Left ventricular hypertrophy. Relation of structure to diastolic function in hypertension

Serum Uric Acid Is Associated with the Progression of Left Ventricular Diastolic Dysfunction in Apparently Healthy Subjects

Background

Left ventricular (LV) diastolic dysfunction (LVDD) is the defining feature of heart failure with preserved ejection fraction (HFpEF) and predicts subsequent incident heart failure (HF) and all-cause mortality. Mounting evidence reveals that cardiometabolic risk factors play critical roles in the development of LVDD. In this study, we sought to investigate the relation between serum uric acid (SUA) level and the progression of LVDD in apparently healthy patients.

Methods

A total of 1082 apparently healthy subjects without diagnosed cardiovascular disease and LVDD were consecutively enrolled. SUA levels were measured, and repeat echocardiography and tissue Doppler imaging (TDI) were performed at baseline and during 1-year follow-up.

Results

By dividing the study population based on quartiles of SUA, we found subjects in higher quartiles had greater increases in TDI-derived early diastolic velocity (e′) and E (peak LV filling velocity)/e′ ratios during 1-year follow-up. After multivariate adjustment, high SUA persisted to be an independent predictor for the subsequent worsening of LVDD (odds ratio: 1.351 [95% CI 1.125~1.625], per 100 μmol/L SUA). Subgroup analysis suggested that the association between SUA and LVDD development was more pronounced in subjects without other cardiometabolic risk factors involved. Factor analysis demonstrated that high SUA was the major cardiometabolic attribute in patients with LVDD progression.

Conclusion

Our findings suggest that high SUA is an independent cardiometabolic risk factor for the progression of LVDD in apparently healthy subjects.

Long Term Osmotic Mini Pump Treatment with Alpha-MSH Improves Myocardial Function in Zucker Diabetic Fatty Rats

The present investigation evaluates the cardiovascular effects of the anorexigenic mediator alpha-melanocyte stimulating hormone (MSH), in a rat model of type 2 diabetes. Osmotic mini pumps delivering MSH or vehicle, for 6 weeks, were surgically implanted in Zucker Diabetic Fatty (ZDF) rats. Serum parameters, blood pressure, and weight gain were monitored along with oral glucose tolerance (OGTT). Echocardiography was conducted and, following sacrifice, the effects of treatment on ischemia/reperfusion cardiac injury were assessed using the isolated working heart method. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity was measured to evaluate levels of oxidative stress, and force measurements were performed on isolated cardiomyocytes to determine calcium sensitivity, active tension and myofilament co-operation. Vascular status was also evaluated on isolated arterioles using a contractile force measurement setup. The echocardiographic parameters ejection fraction (EF), fractional shortening (FS), isovolumetric relaxation time (IVRT), mitral annular plane systolic excursion (MAPSE), and Tei-index were significantly better in the MSH-treated group compared to ZDF controls. Isolated working heart aortic and coronary flow was increased in treated rats, and higher Hill coefficient indicated better myofilament co-operation in the MSH-treated group. We conclude that MSH improves global heart functions in ZDF rats, but these effects are not related to the vascular status.

The Degree of Albuminuria Is Related to Left Ventricular Hypertrophy in Hypertensive Diabetics and Is Associated with Abnormal Left Ventricular Filling: A Pilot Study

The association of albuminuria and left ventricular (LV) hypertrophy (LVH) in diabetics aggra vates the prognosis. The authors studied the relation between LVH and the degree of albu minuria in diabetics and investigated the relationship of albuminuria to LV filling. A comparison was made between 30 hypertensive diabetics, 10 of whom had microalbuminuria (MIC) and 20 had macroalbuminuria (MAC), and 18 diabetics who were normotensive and normalbuminuric (NOR). LV mass index (LVMI) and LV ejection fraction (LVEF) were measured during echocar diography. LV filling pattern at rest and at peak standardized isometric exercise (IME) using handgrip was assessed by measuring E/A (peak velocity of the early/atrial filling waves) of the transmitral flow during Doppler and echocardiography. Each patient underwent a stress ECG test. LVMI was higher in MAC (132.3 ±55.4) than in MIC (115.6 ±32.5) or NOR (90.0 ±31.8) (p<0.01). There were more patients in MAC with LVH (n = 13) and abnormal filling (n = 9 at rest and 16 with IME) than in MIC (LVH = 5, abnormal filling = 1 at rest and 10 during IME) or NOR (LVH = 3, abnormal filling = 1 at rest and 9 during IME) (p < 0.02). LVMI was not related to LVEF. Although blood pressure was not different between MAC and MIC groups, it was signif icantly higher than in the NOR group. This study suggests that a high degree of albuminuria in hypertensive diabetics is associated with greater value for LVMI and an increased incidence of LVH independent of blood pressure level or systolic LV function. LVH is associated with abnormal LV filling. The degree of albuminuria may predict LVMI and LVH, which are associated with abnormal LV filling. This association of abnormal LV filling with albuminuria in hypertensive diabetic patients may account for their high risk of cardiovascular events.

Atrophic cardiomyocyte signaling in hypertensive heart disease

Cardinal pathological features of hypertensive heart disease (HHD) include not only hypertrophied cardiomyocytes and foci of scattered microscopic scarring, a footprint of prior necrosis, but also small myocytes ensnared by fibrillar collagen where disuse atrophy with protein degradation would be predicted. Whether atrophic signaling is concordant with the appearance of HHD and involves oxidative and endoplasmic reticulum (ER) stress remains unexplored. Herein, we examine these possibilities focusing on the left ventricle and cardiomyocytes harvested from hypertensive rats receiving 4 weeks aldosterone/salt treatment (ALDOST) alone or together with ZnSO₄, a nonvasoactive antioxidant, with the potential to attenuate atrophy and optimize hypertrophy. Compared with untreated age-/sex-/strain-matched controls, ALDOST was accompanied by (1) left ventricle hypertrophy with preserved systolic function; (2) concordant cardiomyocyte atrophy (<1000 μm²) found at sites bordering on fibrosis where they were reexpressing β-myosin heavy chain; and (3) upregulation of ubiquitin ligases, muscle RING-finger protein-1 and atrogin-1, and elevated 8-isoprostane and unfolded protein ER response with messenger RNA upregulation of stress markers. ZnSO₄ cotreatment reduced lipid peroxidation, fibrosis, and the number of atrophic myocytes, together with a further increase in cell area and width of atrophied and hypertrophied myocytes, and improved systolic function but did not attenuate elevated blood pressure. We conclude that atrophic signaling, concordant with hypertrophy, occurs in the presence of a reparative fibrosis and induction of oxidative and ER stress at sites of scarring where myocytes are atrophied. ZnSO₄ cotreatment in HHD with ALDOST attenuates the number of atrophic myocytes, optimizes size of atrophied and hypertrophied myocytes, and improves systolic function.

Nebivolol: a multifaceted antioxidant and cardioprotectant in hypertensive heart disease

Cardiomyocyte necrosis with attendant microscopic scarring is a pathological feature of human hypertensive heart disease (HHD). Understanding the pathophysiological origins of necrosis is integral to its prevention. In a rat model of HHD associated with aldosterone/salt treatment (ALDOST), myocyte necrosis is attributable to oxidative stress induced by cytosolic-free [Ca]i and mitochondrial [Ca]m overloading in which the rate of reactive oxygen species generation overwhelms their rate of detoxification by endogenous Zn-based antioxidant defenses. We hypothesized that nebivolol (Neb), unlike another β1 adrenergic receptor antagonist atenolol (Aten), would have a multifaceted antioxidant potential based on its dual property as a β3 receptor agonist, which activates endothelial nitric oxide synthase to stimulate nitric oxide (NO) generation. NO promotes the release of cytosolic Zn sequestered inactive by its binding protein, metallothionein. Given the reciprocal regulation between these cations, increased [Zn]i reduces Ca entry and attendant rise in [Ca]i and [Ca]m. Herein, we examined the antioxidant and cardioprotectant properties of Neb and Aten in rats receiving 4 weeks ALDOST. Compared with untreated age-/sex-matched controls, ALDOST alone or ALDOST with Aten, Neb cotreatment induced endothelial nitric oxide synthase activation, NO generation and a marked increase in [Zn]i with associated decline in [Ca]i and [Ca]m. Attendant antioxidant profile at subcellular and cellular levels included attenuation of mitochondrial H2O2 production and lipid peroxidation expressed as reduced 8-isoprostane concentrations in both mitochondria and cardiac tissue. Myocyte salvage was expressed as reduced microscopic scarring and tissue collagen volume fraction. Neb is a multifaceted antioxidant with unique properties as cardioprotectant in HHD.

The Association of Left Ventricular Hypertrophy with Intraventricular Dyssynchrony at Rest and during Exercise in Hypertensive Patients

Background

Impaired exercise tolerance with dyspnea is common in hypertensive patients and this may be due to the exaggeration of nonuniform ventricular activation during exercise. So we want to evaluate the effect of left ventricular hypertrophy (LVH) on systolic intraventricular dyssynchrony during exercise.

Methods

A total of 85 patients with hypertension who having exertional dyspnea and 30 control individuals were enrolled. Exercise stress echocardiography was performed using a symptom limited, multistage supine bicycle test. To evaluate the dyssynchrony of left ventricular (LV), we calculated the standard deviation (SD) of the averaged time-to-peak systolic velocity (TPs-SD, ms) of 12 middle and basal LV segments obtained from the three standard apical views at rest and peak exercise.

Results

There was no significant difference in systolic blood pressure (BP) and heart rate between the two groups. TPs-SD was significantly higher in patients with LVH at rest (31.5 ± 12.1 vs. 22.0 ± 12.6 ms, p = 0.002) with exaggeration of the degree at peak exercise (39.0 ± 11.9 vs. 24.6 ± 13.3 ms, p < 0.001). Multiple regression analysis showed LV mass index was independently associated with LV dyssynchrony at peak exercise (β = 0.515, p = 0.001) when controlled for age, sex, and systolic BP at peak exercise.

Conclusion

Intraventricular systolic dyssynchrony during exercise is significantly associated with the degree of LVH in hypertensive patients.

Molecular determinants of the cardiometabolic phenotype

The metabolic syndrome represents a clustering of risk factors that has been shown to predict adverse cardiovascular outcomes. Although the precise mechanisms contributing to the cardiometabolic syndrome (CMS) remain poorly defined, accumulating evidence identifies two intersecting candidate pathways responsible for inflammation and energy homeostasis in the pathophysiology that underlie cardiometabolic traits. Although currently no pharmacologic interventions specifically target CMS, future drug development efforts should attempt to capitalize on molecular nodes at the intersections of these pathways in the CMS.

Fibrosis in hypertensive heart disease: molecular pathways and cardioprotective strategies

Fibrosis is a fundamental component of the adverse structural remodelling of myocardium found in hypertensive heart disease (HHD). A replacement fibrosis appears at sites of previous cardiomyocyte necrosis to preserve the structural integrity of the myocardium. Such scarring has adverse functional consequences. The extensive distribution of fibrosis involving the right and left heart suggests cardiomyocyte necrosis is widespread. Together, the loss of these contractile elements and fibrous tissue deposition in the form of stiff in-series and in-parallel elastic elements contribute to the progressive failure of this normally efficient muscular pump. Pathogenic mechanisms modulating fibrous tissue formation at sites of repair include auto/paracrine properties of locally generated angiotensin II and endothelin-1. This study focuses on the signal-transducer-effector pathway involved in cardiomyocyte necrosis and the crucial pathogenic role of intracellular calcium overloading, and the subsequent induction of oxidative stress originating within its mitochondria that dictates the opening of the mitochondrial permeability transition pore. The ensuing osmotic destruction of these organelles is followed by necrotic cell death. It is now further recognized that calcium overloading of cardiac myocytes and mitochondria functioning as pro-oxidant is pathophysiologically counterbalanced by an intrinsically coupled zinc entry, which serves as an antioxidant. The prospect of raising intracellular zinc by adjuvant nutriceutical supplementation can, therefore, be preferentially exploited to uncouple this intrinsically coupled calcium-zinc dyshomeostasis in favour of endogenous antioxidant defences. Novel cardioprotective strategies may thus be at hand and deserve to be explored further in the overall management of patients with HHD.

Electrocardiographic strain pattern in children with left ventricular hypertrophy: a marker of ventricular dysfunction

The objective of this study was to assess the relation between strain pattern on electrocardiogram (ECG-strain) and echocardiographic indices of left ventricular (LV) structure and function in children with LV hypertrophy (LVH). ECG-strain is a marker of LVH and is associated with adverse cardiovascular prognosis in adults. The significance of ECG-strain and its relation to LV structure and function has not been studied in children. We retrospectively analyzed electrocardiograms (ECGs) and echocardiograms of 101 children enrolled in this study. Subjects were divided into three groups: group I (n = 21) comprised children with LVH confirmed by echocardiography (LVH(echo)) with ECG-strain pattern; group II (n = 54) comprised children with LVH(echo) without ECG-strain pattern; and group III (n = 26) comprised children without LVH (control group). ECG-strain was defined as a down-sloping convex ST-segment depression (> or = 0.1 mV) with an inverted asymmetrical T-wave opposite to the QRS axis in leads V5 and/or V6. LV structure and function was measured using conventional and tissue Doppler echocardiography. ECG-strain was associated with greater interventricular septal thickness, posterior wall thickness, and LV mass index (LVMI) compared with those without ECG-strain (P < 0.0001 for each variable). Concentric LVH was more common in those with ECG-strain (16 of 21 vs. 9 of 54 patients; P = < 0.0001). ECG-strain was associated with systolic, diastolic, and combined systolic-diastolic dysfunction in children with LVH(echo). Among children with LVH, ECG-strain is associated with higher LVMI, concentric pattern of LVH, and LV systolic and diastolic dysfunction. Whether this has similar adverse prognostic implications as it does in adults remains to be determined.

Differential effects of antihypertensive treatment on left ventricular diastolic function: an ASCOT (Anglo-Scandinavian Cardiac Outcomes Trial) substudy

OBJECTIVES

We hypothesized that an amlodipine-based regimen would have more favorable effects on left ventricular (LV) diastolic function.

BACKGROUND

Different antihypertensive therapies may vary in their effect on LV diastolic function.

METHODS

The HACVD (Hypertension Associated Cardiovascular Disease) substudy of ASCOT (Anglo-Scandinavian Cardiac Outcomes Trial) collected detailed cardiovascular phenotypic data on a subset of 1,006 participants recruited from 2 centers (St. Mary's Hospital, London, and Beaumont Hospital, Dublin). Conventional and tissue Doppler echocardiography and measurement of plasma B-type natriuretic peptide (BNP) were performed approximately 1 year after randomization to atenolol-based or amlodipine-based antihypertensive treatment to assess LV diastolic function.

RESULTS

On-treatment blood pressure (BP) (mean +/- SD) was similar in both groups: atenolol-based regimen, systolic BP of 137 +/- 17 mm Hg, diastolic BP of 82 +/- 9 mm Hg; amlodipine-based regimen, systolic BP of 136 +/- 15 mm Hg, diastolic BP of 80 +/- 9 mm Hg. Ejection fraction did not differ between groups, but early diastolic mitral annular velocity (E'), a measure of diastolic relaxation, was lower in patients on the atenolol-based regimen: atenolol-based regimen, 7.9 +/- 1.8; amlodipine-based regimen, 8.8 +/- 2.0. A measure of left ventricular filling pressure, E/E', and BNP were significantly higher in patients on the atenolol-based regimen. Differences in E', E/E', and BNP remained significant after adjustment for age and sex. Further adjustment for systolic BP, LV mass index, and heart rate had no impact on differences in mean E' or BNP. The difference in E/E' was attenuated.

CONCLUSIONS

Patients receiving treatment with an amlodipine-based regimen had better diastolic function than patients treated with the atenolol-based regimen. Treatment-related differences in diastolic function were independent of BP reduction and other factors that are known to affect diastolic function.

Myocardial remodeling in low-renin hypertension: molecular pathways to cellular injury in relative aldosteronism

The pathologic hypertrophy of hypertensive heart disease is related to the quality, not the quantity, of myocardium; the presence of fibrosis is inevitably linked to structural and functional insufficiencies with increased cardiovascular risk. Elevations in plasma aldosterone that are inappropriate relative to dietary sodium, or relative aldosteronism, are accompanied by suppressed plasma renin activity, elevation in arterial pressure, and dyshomeostasis of divalent cations. The accompanying hypocalcemia, hypomagnesemia, and hypozincemia of aldosteronism contribute to the appearance of secondary hyperparathyroidism. Parathyroid hormone-mediated intracellular calcium overloading of cardiac myocytes and mitochondria leads to the induction of oxidative stress and molecular pathways associated with cardiomyocyte necrosis and scarring of myocardium, whereas the dyshomeostasis of zinc compromises antioxidant defenses. This dys-homeostasis of calcium and zinc, intrinsically coupling prooxidant calcium and antioxidant zinc, raises the prospect for therapeutic strategies designed to mitigate intracellular calcium overloading while enhancing zinc-mediated antioxidant defenses, thus preventing adverse myocardial remodeling with fibrosis, associated diastolic dysfunction, and cardiac arrhythmias.

Spectrum of M-mode echocardiographic abnormalities in 75 cats with systemic hypertension

A retrospective study was performed in 75 hypertensive cats to determine the spectrum and frequency of M-mode echocardiographic abnormalities. Results indicated that 21.3% of the cats had M-mode measurements within normal reference ranges. For cats with echocardiographic abnormalities, changes were variable. Thirty-nine percent of hypertensive cats had hypertrophy of the interventricular septum in diastole, and 41.3% had hypertrophy of the left ventricular (LV) posterior wall in diastole. One cat in five had a dilated left atrium, while fractional shortening and LV internal dimension in diastole were normal in 82.7% and 86.7% of the cats, respectively. The marked variability of echocardiographic findings in hypertensive cats made echocardiography an unreliable screening test for hypertension.

Regional diastolic dysfunction in individuals with left ventricular hypertrophy measured by tagged magnetic resonance imaging--the Multi-Ethnic Study of Atherosclerosis (MESA)

BACKGROUND

Impairment of global diastolic function is considered to be the mechanism of congestive heart failure in individuals with preserved systolic left ventricular (LV) function. Left ventricular hypertrophy (LVH) is known to be a risk factor for congestive heart failure with preserved systolic function, and this process may begin as a regional process. We investigated whether regional LV diastolic function measured by magnetic resonance tagging is altered in asymptomatic participants of the MESA with LVH and preserved systolic LV function.

METHODS

Regional systolic and diastolic strain rates were calculated from strain data in 218 participants of the MESA study. Circumferential strain was calculated from the midwall layer of the septum, anterior, lateral, and inferior walls at mid-LV level. Global LV function measures were studied by magnetic resonance imaging in 4291 MESA participants. Left ventricular hypertrophy for men and women was defined from the MESA population using previously established Framingham criteria.

RESULTS

Global systolic function was slightly less in the LVH (ejection fraction = 0.66 +/- 0.10) versus the non-LVH group (ejection fraction = 0.69 +/- 0.07, P < .001). Stepwise regression analyses showed a direct relationship between regional diastolic dysfunction and increasing LV mass. Regional systolic strain and strain rate measures from participants with LVH were not significantly different from those without LVH. However, regional diastolic strain rate was significantly reduced in participants with LVH (1.5 +/- 1.1 s(-1)) compared with the non-LVH group (2.2 +/- 1.1 s(-1), P < .001) regardless of age or sex.

CONCLUSIONS

Left ventricular hypertrophy is associated with regional diastolic dysfunction in individuals without evidence of clinical cardiovascular disease and preserved systolic function. Magnetic resonance imaging tagging provides detailed quantification of regional diastolic function noninvasively.

Left ventricular hypertrophy in Caucasian master athletes: Differences with hypertension and hypertrophic cardiomyopathy

AIM

To study, by conventional echocardiography, left ventricular remodelling and function in master athletes, hypertension and hypertrophic cardiomyopathy.

METHODS

We studied 30 master athletes (MA; soccer players; mean age 43.9+/-5.9), 24 subjects with essential hypertension (HYP; 46.6+/-6), 20 patients with hypertrophic cardiomyopathy (HCM; 42.2+/-9) and 30 normal individuals (CG; 43.4+/-5). An integrated M-mode/two-dimensional echocardiographic analysis was performed to determine chambers dimensions, relative wall thickness (RWT) and left ventricular mass (LVM), indexed to height in meters raised to the power of 2.7 (LVM/h(2.7)). Cut-off levels for LVM/h(2.7) and RWT were defined to assess 4 different patterns of LV geometric remodelling. In addition, we measured indexes of global systolic performance and indexes of global diastolic function.

RESULTS

LV wall thickness and LV end-diastolic dimensions were higher in MA than controls, but significantly lower than other groups. LVH/h(2.7) was increased in 79% of HYP and in 95% of HCM, but was within the normal limits in MA. LV geometry was normal in 22 out of 30 MA (73%), while the remaining (8 athletes, 27%) showed a concentric remodelling. Systolic function (FS and EF) was normal in MA, but was slightly reduced in HYP and increased in HCM. Analysis of diastolic function showed an abnormal relaxation pattern in all HYP and 95% of HCM, but was normal in all MA. The ratio between peak filling rate and stroke volume (PFR/SV), a relatively independent index of diastolic function, was significantly greater in hypertensive patients with normal LV remodelling compared to those without it (4+/-0.39 vs. 4.91+/-0.19; P = 0.0002).

CONCLUSION

MA showed lower values of wall thickness, LV dimensions and LV mass compared with HYP and HCM. Despite an abnormal remodelling, all the athletes showed a normal systolic and diastolic function. The differential diagnosis between MA, HYP and HCM is feasible by accurate, comprehensive standard Doppler echocardiography.

Are Myocardial Fibrosis and Diastolic Dysfunction Reversible in Hypertensive Heart Disease?

Diastolic dysfunction is an important factor contributing to the appearance of symptomatic heart failure, particularly among elderly women with arterial hypertension. In hypertensive heart disease, the presence of cardiac fibrosis is an important determinant of abnormal myocardial stiffness that contributes to diastolic dysfunction. Recent studies indicate the feasibility of a pharmacology-based regression of fibrosis and improvement in diastolic stiffness.

Left ventricular hypertrophy and preclinical impaired glucose tolerance and diabetes mellitus contribute to abnormal left ventricular diastolic function in hypertensive patients

BACKGROUND

Impaired left ventricular diastolic function is not uncommon in patients with either diabetes mellitus or hypertension. This study was carried out to assess the contribution of left ventricular hypertrophy, high blood pressure, preclinical impaired glucose tolerance and diabetes mellitus to left ventricular diastolic function in patients attending a hypertension clinic.

METHODS

Echocardiography, 24-h ambulatory blood pressure monitoring and oral glucose tolerance tests were carried out in 152 consecutive hypertensive patients who had no evidence of ischaemic heart disease and were not known to be diabetic. From echocardiography, E/A (peak velocity of early/atrial filling waves of the transmitral flow) at rest and at peak standardized isometric exercise using handgrip, left ventricular mass index and deceleration time of the E wave were derived.

RESULTS

Patients with impaired glucose tolerance and diabetes mellitus had lower E/A than the euglycaemic subjects both at rest (P=0.0073) and during isometric exercise (P<0.0001). E/A significantly reduced during isometric exercise in patients with impaired glucose tolerance and diabetes but not in euglycaemic patients. Deceleration time was shortened with a worsening degree of glucose intolerance in all the patients (P=0.0005), in those with left ventricular hypertrophy (P=0.0006) and in those without left ventricular hypertrophy (P=0.033). When adjusted for age, gender, race, body mass index, smoking history, ambulatory blood pressure findings, cholesterol and triglyceride levels and antihypertensive medications taken, E/A at isometric exercise was related to results of glucose tolerance tests and was inversely proportional to left ventricular mass index (P<0.0001). No significant differences were found whether patients were taking antihypertensive medications or not.

CONCLUSION

In hypertensive patients, left ventricular diastolic function is determined by left ventricular mass index and the status of preclinical glucose intolerance, independent of age, gender, race, body mass index, blood pressure level, nocturnal drop in blood pressure or lipid level. These findings were not prejudiced by antihypertensive medications.

Modified TEI Index: A Promising Parameter in Essential Hypertension?

PURPOSE

Modified TEI index is pointed to be more effective in the evaluation of global cardiac functions compared to systolic and diastolic measurements alone. We planned to determine its applicability in hypertension and relation with left ventricular mass index (LVMI).

METHODS

We studied 48 patients with mild/moderate hypertension and normal coronary angiograms. In total 22 patients (12 men, 10 women, mean age: 55 +/- 6) with normal LVMI were studied in group I, 26 patients (12 men, 14 women, mean age: 57 +/- 7) with increased LVMI in group II, and 20 patients (10 men, 10 women, mean age: 53 +/- 7) with normal blood pressure as a control group. Standard 2D, Doppler, and mitral annulus pulse wave tissue Doppler were used for all measurements. Modified TEI index was calculated as diastolic time interval measured from end of Am wave to origin of Em (a') minus systolic Sm duration (b') divided by b(a'-b'/b').

RESULTS

Modified TEI index was significantly higher in both groups than normal group and in group II than in group I. (

CONTROL GROUP

0.33 +/- 0.05, group I: 0.51 +/- 0.17, group II: 0.68 +/- 0.16, P< 0.0001).

CONCLUSION

Modified TEI index, a marker of left ventricular systolic and diastolic functions, is impaired in hypertensives before hypertrophy develops and impairment is more prominent in hypertrophy. Therefore, (1) modified TEI index in hypertensives is a safe, feasible, and sensitive index for evaluation of global ventricular functions. (2) Evaluation of hypertensives with this index periodically may guide interventions directed toward saving systolic and diastolic functions. (3) Modified TEI index is gaining importance as a complementary parameter to standard Doppler or in cases where standard Doppler has its limitations.

Left ventricular concentric geometry is associated with impaired relaxation in hypertension: the HyperGEN study

AIMS

We tested the hypothesis that abnormal left ventricular (LV) relaxation is associated with concentric LV geometry.

METHODS AND RESULTS

Doppler LV filling properties were studied in 1384 hypertensive participants without cardiovascular disease, from the HyperGEN population (731 women, 784 obese, 236 diabetic) and compared in four LV geometry groups; normal, concentric remodelling (3.5%), eccentric (23%), and concentric LV hypertrophy (4%), based on echocardiographic LV mass index (in g/m(2.7)). Abnormal LV relaxation was identified by European Society of Cardiology criteria in 275 subjects (20%). After accounting for significant confounders, E/A ratio and isovolumic relaxation time were not related to the presence of LV hypertrophy, but indicated abnormal relaxation when LV geometry was concentric (both P<0.0001). Deceleration time of E velocity was prolonged with LV hypertrophy (P<0.03), but the behaviour in relation to concentric LV geometry differed in the presence (prolonged) or absence (reduced) of LV hypertrophy (P=0.05), a difference independently related to the magnitude of both transmitral gradients and stroke volume (all P<0.05). Logistic regression showed that, compared with normal LV geometry, the odds of abnormal LV relaxation was 2.3-fold greater when LV geometry was concentric and that LV hypertrophy conferred a borderline higher risk than normal LV mass.

CONCLUSIONS

In hypertensive individuals without prevalent cardiovascular disease from a multi-ethnic population-based sample, delayed LV relaxation is independently associated with concentric LV geometry.

Postexercise Left Ventricular Function and cTnT in Recreational Marathon Runners

PURPOSE

To assess the impact of prolonged exercise on left ventricular (LV) function and the appearance of cardiac troponin T (cTnT) in older and recreational athletes.

METHODS

Heart rate (HR), blood pressures, and cTnT were recorded in 35 subjects (age range 22-57 yr, finishing time 157-341 min) pre- and postrace. Echocardiograms (N = 26) assessed stroke volume (SV), ejection fraction (EF), sBP/LV end-systolic volume (sBP/ESV), diastolic filling (E:A ratio) as well as preload (LV internal dimension at end-diastole [LVIDd]) and afterload (LV wall stress). HR and core temperature were recorded in-event. Prepost changes in LV function were analyzed by repeated measures t-test. Delta scores for LV function and cTnT data were correlated with each other, age, finishing time, alterations in loading, and in-event data.

RESULTS

SV was significantly decreased postrace (109 +/- 31 vs 85 +/- 25 mL, P < 0.05) likely due to a significant decrease in LVIDd (5.3 +/- 0.4 vs 4.9 +/- 0.5 cm, P < 0.05; r = 0.80, P < 0.05). LV wall stress was unchanged postrace (90 +/- 25 vs 89 +/- 27 g x cm(-2), P > 0.05). EF (70 +/- 12 vs.70 +/- 10%, P > 0.05) and sBP/ESV (3.7 +/- 2.9 vs 4.0 +/- 2.0, P > 0.05) did not change prepost race and were not related to age or finishing time (P > 0.05). E:A ratio was significantly reduced postrace (1.73 +/- 0.38 vs 1.41 +/- 0.25, P < 0.05) and could not be explained by an increased HR (56 +/- 9 vs 84 +/- 10, P < 0.05; r = 0.08, P > 0.05), a reduced LVIDd (r = 0.11, P > 0.05), age, finishing time, or in-event data. Postrace 26/33 subjects presented cTnT values in the range 0.024-0.080 microg x L(-1) that were not related to changes in LV function, loading, age, finishing time, or in-event data.

CONCLUSION

No evidence of load-independent depression in LV systolic function was reported. Changes in cTnT and E:A were not related, and their etiology is uncertain.

Impaired left ventricular diastolic function during isometric exercise in asymptomatic patients with hyperlipidaemia

BACKGROUND

Left ventricular (LV) diastolic dysfunction is an early sign, and may be more sensitive indicator, of ischaemic heart disease (IHD) than systolic dysfunction.

METHODS

LV diastolic function was assessed during isometric exercise (IME) in 37 consecutive normotensive hyperlipidaemics (LIP), without cardiac history or symptoms. Each patient underwent a stress ECG test and 2-D echo and Doppler cardiography. During the latter, transmitral flow at rest and at peak standardised IME using handgrip was studied. From the tracings, the E/A (peak velocity of the early/atrial components), the contribution of atrial systole to LV filling (ACF), the deceleration time (DT) of the E wave and the isovolumic relaxation time (IVRT) were calculated. Results were compared to 37 age-matched normal healthy volunteers (NOR).

RESULTS

Resting E/A was not different between NOR and the LIP. A significant reduction in E/A with IME was observed in LIP but not in NOR. Impaired LV filling (shown by E/A<1) was demonstrated in five patients (13%) at rest and in 20 patients (54%) at peak IME. All NOR had E/A>1 suggesting normal LV filling. Fifteen of the 30 patients with negative stress ECG test demonstrated LV diastolic dysfunction. ACF was higher in LIP than NOR and increased significantly (P<0.005) by 23% during IME. DT and IVRT in LIP were not different from NOR. In neither NOR nor LIP, were the LV diastolic functional parameters related to gender, smoking habit or levels of total cholesterol, LDL- or HDL-cholesterol or triglycerides.

CONCLUSION

The prevalence of LV diastolic dysfunction in asymptomatic patients with hyperlipidaemia despite a negative stress ECG test may be evidence of early underlying pre-clinical myocardial ischaemia.

Effects of afterload increase on systolic and diastolic functions of the myocardium after myocardial infarction

The evaluation of noninfarcted zone function after myocardial infarction by the use of noninvasive methods is very important. The authors speculated that phenylephrine, which increases systemic vascular resistance and blood pressure and has no effect on central ischemic and border-zone myocardium but does have an effect on remote myocardium, could be used as a stress agent as information is gathered about the functional capacity of the left ventricle and the status of coronary arteries in patients with recent myocardial infarction. Forty-six patients with recent myocardial infarction (5 women, 41 men; mean age: 53.6 +/-9.3 years) and 15 individuals with normal findings from coronary angiography and ventriculography (9 women and 6 men; mean age: 39.0 +/-11.2 years) were included in the study. The study was performed on the 4th or 5th day of the myocardial infarction. Preejection period/left ventricular ejection time (PEP/LVET), diastolic mitral flow velocity, isovolumic relaxation time (IVRT), and deceleration time (DT), were measured before and after the phenylephrine infusion, with M-mode, pulse wave, and continuous-wave echocardiography. After pressor stress with phenylephrine infusion, all the parameters were measured again. Coronary angiography and ventriculography were performed on all the patients on the 7th to 10th day of the myocardial infarction. All the patients were grouped according to their ejection fraction and the number of involved coronary arteries. The increase in the PEP/LVET ratio in Group 1 (left ventricle ejection fraction [EF] below 40%) and multivessel coronary artery lesion group was significant (p<0.01). PEP/LVET ratio decreased significantly in both Group C (patients with normal-appearing coronary arteries and ventriculographies) and the single-vessel coronary disease group. Although the early diastole flow/atrial systole flow (E/A) ratio increased significantly in the 3 groups, the 0.5 and more increase in E/A ratio had high sensitivity (86%) and specificity (80%) in differentiating the low EF group. The 0.5 and more increase in E/A ratio had 65% sensitivity and 69% specificity in differentiating the multivessel coronary stenosis group. A deceleration time of 130 msec and below in basal conditions had a high sensitivity (86%) and specificity (92%) for detecting the group in which EF was below 40%. After phenylephrine infusion, the shortening of IVRT was significant in Group 1 (p<0.01). Phenylephrine, which has been shown to be an alpha-1 receptor agonist in low doses and effective only on remote myocardial function, may be given with low complication rates in the early postinfarction period. The increase in PEP/LVET ratio, 0.5 and more increase in E/A ratio, and shortening of DT and IVRT after phenylephrine infusion may be indicators of low LV functional capacity and widespread coronary artery disease. This test may suggest performance of early invasive detection of coronary artery disease and early revascularization. This study may also be interesting from a pathophysiological point of view.

Does the human heart fatigue subsequent to prolonged exercise?

A reduction in left ventricular systolic and diastolic function subsequent to prolonged exercise in healthy humans, often called exercise-induced cardiac fatigue (EICF), has recently been reported in the literature. However, our current understanding of the exact nature and magnitude of EICF is limited. To date, there is no consensus as to the clinical relevance of such findings and whether such alterations in function are likely to impact upon performance. Much of the existing literature has employed field-based competitions. Whilst ecologically valid, this approach has made it difficult to control many factors such as the duration and intensity of effort, fitness and training status of subjects and environmental conditions. The impact of such variables on EICF has not been fully evaluated and is worthy of further research. To date, most EICF studies have been descriptive, with limited success in elucidating mechanisms. To this end, the assessment of humoral markers of cardiac myocyte or membrane disruption has produced contradictory findings partially due to controversy over the validity of specific assays. It is, therefore, important that future research utilises reliable and valid biochemical techniques to address these aetiological factors as well as develop work on other potential contributors to EICF such as elevated free fatty acid concentrations, free radicals and beta-adrenoceptor down-regulation. In summary, whilst some descriptive evidence of EICF is available, there are large gaps in our knowledge of what specific factors related to exercise might facilitate functional changes. These topics present interesting but complex challenges to future research in this field.

Regression of hypertensive myocardial fibrosis by Na(+)/H(+) exchange inhibition

We have recently reported that the inhibition of the Na(+)/H(+) exchanger (NHE) during 1 month in spontaneously hypertensive rats (SHR) is followed by regression of cardiomyocyte hypertrophy but not of myocardial fibrosis. The aim of this study was to evaluate whether a treatment of longer duration could reduce myocardial fibrosis and stiffness. SHR received 3.0 mg/kg per day of the specific NHE-1 inhibitor cariporide; the effect on cardiomyocyte cross-sectional area, myocardial collagen volume fraction, collagen synthesis, and myocardial stiffness (length-tension relation in left papillary muscles) was evaluated at several time points (after 1, 2, or 3 months). A slight decrease of approximately 5 mm Hg in systolic blood pressure was observed after 1 month of treatment with no further changes. After 2 and 3 months of treatment, the size of cardiomyocytes remained within normal values and myocardial fibrosis progressively decreased to normal level. Accordingly, myocardial stiffness and the serum levels of the carboxyterminal propeptide of procollagen type I, a marker of collagen type I synthesis, were normalized after 3 months. Left ventricular weight decreased from 910+/-43 (in untreated SHR) to 781+/-21 mg (treated SHR) after 3 months of treatment. No difference in body weight between treated and untreated SHR was observed after this period of treatment. The present data allow us to conclude that in the SHR the administration of an NHE-1 inhibitor for 2 or 3 months leads to the normalization of collagen type I synthesis, myocardial collagen volume fraction, and stiffness.

Effects of hypertonic saline and dextran 70 on cardiac diastolic function after hemorrhagic shock

BACKGROUND

A bolus of 7.5% NaCl-6% Dextran 70 (HSD) is effective in resuscitating hypovolemic shock. Common hemodynamic findings with HSD are restoration of cardiac output, increased blood pressure, and improvement of peripheral circulation. However, the effect of HSD upon cardiac function is still controversial. In our previous study, when HSD did not improve cardiac contractility, it was speculated that it might affect cardiac diastolic function without a change in contractility. Therefore, we studied the effects of HSD on cardiac diastolic function.

METHODS

Hemorrhagic shock was created by exsanguination of 31.4 +/- 0.9 ml/kg (NS group) or 29.0 +/- 3.6 ml/kg (HSD group). Then mean BP was maintained at 50 mm Hg for 30 min in both groups. The HSD group (n = 6) received HSD (4 ml/kg) and the NS (control) group (n = 5) received normal saline (40 ml/kg) after the shock. Cardiac diastolic functions were measured in both groups using the peak negative dP/dt and the left ventricular end-diastolic pressure-volume relationship (EDPVR) during the experimental period: before shock, immediately, and 2 h after resuscitation.

RESULTS

Hemodynamic parameters in both groups demonstrated similar changes throughout the experimental period. The peak negative dP/dt, stiffness constant, and elasticity obtained by EDPVR did not differ significantly between the two groups.

CONCLUSION

HSD seems to be an effective resuscitation fluid after hemorrhagic shock because the volume of HSD required to maintain circulation is significantly smaller than that of normal saline. However, our data revealed that HSD does not change cardiac diastolic function after hemorrhagic shock.

Left ventricular diastolic function in physiologic and pathologic hypertrophy

BACKGROUND

Patients with hypertensive heart disease and left ventricular hypertrophy demonstrate an impaired left ventricular diastolic filling pattern. The aim of this study was to find out whether physiologic left ventricular hypertrophy induced by endurance training causes disturbances in left ventricular systolic and diastolic filling.

METHODS

We examined 49 athletes with left ventricular (LV) hypertrophy due to endurance training, 49 patients with LV hypertrophy due to arterial hypertension, and 26 untrained healthy control subjects by conventional echocardiography. Parameters of LV diastolic filling using pulse wave and color flow Doppler were also assessed.

RESULTS

All three study groups showed normal fractional shortening and mid-wall fractional shortening. Conventional echocardiography revealed a higher LV muscle mass index in the two study groups compared with the controls (athletes, 99 +/- 10 g; hypertensive patients, 95 +/- 11 g: controls: 52 +/- 7 g; P < .01 for athletes and hypertensive patients). In patients with arterial hypertension, a diastolic dysfunction consisting of a delayed relaxation pattern with a decrease in maximal early velocity of diastolic filling (0.44 +/- 0.1 m/sec) and a compensatory increase of the maximal late velocity of diastolic filling (0.53 +/- 0.1 m/sec) was demonstrated. In athletes with physiologic LV hypertrophy, a normal LV diastolic filling pattern was documented.

CONCLUSIONS

Doppler echocardiographic parameters of LV diastolic function can be of diagnostic importance for discrimination between pathologic and physiologic LV hypertrophy.

Tissue Doppler imaging differentiates physiological from pathological pressure-overload left ventricular hypertrophy in rats

BACKGROUND

The myocardial velocity gradient (MVG) is a recent index of regional myocardial function derived from endocardial and epicardial velocities obtained by tissue Doppler imaging (TDI). This index might be useful for discriminating between physiological and pathological left ventricular hypertrophy (LVH) and for documenting the early transition from compensated LVH to heart failure. We sought to compare MVG measured across the left ventricular posterior wall between normal rats and rats with physiological (exercise) and pathological (pressure-overload) LVH.

METHODS AND RESULTS

Wistar rats were assigned to one of the following groups: sedentary, exercise (swimming), and 2-month or 9-month abdominal aortic banding. Compared with sedentary rats, exercise and 2-month banding led to similar and significant LVH. After 2-month banding, conventional parameters of systolic function (left ventricular fractional shortening and dP/dt(max)) were not affected. However, systolic and diastolic MVG were similar in exercise and sedentary rats but were significantly lower in rats with aortic banding. Aortic debanding after 2 months led to a full recovery of MVG, whereas MVG remained decreased when debanding was performed after 9 months.

CONCLUSIONS

Myocardial contraction and relaxation assessed by TDI were impaired in pressure-overload LVH but not in exercise LVH. Therefore, TDI is more sensitive than conventional echocardiography for assessing myocardial dysfunction in pressure-overload LVH and for predicting early recovery in myocardial function after loading conditions normalization.

MRI analysis of right ventricular function in normal and spontaneously hypertensive rats

Right ventricular structure and function were characterized in spontaneously hypertensive rats (SHR) using non-invasive magnetic resonance imaging (MRI) techniques. These studies therefore complement previous reports preoccupied with left ventricular changes associated with this condition. Eight SHR and eight control normotensive Wistar-Kyoto (WKY) rats were each subdivided into equal age-matched groups of 8 and 12 weeks. The right ventricle was imaged through a series of twelve contiguous 1.37-1.75 mm transverse sections at twelve equally spaced time-points that covered both systole and most of diastole thereby completely reconstructing right ventricular anatomy. This gave measurements of right ventricular myocardial mass that were consistent through all twelve time-points in all four experimental groups throughout their cardiac cycles. However, spontaneous hypertension increased this right ventricular myocardial mass, as well as the end-diastolic (EDV) and end-systolic volumes (ESV). Although stroke volume (SV) was conserved, decreases in ejection fraction (EF), a positive shift in the relationship between SV and EDV, and reduced indices of systolic ejection rates in SHR rats compared with the age-matched normal WKY controls indicated significant systolic dysfunction. Additionally, reductions in the rates of diastolic relaxation suggested the onset of diastolic dysfunction. Thus, the non-invasive nature of MRI has made it possible for the first time to demonstrate alterations in structure of the right ventricle and in quantitative indicators of its systolic and diastolic function in the SHR model of hypertension.

Diastolic function in hypertension

Diastolic dysfunction in patients with hypertension may present as asymptomatic findings on noninvasive testing, or as fulminant pulmonary edema, despite normal left ventricular systolic function. Up to 40% of hypertensive patients presenting with clinical signs of congestive heart failure have normal systolic left ventricular function. In this article we review the pathophysiologic factors affecting diastolic function in individuals with diastolic function, current and emerging tools for measuring diastolic function, and current concepts regarding the treatment of patients with diastolic congestive heart failure.

Left ventricular mass and global function in essential hypertension after antihypertensive therapy

This study compares left ventricular global function in 55 patients (25 with hypertrophy and 30 without hypertrophy) with essential hypertension, whose blood pressure had been stable for longer than 1 year, with that in 35 healthy subjects. Left ventricular global function was calculated using the echocardiographic Doppler index as described by Tei et al. (Tei index). No significant differences were observed in echocardiographic left ventricular systolic function between the three groups. Left ventricular global function differed significantly between the three groups, however, suggesting impaired left ventricular global function even in the absence of left ventricular hypertrophy. Similar changes were observed in the ratio of peak velocity of atrial systole to peak velocity of early diastole during left ventricular inflow waveform (A/E), indicating that this disorder mainly reflects impaired left ventricular diastolic function. Unlike A/E, the Tei index is not affected by increasing age, and, therefore, is appropriate for evaluating left ventricular global function in hypertensive patients, most of whom are middle-aged or older. This index may be useful for determining treatment strategy and evaluating treatment effects.

Cardioreparation in hypertensive heart disease

The normal myocardium is composed of a variety of cells. Cardiac myocytes, tethered within an extracellular matrix of fibrillar collagen, represent one third of all cells; noncardiomyocytes account for the remaining two thirds. Ventricular hypertrophy involves myocyte growth. Hypertensive heart disease (HHD) includes myocyte and nonmyocyte growth that leads to an adverse structural remodeling of the intramural coronary vasculature and matrix. In HHD, it is not the quantity of myocardium but rather its quality that accounts for increased risk of adverse cardiovascular events. Structural homogeneity of cardiac tissue is governed by a balanced equilibrium existing between stimulator and inhibitor signals that regulate cell growth, apoptosis, phenotype, and matrix turnover. Stimulators (eg, angiotensin II, aldosterone, and endothelins) are normally counterbalanced by inhibitors (eg, bradykinin, NO, and prostaglandins) in a paradigm of reciprocal regulation. To reduce the risk of heart failure and sudden cardiac death that accompanies HHD, its adverse structural remodeling must be targeted for pharmacologic intervention. Cardioprotective agents counteract the imbalance between stimulators and inhibitors. They include ACE and endopeptidase inhibitors and respective receptor antagonists. Cardioreparative agents reverse the growth-promoting state and regress existing abnormalities in coronary vascular and matrix structure. ACE inhibition has achieved this outcome with favorable impact on vasomotor reactivity and tissue stiffness. Today's management of hypertension should not simply focus on a reduction in blood pressure, it must also target the adverse structural remodeling that begets HHD.

Right atrial function in hypertensive patients: effects of antihypertensive therapy

OBJECTIVES

The effects (16 weeks) of oral antihypertensive drugs on right atrial (RA) function were evaluated by two-dimensional and Doppler echocardiography in 64 patients with mild-to-moderate essential hypertension. Thirty-two age- and sex-matched normal subjects served as controls.

BACKGROUND

Hypertension alters the diastolic properties of the left ventricle and disturbs the left atrial contractile activities. RA performance may also alter in essential hypertension.

METHODS

From the tricuspid flow velocity curves the E/A ratio, the velocity-time integrals (Ei and Ai, respectively) as well as the sum, TTi = Ei + Ai, were measured. RA active contribution (RAAC) was expressed as the ratio RAAC = Ai/TTi.

RESULTS

RA-A/E ratio, RA-Ai and RAAC were increased while RA-TTi were decreased in hypertensives compared to controls, P < 0.0001 for all comparisions. After therapy TTi increased (from 13.2 +/- 1.6 to 16.2 +/- 2.0 cm with ramipril, and from 12.9 +/- 1.1 to 14.4 +/- 1.2 cm with amlodipine, P < 0.001) and RAAC decreased (from 0.19 +/- 0.01 to 0.13 +/- 0.01, with ramipril and from 0.19 +/- 0.01 to 0.16 +/- 0.00, with amlodipine P < 0.001) while RA dimensions did not change. the decrease in RAAC was significantly greater with ramipril (P < 0.001) and was significantly influenced by the decrease in left ventricular mass (P < 0.001) and right ventricular relaxation (P < 0.001).

CONCLUSIONS

RA function is deteriorated in patients with essential hypertension. The fall in the arterial blood pressure produced by antihypertensive treatment was associated with improved RA performance and reduced left ventricular mass without changes in RA dimensions. The left ventricular mass and the right ventricular relaxation influenced the changes in RA performance.

Effects of antihypertensive agents on the left ventricle: clinical implications

Hypertensive heart disease (HHD) is characterized by left ventricular hypertrophy (LVH), alterations of cardiac function, and coronary flow abnormalities. LVH is an independent cardiovascular risk factor related to cardiovascular complications in patients with hypertension. Therefore, a decrease in left ventricular mass is a therapeutic goal in these patients. The effect of the different antihypertensive agents on LVH regression has been studied in nearly 500 clinical trials. Most studies conclude that there is regression of LVH after significant decrease in blood pressure with most commonly prescribed antihypertensive agents. However, the ability to regress LVH is different between antihypertensive drug classes. ACE inhibitors and calcium channel antagonists are more potent in reducing left ventricular mass than beta-blockers, with diuretics falling in the intermediate group. Recent data suggest that angiotensin AT(1) receptor antagonists reduce left ventricular mass to a similar extent as ACE inibitors or calcium channel antagonists. Although a large number of studies have established that reversal of LVH decreases the occurrence of adverse cardiovascular events in patients with hypertension, the hypothesis that LVH regression is beneficial has not yet been conclusively proven. On the other hand, the time has come to revisit the current management of HHD simply focused on controlling blood pressure and reducing left ventricular mass. In fact, it is necessary to develop new approaches aimed to repair myocardial structure and protect myocardial perfusion and function and, in doing so, to reduce in a more effective manner, adverse risk associated with HHD. The identification of genes involved in both the process of HHD and the response to therapy may be critical for the development of these new approaches. This article will review briefly the available data on the effects of antihypertensive agents on HHD. In addition, the emerging new concepts on the pharmacology of hypertensive myocardial remodeling and the pharmacogenetic basis of the treatment of HHD will be also considered.

Evaluation of coronary blood flow reserve by 13N-NH3 positron emission computed tomography (PET) with dipyridamole in the treatment of hypertension with the ACE inhibitor (Cilazapril)

PURPOSE

The purpose of this study was to evaluate the effect of treatment with an angiotensin-converting enzyme (ACE) inhibitor (Cilazapril) for early hypertensive patients in terms of coronary blood flow reserve evaluated by 13NH3-positron emission tomography (PET).

METHODS

Before and after 12 weeks of ACE inhibitor treatment, 13NH3-PET with dipyridamole provocation test was performed, and definite myocardial perfusion and coronary flow reserve (CFR) were calculated.

RESULTS

Compared to our normal subjects previously reported (2.61+/-0.74), average coronary flow reserve was decreased (1.70+/-0.64 in hypertensive patients), and improved after treatment (1.77+/-0.52), but not significantly. Of 12 patients, five (42%) showed improved coronary flow reserve from 1.34 to 1.99 without a significant change in the resting flow. Only one patient (8%) showed deterioration after the ACE inhibitor treatment. The coronary vascular resistance (CVR) after ACE inhibitor treatment of the patients with CFR < 2.0 decreased significantly compared with those with CFR> or = 2.0 (p < 0.03).

CONCLUSIONS

These results indicate that hypertensive patients at the early stage show decreased coronary flow reserve despite having normal resting flow. Treatment with an ACE inhibitor (Cilazapril) for 12 weeks improved coronary flow reserve in 42% of our patients. The CVR of the patients with CFR < 2.0 showed improvement compared to those with CFR> or = 2.0. This result indicates that an ACE inhibitor (e.g., Cilazapril) should be one of the choices for improving CFR if hypertensive patients in early stage show signs of ischemia or diastolic dysfunction, which may be one of the sequels of reserve restriction.

Obesity and left ventricular diastolic function: noninvasive study in normotensives and newly diagnosed never-treated hypertensives

OBJECTIVE

To evaluate the influence of obesity, per se or associated with hypertension, on left ventricular (LV) diastolic function.

PATIENTS

Thirty-two obese newly-diagnosed never-treated hypertensives; 32 obese normotensives matched for age, sex and BMI with hypertensives; 32 lean newly diagnosed never-treated hypertensives and 32 lean normotensives, matched for age, sex and 24 h blood pressure (BP) with the obese subjects.

METHODS

Twenty-four-hour ambulatory blood pressure monitoring and digitized M-mode LV echocardiograms. PARAMETERS EVALUATED: Twenty-four-hour, day-time and night-time BP and heart rate, percentage nocturnal BP fall; LV end-diastolic diameter index, septal and posterior wall thickness, LV mass index, peak shortening and lengthening rate of LV diameter, peak thinning rate of LV posterior wall.

RESULTS

A main effect was found for obesity on LV diameter and LV mass and for hypertension on LV mass; LV systolic function was normal in all the subjects and similar among the four groups; LV diastolic function was significantly reduced in both obese groups with respect to lean ones. This difference persisted after correction of diastolic parameters for 24 h BP and heart rate, LV diameter and LV mass index and disappeared only after correction for body mass index. This latter was inversely related with diastolic parameters only in the obese groups.

CONCLUSIONS

Obesity is associated with a preclinical impairment of LV diastolic function in both normotensives and hypertensives; the diastolic impairment is independent of haemodynamic factors, such as 24 h BP and heart rate, and bears no relation to LV geometry in normotensives and only little relation in hypertensives, having therefore to be ascribed to obesity itself.

Fibrosis and hypertensive heart disease

The normal myocardium is composed of a variety of cells: cardiac myocytes and noncardiomyocytes, which include endothelial and vascular smooth muscle cells and fibroblasts. Hypertensive heart disease involves a structural remodeling of muscular and nonmuscular compartments. It is not the quantity but rather the quality of myocardium that accounts for pathologic hypertrophy and predisposes to ventricular dysfunction and arrhythmias, which, in turn, confer increased risk of adverse cardiovascular events. Herein, factors regulating growth of these compartments are reviewed and in particular signals involved in promoting adverse remodeling of intramyocardial coronary arteries and arterioles by fibrous tissue.

Ischemia and fibrosis: the risk mechanisms of hypertensive heart disease

Mechanisms underlying risk associated with hypertensive heart disease (HHD) and left ventricular hypertrophy (LVH) are discussed in this report and provide a rationale for understanding this very common and important cause of death from hypertension and its complications. Emphasized are impaired coronary hemodynamics, endothelial dysfunction, and ventricular fibrosis from increased collagen deposition intramurally and perivascularly. Each is exacerbated by aging and, perhaps, also by increased dietary salt intake. These functional and structural changes promote further endothelial dysfunction, altered coronary hemodynamics, and diastolic as well as systolic ventricular contractile function in HHD. The clinical endpoints of HHD include angina pectoris (with or without atherosclerosis of the epicardial coronary arteries), myocardial infarction, cardiac failure, lethal dysrhythmias, and sudden death. The major concept to be derived from these alterations is that not all that is clinically recognized as LVH is true myocytic hypertrophy and structural remodeling. Other major co-morbid changes occur that serve to increase cardiovascular risk including impaired coronary hemodynamics, endothelial dysfunction, and ventricular fibrosis.

Relaxation in hypertrophic cardiomyopathy and hypertensive heart disease: relations between hypertrophy and diastolic function

AIM

To determine the relation between the extent and distribution of left ventricular hypertrophy and the degree of disturbance of regional relaxation and global left ventricular filling.

METHODS

Regional wall thickness (rWT) was measured in eight myocardial regions in 17 patients with hypertrophic cardiomyopathy, 12 patients with hypertensive heart disease, and 10 age matched normal subjects, and an asymmetry index calculated. Regional relaxation was assessed in these eight regions using regional isovolumetric relaxation time (rIVRT) and early to late peak filling velocity ratio (rE/A) derived from Doppler tissue imaging. Asynchrony of rIVRT was calculated. Doppler left ventricular filling indices were assessed using the isovolumetric relaxation time, the deceleration time of early diastolic filling (E-DT), and the E/A ratio.

RESULTS

There was a correlation between rWT and both rIVRT and rE/A in the two types of heart disease (hypertrophic cardiomyopathy: r = 0.47, p < 0.0001 for rIVRT; r = -0.20, p < 0.05 for rE/A; hypertensive heart disease: r = 0.21, p < 0.05 for rIVRT; r = -0.30, p = 0.003 for rE/A). The degree of left ventricular asymmetry was related to prolonged E-DT (r = 0. 50, p = 0.001) and increased asynchrony (r = 0.42, p = 0.002) in all patients combined, but not within individual groups. Asynchrony itself was associated with decreased E/A (r = -0.39, p = 0.01) and protracted E-DT (r = 0.69, p < 0.0001) and isovolumetric relaxation time (r = 0.51, p = 0.001) in all patients. These correlations were still significant for E-DT in hypertrophic cardiomyopathy (r = 0.56, p = 0.02) and hypertensive heart disease (r = 0.59, p < 0.05) and for isovolumetric relaxation time in non-obstructive hypertrophic cardiomyopathy (n = 8, r = 0.87, p = 0.005).

CONCLUSIONS

Non-invasive ultrasonographic examination of the left ventricle shows that in both hypertrophic cardiomyopathy and hypertensive heart disease, the local extent of left ventricular hypertrophy is associated with regional left ventricular relaxation abnormalities. Asymmetrical distribution of left ventricular hypertrophy is indirectly related to global left ventricular early filling abnormalities through regional asynchrony of left ventricular relaxation.

Factors of Importance to Doppler Indexes of Left Ventricular Filling in 50-Year-Old Hypertensive Persons

Altered left ventricular (LV) diastolic filling has been shown in subjects with hypertension. Age is a major determinant of Doppler indexes of LV diastolic filling; therefore, a group of subjects of uniform age should preferably be chosen, if other determinants of diastolic LV filling are to be studied. A limited body of data is available regarding Doppler indexes of LV filling in hypertensive persons of a similar age. We therefore evaluated 26 hypertensive subjects (13 women and 13 men) 50 years old by Doppler echocardiography. The peak velocity of early diastolic filling (E wave), the peak velocity of atrial filling (A wave), the early-to-atrial peak velocity (E/A) ratio, and the deceleration time of early velocity were measured. The peak E wave velocity was 0.76 +/- 0.11 versus 0.62 +/- 0.13 m/s (P < 0.005), and the E/A ratio was 1.11 +/- 0.24 versus 0.93 +/- 0.23 (P < 0.05) in hypertensive women and men, respectively. The peak A wave velocity was increased and the E/A ratio was decreased in both hypertensive women and men compared with healthy 50-year-old subjects. In multivariate analyses, LV diameter, body mass index, and gender correlated with the E/A ratio in hypertensive persons. It is concluded that there is a significant difference in Doppler LV filling indexes between 50-year-old hypertensive women and men. LV diameter, gender, and body mass index are independent determinants of LV diastolic inflow in similarly aged hypertensive persons.

Differentiating systolic from diastolic heart failure using impedance cardiography

OBJECTIVE

Differentiating systolic from diastolic congestive heart failure (CHF) is often difficult in the ED. Impedance cardiography (IC) allows for the noninvasive evaluation of systolic function and measurement of diastolic time intervals. This study was designed to assess the ability of IC to accurately measure isovolumic relaxation time (IVRT) and determine relative cardiac contractility, thereby differentiating systolic from diastolic mechanisms in acute CHF.

METHODS

In an evaluation of the technique, the average differences in the diastolic time intervals measured in normal subjects by both IC tracings and phonocardiography were compared. Likewise, the average Heather index (HI) of patients with known systolic dysfunction (ejection fraction < 30% by echo-cardiography) was compared with the mean HI measured in the normal subjects. In a retrospective analysis, the clinical performance of the method was examined by extracting the values of IVRT and HI from IC tracings of patients presenting with CHF. The determined IVRT and HI values were then correlated to clinical markers for diastolic and systolic dysfunction.

RESULTS

Analysis of 280 IC tracings in eight healthy volunteers revealed an average difference of 0.0075 seconds (95% CI = -0.0067 to 0.0217) when IVRT intervals measured by phonocardiography and IC are compared. The HI in this normal group averaged 14.2 (95% CI = 9.4 to 19.0), contrasting to the much lower value of 2.8 (95% CI = 1.98 to 3.62) seen in eight subjects with documented systolic dysfunction. In 26 patients with decompensated CHF, there was a close correlation (r = 0.81) of the measured IVRT to left ventricular hypertrophy by voltage criteria and while a fall in the HI was correlated with intravascular volume expansion. Though there was considerable overlap (46%) in mechanisms of CHF, 35% of the patients were found to have only systolic dysfunction (HI < 5 and IVRT < 0.125), while 19% had a predominantly diastolic etiology (IVRT > 0.125 and HI > 5) for their failure.

CONCLUSION

IC measures of contractility and diastolic time intervals are a potentially effective method for differentiating the dominant mechanisms of CHF in the emergent setting and categorizing CHF patients into different subsets.