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Biomedical subjects

P Anversa

Publications and source records attributed to P Anversa.

At least 127 records · Page 7Linked to original sources
PubMed1993

Regulation of angiotensin II receptors on ventricular myocytes after myocardial infarction in rats.

To determine the effects of acute myocardial infarction on the regulation of angiotensin II (Ang II) receptors and contractile performance of left and right ventricular myocytes, coronary artery ligation was surgically induced in rats, and Ang II receptor density and affinity and the mechanical properties of surviving muscle cells were examined 1 week later. Physiological determinations of cardiac pump function revealed the presence of ventricular failure, which was associated at the cellular level with a depression in the velocity of myocyte shortening and relengthening, a prolongation of time to peak shortening, and a reduction in the extent of cell shortening. These abnormalities in single-cell function were more prominent in left than in right ventricular myocytes. Cellular hypertrophy was documented by increases in cell length and width, which were also greater in the spared myocytes of the infarcted left ventricle. Reactive hypertrophy was accompanied by a 1.84- and 1.85-fold increase in the density of Ang II receptors on left and right myocytes, respectively. On the other hand, the affinity of Ang II receptors for the radiolabeled antagonist was not altered. However, Ang II-stimulated phosphoinositol turnover was enhanced by 3.7- and 2.5-fold in left and right myocytes, respectively, after infarction. Ventricular myocytes were found to possess the AT1 receptor subtype exclusively. In conclusion, myocardial infarction leads to impairment in the contractile behavior of the remaining cells and to the activation of Ang II receptors and effector pathway associated with these receptors, which may be involved in the reactive growth adaptation of the viable myocytes.

Angiotensin Receptor Antagonists↗
PubMed1993

Myocardial infarction, cardiac anatomy and ventricular loading.

To see whether the hypertrophic response of the surviving myocardium after infarction leads to a complete reconstitution of ventricular mass, the left coronary artery was ligated in rats and the animals killed one month later. In infarcts affecting an average of 38% of the free wall of the left ventricle, the ratio of wall thickness to chamber radius remained essentially constant. On the other hand, the ratio decreased significantly in the presence of infarcts involving an average of 60% of the ventricular wall. In addition, inadequate growth adaptations were detected in both groups of infarcts with respect to myocyte volume and length and to capillary volume and length. These defects in the regeneration of myocardial structures were associated with elevations in diastolic wall stress which were more prominent in the larger infarct group. The limited growth reaction of the myocyte and vascular compartments may be implicated in the persistence of cardiac dysfunction and failure late after infarction.

Animals↗
PubMed1992

Remodeling and reparation of the cardiovascular system.

Growth or altered metabolism of nonmyocyte cells (cardiac fibroblasts, vascular smooth muscle and endothelial cells) alters myocardial and vascular structure (remodeling) and function. However, the precise roles of circulating and locally generated factors such as angiotensin II, aldosterone and endothelin that regulate growth and metabolism of nonmyocyte cells have yet to be fully elucidated. Trials of pharmacologic therapy aimed at preventing structural remodeling and repairing altered myocardial structure to or toward normal in the setting of hypertension, heart failure and diabetes are reviewed. It is proposed that these are therapeutic goals that may reduce cardiovascular morbidity and mortality. Although this hypothesis remains unproved the primary goal of therapy should be to preserve or restore tissue structure and function.

Animals↗
PubMed1992

Cellular basis of ventricular remodeling in hypertensive cardiomyopathy.

This review summarizes the effects of long-term pressure overload hypertrophy on the right and left ventricular myocardium. In particular, the role that the fundamental processes of myocyte growth plays in the remodeling of the wall is analyzed quantitatively. Moreover, emphasis is placed on the observation that the duration of the overload is an important component of the onset, development, and progression of time-dependent myocardial dysfunction associated with hypertensive cardiomyopathy. The deterioration in ventricular pump function is postulated to be accompanied by myocyte cellular hyperplasia and capillary proliferation in an attempt to increase the thickness of the ventricular wall and, consequently, to decrease the magnitude of systolic and diastolic stress generated by the elevation in ventricular systolic and end-diastolic pressures. Myocyte cellular hyperplasia constitutes an essential growth reserve mechanism of the heart. Regeneration of damaged and lost myocardium may be accomplished by hyperplasia of myocytes, a phenomenon considered not feasible for several decades.

Cardiomyopathies↗
PubMed1992

Re-expression of alpha skeletal actin and regulation of alpha 1 adrenoceptor signalling in DOCA-salt hypertension in rats.

OBJECTIVE: To determine the effects of increased sympathetic nervous system activity in humoral hypertension on the regulation of surface alpha 1 adrenoceptors and signal transduction, deoxycorticosterone acetate (DOCA) salt hypertension was induced in rats and the animals killed three weeks following the initiation of hypertension. METHODS: Experiments were performed on male Sprague-Dawley rats, weighing 250-300 g, divided into two groups: DOCA-salt (n = 75), and control (n = 60). Radioligand binding studies of the alpha 1 adrenoceptors, noradrenaline stimulated phosphoinositol turnover, ADP ribosylation of 41 kD substrate by pertussis toxin, and myocardial noradrenaline content were measured in the ventricular myocardium. The expression of sarcomeric actin isoforms was examined by northern blot and hybridisation with specific oligonucleotide probes. RESULTS: The density of alpha 1 adrenoceptors was decreased by 51% in DOCA-salt treated rats. However, noradrenaline stimulated phosphoinositol turnover in myocytes from DOCA-salt hearts was not diminished. The relative quantities of pertussis toxin labelled substrates did not differ in experimental and control hearts. Myocardial noradrenaline content was reduced by 60% in DOCA-salt hearts. Northern blots on RNA extracted from hypertrophic hearts of DOCA-salt treated rats showed an upregulation of alpha skeletal actin. CONCLUSIONS: The adrenergic state present in short term DOCA-salt hypertensive hypertrophy is characterised by enhanced signal transduction via the alpha 1 adrenoceptors and the re-expression of alpha skeletal actin in enlarging myocytes.

Actins↗
PubMed1992

Chronic elevation of norepinephrine in conscious dogs produces hypertrophy with no loss of LV reserve.

Elevated plasma catecholamine levels may cause both myocardial hypertrophy and tissue damage. To determine whether the left ventricle from dogs with chronic norepinephrine infusion can sustain additional functional loads, we altered ventricular preload or afterload and determined both global and left ventricular (LV) wall function. Dogs were instrumented to measure LV wall function, LV internal base diameter, and LV pressures and were allowed to fully recover. Preload was altered by volume loading and afterload by injection of phenylephrine. Osmotic infusion pumps were implanted to continuously release norepinephrine at 0.5 micrograms.kg-1.min-1 for 28 days, and the volume loading and phenylephrine were repeated on days 14 and 28. Heart rate decreased, whereas there were no differences in mean arterial pressure, maximum first derivative of LV pressure (dP/dt), LV dP/dt/developed pressure of 40 mmHg, LV dP/dt/end-diastolic circumference, slope of the pressure-diameter relation, peak systolic wall stress, LV/end-diastolic diameter, or LV/end-systolic diameter during norepinephrine infusion. Diastolic and systolic wall thickness and chamber weights were increased (P less than 0.05). Indexes of diastolic function, including end-diastolic pressure, end-diastolic pressure-end-diastolic diameter relationship, maximum negative dP/dt, and the time constant (tau) were unchanged after chronic norepinephrine infusion, although maximum end-diastolic pressure during volume loading was increased from 17.7 +/- 2.0 to 21.7 +/- 1.0 mmHg. Chronic norepinephrine infusion did not alter tau, and tau increased equivalently with phenylephrine injection in both normal (36 +/- 1 to 62 +/- 5 ms) dogs and in those chronically infused with norepinephrine (36 +/- 1 to 56 +/- 5 ms).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Heterogeneity of ventricular remodeling after acute myocardial infarction in rats.

To determine the effects of acute myocardial infarction on the extent and distribution of systolic and diastolic wall stress on the surviving myocardium, coronary artery occlusion was produced in rats, and the animals were killed 1 wk later. After hemodynamic measurements in vivo, the characteristics of cardiac anatomy at end diastole and peak systole were mimicked in vitro by fixing hearts under diastolic conditions or barium-induced contracture. In the presence of infarcts inducing a 48% loss of myocytes, left ventricular failure was documented by increases in left ventricular minimal and end-diastolic pressures and decreases in peak systolic pressure and positive and negative rates of pressure change with time. End-diastolic and end-systolic volumes increased, whereas stroke volume and cardiac output diminished. Ventricular remodeling in diastole consisted of an increase in the longitudinal axis while both longitudinal and transverse mid-chamber diameters were augmented after systolic contraction. Left ventricular chamber volume enlarged by 44% through a 20% augmentation in the longitudinal diameter and increases in the transverse luminal diameter of 13, 21, 32, and 37% in four consecutive sites from the equatorial region to the apex. As a consequence of infarction, systolic thickening of the spared myocardium of the free wall was reduced progressively from the base to the apex. In the interventricular septum of the infarcted heart, systole thickening occurred mostly in the equatorial region and was reduced at the basal and apical portions. The interaction of hemodynamic impairment with the architectural rearrangements of the wall and chamber provoked a 1.9-fold increase in overall stress on the spared myocardium. However, diastolic stress was augmented by 6.8-fold, markedly exceeding the 1.1-fold increase in systolic stress. Thus large infarcts of the rat left ventricle due to left main coronary occlusion lead to a change in shape of the heart from ellipsoidal to cylindrical. The elevation in overall stress may condition the unfavorable long-term outcome of the infarcted heart.

Animals↗
PubMed1992

Amelioration of effects of hypertension and diabetes on myocardium by cardiac glycoside.

To determine whether digoxin protects the myocardium during the initial phases of hypertension and diabetes combined, adult male Wistar rats with two-kidney, one-clip renal hypertension and streptozotocin-induced diabetes mellitus were treated with digoxin (500 micrograms.kg-1.day-1) by gavage for 10 wk immediately after the onset of hypertension and diabetes. Systemic arterial blood pressures, ventricular pressures, the first time derivative of left ventricular pressure, diastolic wall stress, and the quantitative analysis of the number and distribution of myocardial lesions and capillary density of the myocardium were measured. In comparison to untreated hypertensive-diabetic animals, digoxin-treated rats showed a lesser elevation in left ventricular end-diastolic pressure and diastolic and systolic wall stress despite comparable degrees of hypertension and blood glucose levels. In addition, chamber diameter was smaller and the diffusion distance for oxygen was within normal values in animals treated with this glycoside. However, the numerical density of the foci of replacement fibrosis was similar to that found in untreated hypertensive-diabetic animals. In conclusion, digoxin reduces the magnitude of ventricular remodeling and diastolic wall stress in this model of hypertension and diabetes.

Animals↗
PubMed1992

Cellular mechanisms of ventricular failure: myocyte kinetics and geometry with age.

To determine whether heart failure is a consequence of alterations in cardiac cellular performance, myocytes were isolated from Fischer 344 rats at 4, 12, 20, and 29 mo of age and studied mechanically and morphometrically. Left ventricular myocyte length increased by 14.5, 14.4, and 24.0% at 12, 20, and 29 mo when compared with 4-mo-old animals. An 11.4 and 14.2% increase in length was seen for right ventricular myocytes from 4 to 12 mo and from 20 to 29 mo, respectively. Although no change in cell width was seen in either ventricle as a function of age, myocardial cells were more irregular in shape and consistently longer in the left ventricle at 20 and 29 mo. Left myocytes at 29 mo revealed diminished velocities of shortening (31.7%) and relengthening (59.5%). Contraction duration increased due to a 28.9% prolongation of time to peak shortening and a 26.5% increase in time to relengthening, resulting in a 25.8% decrease in myocyte shortening at 29 mo. Similar changes were observed in right ventricular myocytes, but they occurred later in life. Thus the alterations in myocyte geometry and depression in contractile performance seen here are major contributors to the eccentric dilated ventricular chamber and diminished pump function previously documented in the age-related transition from normal cardiac dynamics to left ventricular dysfunction and failure.

Aging↗
PubMed1992

Long-term coronary stenosis in rats: cardiac performance, myocardial morphology, and contractile protein enzyme activity.

To determine the effects of chronic nonocclusive coronary constriction on cardiac hemodynamics, myocardial structure, and contractile protein enzyme activity, the left coronary artery was narrowed in rats, and measurements of ventricular pump function, extent and localization of tissue damage, and myofibrillar Mg2+ and Ca2+ myosin adenosinetriphosphatase (ATPase) activities were measured 3 mo later. In the presence of coronary artery stenosis averaging 56%, two different degrees of depression in global cardiac performance were identified, and the animals were divided in two groups. In the first group, left ventricular end-diastolic pressure (LVEDP) was increased and LV+ and/or--the first derivative of LV pressure (dP/dt) were decreased, whereas in the second group end-diastolic and peak systolic LV pressures, LV+ and -dP/dt and right ventricular dynamics were all impaired. Thus left ventricular dysfunction and failure occurred with coronary narrowing. Structurally, multiple foci of replacement fibrosis were found across the left ventricular wall, but the number of these lesion profiles was 2.6-fold larger in failing animals than in rats with cardiac dysfunction. Biochemically, Mg(2+)-ATPase activity in myofibrils and Ca2+ myosin ATPase were not altered biventricularly. On the other hand, a shift from V1 to V3 myosin isoenzymic content occurred in the failing left ventricle. In conclusion, the late impairment in ventricular pump function associated with prolonged coronary artery stenosis appears to be sustained more by the magnitude of myocardial damage than by defects in contractile protein enzyme activity.

Animals↗
PubMed1992

Mechanical performance of spared myocytes after myocardial infarction in rats: effects of captopril treatment.

To determine the effects of myocardial infarction-induced left ventricular failure on the mechanical characteristics of the remaining viable myocytes, coronary arterial occlusion was performed in rats, and cell function was examined 1 wk later. Moreover, to establish the mechanisms by which treatment with angiotensin-converting enzyme inhibitors ameliorates cardiac dynamics, captopril was administered immediately after surgery, and the contractile behavior of the unaffected cells was similarly analyzed 7 days later. The severe impairment in left-side pump function was found to be associated with a decrease in the velocities of myocyte shortening and relengthening and peak shortening despite a prolongation of contraction duration. In addition, a uniform property was recognized in myocytes from infarcted and noninfarcted hearts. Longer cells manifested greater velocity of shortening, whereas wider cells of identical length exhibited depressed shortening velocity. After infarction, the depression in cell contractility coupled with lateral expansion of myocytes exceeded the influence on cell mechanical behavior linked to myocyte lengthening leading to an overall decrease in contractility of the hypertrophied cells. Captopril therapy preserved, in part, the ability of myocytes to shorten and relengthen, which was accompanied by a decrease in the lateral and longitudinal expansions of these cells.

Animals↗
PubMed1992

Chronic coronary arterial stenosis impairs alpha 1-adrenoreceptor signaling and cardiac performance in rats.

Coronary stenosis was induced in rats to determine whether chronic coronary artery constriction resulted in impairment of cardiac pump performance, alterations in alpha 1-adrenoreceptor signal transduction, and inadequate myocardial hypertrophy, and these parameters were examined 6 mo later. A 50% reduction in coronary diameter was associated with an elevation in left ventricular end-diastolic pressure, whereas left ventricular peak systolic pressure, rate of pressure rise and decay were reduced. The hypertrophic response was modest, since statistically significant increases of 11% and 23% in left and right ventricular weights were measured. Radioligand binding documented an 18% and a 38% statistically significant reduction in alpha 1-adrenoreceptor density of the left and right myocardium, respectively. ADP ribosylation of the 41-kDa substrate by pertussis toxin showed a 16% significant decrease of this parameter in the left myocardium. Moreover, a 29% decrease in norepinephrine stimulated phosphoinositol turnover was seen in myocytes, and this change was statistically significant. The depressed generation of intracellular second messengers linked to the alpha 1-adrenoreceptors was found in conjunction with a 19% significant reduction in myocardial norepinephrine content. In conclusion, the long-term effects of coronary stenosis involve impaired transduction of adrenergic signals, which, in combination with constraints on myocardial growth, may participate in the onset of ventricular dysfunction in this model.

Actins↗
PubMed1992

Chronic nonocclusive coronary artery constriction impairs ventricular function, myocardial structure, and cardiac contractile protein enzyme activity in rats.

To determine the effects of chronic nonocclusive coronary constriction on cardiac hemodynamics, structural integrity, and contractile protein enzyme activity, the left coronary artery was narrowed in rats, and measurements of ventricular performance, magnitude, and distribution of tissue damage and myofibrillar Mg2+ and Ca2+ myosin ATPase activities were evaluated 1 month later. In the presence of coronary artery stenosis averaging 58%, three levels of involvement of global cardiac performance were identified, and the rats were divided accordingly. In the first group, only left ventricular end-diastolic pressure (LVEDP) was increased; in the second group, LVEDP and left ventricular +dP/dt and/or -dP/dt were affected; and in the third group, LVEDP, left ventricular +dP/dt and -dP/dt, and right ventricular end-diastolic pressure were impaired. Thus, left ventricular moderate dysfunction, severe dysfunction, and failure occurred with coronary narrowing. On a structural basis, coronary constriction resulted in an ongoing process characterized by acute myocytolytic necrosis and foci of replacement fibrosis in different stages of healing. The number of these lesion profiles in the left ventricular myocardium increased 4.7-, 4.4-, and 8.3-fold in rats with moderate dysfunction, severe dysfunction, and failure, respectively. Biochemically, Mg(2+)-ATPase activity of myofibrils increased biventricularly when moderate dysfunction was present. However, this parameter decreased with the appearance of severe dysfunction, reaching control values in ventricular failure. Ca2+ myosin ATPase activity was reduced in the left ventricle of rats with severe dysfunction and failure, whereas it was elevated in the right ventricle of rats with severe dysfunction. In conclusion, a fixed lesion of the left main coronary artery with a modest reduction in vessel luminal diameter generates a conditioned state of the heart characterized by a continuous loss of myocytes and replacement scarring, which, in combination with alterations in contractile protein enzyme activity, may be responsible for a number of abnormalities in cardiac dynamics ranging from moderate dysfunction to pump failure.

Adenosine Triphosphatases↗
PubMed1992

Myocardial mechanical, biochemical, and structural alterations induced by chronic ethanol ingestion in rats.

To determine the effects of moderate ethanol consumption on the mechanical, biochemical, and structural characteristics of the heart, myocardial mechanical performance, contractile protein enzyme activity, and the number and size of myocytes were measured in male Fischer 344 rats after the ingestion of 30% oral ethanol. Papillary muscles removed from the left ventricle were greater in length, weight, and cross-sectional area than the corresponding muscles from the right side. However, no differences were found between control and ethanol-treated myocardium when either the left or right side was compared separately. Chronic ethanol ingestion resulted in an increase in resting tension in left ventricular muscles, with no alteration in peak developed tension. Moreover, time to peak tension was significantly prolonged, whereas a depression was observed in the peak rate of isometric tension development. Isotonically, left muscles from ethanol-treated rats revealed a prolongation of time to peak shortening and a marked depression in the velocity of shortening at physiological loads. No changes were noted in muscles from the right ventricle. Contractile protein enzyme activity revealed no differences in myofibrillar Mg(2+)-ATPase activity in right and left ventricular myocardium between control and ethanol-treated rats in the presence of EGTA. However, at physiological activating levels of calcium, an upward shift of the myofibrillar Mg(2+)-ATPase activity-calcium curve occurred in left myocardium, whereas a depression in this relation was seen in the right ventricle. As a result of chronic ethanol intake, a decrease was noted in the volume percent of myocardium occupied by myocytes, and that myocyte cell volume per nucleus was found to remain essentially constant throughout the various layers of the ventricular wall. Importantly, a 14% significant decrease in the total number of myocyte nuclei was demonstrated in the left ventricular myocardium of rats on chronic ethanol consumption. Thus, chronic but moderate alcohol ingestion resulted in depressed contractile performance, alterations in myofibrillar Mg(2+)-ATPase activity, and myocyte loss. These events may serve to function as preliminary indicators of the onset of heart failure of alcoholic origin in this animal model.

Adenosine Triphosphatases↗
PubMed1992

Ventricular loading is coupled with DNA synthesis in adult cardiac myocytes after acute and chronic myocardial infarction in rats.

To determine whether the overload associated with myocardial infarction and ventricular failure in rats is coupled with activation of DNA synthesis in the remaining left and right ventricular myocytes, flow cytometric analysis was performed on myocyte nuclei prepared from both ventricles 7 and 30 days after coronary occlusion. In addition, oral captopril was administered in separate groups of control and experimental rats to establish whether a relation existed between attenuation of ventricular loading and magnitude of DNA synthesis in myocytes. Results demonstrated that left ventricular failure and right ventricular dysfunction at 7 days after infarction were biventricularly associated with marked increases in the number of myocyte nuclei in the G2M phase of the cell cycle. In contrast, the fraction of nuclei in the G0+G1 phase decreased. In comparison with the earlier time point, the 30-day interval was characterized by a significant magnitude of cardiac hypertrophy, a moderate amelioration of ventricular pump function, and a decrease in the percentage of myocyte nuclei in the G2M phase in both ventricles. However, 30 days after infarction, the number of right ventricular myocyte nuclei in the S and G2M phases remained elevated with respect to control animals. Captopril therapy reduced the extent of ventricular loading and the population of myocyte nuclei in the cell cycle at 7 days. In conclusion, DNA synthesis in myocyte nuclei may represent an important adaptive component of the myocardial response to infarction.

Animals↗
PubMed1992

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

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 in-dP/dt. Failure was defined on the basis of a 4.7-fold elevation in LVEDP, and a 26%, 47%, 45%, and 41% decrease in LVPSP, DP, +dP/dt, and -dP/dt. Moreover, in this group, right ventricular end diastolic and systolic pressures increased 5.5- and 1.2-fold. Left and right ventricular weights expanded 23% and 51% with dysfunction and 30% and 56% with failure. Left ventricular hypertrophy was characterized by ventricular dilation and wall thinning which were more severe in the failing animals. Foci of damage were found in both groups but tissue injury was more prominent in the endomyocardium and in failing rats. Finally, myocyte loss in the ventricle was 10% and 20% with dysfunction and failure whereas the corresponding enlargements of the unaffected myocytes were 34% and 53%. Thus, coronary narrowing led to abnormalities in cardiac dynamics with an increase in diastolic wall stress and extensive ventricular remodeling in spite of a moderate loss of myocytes and compensatory reactive hypertrophy of the viable cells.

Animals↗
PubMed1992

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

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 (mmHg/s) were reduced by 9% and 14%, respectively. Moreover, developed peak systolic ventricular pressure and maximal dP/dt diminished 14% and 12%. After perfusion fixation of the coronary vasculature and the myocardium, at a left ventricular intracavitary pressure equal to the in vivo measured end diastolic pressure, a 10% thickening of the left ventricular wall was measured in association with a 13% increase in the equatorial cavitary diameter and a 44% augmentation in ventricular mass. The 52% hypertrophy of the right ventricle was characterized by an 11% thicker wall and a 37% larger ventricular area. The 33% expansion in the aggregate myocyte volume of the left ventricle was found to be due to a 14% myocyte cellular hypertrophy and a 17% myocyte cellular hyperplasia. These cellular parameters were calculated from the estimation of the number of myocyte nuclei per unit volume of myocardium in situ and the evaluation of the distribution of nuclei per cell in enzymatically dissociated myocytes. Myocyte cellular hyperplasia provoked a 9% increase in the absolute number of cells across the left ventricular wall. In contrast, myocyte cellular hypertrophy (42%) was responsible for the increase in myocyte volume of the right ventricle. The proliferative response of left ventricular myocytes was not capable of restoring diastolic cell stress, which was enhanced by the changes in ventricular anatomy with anemia. In conclusion, chronic anemia induced an unbalanced load on the left ventricle, which evoked a hyperplastic reaction of preexisting myocytes, in an attempt to normalize diastolic wall and myocyte stress.

Anemia↗