ stores by thapsigargin (TG) elicited a transient rise in cytoplasmic Ca2+ ([Ca2+]i), followed by sustained increase depending on extracellular Ca2+. But, TRP channels inhibitor (SKF96365), not L-type channels or the Na+/Ca2+ exchanger inhibitors, inhibited [Ca2+]i relatively high. Then, we found that the stimulation of CaR with its activator gadolinium chloride (GdCl3) or by an increased extracellular Ca2+([Ca2+]o) increased the concentration of intracelluar Ca2+, whereas, the sustained elevation of [Ca2+]i was reduced in the presence of SKF96365. Similarly, the duration of [Ca2+]i increase was also shortened in the absence of extracellular Ca2+. Western blot analysis showed that GdCl3 increased the expression of TRPC6, which was reversed by SKF96365. Additionally, SKF96365 reduced cardiomyocyte apoptosis induced by GdCl3. Our results suggested that CCE exhibited in rat neonatal myocytes and CaR activation induced Ca2+-permeable cationic channels TRPCs to gate the CCE, for which TRPC6 was one of the most likely candidates. TRPC6 channel was functionally coupled with CaR to enhance the cardiomyocyte apoptosis.

285

pH-dependent and -independent effects inhibit Ca(2+)-induced Ca2+ release during metabolic blockade in rat ventricular myocytes.  

Science.gov (United States)

We have investigated the role of changes of intracellular pH (pHi) in the effects of metabolic blockade (cyanide plus 2-deoxyglucose) on Ca2+ release from the sarcoplasmic reticulum (SR) in rat ventricular myocytes. pHi and cell length were measured simultaneously. Metabolic blockade decreased the frequency of Ca2+ waves, an effect previously shown to be due to inhibition of Ca2+ release from the SR. This was accompanied by an intracellular acidification. Intracellular acidification was produced in the absence of metabolic inhibition by application of sodium butyrate. A maintained intracellular acidosis produced a decrease of wave frequency. A hysteresis between pHi and wave frequency was observed such that during the onset of the acidification the wave frequency decreased more than in the steady state. Comparison of the steady state relationship between pHi and wave frequency showed that the decrease of wave frequency produced by metabolic blockade was greater than could be accounted for simply by the accompanying decrease of pHi. In other experiments the buffering power of the solution was increased. Under these conditions, metabolic blockade produced no change of pHi but the decrease of wave frequency persisted. We conclude that, although intracellular acidification occurs during metabolic blockade, it is not responsible for most of the inhibition of Ca2+ release from the SR. PMID:12766236

O'Neill, S C; Eisner, D A

2003-07-15

286

Effects of itopride hydrochloride on the delayed rectifier K+ and L-type CA2+ currents in guinea-pig ventricular myocytes.  

Science.gov (United States)

The effects of itopride hydrochloride, a new drug used to regulate motility in the gastrointestinal tract, on the delayed rectifier K+ current (I(K)) and the L-type Ca2+ current (I(Ca)) were evaluated in guinea-pig ventricular myocytes at concentrations of 1, 10 and 100 microM to determine whether the drug has a proarrhythmic effect through blockade of I(K). Itopride did not affect I(K) at concentrations of 100 microM or less, and no significant effects of 1, 10 or 100 microM itopride were observed on the inward rectifier K+ current (I(K1)) responsible for the resting potential and final repolarization phase of the action potential. We next investigated the effects of itopride on L-type Ca2+ current (I(Ca)). Significant inhibition of I(Ca) was observed at itopride concentrations greater than 10 microM. These results suggested that itopride hydrochloride has an inhibitory effect on I(Ca) at concentrations much higher than those in clinical use. PMID:11127807

Morisawa, T; Hasegawa, J; Hama, R; Kitano, M; Kishimoto, Y; Kawasaki, H

1999-01-01

287

Loss of T-tubules and other changes to surface topography in ventricular myocytes from failing human and rat heart  

OpenAIRE

T-tubular invaginations of the sarcolemma of ventricular cardiomyocytes contain junctional structures functionally coupling L-type calcium channels to the sarcoplasmic reticulum calcium-release channels (the ryanodine receptors), and therefore their configuration controls the gain of calcium-induced calcium release (CICR). Studies primarily in rodent myocardium have shown the importance of T-tubular structures for calcium transient kinetics and have linked T-tubule disruption to delayed CICR....

Lyon, Alexander R.; Macleod, Ken T.; Zhang, Yanjun; Garcia, Edwin; Kanda, Gaelle Kikonda; Lab, Max J.; Korchev, Yuri E.; Harding, Sian E.; Gorelik, Julia

2009-01-01

288

Endothelin enhances the contractile responsiveness of adult rat ventricular myocytes to calcium by a pertussis toxin-sensitive pathway.  

OpenAIRE

It has long been assumed that the primary influences regulating cardiac contractility are the extent of mechanical loading of muscle fibers and the activity of the autonomic nervous system. However, the vasoactive peptide endothelin, initially found in vascular endothelium, is among the most potent positively inotropic agents yet described in mammalian myocardium. In isolated adult rat ventricular cells, endothelin's action was slow in onset but very long lasting with an EC50 of 50 pM that ap...

Kelly, R. A.; Eid, H.; Kra?mer, Bernhard K.; O Neill, M.; Liang, B. T.; Reers, M.; Smith, T. W.

1990-01-01

289

Ligand activation of cannabinoid receptors attenuates hypertrophy of neonatal rat cardiomyocytes.  

Science.gov (United States)

: Endocannabinoids are bioactive amides, esters, and ethers of long-chain polyunsaturated fatty acids. Evidence suggests that activation of the endocannabinoid pathway offers cardioprotection against myocardial ischemia, arrhythmias, and endothelial dysfunction of coronary arteries. As cardiac hypertrophy is a convergence point of risk factors for heart failure, we determined a role for endocannabinoids in attenuating endothelin-1-induced hypertrophy and probed the signaling pathways involved. The cannabinoid receptor ligand anandamide and its metabolically stable analog, R-methanandamide, suppressed hypertrophic indicators including cardiomyocyte enlargement and fetal gene activation (ie, the brain natriuretic peptide gene) elicited by endothelin-1 in isolated neonatal rat ventricular myocytes. The ability of R-methanandamide to suppress myocyte enlargement and fetal gene activation was mediated by CB2 and CB1 receptors, respectively. Accordingly, a CB2-selective agonist, JWH-133, prevented only myocyte enlargement but not brain natriuretic peptide gene activation. A CB1/CB2 dual agonist with limited brain penetration, CB-13, inhibited both hypertrophic indicators. CB-13 activated AMP-activated protein kinase (AMPK) and, in an AMPK-dependent manner, endothelial nitric oxide synthase (eNOS). Disruption of AMPK signaling, using compound C or short hairpinRNA knockdown, and eNOS inhibition using L-NIO abolished the antihypertrophic actions of CB-13. In conclusion, CB-13 inhibits cardiomyocyte hypertrophy through AMPK-eNOS signaling and may represent a novel therapeutic approach to cardioprotection. PMID:24979612

Lu, Yan; Akinwumi, Bolanle C; Shao, Zongjun; Anderson, Hope D

2014-11-01

290

Diagnóstico electrocardiográfico de la Hipertrofia Ventricular Izquierda en pacientes hipertensos. Utilidad del producto duración por voltaje del QRS / Electrocardiography Diagnosis of the Left Ventricular Hypertrophy in hypertensive patients. Usefulness of the product of the duration of voltage of QRS  

Scientific Electronic Library Online (English)

Full Text Available SciELO Cuba | Language: Spanish Abstract in spanish Introducción: las enfermedades cardiovasculares provocan la muerte de uno de cada tres cubanos. La Hipertensión arterial (HTA) y consecuentemente la Hipertrofia Ventricular Izquierda (HVI) constituye un factor de riesgo prevalente y capaz de desencadenar serias complicaciones. Objetivo: identificar [...] el comportamiento de los criterios electrocardiográficos de Sokolow, Cornell y el Producto de la Duración por el Voltaje (PDV) del QRS en pacientes con HVI ecocardiográfica. Material y Método: la muestra seleccionada coincide con el universo y consta de 76 pacientes portadores de hipertensión arterial (HTA) atendidos en la consulta de Cardiología. Se les realizó una encuesta sobre la presencia de factores de riesgo, determinación del índice de masa corporal, realización de electrocardiograma y ecocardiograma para establecer la HVI. Resultados: el 61% de los pacientes eran portadores del HVI ecocardiográfica (Prueba de Oro diagnóstica). Para los índices electrocardiográficos de Sokolow y Cornell la sensibilidad (S) fue respectivamente de 22%, y 24%, existiendo en ambos una especificidad (E) de 93%. La (S) para el PDV-Sokolow alcanzó 33%, 22% entre los hombres y 11% entre las mujeres con una (E) total de 97%, mientras el PDV-Cornell tuvo una (S) de 35%, 11% entre los hombres y 24% entre las mujeres, con una (E) total para este índice de 93%. Conclusiones: el ECG es indispensable para el diagnóstico de HVI; el PDV-C y el PDV-S son de mayor sensibilidad diagnóstica que los índices de voltaje aislados; el primero es más útil en mujeres con características epidemiológicas bien definidas. Abstract in english Introduction: cardiovascular diseases cause the death of one out of three Cubans. High Blood Pressure and consequently Left Ventricular Hyperthrophty constitutes a prevalent risk factor able to trigger serious complications. Objective: to identify the behavior of the electrocardiographic approaches [...] of Sokolow, Cornell and the Product of the Duration of Voltage of QRS in patients with Echocardiography Left Ventricular Hypertrophy. Material and Method: the sample coincides with the universe which consists of 76 patients suffering from High Blood Pressure and treated at the Consultation of Cardiology. The patients were surveyed about the presence of risk factors, body mass index and records of electrocardiogram and echocardiogram to confirm their left ventricular hypertrophy. Results: 61% of the patients had echocardiograph left ventricular hypertrophy. For the electrocardiographic indexes of Sokolow and Cornell the sensitivity was 26% and 24% respectively, both tests showed a specificity of 93%. The sensitivity for the Product of the Duration of Voltage for Sokolow reached 33% with a specificity of 97% while the Product of the Duration of Voltage for Cornell had a sensitivity of 35% and a specificity of 93%. Conclusions: ECG is essential in the diagnosis of Left Ventricular Hypertrophy, the Product of the Duration of Voltage for Cornell and the Product of the Duration of Voltage for Sokolow have a higher diagnostic sensitivity than isolated voltage indexes, the former is more useful in women with well defined epidemiological features.

Juan Lázaro, González Moreno; Belkis, Martínez Martínez; Olga María, Rivero González; Adys H, Salgado Friol; Pablo José, Díaz San Jorge.

2013-09-01

291

Sensibilidade do eletrocardiograma na hipertrofia ventricular de acordo com gênero e massa cardíaca Electrocardiogram sensitivity in left ventricular hypertrophy according to gender and cardiac mass  

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FUNDAMENTO: Sabe-se que vários fatores interferem na sensibilidade do Eletrocardiograma (ECG) no diagnóstico da Hipertrofia Ventricular Esquerda (HVE), sendo o gênero e a massa cardíaca alguns dos principais. OBJETIVO: Avaliar a influência do sexo na sensibilidade de alguns dos critérios utilizados para a detecção de HVE, de acordo com a progressão do grau de hipertrofia ventricular. MÉTODOS: De acordo com o gênero e com o grau de HVE ao ecocardiograma, os pacientes foram divididos...

Colossimo, Ana P.; Francisco Assis Costa; Riera, Andre?s R. P.; Bombig, Maria T. N.; Lima, Valter C.; Fonseca, Francisco A. H.; Izar, Maria C. O.; Filho, Bra?ulio L.; Dilma Souza; Povoa, Rui M. S.

2011-01-01

292

Effect of Glycemic Control on the Progress of Left Ventricular Hypertrophy and Diastolic Dysfunction in Children with Type I Diabetes Mellitus  

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Full Text Available The present research evaluated the progression of left ventricular structural and functional changes in children and adolescent patients with type I DM and the effect of glycemic control on these changes. A Prospective, case-controlled, observational study was carried out in tertiary referral hospital in Holly Makkah-KSA including 135 young patients with type I DM recruited from the endocrinology clinic and were followed up in the hospital cardiac center unit. Patients were divided into 2 groups: group composed of 46 patients with type I DM and left ventricular hypertrophy (LVH+ve group compared to another group, composed of 89 patients with type I DM but had a normal left ventricular echocardiographic parameters (LVH -ve group. All the studied patients were subjected to full history taking, clinical and cardiac examination. Electrocardiogram, laboratory tests for glycosylated hemoglobin, lipid profile, albuminuria and careful ecocardiographic examination were done. All patients were followed up and participated in a program for glycemic control. Echocardiographic follow-up was done thoroughly again for patients who had left ventricular hypertrophy (LVH after two years. Our results showed that echocardiographic parameters after 2 years follow up showed statistically significant difference regarding cardiac structural and functional parameters in favor for the patients in group who achieved glycemic control. Also comparing echocardiographic parameters of those patients who achieved glycemic control to their baseline results showed that mean value of interventricular septal dimension (IVSd decreased from 1.12cm to 1.03 (p = 0.04, posterior wall dimension (PWd decreased from 1.07-0.97 (p = 0.05 however diastolic dysfunction represented by isovolumic relaxation time (IVRT and E/A did not show a statistically significant change. Patients who did not achieve glycemic control showed worsening of their echocardiographic parameters: IVSd increased significantly (p = 0.01, E/A ratio showed a significant decrease (p = 0.006 and IVRT significantly increased (p = 0.04. We concluded that good glycemic control in diabetic patients could improve some structural parameters of the heart while failure to achieve glycemic control leads to deterioration in functional and structural parameters of the heart. Follow up and early detection of myocardial structural and functional changes in young patients with type I DM contribute to better knowledge of diabetic cardiomyopathy and may help to prevent the natural progression of the disease.

Inas Abdul-Sattar Saad

2007-01-01

293

Association of the beta-1 adrenergic receptor carboxyl terminal variants with left ventricular hypertrophy among diabetic and non-diabetic survivors of acute myocardial infarction  

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Full Text Available Abstract Background The beta-1 adrenergic receptor (?1AR plays a fundamental role in the regulation of cardiovascular functions. It carries a nonsynonymous single nucleotide polymorphism in its carboxyl terminal tail (Arg389Gly, which has been shown to associate with various echocardiographic parameters linked to left ventricular hypertrophy (LVH. Diabetes mellitus (DM, on the other hand, represents a risk factor for LVH. We investigated the possible association between the Arg389Gly polymorphism and LVH among non-diabetic and diabetic acute myocardial infarction (AMI survivors. Methods The study population consisted of 452 AMI survivors, 20.6% of whom had diagnosed DM. Left ventricular parameters were measured with two-dimensional guided M-mode echocardiography 2-7 days after AMI, and the Arg389Gly polymorphism was determined using a polymerase chain reaction-restriction fragment length polymorphism assay. Results The Arg389 homozygotes in the whole study population had a significantly increased left ventricular mass index (LVMI when compared to the Gly389 carriers (either Gly389 homozygotes or Arg389/Gly389 heterozygotes [62.7 vs. 58.4, respectively (p = 0.023]. In particular, the Arg389 homozygotes displayed thicker diastolic interventricular septal (IVSd measures when compared to the Gly389 carriers [13.2 vs. 12.3 mm, respectively (p = 0.004]. When the euglycemic and diabetic patients were analyzed separately, the latter had significantly increased LVMI and diastolic left ventricular posterior wall (LVPWd values compared to the euglycemic patients [LVMI = 69.1 vs. 58.8 (p = 0.001 and LVPWd = 14.2 vs. 12.3 mm (p Conclusions The data suggest an association between the ?1AR Arg389Gly polymorphism and LVH, particularly the septal hypertrophy. The Arg389 variant appears to confer a higher risk of developing LVH than the corresponding Gly389 variant among patients who have suffered AMI. This association cannot be considered to be universal, however, since it does not appear to exist among diabetic AMI survivors.

Hakalahti Anna E

2010-08-01

294

Study in Southern India Among Hypertensive Patients Using ECG To Screen Left Ventricular Hypertrophy – Can We Do It in Rural Health Centres?  

Science.gov (United States)

Background: Electrocardiogram (ECG) is a cost effective tool to evaluate left ventricular hypertrophy (LVH). However, its reliability is often questionable when compared to the gold standard - echocardiography.The validation of ECG as a tool to diagnose LVH would benefit centres that lack access to echocardiography. Aim: (1) To assess the efficacy of ECG criteria to screen for left ventricular hypertrophy in comparison to echocardiography. (2) To determine whether ECG can be used as a screening tool for LVH in rural primary health centres. Materials and Methods: Fifty hypertensive patients admitted to a tertiary level hospital fulfilling the inclusion and the exclusion criteria, were evaluated for LVH using ECG and echocardiography. Romhilt-Estes and Sokolow-Lyon criteria were applied to all subjects and their efficiency in detecting LVH was measured using Kappa statistics in comparison to echocardiography. Results: Among the 50 patients, 23 had LVH by echocardiography. In comparison to echocardiography, Romhilt-Estes and Sokolow-Lyon criteria were specific for LVH (96.3%, 88.9% respectively), but were poorly sensitive (43.5%, 43.5%). Combining both the criteria, raised the sensitivity to 60.9% and specificity to 85.2%. Kappa statistical analysis showed moderate to fair agreement of the Romhilt-Estes criteria with echocardiography. Both criteria had high positive predictive values (90.9%, 76.9%). Conclusion: Both Romhilt-Estes and Sokolow-Lyon ECG criteria are poor screening tools due to low sensitivity. But during routine screening of hypertensive patients with ECG alone, if any patient is positive by Romhilt-Estes criteria or both criteria, it would certainly warrant echocardiographic evaluation. As echocardiography cannot be recommended to screen every patient with hypertension in developing countries, initial evaluation using ECG can certainly help in selecting those who require echocardiography. PMID:24783082

Pinto, Jostol; George, Peter; Hegde, Narasimha

2014-01-01

295

La disfunción diastólica en pacientes hipertensos no es debida a hipertrofia ventricular izquierda / Diastolic dysfunction in hypertensive patients is not due to left ventricular hypertrophy / A disfunção diastólica em pacientes hipertensos não é devida à hipertrofia ventricular esquerda  

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Full Text Available SciELO Argentina | Language: Spanish Abstract in portuguese Introdução. .A hipertrofia ventricular esquerda (HVE) é uma complicação comum da hipertensão e pode estar associada com disfunção diastólica (DD). Objetivos. Determinar a prevalência de DD em pacientes hipertensos (HT) sem HVE. Material e métodos. Foram incluídos 98 pacientes HT, 66 pacientes sem HV [...] E e 32 pacientes com HVE medida pelo método de Devereux, considerando HVE um índice de massa ventricular esquerda >110 g/m2 em mulheres e 125 g/m2 em homens. Foi realizado Doppler pulsado do orifício da válvula mitral, e foi medida a razão velocidade instantânea pico E / velocidade instantânea pico A (VE/VA) e tempo de relaxamento isovolumétrico (TRIV), ambos foram corrigidos pela idade; e Doppler tecidual do septo interventricular, e foi medida a taxa de pico de velocidade instantânea E'/ pico de velocidade instantânea A' (VE'/VA') e de pico e velocidade instantânea E / pico de velocidade instantânea E' (VE/VE'). Resultados. A média de idade 60,3 ± 36,7 anos, 45 pacientes do sexo masculino (45,9%), 8 pacientes diabéticos (8,2%). A tabela apresenta os resultados da avaliação da função diastólica Conclusões. 1) Alta freqüência de DD em pacientes com hipertensão sem HVE; 2) A única diferença na função diastólica entre pacientes com hipertensão sem e com HVE é maior a pressão diastólica ventricular esquerda expressa por VE/VE'; 3) HVE não é causa do DD em pacientes com hipertensão. Abstract in spanish Introducción. La hipertrofia ventricular izquierda (HVI) es una complicación frecuente en hipertensión arterial y se puede acompañar de disfunción diastólica (DD). Objetivos. Determinar la prevalencia de DD en pacientes hipertensos (HT) sin HVI. Material y métodos. Se incluyeron 98 pacientes con HT, [...] 66 pacientes sin HVI y 32 pacientes con HVI medida por método de Devereux, considerándose HVI un índice de masa ventricular izquierda >110 g/m2 en mujeres y 125 g/m2 en hombres. Se efectuó Doppler pulsado del orificio valvular mitral y se midió la relación velocidad instantánea pico E/velocidad instantánea pico A (VE/VA) y el tiempo de relajación isovolumétrica (TRIV), ambos fueron corregidos por edad, y Doppler tisular del septum interventricular, midiéndose la relación velocidad instantánea pico E´/velocidad instantánea pico A´ (VE´/VA´) y velocidad instantánea pico E/velocidad instantánea pico E´ (VE/VE´). Resultados. Edad media: 60,3±36,7 años; sexo masculino: 45 pacientes (45,9 %); 8 pacientes diabéticos (8,2%). La tabla presenta los resultados de la evaluación de función diastólica. Conclusiones. 1) Alta frecuencia de DD en pacientes HT sin HVI. 2) La única diferencia en la función diastólica entre pacientes HT sin y con HVI es la mayor presión de fin de diástole del ventrículo izquierdo expresada por VE/VE´. 3) La HVI no es la causa de DD en pacientes HT. Abstract in english Background. Left ventricular hypertrophy (LVH) is a common complication of hypertension and may be associated with diastolic dysfunction (DD). Objectives. To determine the prevalence of DD in hypertensive (HT) patients without LVH. Methods and material. 98 HT patients were included, 66 with LVH and [...] 32 without LVH measured by the method ofDevereux, LVH was considered a left ventricular mass index >110 g/m2 in women and 125 g/m2 in men. Mitral valve orifice pulsed Doppler was performed and it was measured the peak instantaneous velocity ratio E/A (VE/VA) and isovolumetric relaxation time (IVRT), both were corrected by age; and tissue Doppler of the interventricular septum was also preformed, and it was measured the peak instantaneous velocity ratio E'/A' (VE'/ VA') and instantaneous velocity peak E/E' (VE/VE'). Results. Mean age 60.3±36.7 years, male 45 patients (45,9%), 8 diabetic patients (8.2%). The table presents the results of the assessment of diastolic function. Conclusions. 1) High frequency of DD in HT patients without LVH, 2) The only one difference between patients

Daniel, Piskorz; Alicia, Tommasi.

2011-03-01

296

Correlation of heart rate variability with cardiac functional and metabolic variables in cyclists with training induced left ventricular hypertrophy  

OpenAIRE

OBJECTIVE—To examine the correlation between heart rate variability and left ventricular mass in cyclists with an athlete's heart.?METHODS—Left ventricular mass and diastolic function were determined at rest and myocardial high energy phosphates were quantified at rest and during atropine-dobutamine stress in 12 male cyclists and 10 control subjects, using magnetic resonance techniques. Ambulatory 24 hour ECG recordings were obtained, and time and frequency domain heart rate variabil...

Pluim, B.; Swenne, C.; Zwinderman, A.; Maan, A.; Laarse, A.; Doornbos, J.; Wall, E. E.

1999-01-01

297

Comparison of the effects on blood pressure and left ventricular hypertrophy of lacidipine and hydrochlorothiazide in hypertensive patients.  

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We evaluated the effects of lacidipine and hydrochlorothiazide on blood pressure and left ventricular mass in hypertensive patients of mild-to-moderate degree. Both antihypertensive agents significantly decreased systolic and diastolic blood pressure without relevant symptoms and signs of reflex activation of the sympathetic nervous system. Posterior wall and interventricular septal thickness and the left ventricular mass were significantly decreased by lacidipine and hydrochlorothiazide after 3 and 6 months of treatment without clinical symptoms of reduced cardiac function. PMID:1839161

Leonetti, G; Fogari, R; Mazzola, C; Mangiameli, S; Castello, C

1991-12-01

298

Differential effects of the sodium calcium exchange inhibitor, KB-R7943, on ischemia and reperfusion injury in isolated guinea pig ventricular myocytes.  

Science.gov (United States)

Effects of the Na(+)-Ca(2+) exchange (NCX) inhibitor KB-R7943 on electrical and contractile function were examined in guinea pig ventricular myocytes exposed to ischemia and reperfusion. Action potentials and transmembrane currents were recorded with microelectrodes; contractions were measured with an edge detector. Cells were exposed to simulated ischemia (hypoxia, hypercapnia, hyperkalemia, acidosis, lactate accumulation, no glucose) for 20 min and reperfused with Tyrode's solution. Experiments were conducted at 37 degrees C in the absence or presence of KB-R7943. Low concentrations of KB-R7943 (0.1 microM) had little impact on changes in contractions, membrane potential, or Ca(2+) current induced by ischemia and reperfusion. However, higher concentrations of KB-R7943 (0.5 and 1.0 microM) reduced the magnitude of Ca(2+) current and promoted action potential abbreviation in both ischemia and reperfusion. High concentrations of KB-R7943 also promoted post-ischemic contractile dysfunction (stunning) in reperfusion. In the absence of KB-R7943, the arrhythmogenic transient inward current (I(TI)) plus aftercontractions occurred upon reperfusion, and some cells exhibited irreversible cell injury (hypercontracture). Higher concentrations of KB-R7943 (0.5 and 1.0 micoM) did not affect the occurrence or magnitude of I(TI) and aftercontractions and did not affect the occurrence of hypercontracture. In contrast, 0.1 microM KB-R7943 virtually abolished I(TI), aftercontractions and hypercontracture. Thus, low concentrations of KB-R7943 protected against ischemia and reperfusion injury, but higher concentrations of drug actually exacerbated detrimental effects of ischemia and reperfusion. These results suggest that inhibition of I(TI) may contribute to the antiarrhythmic effects of KB-R7943 on reperfusion-induced arrhythmias. PMID:18036586

MacDonald, Ashley C; Howlett, Susan E

2008-02-01

299

Inhibition of the sarcoplasmic reticulum Ca2+ pump with thapsigargin to estimate the contribution of Na+-Ca2+ exchange to ventricular myocyte relaxation  

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Full Text Available Relaxation in the mammalian ventricle is initiated by Ca2+ removal from the cytosol, which is performed by three main transport systems: sarcoplasmic reticulum Ca2+-ATPase (SR-A, Na+-Ca2+ exchanger (NCX and the so-called slow mechanisms (sarcolemmal Ca2+-ATPase and mitochondrial Ca2+ uptake. To estimate the relative contribution of each system to twitch relaxation, SR Ca2+ accumulation must be selectively inhibited, usually by the application of high caffeine concentrations. However, caffeine has been reported to often cause changes in membrane potential due to NCX-generated inward current, which compromises the reliability of its use. In the present study, we estimated integrated Ca2+ fluxes carried by SR-A, NCX and slow mechanisms during twitch relaxation, and compared the results when using caffeine application (Cf-NT and an electrically evoked twitch after inhibition of SR-A with thapsigargin (TG-TW. Ca2+ transients were measured in 20 isolated adult rat ventricular myocytes with indo-1. For transients in which one or more transporters were inhibited, Ca2+ fluxes were estimated from the measured free Ca2+ concentration and myocardial Ca2+ buffering characteristics. NCX-mediated integrated Ca2+ flux was significantly higher with TG-TW than with Cf-NT (12 vs 7 µM, whereas SR-dependent flux was lower with TG-TW (77 vs 81 µM. The relative participations of NCX (12.5 vs 8% with TG-TW and Cf-NT, respectively and SR-A (85 vs 89.5% with TG-TW and Cf-NT, respectively in total relaxation-associated Ca2+ flux were also significantly different. We thus propose TG-TW as a reliable alternative to estimate NCX contribution to twitch relaxation in this kind of analysis.

Bassani R.A.

2003-01-01

300

Inhibition of the sarcoplasmic reticulum Ca2+ pump with thapsigargin to estimate the contribution of Na+-Ca2+ exchange to ventricular myocyte relaxation  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Relaxation in the mammalian ventricle is initiated by Ca2+ removal from the cytosol, which is performed by three main transport systems: sarcoplasmic reticulum Ca2+-ATPase (SR-A), Na+-Ca2+ exchanger (NCX) and the so-called slow mechanisms (sarcolemmal Ca2+-ATPase and mitochondrial Ca2+ uptake). To e [...] stimate the relative contribution of each system to twitch relaxation, SR Ca2+ accumulation must be selectively inhibited, usually by the application of high caffeine concentrations. However, caffeine has been reported to often cause changes in membrane potential due to NCX-generated inward current, which compromises the reliability of its use. In the present study, we estimated integrated Ca2+ fluxes carried by SR-A, NCX and slow mechanisms during twitch relaxation, and compared the results when using caffeine application (Cf-NT) and an electrically evoked twitch after inhibition of SR-A with thapsigargin (TG-TW). Ca2+ transients were measured in 20 isolated adult rat ventricular myocytes with indo-1. For transients in which one or more transporters were inhibited, Ca2+ fluxes were estimated from the measured free Ca2+ concentration and myocardial Ca2+ buffering characteristics. NCX-mediated integrated Ca2+ flux was significantly higher with TG-TW than with Cf-NT (12 vs 7 µM), whereas SR-dependent flux was lower with TG-TW (77 vs 81 µM). The relative participations of NCX (12.5 vs 8% with TG-TW and Cf-NT, respectively) and SR-A (85 vs 89.5% with TG-TW and Cf-NT, respectively) in total relaxation-associated Ca2+ flux were also significantly different. We thus propose TG-TW as a reliable alternative to estimate NCX contribution to twitch relaxation in this kind of analysis.

R.A., Bassani; J.W.M., Bassani.

1717-17-01

301

The H{sub 1}–H{sub 2} domain of the ?{sub 1} isoform of Na{sup +}–K{sup +}–ATPase is involved in ouabain toxicity in rat ventricular myocytes  

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The composition of different isoforms of Na{sup +}-K{sup +}-ATPase (NKA, Na/K pump) in ventricular myocytes is an important factor in determining the therapeutic effect and toxicity of cardiac glycosides (CGs) on heart failure. The mechanism whereby CGs cause these effects is still not completely clear. In the present study, we prepared two site-specific antibodies (SSA78 and WJS) against the H{sub 1}–H{sub 2} domain of ?{sub 1} and ?{sub 2} isoforms of NKA in rat heart, respectively, and compared their influences on the effect of ouabain (OUA) in isolated rat ventricular myocytes. SSA78 or WJS, which can specifically bind with the ?{sub 1} or ?{sub 2} isoform, were assessed with enzyme linked immunosorbent assay (ELISA), Western blot and immunofluorescent staining methods. Preincubation of myocytes with SSA78 inhibited low OUA affinity pump current but not high OUA affinity pump current, reduced the rise in cytosolic calcium concentration ([Ca{sup 2+}]{sub i}), attenuated mitochondrial Ca{sup 2+} overload, restored mitochondrial membrane potential reduction, and delayed the decrease of the myocardial contractile force as well as the occurrence of arrhythmic contraction induced by high concentrations (1 mM) but not low concentrations (1 ?M) of OUA. Similarly, preincubation of myocytes with WJS inhibited high OUA affinity pump current, reduced the increase of [Ca{sup 2+}]{sub i} and the contractility induced by 1 ?M but not that induced by 1 mM OUA. These results indicate that the H{sub 1}–H{sub 2} domain of the NKA ?{sub 1} isoform mediates OUA-induced cardiac toxicity in rat ventricular myocytes, and inhibitors for this binding site may be used as an adjunct to CGs treatment for cardiovascular disease. -- Highlights: ? We prepared two antibodies against the H{sub 1}-H{sub 2} domain of ?{sub 1} and ?{sub 2} isoforms of NKA. ? The H{sub 1}-H{sub 2} domain of the NKA ?{sub 1} isoform mediates OUA-induced cardiac toxicity. ? The H{sub 1}-H{sub 2} domain of the NKA ?{sub 2} isoform mediates OUA-induced positive inotropic.

Xiong, Chen; Li, Jun-xia; Guo, Hui-cai; Zhang, Li-nan; Guo, Wei; Meng, Jing; Wang, Yong-li, E-mail: wangyongli@gmail.com

2012-07-01

302

[Effects of Shenmai injection on afterdepolarization and triggered activities in left ventricular papillary muscle in rat cardiac hypertrophy].  

Science.gov (United States)

This study is to evaluate the effects of Shenmai injection on the temporal alterations of action potential (AP), early afterdepolarization (EAD) and delayed afterdepolarization (DAD) in papillary muscles. The action potentials were recorded by a glass electrode. APD at 90% repolarization (APD9 ) was measured, and spontaneous EAD and DAD were observed. The results show APD90 was significantly prolonged in model group compared with sham-operated group, whereas it was remained unchanged in Shenmai injec- tion treatment group and amiodarone group. The spontaneous EADs and DADs were frequently visible in model group. In conclusion, EAD, DAD and trigger activities increase gradually during pathological progression of rat cardiac hypertrophy, and Shenmai injection could improve the action potential change in rat cardiac hypertrophy. PMID:25507562

Jiao, Hong; Wang, Xiao-Ling; Chen, Yan-Jing; Xiang, Li-Hua; Zhang, Sheng-Nan

2014-08-01

303

Left ventricular function and cardiac hypertrophy in the cases of mild hypertension with marked ST-T changes in electrocardiogram  

International Nuclear Information System (INIS)

The characteristics of the hemodynamic pattern and cardiac hypertrophy of mild hypertensive patients with giant negative T waves in electrocardiogram (ECG) (group I, 12 patients) were examined by the radionuclide methods, the cardiac catheterization and the echocardiogram. As control groups, the patients of essential hypertension (EH) with high voltage in ECG (group II, 36 patients), those with high voltage and mild ST-T changes in ECG (group III, 9 patients), and the patients with normotensive hypertrophic cardiomyopathy (group IV, 8 patients) were studied. Ejection fraction and cardiac index in group I were increased compared with those in group II (p 201Tl) myocardial images was significantly lower than in group II and III (p 201Tl-uptake index in cardiac apex determined by apical/total counts was increased in group I compared with other groups. These results suggest that group I is hyperkinetic state and has marked apical hypertrophy. The possibility exists that the increased afterload might be a trigger of apical hypertropoad might be a trigger of apical hypertrophy in predisposed individuals. (author)

304

Detection of incipient left ventricular hypertrophy in mild to moderate arterial hypertension with normal electrocardiogram and echocardiogram: a new use for signal-averaged electrocardiography  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english OBJECTIVE: To assess signal-averaged electrocardiogram (SAECG) for diagnosing incipient left ventricular hypertrophy (LVH). METHODS: A study with 115 individuals was carried out. The individuals were divided as follows: GI - 38 healthy individuals; GII - 47 individuals with mild to moderate hyperten [...] sion and normal findings on echocardiogram and ECG; and GIII - 30 individuals with hypertension and documented LVH. The magnitude vector of the SAECG was analyzed with the high-pass cutoff frequency of 40 Hz through the bidirectional four-pole Butterworth high-pass digital filter. The mean quadratic root of the total QRS voltage (RMST) and the two-dimensional integral of the QRS area of the spectro-temporal map were analyzed between 0 and 30 Hz for the frequency domain (Int FD), and between 40 and 250 Hz for the time domain (Int TD). The electrocardiographic criterion for LVH was based on the Cornell Product. Left ventricular mass was calculated with the Devereux formula. RESULTS: All parameters analyzed increased from GI to GIII, except for Int FD (GII vs GIII) and RMST log (GII vs GIII). Int TD showed greater accuracy for detecting LVH with an appropriate cutoff > 8 (sensitivity of 55%, specificity of 81%). Positive values (> 8) were found in 56.5% of the G II patients and in 18.4% of the GI patients (p

Paulo, Ginefra; Eduardo C., Barbosa; P. R., Benchimol-Barbosa; Alfredo S., Bomfim; Sílvia H., Boghossian; Angelo A., Salgado; Flávia G., Brasil; Elizabete A., Freitas; Francisco M., Albanesi Filho.

2003-07-01

305

Detection of incipient left ventricular hypertrophy in mild to moderate arterial hypertension with normal electrocardiogram and echocardiogram: a new use for signal-averaged electrocardiography  

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Full Text Available OBJECTIVE: To assess signal-averaged electrocardiogram (SAECG for diagnosing incipient left ventricular hypertrophy (LVH. METHODS: A study with 115 individuals was carried out. The individuals were divided as follows: GI - 38 healthy individuals; GII - 47 individuals with mild to moderate hypertension and normal findings on echocardiogram and ECG; and GIII - 30 individuals with hypertension and documented LVH. The magnitude vector of the SAECG was analyzed with the high-pass cutoff frequency of 40 Hz through the bidirectional four-pole Butterworth high-pass digital filter. The mean quadratic root of the total QRS voltage (RMST and the two-dimensional integral of the QRS area of the spectro-temporal map were analyzed between 0 and 30 Hz for the frequency domain (Int FD, and between 40 and 250 Hz for the time domain (Int TD. The electrocardiographic criterion for LVH was based on the Cornell Product. Left ventricular mass was calculated with the Devereux formula. RESULTS: All parameters analyzed increased from GI to GIII, except for Int FD (GII vs GIII and RMST log (GII vs GIII. Int TD showed greater accuracy for detecting LVH with an appropriate cutoff > 8 (sensitivity of 55%, specificity of 81%. Positive values (> 8 were found in 56.5% of the G II patients and in 18.4% of the GI patients (p< 0.0005. CONCLUSION: SAECG can be used in the early diagnosis of LVH in hypertensive patients with normal ECG and echocardiogram.

Ginefra Paulo

2003-01-01

306

Detection of impaired fatty acid metabolism in right ventricular hypertrophy: assessment by I-123 beta-methyl iodophenyl pentadecanoic acid (BMIPP) myocardial single-photon emission computed tomography.  

Science.gov (United States)

Fatty acid metabolism has been reported to be impaired earlier than myocardial blood flow in left ventricular hypertrophic myocardium, e.g., in hypertrophic cardiomyopathy or hypertensive heart disease. The purpose of this study was to determine whether impaired fatty acid metabolism also occurs in right ventricular (RV) hypertrophy. The subjects consisted of 6 patients with chronic obstructive pulmonary disease, 4 with primary pulmonary hypertension, 2 each with refractory pulmonary tuberculosis, tricuspid insufficiency, pulmonary embolism, 1 each with atrial septal defect, ventricular septal defect (Eisenmenger complex), Ebstein anomaly, and endocardial defect, and 7 healthy controls. SPECT imaging with Tl-201 (Tl) and I-123 beta-methyliodophenyl pentadecanoic acid (BMIPP), and Tc-99m RBC first pass and gated blood pool scintigraphy were performed. Based on Tl planar images, the subjects were classified into 3 groups: 7 patients with no RV visualization (Group A), 11 with moderate RV visualization (Group B) and 9 with marked RV visualization (Group C). As a semi-quantitative evaluation by Tl myocardial SPECT, 3 regions in 3 representative short axial images were divided into 9 segments, each of which was graded from 0 to +3, and their sum was calculated as the RV score. The right ventricular ejection fraction (RVEF) and the left ventricular ejection fraction were obtained by Tc-99m RBC cardiac scintigraphy. The groups with marked visualization of the right ventricle had lower RVEF (p correlation between the RVEF and the RV score with both Tl and BMIPP (Tl: r = -0.79, BMIPP: r = -0.70). Although a good correlation was demonstrated between the RV score with Tl and BMIPP in Groups A and B (r = 0.86, p < 0.001), in Group C, in which there was marked RV T1 visualization, the RV score with BMIPP was significantly smaller than with Tl (BMIPP vs. Tl: 11.5 +/- 3.7 vs. 16.4 +/- 3.8, p < 0.01). These findings suggest that impaired fatty acid metabolism may exist in severely hypertrophic right ventricle due to RV overload. PMID:9310169

Kim, Y; Goto, H; Kobayashi, K; Sawada, Y; Miyake, Y; Fujiwara, G; Chiba, H; Okada, T; Nishimura, T

1997-08-01

307

Rat cardiac myocyte adenosine transport and metabolism  

International Nuclear Information System (INIS)

Based on the importance of myocardial adenosine and adenine nucleotide metabolism, the adenosine salvage pathway in ventricular myocytes was studied. Accurate estimates of transport rates, separate from metabolic fllux, were determined. Adenosine influx was constant between 3 and 60 s. Adenosine metabolism maintained intracellular adenosine concentrations < 10% of the extracellular adenosine concentrations and thus unidirectional influx could be measured. Myocytes transported adenosine via saturable and nonsaturable processes. A minimum estimate of the V/sub max/ of myocytic adenosine kinase indicated the saturable component of adenosine influx was independent of adenosine kinase activity. Saturable transport was inhibited by nitrobenzylthioinosine and verapamil. Extracellular adenosine taken up myocytes was rapidly phosphorylated to adenine taken up by myocytes was rapidly phosphorylated to adenine nucleotides. Not all extracellular adenosine, though, was phosphorylated on entering myocytes, since free, as opposed to protein-bound, intracellular adenosine was detected after digitonin extraction of cells in the presence of 1 mM ethylene-diaminetetraacetic acid

308

Localization of Kv4.2 and KChIP2 in lipid rafts and modulation of outward K(+) currents by membrane cholesterol content in rat left ventricular myocytes.  

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Lipid rafts are cholesterol-enriched microdomains of the cell membrane. Here we investigate the localization of the pore forming K(+)-channel ?-subunit Kv4.2 and the ?-subunit KChIP2, underlying the transient outward K(+) current (I to), in lipid rafts in left ventricular myocytes. Furthermore, we explored the impact of membrane cholesterol depletion (using 20 mM methyl-beta-cyclodextrin (MBCD)) on K(+) outward currents. Cholesterol-saturated MBCD (20 mM) served as control. Myocytes were isolated from the left ventricular free wall of Wistar rats. The Triton X-100 (4 °C) insoluble fraction of whole cell protein was analyzed by sucrose density gradient centrifugation followed by Western blot. Kv4.2 and KChIP2 were partially detected in low-density fractions (lipid rafts). MBCD treatment (5 min) resulted in a shift of Kv4.2 and KChIP2 towards high-density fractions. K(+) currents were assessed by whole-cell patch-clamp. MBCD treatment resulted in a 29?±?3 % decrease in I to (20.0?±?1.6pApF(-1) vs. 28.5?±?2.0pApF(-1), n?=?15, p?rectifier current. PMID:24793047

Rudakova, Elena; Wagner, Michael; Frank, Magdalena; Volk, Tilmann

2015-02-01

309

Transverse shape characteristics of cardiac myocytes from rats and humans.  

Science.gov (United States)

The shape of the cardiac myocyte is complex; but, in general, it resembles that of an elliptical cylinder. Quantitative data, however, are lacking and adaptive changes in cross-sectional shape are unknown. The major and minor transverse diameters of myocytes from adult rats were measured using three independent methods: profile tracings of intact isolated myocytes, sectioned isolated myocytes, and whole-sectioned tissue. Values for major and minor diameters were virtually identical with all three methods. Using profile tracings of intact isolated myocytes, major and minor diameters were examined in isolated myocytes from freshly explanted human hearts. Five were non-failing donor hearts regarded as unsuitable for transplantation, of which 2 were normal hearts and 3 had concentric hypertrophy. Six were dilated, failing human hearts with ischemic cardiomyopathy. Major and minor diameters from the normal hearts were similar to those from normal rats. Although the number of patients was limited, the minor diameter was largest in myocytes from patients with concentric hypertrophy while the major diameter was greatest in cells from patients with ischemic cardiomyopathy. We conclude that the cross-sectional shape of structurally-intact myocytes is not altered by cell isolation. The data suggest that the transverse shape of normal human cardiac myocytes is similar to that found in rats, and that it may be altered in hypertrophy and failure. PMID:8204795

Gerdes, A M; Kellerman, S E; Malec, K B; Schocken, D D

1994-03-01

310

The clinical value of apex beat and electrocardiography for the detection of left ventricular hypertrophy from the standpoint of the distance factors from the heart to the chest wall: a multislice CT study  

OpenAIRE

The aim of this study was to investigate the clinical value of the apex beat and two ECG voltage criteria in the detection of left ventricular hypertrophy (LVH) while considering two distances, from the heart to the inner chest wall and to the chest surface, measured by using multislice CT (MSCT). The study population consisted of 151 patients clinically judged as requiring MSCT angiography. The apex beat was palpated with patients in the supine. Sokolow–Lyon voltage and Cornell voltage to ...

Ehara, Shoichi; Shirai, Nobuyuki; Matsumoto, Kenji; Okuyama, Takuhiro; Matsumura, Yoshiki; Yoshikawa, Junichi; Yoshiyama, Minoru

2011-01-01

311

Fixed combination of valsartan and amlodipine: effects on the left ventricular hypertrophy regression, albuminuria reduction and endothelium function in hypertensive patients with metabolic syndrome  

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Full Text Available Aim. To study effects of fixed combination of valsartan and amlodipine on of left ventricular hypertrophy (LVH regression, microalbuminuria reduction and endothelium function in hypertensive patients with metabolic syndrome (MS.Materials and methods. 20 hypertensive patients (15 females and 5 males with metabolic syndrome and a history of previous ineffective antihypertensive therapy were studied. Combined antihypertensive therapy was applied during 12-24 weeks. Amlodipine and valsartan dose was 5/160 or 10/160 mg/day depending on blood pressure level. Endothelial function, blood pressure level, urinary albumin excretion and LVH regression were estimated.Results. Blood pressure reduction to the target level was revealed. There was a significant reduction in microalbuminuria by -55.3±39.2% (?=0.022 in comparison with the baseline. Endothelium-dependent vasodilation increased in 3.6±7.2% (?=0.05 in comparison with baseline, LVH decreased by -9.1±12.4 g/m2 (?=0.021.Conclusion. Therapy with fixed combination of valsartan and amlodipine results in blood pressure and microalbuminuria reduction, endothelium-dependent vasodilation improvement, LVH regression in hypertensive patients with MS. These findings show that the fixed combination of these antihypertensives has a multifaceted impact on cardiovascular risk.

Ye.I. Tarlovskaya

2010-01-01

312

SIRT1 Functions as an Important Regulator of Estrogen-Mediated Cardiomyocyte Protection in Angiotensin II-Induced Heart Hypertrophy  

Science.gov (United States)

Background. Sirtuin 1 (SIRT1) is a member of the sirtuin family, which could activate cell survival machinery and has been shown to be protective in regulation of heart function. Here, we determined the mechanism by which SIRT1 regulates Angiotensin II- (AngII-) induced cardiac hypertrophy and injury in vivo and in vitro. Methods. We analyzed SIRT1 expression in the hearts of control and AngII-induced mouse hypertrophy. Female C57BL/6 mice were ovariectomized and pretreated with 17?-estradiol to measure SIRT1 expression. Protein synthesis, cardiomyocyte surface area analysis, qRT-PCR, TUNEL staining, and Western blot were performed on AngII-induced mouse heart hypertrophy samples and cultured neonatal rat ventricular myocytes (NRVMs) to investigate the function of SIRT1. Results. SIRT1 expression was slightly upregulated in AngII-induced mouse heart hypertrophy in vivo and in vitro, accompanied by elevated cardiomyocyte apoptosis. SIRT1 overexpression relieves AngII-induced cardiomyocyte hypertrophy and apoptosis. 17?-Estradiol was able to protect cardiomyocytes from AngII-induced injury with a profound upregulation of SIRT1 and activation of AMPK. Moreover, estrogen receptor inhibitor ICI 182,780 and SIRT1 inhibitor niacinamide could block SIRT1's protective effect. Conclusions. These results indicate that SIRT1 functions as an important regulator of estrogen-mediated cardiomyocyte protection during AngII-induced heart hypertrophy and injury. PMID:25614777

Shen, Tao; Ding, Ling; Ruan, Yang; Qin, Weiwei; Lin, Yajun; Xi, Chao; Lu, Yonggang; Dou, Lin; Zhu, Yuping; Cao, Yuan; Man, Yong; Bian, Yunfei; Wang, Shu; Xiao, Chuanshi; Li, Jian

2014-01-01

313

Coronary artery disease, left ventricular hypertrophy and diastolic dysfunction are associated with stroke in patients affected by persistent non-valvular atrial fibrillation: a case-control study  

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Full Text Available Persistent non-valvular atrial fibrillation (NVAF is associated with an increased risk of cardiovascular events such as stroke, and its rate is expected to rise because of the ageing population. The absolute rate of stroke depends on age and comorbidity. Risk stratification for stroke in patients with NVAF derives from populations enrolled in randomized clinical trials. However, participants in clinical trials are often not representative of the general population. Many stroke risk stratification scores have been used, but they do not include transthoracic echocardiogram (TTE, pulsate wave Doppler (PWD and tissue Doppler imaging (TDI, simple and non-invasive diagnostic tools. The role of TTE, PWD and TDI findings has not been previously determined. Our study goal was to determine the association between TTE and PWD findings and stroke prevalence in a population of NVAF prone outpatients. Patients were divided into two groups: P for stroke prone and F for stroke free. There were no statistically significant differences between the two groups concerning cardiovascular risk factors, age (p=0.2, sex (p=0.2, smoking (p=0.3, diabetes (p=0.1 and hypercholesterolemia (p=0.2; hypertension was statistically significant (p less than 0.001. There were statistically significant differences concerning coronary artery disease, previous acute myocardial infarction (AMI (p less than 0.05 and non- AMI coronaropathy (p less than 0.04, a higher rate being in the P group. Concerning echo-Doppler findings, a higher statistically significant rate of left ventricular hypertrophy (LVH (p less than  0.05 and left ventricular diastolic dysfunction (p less than 0.001 was found in the P group and dilated left atrium (p less than  0.04 in the F group, the difference was not significant for mitral regurgitation (p=0.7. Stroke prone NVAF patients have a higher rate of hypertension, coronary artery disease, with and without AMI, LVH and left ventricular diastolic dysfunction, but not left atrial dilatation. M-B mode echocardiography and PWD examination help to identify high-risk stroke patients among NVAF subjects; therefore, they may help in the selection of appropriate therapy for each patient.

Andrea Passantino

2009-04-01

314

Alterações morfológicas e funcionais cardíacas e análise dos fatores determinantes de hipertrofia ventricular esquerda em 40 pacientes com acromegalia Cardiac morphology and performance alterations and analysis of determinant factors of left ventricular hypertrophy in 40 patients with acromegaly  

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Full Text Available A acromegalia é uma doença de alta mortalidade, especialmente em razão de complicações cardiovasculares. Com o objetivo de avaliar os fatores determinantes da hipertrofia ventricular esquerda (HVE e as alterações cardíacas na acromegalia, analisamos 40 acromegálicos submetidos a exames clínico-laboratoriais e ao ecocardiograma. As variáveis analisadas foram idade, sexo, duração de doença, hipertensão arterial (HA, intolerância à glicose/DM, uso ou não de octreotide, GH e %IGF-I. Na análise univariada, pacientes com HVE foram mais idosos (p= 0,031, apresentaram maior prevalência de HA (p= 0,009 e maiores valores da %IGF-I (p= 0,002, comparados aos sem HVE. Na análise multivariada, HA e %IGF-I foram determinantes de HVE (p= 0,035 e p= 0,016. Após a dicotomização da %IGF-I, foi criado um escore e a freqüência de HVE foi 9%, 65%, 92% x 0, 1, 2; pAcromegaly has a high mortality rate due mainly to cardiovascular complications. The aim was to evaluate the determinant factors of left ventricular hypertrophy (LVH and cardiac alterations in 40 acromegalic patients submitted to clinical-laboratorial studies and echocardiogram. The variables analyzed were age, sex, disease duration, arterial hypertension (AH, impaired glucose tolerance/DM, previous treatment with octreotide, GH and %IGF-I. Univaried analysis showed that patients with LVH were older (p= 0.031, had higher prevalence of AH (p= 0.009 and higher %IGF-I (p= 0.002, than those without LVH. Multivaried analysis showed AH and %IGF-I as determinants of LVH (p= 0.035 and p= 0.016. After dichotomizing of %IGF-I, a score was created and the frequency of LVH was 9%, 65%, 92% x 0, 1, 2; p< 0.0001. Prevalence of aortic ectasia was higher and valvar disease was smaller than reported in the literature. We conclude that AH and %IGF-I were determinants of LVH.

Alessandra Ferri Casini

2006-02-01

315

Alterações morfológicas e funcionais cardíacas e análise dos fatores determinantes de hipertrofia ventricular esquerda em 40 pacientes com acromegalia / Cardiac morphology and performance alterations and analysis of determinant factors of left ventricular hypertrophy in 40 patients with acromegaly  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese A acromegalia é uma doença de alta mortalidade, especialmente em razão de complicações cardiovasculares. Com o objetivo de avaliar os fatores determinantes da hipertrofia ventricular esquerda (HVE) e as alterações cardíacas na acromegalia, analisamos 40 acromegálicos submetidos a exames clínico-labo [...] ratoriais e ao ecocardiograma. As variáveis analisadas foram idade, sexo, duração de doença, hipertensão arterial (HA), intolerância à glicose/DM, uso ou não de octreotide, GH e %IGF-I. Na análise univariada, pacientes com HVE foram mais idosos (p= 0,031), apresentaram maior prevalência de HA (p= 0,009) e maiores valores da %IGF-I (p= 0,002), comparados aos sem HVE. Na análise multivariada, HA e %IGF-I foram determinantes de HVE (p= 0,035 e p= 0,016). Após a dicotomização da %IGF-I, foi criado um escore e a freqüência de HVE foi 9%, 65%, 92% x 0, 1, 2; p Abstract in english Acromegaly has a high mortality rate due mainly to cardiovascular complications. The aim was to evaluate the determinant factors of left ventricular hypertrophy (LVH) and cardiac alterations in 40 acromegalic patients submitted to clinical-laboratorial studies and echocardiogram. The variables analy [...] zed were age, sex, disease duration, arterial hypertension (AH), impaired glucose tolerance/DM, previous treatment with octreotide, GH and %IGF-I. Univaried analysis showed that patients with LVH were older (p= 0.031), had higher prevalence of AH (p= 0.009) and higher %IGF-I (p= 0.002), than those without LVH. Multivaried analysis showed AH and %IGF-I as determinants of LVH (p= 0.035 and p= 0.016). After dichotomizing of %IGF-I, a score was created and the frequency of LVH was 9%, 65%, 92% x 0, 1, 2; p

Alessandra Ferri, Casini; Paula Bruna, Araújo; Rosita, Fontes; Sérgio Salles, Xavier; Mônica R., Gadelha.

2006-02-01

316

Addition of Highly Sensitive Troponin T and N-Terminal Pro-BNP to Electrocardiography for Detection of Left Ventricular Hypertrophy: Results from the Dallas Heart Study  

Science.gov (United States)

Left ventricular hypertrophy (LVH) is an independent, modifiable risk factor for cardiovascular disease. However, current screening strategies are limited. In 2478 participants without clinical disease from the Dallas Heart Study, we evaluated a multi-marker screening strategy that complements electrocardiographic (ECG) criteria for LVH with two biomarkers, amino-terminal pro-B-type natriuretic peptide (NT-proBNP) and highly sensitive cardiac troponin T (cTnT). An integer LVH risk score from 0 to 3 was determined as the sum of: (1) LVH by Sokolow-Lyon ECG, (2) NT-proBNP in the highest sex-specific quartile, and (3) detectable cTnT. Cardiac MRI-determined LVH served as the primary outcome. The probability of LVH increased from 2% with an LVH risk score of 0 to 50% with a score of 3 (p < 0.001). S-L ECG afforded low sensitivity (26%, 95% CI 17–32%) and high specificity (96%, 95% CI 95–97%), while a risk score ?2 offered higher sensitivity (44%, 95% CI 34–51%) with good specificity (90%, 95% CI 89–93%), a score threshold of 1 offered reasonable sensitivity (76%, 95% CI 67–83%) with lower specificity (55%, 95% CI 53–61%) and high negative predictive value (98%, 95% CI 97–98%). AUC improved from 0.760 (95% CI 0.716–0.804) for ECG alone to 0.798 (95% CI 0.754–0.842) for the LVH risk score (p = 0.0012) consistent with modest improvement in overall discrimination. Better screening for LVH may be achieved by combining simple tests, which collectively provide additional information compared to ECG alone. Further studies are needed to evaluate the impact and cost-effectiveness of a multi-marker screening strategy. PMID:23150502

Martinez-Rumayor, Abelardo A.; de Lemos, James A.; Rohatgi, Anand K.; Ayers, Colby R.; Powell-Wiley, Tiffany M.; Lakoski, Susan G.; Berry, Jarett D.; Khera, Amit; Das, Sandeep R.

2012-01-01

317

False-positive defects in technetium-99m sestamibi myocardial single-photon emission tomography in healthy athletes with left ventricular hypertrophy  

International Nuclear Information System (INIS)

Exercise ECG and myocardial single-photon emission tomography (SPET) are fundamental in the non-invasive evaluation of patients suspected of having coronary artery disease (CAD). The purpose of the present study was to investigate the influence of physiological left ventricular hypertrophy (LVH) on myocardial sestamibi SPET in healthy young and old athletes. Eighteen young male elite athletes (ten rowers, five power/weight lifters and three triathletes) and 14 well-trained elderly rowers were studied. All underwent a bicycle test as part of a 2-day sestamibi SPET protocol. Attenuation correction was not performed. The studies were evaluated visually and quantitatively analysed by the CEqual program with its reference files and with a file from a local non-athletic age-matched population. Echocardiographic LVH was an inclusion criterion in the young athletes. Exercise ECG was normal in all subjects. In at least three of the young athletes a reversible defect was observed by visual analysis. On quantitative analysis one-third of the young athletes had ''significant'' (>10 pixels) defects compared with both the local reference base and the CEqual reference population. Nearly all defects were found in the anterior or inferior wall. The remaining subjects, including all old rowers, had normal SPET findings. Anterior and inferior wall defects are so common in healthy athletes with physiological LVH that the specificity of myocardial SPET, in contrast to exercise ECG, seems SPET, in contrast to exercise ECG, seems to be too low for evaluation of chest pain in this group. The mechanism of anterior and inferior defects may be related to hot spots (papillary muscles?) in the lateral wall. The specificity of SPET is maintained in athletes without LVH. (orig.)

318

Management of high-risk patients with hypertension and left ventricular hypertrophy in Germany: differences between cardiac specialists in the inpatient and outpatient setting  

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Full Text Available Abstract Background Among patients with hypertension, those with established left ventricular hypertrophy (LVH represent a high risk cohort with poor prognosis. We aimed to investigate differences in characteristics and health care management of such patients treated as inpatients or outpatients by cardiac specialists. Methods Prospective cross-sectional study in patients with hypertension and LVH who were referred to either inpatient care (rehabilitation hospitals or to outpatient care (cardiology practices. Results A total of 6358 inpatients (59.6% males; mean age 66.6 years and 2246 outpatients (59.5% males; mean age 63.2 years were followed up for a mean of 23 vs. 52 days, respectively. Inpatients compared to outpatients had a significantly higher prevalence of coronary heart disease, history of stroke, renal failure or diabetes. Mean blood pressure of inpatients compared to outpatients was significantly lower both at entry (150/84 vs. 161/93 mmHg and at end of follow-up (129/75 vs. 139/83 mmHg. After adjustment for baseline blood pressure and a propensity score, differences between out- and inpatients at end of follow-up were 8.0/5.1 mmHg in favour of inpatients. Blood pressure goals as specified by guidelines were not met by 32% of inpatients and 55% of outpatients. Conclusion Inpatients had a higher rate of comorbidities and more advanced atherosclerotic disease than outpatients. Control of hypertension of inpatients was already better on admission than in outpatients, and treatment intensity in this group was also higher during the observation period. While blood pressure lowering was substantial in both groups, there were still a high proportion of patients who did not achieve treatment goals at discharge.

Wegscheider Karl

2006-10-01

319

Functional contribution of ?1D-adrenoceptors in the renal vasculature of left ventricular hypertrophy induced with isoprenaline and caffeine in Wistar-Kyoto rats.  

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This study investigated the role of ?1D-adrenoceptor in the modulation of renal haemodynamics in rats with left ventricular hypertrophy (LVH). LVH was established in Wistar-Kyoto (WKY) rats with isoprenaline (5.0 mg · (kg body mass)(-1), by subcutaneous injection every 72 h) and caffeine (62 mg · L(-1) in drinking water, daily for 14 days). Renal vasoconstrictor responses were measured for noradrenaline (NA), phenylephrine (PE), and methoxamine (ME) before and immediately after low or high dose intrarenal infusions of BMY?7378, a selective ?1D-adrenoceptor blocker. The rats with LVH had higher mean arterial blood pressure and circulating NA levels, but lower renal cortical blood perfusion compared with the control group (all P < 0.05). In the LVH group, the magnitude of the renal vasoconstrictor response to ME was blunted, but not the response to NA or PE (P < 0.05), compared with the control group (LVH vs. C, 38% vs. 50%). The magnitude of the drop in the vasoconstrictor responses to NA, PE, and ME in the presence of a higher dose of BMY?7378 was significantly greater in the LVH group compared with the control group (LVH vs. C, 45% vs. 25% for NA, 52% vs. 33% for PE, 66% vs. 53% for ME, all P < 0.05). These findings indicate an impaired renal vasoconstrictor response to adrenergic agonists during LVH. In addition, the ?1D-adrenoceptor subtype plays a key role in the modulation of vascular responses in this diseased state. PMID:25403946

Ahmad, Ashfaq; Sattar, Munavvar A; Rathore, Hassaan A; Abdulla, Mohammad H; Khan, Safia A; Abdullah, Nor A; Kaur, Gurjeet; Johns, Edward J

2014-12-01

320

Participação do estado contrátil e do relaxamento miocárdico na disfunção ventricular durante a transição hipertrofia-falência cardíaca / Myocardial function during the transition from compensated left ventricular hypertrophy to failure  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese OBJETIVO: Avaliar a participação do estado contrátil e do relaxamento miocárdico na disfunção do músculo cardíaco durante a transição hipertrofia-falência cardíaca em ratos espontaneamente hipertensos (SHR). MÉTODOS: Músculos papilares isolados do ventrículo esquerdo de SHR com insuficiência cardíac [...] a (SHR-IC) e sem falência cardíaca (SHR) e de ratos normotensos controle Wistar-Kyoto (WKY) foram estudados em contrações isométrica e isotônica, em solução de Krebs-Henseleit (1,25 mM Ca2+, 28ºC). RESULTADOS: Os valores da tensão máxima desenvolvida (TD) e da velocidade máxima de encurtamento (Vmáx) foram menores nos SHR-IC e SHR, em relação aos WKY (p0,05). A rigidez passiva do músculo aumentou significantemente nos SHR-IC (p0,05). CONCLUSÃO: Os dados obtidos mostram que a transição da fase de hipertrofia estável para insuficiência cardíaca nos ratos espontaneamente hipertensos está associada ao aumento da rigidez passiva do miocárdio e não à piora da função contrátil do músculo cardíaco. Abstract in english PURPOSE: To investigate the participation of contractile state and relaxation in cardiac muscle dysfunction during the transition from stable hypertrophy to cardiac decompensation in aging spontaneously hypertensive rats (SHR). METHODS: Isolated left ventricular papillary muscle function was studied [...] in SHR with heart failure (SHR-F), in age-matched SHR without evidence of heart failure (SHR-NF), and in nonhypertensive controls Wistar-Kyoto rats (WKY). Muscles were analised in isometric and isotonic contractions in Krebs-Henseleit solution with calcium concentration of 1.25mM at 28ºC. RESULTS: Papillary muscles from SHR-F and SHR-NF demonstrated decreased active tension development and shortening velocity relative to normotensive WKY (p0.05). CONCLUSION: These data suggest that the progression from stable hypertrophy to heart failure is associated with changes in the passive stiffness and is not related to depression of myocardial contractile function.

Antonio Carlos, Cicogna; Kathleen G., Robinson; Chester H., Conrad; Robin, Squire; Marina P., Okoshi; Oscar H. L., Bing.

1997-12-01

321

Suppression of voltage-gated L-type Ca2+ currents by polyunsaturated fatty acids in adult and neonatal rat ventricular?myocytes  

OpenAIRE

Our recent data show that in cardiac myocytes polyunsaturated fatty acids (PUFAs) are antiarrhythmic. They reduce INa, shorten the action potential, shift the threshold for excitation to more positive potentials, and prolong the relative refractory period. In this study we use patch-clamp techniques in whole-cell mode and confocal Ca2+ imaging to examine the effects of PUFAs on the voltage-gated L-type Ca2+ current (ICa,L), elementary sarcoplasmic reticulum Ca2+-release events (Ca2+-sparks), ...

Xiao, Yong-fu; Gomez, Ana Maria; Morgan, James P.; Lederer, W. J.; Leaf, Alexander

1997-01-01

322

Relation of electrocardiographic left ventricular hypertrophy to blood pressure, body mass index, serum lipids and blood sugar levels in adult Nigerians.  

Science.gov (United States)

Left ventricular hypertrophy (LVH) is considered an independent risk factor even in the absence of systemic hypertension. Electrocardiographic (ECG) LVH with repolarisation changes has been found in some countries to carry more coronary risk than LVH alone. How far this observation is true among adult Nigerians is not known. We therefore decided to study adult Nigerians with ECG-LVH with or without ST-T waves changes and compare them with normal age matched controls (without ECG-LVH) in relation with established modifiable risk factors such as systemic hypertension (BP), body mass index (BMI), fasting blood sugar (FBS) and serum lipids such as total cholesterol (Tc), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C) and triglyceride (TG). Adult Nigerians who were consecutively referred to the ECG laboratory were randomly recruited. Three hundred patients were studied. Their blood pressures (BP) as well as body mass indices were recorded after recording their resting 12 read ECG using portable Seward 9953 ECG machine. Their waist-hip ratio (WHR) was also recorded. Blood samples were taken to determine their fasting blood sugar and serum lipids. Their ECG tracings were read by the cardiologists involved in the study while the blood samples were analysed by the chemical pathologist also involved in the study. At the end of the ECG reading, the patients were divided into 3 groups according to whether there was no ECG-LVH (control group A), ECG-LVH alone (group B), and ECG-LVH with ST-T waves changes (group C). One hundred and fifty (50%) patients belonged to group A, 100 (33.3%) patients to group B and 50 (16.7%) group C. Group B patients were found to have higher modifiable risk factors in form of systemic BP. Tc, LDL-C, and WHR compared to group A. However, the group C patients had increased load of these coronary risk factors in terms of BP elevation, higher BMI, FBS, and scrum cholesterol compared to group B. In addition, more female patients were involved in group C. The mean age of group C patients compared to group B was also significantly higher (P<0.001) even though no significant age difference was noted between group C and group A patients. It is concluded that Nigerians with ECG-LVH with ST-T waves changes have increased risk of cardiovascular risk factors compared to normal group A patients and even patients with EGC-LVH (group B) alone. Hence, they represent subset of patients to be aggressively followed up with multiple risk factors intervention. PMID:15259925

Opadijo, O G; Omotoso, A B O; Akande, A A

2003-12-01

323

Clinical Implications of Electrocardiographic Left Ventricular Strain and Hypertrophy in Asymptomatic Patients with Aortic Stenosis: The Simvastatin and Ezetimibe in Aortic Stenosis Study  

DEFF Research Database (Denmark)

BACKGROUND: The prognostic impact of electrocardiographic left ventricular (LV) strain and hypertrophy (LVH) in asymptomatic aortic stenosis (AS) is not well described. METHODS AND RESULTS: Data were obtained in asymptomatic patients randomized to simvastatin/ezetimibe combination vs. placebo in the Simvastatin and Ezetimibe in Aortic Stenosis (SEAS) study. Primary endpoint was the first of myocardial infarction, non-hemorrhagic stroke, heart failure, aortic valve replacement (AVR) or cardiovascular death. Predictive value of electrocardiographic LV strain (defined as T-wave inversion in leads V(4-6)) and LVH (assessed by Sokolow-Lyon voltage criterion (R(V5-6)+S(V1) =35 mV) and Cornell voltage-duration criteria ((RaVL+S(V3)+[6 mV in women]) × QRS-duration =2440 mV msec), was evaluated by adjusting for other prognostic covariates. 1,533 patients were followed 4.3±0.8 years (6,592 patient-years of follow-up), 627 cardiovascular events occurred. Electrocardiographic strain was present in 340 (23.6%) patients; LVH by Sokolow-Lyon voltage in 260 (17.1%) and in 220 (14.6%) by Cornell voltage-duration product. In multivariable analyses, electrocardiographic LV strain was associated with 3.1-fold higher risk of in-study myocardial infarction (95% confidence interval [CI], 1.4 to 6.8, p=0.004). Similarly, electrocardiographic LVH by both criteria predicted, compared to no electrocardiographic LVH, 5.8-fold higher risk of heart failure (95% CI, 2.0 to 16.8), 2.0-fold higher risk of AVR (95% CI, 1.3 to 3.1, both p=0.001) and 2.5-fold higher risk of a combined endpoint of myocardial infarction, heart failure or cardiovascular death (95% CI, 1.3 to 4.9, p=0.008). CONCLUSIONS: Electrocardiographic LV strain and LVH were independently predictive of poor prognosis in asymptomatic AS. CLINICAL TRIAL REGISTRATION: http://www.ClinicalTrials.gov; NCT00092677.

Greve, Anders M; Boman, Kurt

2012-01-01

324

123I-metaiodobenzylguanidine imaging of the heart in essential hypertension. The effect of left ventricular hypertrophy and performance reserve upon it  

International Nuclear Information System (INIS)

To study myocardial norepinephrine (NE) activity in essential hypertension (HT) and the effect of left ventricular (LV) hypertrophy and LV performance reserve upon it, myocardial imaging was performed with 123I-metaiodobenzylguanidine (123I-MIBG) and 201Tl at rest in 23 patients with HT and 10 normal subjects. Uptake Ratio (%Uptake of 123I-MIBG in delayed image divided by %Uptake of 201Tl) was calculated as the index of myocardial 123I-MIBG uptake. Reduction of myocardial 123I-MIBG during 3h (WOR) was also calculated. The defect from the Bull's-eye map was quantitatively assessed as Defect Score. Patients were divided into 2 groups according to the LV mass (LVM) by echocardiography. Uptake Ratio was lower in Group I (LVM>l30g/m2, n=16) than that Group II (LVM2, n=7). WOR was accelerated in Group I than Group II. Uptake Ratio and WOR were identical between Group II and normal subjects. The incidence of 123I-MIBG defect and Defect Score were significantly greater in Group I (incidence: 94%, Defect Score: 3.0±1.3) than Group II (incidence: 43%, Defect Score: 1.1±0.6). To study the effect of LV performance reserve, patients were divided into 2 groups according to LV ejection fraction (EF) responses to exercise stress (Ex) obtained by 99mTc blood pool imaging. LVEF increased by Ex in 13 patients (Group A) and decreased or did not change by Ex inand decreased or did not change by Ex in 7 (Group B). Uptake Ratio was significantly smaller and WOR was significantly accelerated in Group B than Group A and normal subjects. The incidence of 123I-MIBG defect and Defect Score were greater in Group B than Group A, with no significant difference. LVM and LVEF response seemed to influence upon myocardial NE kinetics independently. These results suggested that LVM and LV performance reserve influenced upon myocardial NE kinetics in HT patients and quantitative analysis of 123I-MIBG imaging may be helpful for assessing HT prognosis. (J.P.N.)

325

Determinants of discrepancies in detection and comparison of the prognostic significance of left ventricular hypertrophy by electrocardiogram and cardiac magnetic resonance imaging.  

Science.gov (United States)

Despite the low sensitivity of the electrocardiogram (ECG) in detecting left ventricular hypertrophy (LVH), ECG-LVH is known to be a strong predictor of cardiovascular risk. Understanding reasons for the discrepancies in detection of LVH by ECG versus imaging could help improve the diagnostic ability of ECG. We examined factors associated with false-positive and false-negative ECG-LVH, using cardiac magnetic resonance imaging (MRI) as the gold standard. We also compared the prognostic significance of ECG-LVH and MRI-LVH as predictors of cardiovascular events. This analysis included 4,748 participants (mean age 61.9 years, 53.5% females, 61.7% nonwhites). Logistic regression with stepwise selection was used to identify factors associated with false-positive (n = 208) and false-negative (n = 387), compared with true-positive (n = 208) and true-negative (n = 4,041) ECG-LVH, respectively. A false-negative ECG-LVH status was associated with increased odds of Hispanic race/ethnicity, current smoking, hypertension, increased systolic blood pressure, prolongation of QRS duration, and higher body mass index and with lower odds of increased ejection fraction (model-generalized R(2) = 0.20). A false-positive ECG-LVH status was associated with lower odds of black race, Hispanic race/ethnicity, minor ST-T abnormalities, increased systolic blood pressure, and presence of any major electrocardiographic abnormalities (model-generalized R(2) = 0.29). Both ECG-LVH and MRI-LVH were associated with an increased risk of cardiovascular disease events (hazard ratio 1.51, 95% confidence interval 1.03 to 2.20 and hazard ratio 1.81, 95% confidence interval 1.33 to 2.46, respectively). In conclusion, discrepancy in LVH detection by ECG and MRI can be relatively improved by considering certain participant characteristics. Discrepancy in diagnostic performance, yet agreement on predictive ability, suggests that LVH by ECG and LVH by imaging are likely to be two distinct but somehow related phenotypes. PMID:25542394

Bacharova, Ljuba; Chen, Haiying; Estes, E Harvey; Mateasik, Anton; Bluemke, David A; Lima, Joao A C; Burke, Gregory L; Soliman, Elsayed Z

2015-02-15

326

Visualization of hypertrophied papillary muscle mimicking left ventricular mass on gated blood pool and T1-201 myocardial perfusion imaging  

International Nuclear Information System (INIS)

A sixty-year old man with acute myocardial infarction was incidentally found to have a hypertrophied anterolateral papillary muscle (ALPPM) of the left ventricle on gated blood pool (GBP) and T1-201 myocardial perfusion images. Hypertrophy of the ALPPM was visualized as a movable defect in the lateral basal area on GBP imaging throughout the cardiac cycle and on the TI-201 study as a radionuclide accumulating structure, consistent with the defect in the GBP. A combination of these findings may suggest the presence of a hypertrophied papillary muscle of the left ventricle

327

Simvastatin Modulates Remodeling of Kv4.3 Expression in Rat Hypertrophied Cardiomyocytes  

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Full Text Available Objectives: Hypertrophy has been shown to be associated with arrhythmias which can be caused by abnormal remodeling of the Kv4-family of transient potassium channels. Inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase (statins have recently been shown to exert pleiotropic protective effects in cardiovascular diseases, including anti-arrhythmias. It is hypothesized that remodeling of Kv4.3 occurs in rat hypertrophied cardiomyocytes and is regulated by simvastatin.Methods: Male Sprague-Dawley rats and neonatal rat ventricular myocytes (NRVMs underwent abdominal aortic banding (AAB for 7 weeks and angiotensin II (AngII treatment, respectively, to induce cardiac hypertrophy. Kv4.3 expression by NRVMs and myocardium (subepicardial and subendocardial in the left ventricle was measured. The transient outward potassium current (Ito of NRVMs was recorded using a whole-cell patch-clamp method.Results: Expression of the Kv4.3 transcript and protein was significantly reduced in myocardium (subepicardial and subendocardial in the left ventricle and in NRVMs. Simvastatin partially prevented the reduction of Kv4.3 expression in NRVMs and subepicardial myocardium but not in the subendocardial myocardium. Hypertrophied NRVMs exhibited a significant reduction in the Ito current and this effect was partially reversed by simvastatin.Conclusions: Simvastatin alleviated the reduction of Kv4.3 expression, Ito currents in hypertrophied NRVMs and alleviated the reduced Kv4.3 expression in subepicardial myocardium from the hypertrophied left ventricle. It can be speculated that among the pleiotropic effects of simvastatin, the anti-arrhythmia effect is partly mediated by its effect on Kv4.3.

Feifei Su, Miaoqian Shi, Zhiqiang Yan, Dongbo Ou, Juntang Li, Zifan Lu, Qiangsun Zheng

2012-01-01

328

New frontiers in heart hypertrophy during pregnancy  

OpenAIRE

During Pregnancy, heart develops physiological left ventricular hypertrophy as a result of the natural volume overload. Previously we have characterized the molecular and functional signature of heart hypertrophy during pregnancy. Cardiac hypertrophy during pregnancy is a complex process that involves many changes including in the signalling pathways, composition of extracellular matrix as well as the levels of sex hormones. This review summarises the recent advances and the new frontiers in ...

Li, Jingyuan; Umar, Soban; Amjedi, Marjan; Iorga, Andrea; Sharma, Salil; Nadadur, Rangarajan D.; Regitz-zagrosek, Vera; Eghbali, Mansoureh

2012-01-01

329

Comparison of dobutamine stress echocardiography and technetium-99m sestamibi single-photon emission tomography for the diagnosis of coronary artery disease in hypertensive patients with and without left ventricular hypertrophy  

International Nuclear Information System (INIS)

The aim of this study was to compare the accuracy of these two imaging modalities in conjunction with dobutamine stress test for the diagnosis of coronary artery disease in hypertensive patients with and without left ventricular hypertrophy. Dobutamine stress echocardiography in conjunction with sestamibi (MIBI) SPET was performed in 84 patients with the diagnosis of systemic hypertension who had been referred for evaluation of myocardial ischaemia. Significant coronary artery disease (?50% luminal diameter stenosis) was detected in 66 patients (79%). The sensitivity, specificity and accuracy of the ischaemic pattern at echocardiography for the diagnosis of coronary artery disease were 73% (CI 63%-82%), 83% (CI 75%-91%) and 75% (CI 66%-84%), those for MIBI were 67% (CI 57%-77%), 83% (CI 75%-91%) and 70% (CI 60%-80%) respectively (P = NS vs echocardiography). Significant stenosis was detected in 123 (49%) of the 252 analysed coronary arteries. The sensitivity, specificity and accuracy of echocardiography for the regional diagnosis of coronary artery disease were 63% (CI 56%-69%), 90% (CI 86%-94%) and 77% (CI 72%-82%). Those for MIBI were 58% (CI 51%-64%), 91% (CI 87%-94%) and 75% (CI 69%-80) respectively (P = NS vs echocardiography). Left ventricular hypertrophy was detected in 59 patients (70%) by echocardiography and did not influence the overall or regional specificity of echocardiography or MIBI SPET.(orig./MG) (orig.)

330

Comparison of dobutamine stress echocardiography and technetium-99m sestamibi single-photon emission tomography for the diagnosis of coronary artery disease in hypertensive patients with and without left ventricular hypertrophy  

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The aim of this study was to compare the accuracy of these two imaging modalities in conjunction with dobutamine stress test for the diagnosis of coronary artery disease in hypertensive patients with and without left ventricular hypertrophy. Dobutamine stress echocardiography in conjunction with sestamibi (MIBI) SPET was performed in 84 patients with the diagnosis of systemic hypertension who had been referred for evaluation of myocardial ischaemia. Significant coronary artery disease ({>=}50% luminal diameter stenosis) was detected in 66 patients (79%). The sensitivity, specificity and accuracy of the ischaemic pattern at echocardiography for the diagnosis of coronary artery disease were 73% (CI 63%-82%), 83% (CI 75%-91%) and 75% (CI 66%-84%), those for MIBI were 67% (CI 57%-77%), 83% (CI 75%-91%) and 70% (CI 60%-80%) respectively (P = NS vs echocardiography). Significant stenosis was detected in 123 (49%) of the 252 analysed coronary arteries. The sensitivity, specificity and accuracy of echocardiography for the regional diagnosis of coronary artery disease were 63% (CI 56%-69%), 90% (CI 86%-94%) and 77% (CI 72%-82%). Those for MIBI were 58% (CI 51%-64%), 91% (CI 87%-94%) and 75% (CI 69%-80) respectively (P = NS vs echocardiography). Left ventricular hypertrophy was detected in 59 patients (70%) by echocardiography and did not influence the overall or regional specificity of echocardiography or MIBI SPET.(orig./MG) (orig.) With 2 figs., 4 tabs., 39 refs.

Elhendy, A.; Geleijnse, M.L.; Van Domburg, R.T.; Bax, J.J.; Nierop, P.R.; Beerens, S.A.M.; Mohsen Ibrahim, M.; Roelandt, J.R.T.C. [Thoraxcenter, University Hospital Rotterdam-Dijkzigt, Rotterdam (Netherlands); Valkema, R.; Krenning, E.P. [Department of Nuclear Medicine, University Hospital Rotterdam-Dijkzigt, Rotterdam (Netherlands)

1998-01-01

331

Descenso espontáneo de la frecuencia cardíaca y regresión de la hipertrofia ventricular izquierda / Spontaneous decrease of heart rate and left ventricular hypertrophy regression / Descenso espontâneo da frequência cardíaca e regressão da hipertrofia ventricular esquerda  

Scientific Electronic Library Online (English)

Full Text Available SciELO Argentina | Language: Spanish Abstract in portuguese Antecedentes. A análise da frequência cardíaca demonstrou ter impacto prognóstico em sujeitos sãos, pacientes hipertensos, e portadores de insuficiência cardíaca ou cardiopatia isquêmica. O objetivo do presente trabalho é determinar se existe uma relação, e de que tipo, entre as mudanças espontâneas [...] na frequência cardíaca durante o tratamento de pacientes hipertensos e o índice de massa ventricular esquerda. Material e métodos. Incluíram-se 40 pacientes hipertensos tratados durante 1 ano sem drogas que interferissem na frequência e no ritmo cardíaco. Análise estatística. Aplicou-se test de correlação, e considerou-se de significação estatístico um valor de p Abstract in spanish Antecedentes. El análisis de la frecuencia cardíaca ha demostrado tener impacto pronóstico en sujetos sanos, pacientes hipertensos, y portadores de insuficiencia cardíaca o cardiopatía isquémica. El objetivo del presente trabajo es determinar si existe una relación, y de qué tipo, entre los cambios [...] espontáneos en la frecuencia cardíaca durante el tratamiento en pacientes hipertensos y el índice de masa ventricular izquierda. Material y métodos. Se incluyeron 40 pacientes hipertensos tratados 1 año sin drogas que interfieran sobre la frecuencia ni el ritmo cardíaco. Análisis estadístico. Se aplicó test de correlación, y se consideró significación estadística un valor de p Abstract in english Background. The analysis of heart rate has been shown to have prognostic impact in healthy subjects, and in hypertensive, heart failure or ischemic heart disease patients. The aim of this study is to determine if a relationship exists, and what kind, between the spontaneous changes in heart rate dur [...] ing treatment in patients with hypertension and left ventricular mass index. Material and methods. We included 40 hypertensive patients treated during 1 year without drugs that interfere on heart rate. Statistical analysis. Correlation test was applied, and statistical significance was considered p

Daniel, Piskorz; Luciano, Citta; Norberto, Citta; Marcelo, Lanzotti; Roberto, Lanzotti; Horacio, Locatelli; Alicia, Tommasi.

2009-03-01

332

Point-of-care screening for left ventricular hypertrophy and concentric geometry using hand-held cardiac ultrasound in hypertensive patients  

OpenAIRE

Background: The introduction of the hand-held cardiac ultrasound (HCU) may potentially increase detection of LV hypertrophy in hypertensive patients. However, whether point-of-care screening for LV hypertrophy and concentric LV geometry by HCU in hypertensive patients is feasible and comparable to that of standard state-of-the-art echocardiography (SE) evaluation remains to be elucidated. Methods and Results: Accordingly, one hundred consecutive patients (66 female, mean age=58±13 years, 32%...

Stoica, Roxana; Heller, Eliot N.; Bella, Jonathan N.

2011-01-01

333

Isoproterenol-induced myocardial fibrosis in relation to myocyte necrosis  

International Nuclear Information System (INIS)

Treatment of rats with the beta-adrenergic agonist isoproterenol results in cardiac hypertrophy, myocyte necrosis, and interstitial cell fibrosis. Our objectives in this study have been to examine whether hypertrophy and fibrosis occur in a compensatory and reparative response to myocyte loss or whether either process may be occurring independently of myocyte loss and thus be a reactive response to adrenergic hormone stimulation. We have examined this question by evaluating each of these responses in rats treated with different doses and forms of isoproterenol administration. Myocyte necrosis was evaluated using in vivo labeling with monoclonal antimyosin for identification of myocytes with permeable sarcolemma, which was indicative of irreversible injury. Myocardial fibrosis was evaluated by morphometric point counting of Gomori-stained tissue sections and by assessment of the stimulation of fibroblast proliferation by determination of increased levels of DNA synthesis. Stimulation of fibroblast DNA synthesis was determined from DNA specific radioactivities and radioautography after pulse labeling with [3H]thymidine. The evidence provided by this study suggests that the degree and timing of myocardial hypertrophy does not follow the course of myocyte loss and, thus, appears to be either a response to altered cardiac loading or a reactive response to beta-adrenergic hormone stimulation rather than a compensation for myocyte loss. Myocardial fibrosis, on the other handss. Myocardial fibrosis, on the other hand, appears to be more closely related to myocyte necrosis with respect to collagen accumulation in the same areas of the heart, its dose-response relation to the amount of isoproterenol administered, and the timing of increased DNA synthesis, or fibroblast proliferation, after myocyte loss

334

Isoproterenol-induced myocardial fibrosis in relation to myocyte necrosis  

Energy Technology Data Exchange (ETDEWEB)

Treatment of rats with the beta-adrenergic agonist isoproterenol results in cardiac hypertrophy, myocyte necrosis, and interstitial cell fibrosis. Our objectives in this study have been to examine whether hypertrophy and fibrosis occur in a compensatory and reparative response to myocyte loss or whether either process may be occurring independently of myocyte loss and thus be a reactive response to adrenergic hormone stimulation. We have examined this question by evaluating each of these responses in rats treated with different doses and forms of isoproterenol administration. Myocyte necrosis was evaluated using in vivo labeling with monoclonal antimyosin for identification of myocytes with permeable sarcolemma, which was indicative of irreversible injury. Myocardial fibrosis was evaluated by morphometric point counting of Gomori-stained tissue sections and by assessment of the stimulation of fibroblast proliferation by determination of increased levels of DNA synthesis. Stimulation of fibroblast DNA synthesis was determined from DNA specific radioactivities and radioautography after pulse labeling with (3H)thymidine. The evidence provided by this study suggests that the degree and timing of myocardial hypertrophy does not follow the course of myocyte loss and, thus, appears to be either a response to altered cardiac loading or a reactive response to beta-adrenergic hormone stimulation rather than a compensation for myocyte loss. Myocardial fibrosis, on the other hand, appears to be more closely related to myocyte necrosis with respect to collagen accumulation in the same areas of the heart, its dose-response relation to the amount of isoproterenol administered, and the timing of increased DNA synthesis, or fibroblast proliferation, after myocyte loss.

Benjamin, I.J.; Jalil, J.E.; Tan, L.B.; Cho, K.; Weber, K.T.; Clark, W.A. (Michael Reese Hospital, Chicago, IL (USA))

1989-09-01

335

Stimulation of gene expression in neonatal rat ventricular myocytes by Ras is mediated by Ral guanine nucleotide dissociation stimulator (Ral.GDS) and phosphatidylinositol 3-kinase in addition to Raf.  

Science.gov (United States)

Treatment of cultured neonatal ventricular myocytes with oncogenic Ras increases their size and stimulates the re-expression of genes which are normally restricted to the fetal stage of ventricular development, including atrial natriuretic factor (ANF) and skeletal muscle (SkM)-alpha-actin. To determine which signalling pathways mediate these responses, myocytes were transfected with oncogenic (V12) Ras mutants which interact selectively with different effectors and their effects on luciferase (LUX) reporter plasmids were examined. V12 human Ras (V12HRas), itself, activated ANF-LUX 9. 6-fold, whereas mutants of V12HRas, which selectively stimulate Ral guanine nucleotide dissociation stimulator (Ral.GDS) (E37G), c-Raf (D38E) and phosphatidylinositol 3-kinase (PI-3-K; Y40C) enhanced ANF-LUX expression 3.0-, 3.7- and 1.7-fold respectively. The full response of ANF-LUX to V12HRas was restored by using a combination of the individual effector domain mutants. Likewise, SkM-alpha-actin-LUX expression was activated 12.0-, 3.5-, 4.5- and 3. 0-fold by V12HRas, E37G, D38E and Y40C respectively, and a similar pattern of activation was also observed using a c-fos serum-response element-LUX reporter gene. Cell size was also increased by each of the mutants, but simultaneous expression of all three mutant constructs was needed to reconstitute the full effect of V12HRas on cell size (50% increase). Transfection with a constitutively active mutant of PI-3-K (p110K227E) stimulated ANF-LUX, SkM-alpha-actin-LUX, c-fos-serum-response element-LUX and Rous sarcoma virus-LUX by 3.1-, 3.2-, 2.1- and 2.9-fold respectively, but the co-transfected cytomegalovirus-beta-galactosidase reporter gene was activated to a similar extent (1.9-fold). These results suggest that Raf, Ral.GDS and PI-3-K can all transduce transcriptional responses to V12HRas, but that the specific induction of genes associated with the hypertrophic response is not mediated through PI-3-K. PMID:9761720

Fuller, S J; Finn, S G; Downward, J; Sugden, P H

1998-10-15

336

Left ventricular strain and transmural distribution of structural remodeling in hypertensive heart disease.  

Science.gov (United States)

Left ventricular (LV) systolic wall strain is a new candidate for prognostic indicator of hypertensive heart failure. It remains unclear how underlying transmural structural remodeling corresponds to LV wall systolic deformation as hypertensive hypertrophy progresses. We fed 68 Dahl salt-sensitive rats a high-salt (hypertensive group) or low-salt diet (control group) from 6 weeks old. At 10, 14, and 18 weeks, pressure-volume relation, transmural distribution of LV fibrosis, and myocyte hypertrophy were evaluated. LV global longitudinal and circumferential strain was measured with speckle tracking echocardiography. Emax was preserved throughout the study period, whereas ? and end-diastolic pressure-volume relation progressively deteriorated from 14 weeks (diastolic dysfunction stage). Lung weight increased significantly at 18 weeks (decompensated stage). Histological percentage area fibrosis and collagen type I/III, myocyte hypertrophy, and ?-myosin heavy chain isoform increased in the subendocardial layer at 14 weeks and progressed into the midlayer at 18 weeks. Longitudinal strain progressively deteriorated in the hypertensive group versus control group at 14 weeks (hypertensive group: -17±3%, control: -27±4%; P<0.001), and circumferential strain decreased at 18 weeks (hypertensive group: -17±2%, control: -27±3%; P=0.002). After adjustment for systolic wall stress, subendocardial percentage area fibrosis was selected as the independent determinant of longitudinal strain. This study showed that LV wall strain alternations were accompanied by fibrosis and myocyte hypertrophy from subendocardium to epicardium, and longitudinal strain related significantly to subendocardial layer fibrosis. Longitudinal strain could be a surrogate of subendocardial fibrotic changes and may be useful for risk stratification of hypertensive heart failure. PMID:24396022

Ishizu, Tomoko; Seo, Yoshihiro; Kameda, Yuri; Kawamura, Ryo; Kimura, Taizou; Shimojo, Nobutake; Xu, Dongzhu; Murakoshi, Nobuyuki; Aonuma, Kazutaka

2014-03-01

337

Effects of N-n-butyl haloperidol iodide on L-type calcium channels and intracellular free calcium in rat ventricular myocytes.  

Science.gov (United States)

The ability of N-n-butyl haloperidol iodide (F2) to cause vasodilation, and thereby produce a cardioprotective effect, has been well documented. The aim of this study was to investigate whether F2 might act as a Ca2+ antagonist. Myocytes were obtained from rat heart, and the whole-cell patch-clamp technique was used to record Ca2+ current. Laser scanning confocal microscopy was used to measure intracellular free calcium ([Ca2+]i). The results obtained from this study demonstrate that F2 reduced calcium current (ICa) in a concentration-dependent manner with an IC50 of 1.19 micromol/L, upshifted the current-voltage curve of ICa, shifted the inactivation kinetics of ICa leftward, and slowed down the recovery of ICa from inactivation. F2 decreased the fluorescent intensity of [Ca2+]i elevation induced by KCl with an IC50 of 1.61 micromol/L, and had no effects on the intracellular calcium release induced by caffeine and inositol-1,4,5-trisphosphate. These findings indicate that F2 may act as a calcium antagonist, which could account for its cardiovascular benefits. PMID:17534398

Huang, Zhanqin; Shi, Ganggang; Gao, Fenfei; Zhang, Yanmei; Liu, Xingping; Christopher, Theodore A; Lopez, Bernard; Ma, Xinliang

2007-04-01

338

A Carbohydrate Fraction, AIP1, from Artemisia Iwayomogi Reduces the Action Potential Duration by Activation of Rapidly Activating Delayed Rectifier K+ Channels in Rabbit Ventricular Myocytes  

OpenAIRE

We investigated the effects of a hot-water extract of Artemisia iwayomogi, a plant belonging to family Compositae, on cardiac ventricular delayed rectifier K+ current (IK) using the patch clamp technique. The carbohydrate fraction AIP1 dose-dependently increased the heart rate with an apparent EC50 value of 56.1±5.5 µg/ml. Application of AIP1 reduced the action potential duration (APD) in concentration-dependent fashion by activating IK without significantly altering the resting membrane po...

Park, Won Sun; Son, Youn Kyoung; Ko, Eun A.; Choi, Seong Woo; Kim, Nari; Choi, Tae-hoon; Youn, Hyun Joo; Jo, Su-hyun; Hong, Da Hye; Han, Jin

2010-01-01

339

Involvement of the phosphatidylinositol kinase pathway in augmentation of ATP-sensitive K(+) channel currents by hypo-osmotic stress in rat ventricular myocytes.  

Science.gov (United States)

The objective of this study was to investigate the mechanisms of increase in the efficacy of ATP-sensitive K(+) channel (KATP) openings by hypo-osmotic stress. The whole-cell KATP currents (IK,ATP) stimulated by 100 ?mol/L pinacidil, a K(+) channel opening drug, were significantly augmented during hypo-osmotic stress (189 mOsmol/L) compared with normal conditions (303 mOsmol/L). The EC50 and Emax value for pinacidil-activated IK,ATP (measured at 0 mV) was 154 ?mol/L and 844 pA, respectively, in normal solution and 16.6 ?mol/L and 1266 pA, respectively, in hypo-osmotic solution. Augmentation of IK,ATP during hypo-osmotic stress was attenuated by wortmannin (50 ?mol/L), an inhibitor of phosphatidylinositol 3- and 4-kinases, but not by (i) phalloidin (30 ?mol/L), an actin filament stabilizer, (ii) the absence of Ca(2+) from the internal and external solutions, and (iii) the presence of creatine phosphate (3 mmol/L), which affects creatine kinase regulation of the KATP channels. In the single-channel recordings, an inside-out patch was made after approximately 5 min exposure of the myocyte to hypo-osmotic solution. However, the IC50 value for ATP under such conditions was not different from that obtained in normal osmotic solution. In conclusion, hypo-osmotic stress could augment cardiac IK,ATP through intracellular mechanisms involving the phosphatidylinositol kinase pathway. PMID:23984989

Mitsuyama, Hirofumi; Yokoshiki, Hisashi; Irie, Yuki; Watanabe, Masaya; Mizukami, Kazuya; Tsutsui, Hiroyuki

2013-09-01

340

Tratamiento con eritropoyetina recombinante humana, hipertrofia ventricular izquierda y balance beneficio riesgo en la ERC-3b / Treatment with recombinant erythropoietin, left ventricular hypertrophy and balance benefit-risk in CKD-3b  

Scientific Electronic Library Online (English)

Full Text Available SciELO Cuba | Language: Spanish Abstract in spanish Introducción: la anemia renal es frecuente en la enfermedad renal crónica avanzada (ERC 3b-4) y el tratamiento con eritropoyetina recombinante humana la mejora pero aún está a debate cual meta de hemoglobina alcanzar y cuál es su repercusión sobre las funciones cardíacas. Objetivo de este trabajo fu [...] e evaluar la mejoría de la anemia tratada con EPOrHu sobre parámetros de la función cardiovascular ventricular izquierda en la ERC 3b-4 y el riesgo beneficio. Material y métodos: ensayo clínico abierto, no controlado, no aleatorizado, multicéntrico, prospectivo, seguimiento durante 56 semanas de seguimiento. Se evalúan los cambios en la Tasa de Filtración Glomerular por la fórmula del MDRD y por ecocardiografía en relación al nivel basal, al final del seguimiento estimada la variación al año de la HVI. Resultados: se observó un incremento significativo del hematócrito en todos los pacientes al final del estudio (n = 33, 0.29 ± 0,02 (V%) versus 0.38 ± 0.03, P (Wilcoxon)= 0.000. Al eco inicial el 90,9% tenían HVI y al final solo el 78.8% con una disminución de 2.2 mm (14 a 11.8 mm), y una correlación inversa lineal entre la HVI y la mejoría de la hemoglobina (r = -0.379; p = 0.030). La progresión del daño renal fue lenta (mL/min). En los pacientes diabéticos de 37.2 ± 8.4 versus 34.7 ± 6.7, (p Wilcoxon=0.119) y en los no diabéticos de 35.1 ± 7.833.6 ± 7.7 (p Wilcoxon= 0.119). El 48.5% de los pacientes presentaron algún tipo de evento adverso, ninguno falleció o comenzó hemodiálisis durante el seguimiento. El Balance Beneficio- Riesgo (EA moderados o graves) estimados por el cálculo del Factor de Bayes fue a favor del Beneficio (FB=1,5). Conclusiones: la corrección de la anemia renal en pacientes con ERC-3b con EPOrHu cubana mejora la HVI sin provocar otros daños Este trabajo apoya el tratamiento de la anemia severa con EPOrHU. Abstract in english Introduction: renal anemia is a frequent complication among patients with chronic kidney disease (CKD). The introduction of recombinant erythropoietin (rhuEpo) treatment has changed anemia management, but the therapeutic hemoglobin (Hb) target is still under debate, and clinical evidence for its eff [...] ect on cardiac functions is in discussion. Objective: this study aimed to explore the effect of pre-dialysis erythropoiesis-stimulating agent (ESA) use on the left ventricular hypertrophy (LVH) or general and renal function protective effect in CKD3b-4 patients. Different than in introducción in Spanish. Patients and methods: open multicentric assay. A 56-week follow-Up dose-response study. The change from baseline to the end of treatment was calculated for glomerular filtration rate by MDRD (GFR,) and, LVH by echocardiography at 24 months. Results: the treatment significantly increased hematocrit (Htc) in all patients who completed the study (n = 33, 0.29 ± 0.02(V%) versus 0.38 ± 0.03, P (Wilcoxon)= 0.000. In the beginning 90,9% At the end only the 78.8% the patients had LVH, it was decreased 2.2 mm (14 a 11.8 mm), and significant reverse lineal correlation between the change in the LVH and Hb concentration was noted (r = -0.379; p = 0.030). Progression of the CKD was slow (mL/min). Diabetics 37.2 ± 8.4 versus 34.7 ± 6.7 (p Wilcoxon=0.119) non diabetics 35.1 ± 7.833.6 ± 7.7 (p Wilcoxon= 0.119). 48.5% of the patients had Adverse effects (AE). No patients died or started in dialysis. The Balance Benefit- Risk (AE moderate or severe) estimated from the Bayes Factor was evidence to the benefit (BF=1, 64). Conclusion: we observed that correction of anemia with rhuEpo in patients with CKD 3b seems to improve the LVH without another problems and it is beneficial. The results of this study support the treatment of severe anemia with EPO.

Jorge F, Pérez-Oliva Díaz; Martha, Casanova González; Orosmán, Cuesta Panaco; Osniel, Bencomo Rodríguez; Beatriz, López Tórres; Claudio, González; Liván, Cruz Benítez; Idrian, García García; Ángela D, Tuero Iglesias; Carmen M, Valenzuela Silva; Pedro A, López Saura.

2013-09-01

341

Relación entre hiperinsulinemia, disfunción diastólica e hipertrofia del ventrículo izquierdo en pacientes con hipertensión arterial sistémica / Association of hyperinsulinemia with left ventricular hypertrophy and diastolic dysfunction in patients with hypertension  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: Spanish Abstract in spanish [...] Abstract in english Background: Hypertension is the main independent cardiovascular risk factor. However, there are additional factors that induce organic damage. Aim: To assess the association between hyperinsulinemia, ventricular hypertrophy and left ventricular diastolic function. Patients and Methods: Seventy-four [...] patients aged 30 to 65 years, with mild or moderate systemic hypertension, with overweight or mild obesity and normal glucose tolerance curve (GTC), were studied. Serum insulin was measured during GTC. The maximum levels of insulin and glucose were observed 60 minutes after the oral glucose load and they were expressed as rG/1. Patients were stratified in three groups according to their glucose and insulin fasting levels (I0) and post-glucose challenge levels (rG/I): Group 1 (normoinsulinemic patients) I0 2 (2.45+0.4). Group 2 (post-prandial hyperinsulinemic patients) I0 1 (1.34+0.3). Group 3 (persistently hyperinsulinemic patients) I0 >17 mU/mL and

Ernesto Germán, Cardona-Muñoz; David, Cardona-Müller; Sylvia, Totsuka-Sutto; Carlos Martín, Nuño-Guzmán; Sara, Pascoe-González; Marina, Romero-Prado; Alejandra G, Miranda-Díaz.

1125-11-01

342

Metformin and its Effects on Myocardial Dimension and Left ventricular hypertrophy in Normotensive patients with Coronary Heart Disease (The MET-REMODEL Study): Rationale and Design of the MET-REMODEL Study.  

Science.gov (United States)

Left ventricular hypertrophy (LVH) is a common and independent risk factor for cardiovascular events in patients with coronary artery disease (CAD). Controlling blood pressure is the standard approach to the management of LVH, but this is only partially effective as LVH also persists in normotensive patients. Apart from blood pressure (BP), other main risk factors associated with LVH are insulin resistance (IR) and central obesity. The diabetic medication, Metformin, reduces IR and aids weight loss and may therefore regress LVH. The MET REMODEL study will investigate the ability of Metformin to regress LVH in 64 patients with CAD. The MET-REMODEL trial is a single-center, phase IV, double blind, randomized, placebo-controlled trial to investigate the efficacy of Metformin in regression of the independent cardiac risk factor of LVH in patients with CAD who are insulin resistant. A minimum of 64 adults with a history of CAD with LVH and IR will be randomized into two groups to receive, either Metformin XL or placebo. The primary endpoint of this trial is to investigate any change in left ventricular mass index. Secondary endpoints include changes to insulin resistance measured using fasting insulin resistance index (FIRI), obesity, LV size, and function and improvement in endothelial function. A positive result will assist clinicians to identify a new mechanism for LVH regression by administering Metformin XL. This may also lead to investigating the mortality benefit of Metformin in patients with CAD and LVH. PMID:25545400

Mohan, Mohapradeep; McSwiggan, Stephen; Baig, Fatima; Rutherford, Lynn; Lang, Chim C

2015-02-01

343

The clinical value of apex beat and electrocardiography for the detection of left ventricular hypertrophy from the standpoint of the distance factors from the heart to the chest wall. A multislice CT study  

International Nuclear Information System (INIS)

The aim of this study was to investigate the clinical value of the apex beat and two electrocardiographic (ECG) voltage criteria in the detection of left ventricular hypertrophy (LVH) while considering two distances, from the heart to the inner chest wall and to the chest surface, measured by using multislice CT (MSCT). The study population consisted of 151 patients clinically judged as requiring MSCT angiography. The apex beat was palpated with patients in the supine. Sokolow-Lyon voltage and Cornell voltage to detect LVH were determined. The pattern of sustained or double apical impulse and Cornell voltage had higher specificity as an indicator of LVH than Sokolow-Lyon voltage. Furthermore, the distance to the inner chest wall was negatively correlated with left ventricular end-diastolic volume and mass. Contrarily, the distance to the chest surface was correlated with the body mass index. Multivariate analyses revealed that the pattern of sustained or double apical impulse showed a stronger association with the distance to the inner chest wall than to the chest surface, but Sokolow-Lyon voltage was associated with the distance to the chest surface. Among the screening tests for excluding patients with LVH, Cornell voltage or the apex beat would be better than Sokolow-Lyon voltage because these are less dependent on body size and have higher specificity. (author)

344

Let-7 miRNA profiles are associated with the reversal of left ventricular hypertrophy and hypertension in adult male offspring from mothers undernourished during pregnancy after preweaning growth hormone treatment.  

Science.gov (United States)

Maternal undernutrition (UN) is known to cause cardiac hypertrophy, elevated blood pressure, and endothelial dysfunction in adult offspring. Maternal UN may also lead to disturbances in GH regulation in offspring. Because GH plays a key role in cardiac development, we used a model of maternal UN to examine the effects of neonatal GH treatment on cardiac hypertrophy, cardiac micro RNA (miRNA) profiles, and associated gene regulation in adult offspring. Female Sprague-Dawley rats were fed either a standard control diet (CON) or 50% of CON intake throughout pregnancy (UN). From neonatal day 3 until weaning (d 21), CON and UN pups received either saline (S) (CON-S, UN-S) or GH (2.5 ?g/g·d) (CON-GH, UN-GH). Heart structure was determined by hematoxylin and eosin staining, and miRNA was isolated from cardiac tissue and miRNA expression analyzed using Cardiovascular miRNA gene Arrays (SABiosciences Ltd). Maternal UN caused marked increases in cardiac hypertrophy and left ventricular cardiomyocyte area, which were reversed by preweaning GH treatment. Systolic blood pressure was increased in UN-S groups and normalized in UN-GH groups (CON-S 121 ± 2 mmHg, CON-GH 115 ± 3 mm Hg, UN-S 146 ± 3 mmHg, and UN-GH 127 ± 2 mmHg). GH treatment during early development facilitated a reversal of pathological changes in offspring hearts caused by UN during pregnancy. Specific cardiac miRNA profiles were exhibited in response to maternal UN, accompanied by up-regulation of the lethal-7 (LET-7) miRNA family in GH-treated offspring. miRNA target analysis revealed a number of genes associated with inflammation and cardiovascular development, which may be involved in the altered cardiac function of these offspring. Up-regulation of the LET-7 family of miRNAs observed in GH groups may mediate the reversal of cardiac hypertrophy observed in adult offspring males of UN mothers. PMID:25264936

Gray, Clint; Li, Minglan; Patel, Rachna; Reynolds, Clare M; Vickers, Mark H

2014-12-01

345

Effect of renal denervation procedure on left ventricular hypertrophy of hypertensive rats and its mechanisms / Efeito da denervação renal na hipertrofia do ventrículo esquerdo de ratos hipertensos e seu mecanismo  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese OBJETIVO: Investigar o efeito da denervação renal na pressão sanguínea, na hipertrofia do ventrículo esquerdo e a expressão miocárdica de TLR4/NF-kB em ratos espontaneamente hipertensos. MÉTODOS: Trinta e seis SHR ratos foram aleatoriamente distribuídos em grupo controle, grupo denervação renal (D) [...] e grupo sham(S). 12 WKY ratos de mesma idade serviram de controle. Os ratos controles foram sacrificados, mas os ratos com denervação renal e sham foram sacrificados uma semana e seis semanas após a cirurgia. O coração foi retirado e o ventrículo esquerdo pesado seguido pelo cálculo da massa ventricular (LVMI). RESULTADOS: No grupo DO, a pressão sanguínea, LVMI e a expressão proteica de TLR4, NF-?B, TNF-? e IL-6, no miocárdio foram marcadamente maiores do que o grupo WKY (p Abstract in english PURPOSE: To investigate the effect of renal denervation (RDN) on the blood pressure, left ventricular hypertrophy and myocardial expression of TLR4/NF-?B in spontaneously hypertensive rats (SHR). METHODS: A total of 36 SHR were randomly assigned into control group (D0), RDN group (D) and sham group [...] (S). 12 WKY rats of same age served as controls (WKY group). Rats in the D0 and WKY groups were sacrificed, but rats in the D and S group were sacrificed at one week and six weeks after surgery. The heart was collected and the left ventricle weighted followed by calculation of left ventricular mass index (LVMI). RESULTS: In the D0 group, the blood pressure, LVMI and protein expression of TLR4, NF-?B, TNF-? and IL-6 in the myocardium were markedly higher than that in the WKY group (p

Weihong, Jiang; Lihua, Tan; Yunzhong, Guo; Xiaogang, Li; Xiaohong, Tang; Kan, Yang.

2012-11-01

346

O eletrocardiograma no diagnóstico da hipertrofia ventricular de pacientes com doença renal crônica El electrocardiograma en el diagnóstico de la hipertrofia ventricular de pacientes con enfermedad renal crónica Electrocardiography in the diagnosis of ventricular hypertrophy in patients with chronic renal disease  

Directory of Open Access Journals (Sweden)

Full Text Available FUNDAMENTO: A hipertrofia ventricular esquerda (HVE é um fator preditor independente de risco cardiovascular e sua caracterização e prevalência na doença renal crônica (DRC carecem de melhor estudo. OBJETIVO: Estabelecer o diagnóstico de HVE em pacientes com DRC em estágio 5 por seis diferentes critérios eletrocardiográficos, correlacionando-os com o índice de massa do ventrículo esquerdo (IMVE obtido pelo ecocardiograma. MÉTODOS: Estudo transversal que incluiu 100 pacientes (58 homens e 42 mulheres, idade de 46,2 ± 14,0 anos com DRC de todas as etiologias, há pelo menos seis meses em hemodiálise (HD. Foram obtidos eletrocardiograma (ECG e ecocardiograma dos pacientes, sempre até uma hora após o término das sessões de HD. RESULTADOS: A HVE foi detectada em 83 pacientes (83%, dos quais 56 (67,4% apresentavam o padrão concêntrico e 27 (32,6% o padrão excêntrico de HVE. Todos os métodos eletrocardiográficos estudados tiveram sensibilidade, especificidade e acurácia diagnósticas acima de 50%. Pela correlação linear de Pearson com o IMVE, apenas o critério de Sokolow-Lyon voltagem não apresentou coeficiente > 0,50. Já o cálculo da razão de verossimilhança mostrou que o ECG possui poder discriminatório para diagnóstico de HVE na população estudada, com ênfase para os critérios de Cornell produto e Romhilt-Estes. Não houve correlação entre IMVE com o QTc e sua dispersão. CONCLUSÃO: O ECG é um método útil, eficaz e de alta reprodutibilidade no diagnóstico de HVE dos pacientes em HD. Nessa população, o critério de Cornell produto mostrou-se o mais fidedigno para a detecção de HVE.FUNDAMENTO: La hipertrofia ventricular izquierda (HVI es un factor predictor independiente de riesgo cardiovascular y su caracterización y prevalencia en la enfermedad renal crónica (ERC carecen de mejor estudio. OBJETIVO: Establecer el diagnóstico de HVI en pacientes con ERC en estadio 5 por seis diferentes criterios electrocardiográficos, correlacionándolos al índice de masa del ventrículo izquierdo (IMVI que se obtuvo mediante el ecocardiograma. MÉTODOS: Estudio transversal que incluyó a 100 pacientes (58 varones y 42 mujeres, edad de 46,2 ± 14,0 años con ERC de todas las etiologías, desde hace al menos 6 meses en hemodiálisis (HD. Se obtuvieron electrocardiograma (ECG y ecocardiograma de los pacientes, siempre hasta una hora tras el término de las sesiones de HD. RESULTADOS: La HVI se detectó en 83 pacientes (83%, de los que 56 (67,4% presentaban el estándar concéntrico y 27 (32,6% el estándar excéntrico de HVI. Todos los métodos electrocardiográficos estudiados tuvieron sensibilidad, especificidad y exactitud diagnósticas superiores al 50%. Mediante la correlación lineal de Pearson con el IMVI, solamente el criterio de Sokolow-Lyon voltaje no presentó coeficiente > 0,50. Sin embargo, el cálculo de la razón de verosimilitud evidenció que el ECG tiene poder discriminatorio para diagnóstico de HVI en la población estudiada, con énfasis para los criterios de Producto de Cornell y Romhilt-Estes. No hubo correlación entre IMVI con el QTc y su dispersión. CONCLUSIÓN: El ECG es un método útil, eficaz y de alta reproductibilidad en el diagnóstico de HVI de los pacientes en HD. En esa población, el criterio de Producto de Cornell fue más fiable para la detección de HVI.BACKGROUND: Left ventricular hypertrophy (LVH is an independent predictor of cardiovascular risk, and its characterization and prevalence in chronic renal disease (CRD should be further studied. OBJECTIVE: To establish the diagnosis of LVH in patients with stage-5 CRD using six different electrocardiographic criteria, and to correlate them with left ventricular mass index (LVMI as obtained by echocardiography. METHODS: Cross-sectional study including 100 patients (58 men and 42 women, mean age 46.2 ± 14.0 years with CRD of all causes undergoing hemodialysis (HD for at least six months. Electrocardiography (ECG and echocardiography were performed in all patients, always up to one h

Francisco de Assis Costa

2009-10-01

347

O eletrocardiograma no diagnóstico da hipertrofia ventricular de pacientes com doença renal crônica / Electrocardiography in the diagnosis of ventricular hypertrophy in patients with chronic renal disease / El electrocardiograma en el diagnóstico de la hipertrofia ventricular de pacientes con enfermedad renal crónica  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese FUNDAMENTO: A hipertrofia ventricular esquerda (HVE) é um fator preditor independente de risco cardiovascular e sua caracterização e prevalência na doença renal crônica (DRC) carecem de melhor estudo. OBJETIVO: Estabelecer o diagnóstico de HVE em pacientes com DRC em estágio 5 por seis diferentes cr [...] itérios eletrocardiográficos, correlacionando-os com o índice de massa do ventrículo esquerdo (IMVE) obtido pelo ecocardiograma. MÉTODOS: Estudo transversal que incluiu 100 pacientes (58 homens e 42 mulheres, idade de 46,2 ± 14,0 anos) com DRC de todas as etiologias, há pelo menos seis meses em hemodiálise (HD). Foram obtidos eletrocardiograma (ECG) e ecocardiograma dos pacientes, sempre até uma hora após o término das sessões de HD. RESULTADOS: A HVE foi detectada em 83 pacientes (83%), dos quais 56 (67,4%) apresentavam o padrão concêntrico e 27 (32,6%) o padrão excêntrico de HVE. Todos os métodos eletrocardiográficos estudados tiveram sensibilidade, especificidade e acurácia diagnósticas acima de 50%. Pela correlação linear de Pearson com o IMVE, apenas o critério de Sokolow-Lyon voltagem não apresentou coeficiente > 0,50. Já o cálculo da razão de verossimilhança mostrou que o ECG possui poder discriminatório para diagnóstico de HVE na população estudada, com ênfase para os critérios de Cornell produto e Romhilt-Estes. Não houve correlação entre IMVE com o QTc e sua dispersão. CONCLUSÃO: O ECG é um método útil, eficaz e de alta reprodutibilidade no diagnóstico de HVE dos pacientes em HD. Nessa população, o critério de Cornell produto mostrou-se o mais fidedigno para a detecção de HVE. Abstract in spanish FUNDAMENTO: La hipertrofia ventricular izquierda (HVI) es un factor predictor independiente de riesgo cardiovascular y su caracterización y prevalencia en la enfermedad renal crónica (ERC) carecen de mejor estudio. OBJETIVO: Establecer el diagnóstico de HVI en pacientes con ERC en estadio 5 por seis [...] diferentes criterios electrocardiográficos, correlacionándolos al índice de masa del ventrículo izquierdo (IMVI) que se obtuvo mediante el ecocardiograma. MÉTODOS: Estudio transversal que incluyó a 100 pacientes (58 varones y 42 mujeres, edad de 46,2 ± 14,0 años) con ERC de todas las etiologías, desde hace al menos 6 meses en hemodiálisis (HD). Se obtuvieron electrocardiograma (ECG) y ecocardiograma de los pacientes, siempre hasta una hora tras el término de las sesiones de HD. RESULTADOS: La HVI se detectó en 83 pacientes (83%), de los que 56 (67,4%) presentaban el estándar concéntrico y 27 (32,6%) el estándar excéntrico de HVI. Todos los métodos electrocardiográficos estudiados tuvieron sensibilidad, especificidad y exactitud diagnósticas superiores al 50%. Mediante la correlación lineal de Pearson con el IMVI, solamente el criterio de Sokolow-Lyon voltaje no presentó coeficiente > 0,50. Sin embargo, el cálculo de la razón de verosimilitud evidenció que el ECG tiene poder discriminatorio para diagnóstico de HVI en la población estudiada, con énfasis para los criterios de Producto de Cornell y Romhilt-Estes. No hubo correlación entre IMVI con el QTc y su dispersión. CONCLUSIÓN: El ECG es un método útil, eficaz y de alta reproductibilidad en el diagnóstico de HVI de los pacientes en HD. En esa población, el criterio de Producto de Cornell fue más fiable para la detección de HVI. Abstract in english BACKGROUND: Left ventricular hypertrophy (LVH) is an independent predictor of cardiovascular risk, and its characterization and prevalence in chronic renal disease (CRD) should be further studied. OBJECTIVE: To establish the diagnosis of LVH in patients with stage-5 CRD using six different electroca [...] rdiographic criteria, and to correlate them with left ventricular mass index (LVMI) as obtained by echocardiography. METHODS: Cross-sectional study including 100 patients (58 men and 42 women, mean age 46.2 ± 14.0 years) with CRD of all causes under

Francisco de Assis, Costa; Ivan Romero, Rivera; Mirian Lira Castro de, Vasconcelos; André Falcão Pedrosa, Costa; Rui Manoel dos Santos, Póvoa; Maria Tereza Nogueira, Bombig; Bráulio, Luna Filho; Valter Correia de, Lima.

2009-10-01

348

Myocardial hypertrophy after pulmonary regurgitation and valve implantation in pigs  

DEFF Research Database (Denmark)

BACKGROUND: Patients may suffer from right ventricular (RV) failure and malignant cardiac arrhythmias after late pulmonary valve replacement correcting pulmonary regurgitation (PR). But the underlying mechanisms of the refractory arrhythmias are not well understood. METHODS: The aim of present study was to characterize the RV myocardium after percutaneous pulmonary valve implantation (PPVI) in a porcine model after severe PR for 3months. RV histology was evaluated with morphometric methods and RV function was assessed with electrophysiology, echocardiography, and biochemical measures: The results were compared with age-matched sham-operated animals. RESULTS: At euthanasia, RV weight was increased compared to sham-animals, median 127g (115-137) vs. 71g (69.5-76.5), p=0.0007. RV myocyte diameters corrected for individual variation with the RV/LV ratio were enlarged, 1.06 (1.02-1.13) vs. 0.84 (0.80-0.91), p=0.0006. There were no excess collagen tissue (RV/LV ratio), p=0.77. Electrophysiological stimulation resulted in RV arrhythmia in 67% of the animals compared to 25% in the sham-operated animals, but this difference was not statistically significant, p=0.28. Echocardiography revealed geometrical dilation in end-systolic RV area, mean±SD, 11.8±4.9cm(2) vs. 6.0±3.5cm(2), p=0.05, and end-diastolic area, 23.3±10.4cm(2) vs. 12.7±2.5cm(2), p=0.08. RV anterior free wall thickness was not increased, 0.7±0.2cm vs. 0.7±0.1cm, p=0.66. Echocardiographic functional parameters and plasma natriuretic peptides were unchanged. CONCLUSIONS: The RV does not completely recover after three months of PR with persistent myocardial hypertrophy one month after PPVI. Future studies should address whether RV chamber and cellular hypertrophy, without fibrosis or interventional scar tissue, may be substrate for arrhythmia.

Smith, Julie; Goetze, Jens Peter

2012-01-01

349

Detection of impaired fatty acid metabolism in right ventricular hypertrophy. Assessment by I-123 ?-methyl iodophenyl pentadecanoic acid (BMIPP) myocardial single-photon emission computed tomography  

International Nuclear Information System (INIS)

The subjects consisted of 6 patients with chronic obstructive pulmonary disease, 4 with primary pulmonary hypertension, 2 each with refractory pulmonary tuberculosis, tricuspid insufficiency, pulmonary embolism, 1 each with atrial septal defect, ventricular septal defect (Eisenmenger complex), Ebstein anomaly, and endocardial defect, and 7 healthy controls. SPECT imaging with Tl-201 (Tl) and I-123 BMIPP, and Tc-99m RBC first pass and gated blood pool scintigraphy were performed. Based on Tl planar images, the subjects were classified into 3 groups: 7 patients with no RV visualization (Group A), 11 with moderate RV visualization (Group B) and 9 with marked RV visualization (Group C). As a semi-quantitative evaluation by a myocardial SPECT, 3 regions in 3 representative short axial images were divided into 9 segments, each of which was graded from 0 to +3, and their sum was calculated as the RV score. The right ventricular ejection fraction (RVEF and the left ventricular ejection fraction were obtained by Tc-99m RBC cardiac scintigraphy. The groups with marked visualization of the right ventricle had lower RVEF, and there was a good correlation between the RVEF and the RV score with both a and BMIPP. Although a good correlation was demonstrated between the RV score with Tl and BMIPP in Groups A and B, in Group C, in which there was marked RV Tl visualization, the RV score with BMIPP was significantly smaller than with Tl. These findings suggest that impaired fatty acid findings suggest that impaired fatty acid metabolism may exist in severely hypertrophic right ventricle due to RV overload. (K.H.)

350

Left ventricular adaptation to chronic pressure overload induced by inhibition of nitric oxide synthase in rats.  

Science.gov (United States)

Recent studies have indicated that chronic inhibition of nitric oxide synthase induces arterial hypertension without myocardial hypertrophy. We investigated the mechanisms of left ventricular (LV) adaptation to this condition. Also, we analyzed the effect of the angiotensin-converting enzyme inhibitor (ACEI), lisinopril, in this experimental model of ventricular pressure overload. Fifty-eight Wistar rats received eight weeks of treatment with either NW-nitro-L-arginine-methyl ester (L-NAME group, n = 19), lisinopril (LISINOPRIL group, n = 19) or the combination of both drugs (LNAMELIS group, n = 20). All results were compared to age and sex matched untreated rats (CONTROL group, n = 18). Tail-cuff blood pressure rose significantly in L-NAME treated rats (195 +/- 29 mm Hg) compared to the CONTROL (141 +/- 12 mm Hg), LISINOPRIL (97 +/- 13 mm Hg), and LNAMELIS (113 +/- 16 mm Hg) groups. There was no myocardial hypertrophy in the chronically hypertensive rats. The ventricular unstressed volume was significantly reduced in the L-NAME group (0.119 +/- 0.027 mL) compared to the CONTROL (0.158 +/- 0.026 mL) indicating a disproportional reduction in ventricular volume related to the myocardial mass. The chamber size modification resulted in a systolic stress which was comparable to the CONTROL even though the isovolumetric systolic pressure was higher. The systolic functional data indicated preserved myocardial contractility in L-NAME. LV compliance was increased in the LISINOPRIL group and myocardial passive stiffness was lower in all treated rats compared to CONTROL. We conclude that LV. adaptation to chronic pressure overload without hypertrophy involves changes in chamber geometry and myocardial diastolic mechanical properties. Also, ACEI fully prevents L-NAME induced hypertension, reduces myocyte cross-sectional area, and myocardial passive stiffness. The combination of L-NAME plus lisinopril decreases the load independent index of myocardial contractility. PMID:9689443

Matsubara, B B; Matsubara, L S; Zornoff, L A; Franco, M; Janicki, J S

1998-06-01

351

Collagen network remodelling and diastolic stiffness of the rat left ventricle with pressure overload hypertrophy.  

Science.gov (United States)

This study had two objectives: (a) to determine the accumulation of collagen and its structural remodelling in the hypertrophied rat left ventricle after 4 and 8 weeks of abdominal aorta banding; and (b) to correlate these findings with the diastolic stress-strain relation of the intact myocardium. In comparison to age and sex matched controls, the collagen volume fraction of the hypertrophied myocardium after 4 and 8 weeks of aortic banding increased significantly from 3.5(SD1.0)% to 7.8(4.2)% and 6.2(2.0)% respectively. This accumulation of collagen, or fibrosis, occurred in the absence of myocyte necrosis. Scanning electron microscopy showed increased density and thickness of the collagen weave and tendons. At 4 weeks, light microscopy showed interstitial oedema and disrupted collagen fibrils. Left ventricular diastolic stress-strain relations of both pressure overload groups were significantly steeper than that of the control group. Thus the response of the interstitium to the hypertrophic process that accompanies abdominal aorta banding is a complex process that includes a structural remodelling of the fibrillar collagen matrix and the early appearance of interstitial oedema, each of which may contribute to a rise in the passive stiffness of the intact myocardium. PMID:2978464

Doering, C W; Jalil, J E; Janicki, J S; Pick, R; Aghili, S; Abrahams, C; Weber, K T

1988-10-01

352

Alterações morfológicas e funcionais cardíacas e análise dos fatores determinantes de hipertrofia ventricular esquerda em 40 pacientes com acromegalia Cardiac morphology and performance alterations and analysis of determinant factors of left ventricular hypertrophy in 40 patients with acromegaly  

OpenAIRE

A acromegalia é uma doença de alta mortalidade, especialmente em razão de complicações cardiovasculares. Com o objetivo de avaliar os fatores determinantes da hipertrofia ventricular esquerda (HVE) e as alterações cardíacas na acromegalia, analisamos 40 acromegálicos submetidos a exames clínico-laboratoriais e ao ecocardiograma. As variáveis analisadas foram idade, sexo, duração de doença, hipertensão arterial (HA), intolerância à glicose/DM, uso ou não de octreotide, GH e %...

Alessandra Ferri Casini; Paula Bruna Araújo; Rosita Fontes; Sérgio Salles Xavier; Gadelha, Mo?nica R.

2006-01-01

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pH regulation in adult cardiac myocytes  

International Nuclear Information System (INIS)

The purpose of this study is to examine the pHi regulatory mechanisms of adult ventricular myocytes, the cells that perform the pumping work of the heart. The cell system for this study was the ventricular myocyte, isolated by enzymatic dissociation from adult rate heart. In agreement with the findings on other cardiac model cells, I demonstrated the existence of a Cl-/HCO3- exchanger and a Na+/H+ exchanger in ventricular myocytes. The existence of the anion exchanger was demonstrated in 36Cl- flux experiments and as stilbene disulfonate-inhibitable and Cl- gradient-dependent intracellular pH shifts in the presence of bicarbonate. The fluorescein derivative BCECF served as a fluorescent probe of intracellular pH in the these experiments. The existence of the Na+/H+ exchanger was demonstrated in pHi experiments using BCECF. Further experiments characterized the kinetics of the Na+/H+ exchanger and its regulation. The steady-state pHi of ventricular myocytes was 7.16 ± 0.11 at pH0 = 7.4. Several agonists caused a rise in steady-state pHi: the protein kinase stimulator phorbol myristate acetate (PMA), the ?1-adrenergic agonist 6-fluoro-norepinephrine (6F-NE) and the ?-agonist UK14304, and ATP

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Frecuencia y factores de riesgo de la hipertrofia ventricular izquierda como marcador de daño cardiovascular en el trasplante renal / Frequency and risk factors of the left ventricular hypertrophy like scoreboard of cardiovascular damage in renal transplant  

Scientific Electronic Library Online (English)

Full Text Available SciELO Cuba | Language: Spanish Abstract in spanish Introducción: las complicaciones cardiovasculares son frecuentes y constituyen la principal causa de muerte en los pacientes con trasplantes renales, su alta incidencia está dada por múltiples factores de riesgo. Objetivos: determinar la frecuencia de la hipertrofia del ventrículo izquierdo como ma