Regression of left ventricular hypertrophy results in improvement of QT dispersion in patients with hypertension

OBJECTIVES: Increased QT dispersion has been considered as predisposing to ventricular arrhythmias in hypertrophic cardiomyopathy, congestive heart failure, and coronary artery disease. An increased QT dispersion has also been found in hypertensive patients with left ventricular hypertrophy (LVH). The data on the effect of LVH regression on QT dispersion are limited. METHODS AND RESULTS: To assess the relation of LVH regression and QT dispersion decrease, 68 patients (42 men and 26 women, mean age 56.3+/-9.5 years) with uncomplicated essential hypertension were studied. All underwent full electrocardiographic and echocardiographic studies at baseline and after 6 months of monotherapy, 29 with angiotensin-converting enzyme inhibitors and 39 with calcium antagonists. QT dispersion was calculated by subtracting the shortest QT from the longest QT, in absolute value (QTmax - QTmin). It was also corrected with Bazett's formula (QTc dispersion). Left ventricular mass index was assessed according to the Devereux formula. After treatment, LVH decreased with both angiotensin-converting enzyme inhibitors (from 155 to 130 g/m2, P < .001) and calcium antagonists (156 to 133/92/m2, P < .001). QT dispersion decreased both after angiotensin-converting enzyme inhibitor treatment (from 82 to 63 ms) and calcium antagonist treatment (from 77 to 63 ms, both P < .001 ). There was a significant correlation of QT dispersion and left ventricular mass after therapy (r = 0.36, P < .005). There was a correlation of the degree of LVH and QT dispersion decrease (r = 0.27, P < .05). CONCLUSIONS: It is concluded that LVH regression influences AQT favorably. Its prognostic value has yet to be determined.     

The importance of left ventricular hypertrophy in human hypertension

Hemodynamic and non-hemodynamic factors contribute to the development of left ventricular hypertrophy (LVH). The presence of LVH is an important independent risk factor for total mortality and for cardiovascular morbidity and mortality. Direct cardiac effects of LVH include an increased risk of developing of congestive heart failure, an increased risk of arrhythmic events, and a reduced coronary flow reserve, promoting myocardial ischemic episodes. In addition, hypertension may promote the development of coronary artery atherosclerosis. The prognostic implications of LVH underscore the importance of diagnostic procedures. The electrocardiogram has a high specificity to identify patients with LVH but the sensitivity is fairly low. Echocardiography provides higher sensitivity and also gives important information, such as the pattern of left ventricular geometry, which is of prognostic importance, and the presence of diastolic dysfunction, which is an early abnormality in the evolution of hypertensive LVH. Reversal of LVH appears to improve prognosis. Reduction of blood pressure is one important component in the regression of LVH. Important quantitative differences exist between drug classes in the reversal of cardiac hypertrophy despite similar antihypertensive effects, suggesting other factors to be of importance in the regression of left ventricular mass. LVH is reduced more by angiotensin-converting enzyme inhibitors than by other antihypertensive drug classes, suggesting an effect on structural myocardial changes beyond that provided by the reduction of blood pressure. Recent data suggest that angiotensin II receptor antagonists (AIIRAs) have quantitatively similar effects on left ventricular mass as do angiotensin-converting enzyme inhibitors. A comparative trial of the AIIRA irbesartan and the beta-blocker atenolol demonstrated that despite similar reductions in blood pressure, the reductions attained in left ventricular mass with irbesartan were progressive and numerically greater than those attained with atenolol. Taken together, these findings provide circumstantial evidence for an important role of angiotensin II acting on angiotensin type 1 (AT1) receptors in the development or maintenance of cardiac hypertrophy. Confirmation of the favorable effects of angiotensin-converting enzyme inhibitors and AIIRAs on left ventricular mass in larger trials, including those assessing cardiovascular morbidity and mortality, will be of major importance in the future treatment of hypertension.     

Left ventricular geometry and severe left ventricular hypertrophy in children and adolescents with essential hypertension

BACKGROUND: Left ventricular (LV) hypertrophy has been established as an independent risk factor for cardiovascular disease in adults. Recent research has refined this relationship by determining a cutpoint of 51 g/m(2.7) for LV mass index indicative of increased risk and defining LV geometric patterns that are associated with increased risk. The purpose of this study was to evaluate severe LV hypertrophy and LV geometry in children and adolescents with essential hypertension. METHODS AND RESULTS: A cross-sectional study of young patients (n=130) with persistent blood pressure elevation above the 90th percentile was conducted. Nineteen patients (14%) had LV mass greater than the 99th percentile; 11 of these were also above the adult cutpoint of 51 g/m(2.7). Males, subjects with greater body mass index, and those who had lower heart rate at maximum exercise were at significantly (P<.05) higher risk of severe LV hypertrophy. In addition, 22 patients (17%) had concentric LV hypertrophy, a geometric pattern that is associated with increased risk of cardiovascular disease in adults. Seven patients had LV mass index above the cutpoint and concentric hypertrophy. No consistent significant determinants of LV geometry were identified in these children and adolescents with hypertension. CONCLUSIONS: Severe LV hypertrophy and abnormal LV geometry are relatively prevalent in young patients with essential hypertension. These findings suggest that these patients may be at risk for future cardiovascular disease and underscore the importance of recognition and treatment of blood pressure elevation in children and adolescents. Weight loss is an important component of therapy in young patients with essential hypertension who are overweight.     

Glucose intolerance exaggerates left ventricular hypertrophy and dysfunction in essential hypertension

The influence of glucose intolerance, the preclinical stage of diabetes mellitus, on the progression of left ventricular hypertrophy and left ventricular dysfunction in essential hypertension, was assessed with two-dimensional M-mode echocardiography in age- and sex-matched essential hypertensive patients with (n = 28) or without (n = 44) glucose intolerance, and normotensive control subjects (n = 29). Left ventricular mass index in hypertensive patients with glucose intolerance was significantly higher than that in hypertensive patients without glucose intolerance (mean +/- SD, 115.6 +/- 28.2 v 102.1 +/- 22.1 g/m2; P < .05). Left ventricular diastolic function as reflected by peak lengthening rate was reduced in glucose-intolerant hypertensive patients than in hypertensive patients without glucose intolerance (2.68 +/- 0.71 v 3.16 +/- 0.82/sec; P < .05). End-systolic wall stress/left ventricular end-systolic volume index, an index of left ventricular contractility, was reduced more in glucose-intolerant hypertensive patients than in hypertensive patients without glucose intolerance (2.75 +/- 0.55 v 3.13 +/- 0.55 10(3) dyn.m2/cm2.mL-1; P < .01). These findings suggest that glucose intolerance accelerates progression of left ventricular hypertrophy and deteriorates left ventricular diastolic function and contractility in essential hypertension.     

Regression of hypertrophy of the left ventricle in patients with hypertension after 6-month treatment with Fludex

Indapamide (Fludex) administered in daily doses of 2.5 mg resulted in optimal improvement of the blood pressure in patients with mild or moderate hypertension. During the period of 6 months treatment that was tolerated well by the patients, no influence of indapamide on the levels of glucose, cholesterol, triglycerides, and creatinine in blood was observed. A mild decrease of serum potassium in blood was clinically not relevant. Using echocardiography and electrocardiography a regression of the hypertrophy of the left ventricle of the heart was observed.     

Regression of left ventricular hypertrophy after aortic valve replacement for aortic stenosis with different valve substitutes

OBJECTIVE: Stentless biologic aortic valves are less obstructive than stented biologic or mechanical valves. Their superior hemodynamic performances are expected to reflect in better regression of left ventricular hypertrophy. We compared the regression of left ventricular hypertrophy in 3 groups of patients undergoing aortic valve replacement for severe aortic stenosis. Group I (10 patients) received stentless biologic aortic valves, group II (10 patients) received stented biologic aortic valves, and group III (10 patients) received bileaflet mechanical aortic valves. METHODS: Echocardiographic evaluations were performed before the operation and after 1 year, and the results were compared with those of a control group. Left ventricular diameters and function, left ventricular wall thickness, and left ventricular mass were assessed by echocardiography. RESULTS: Group I patients had a significantly lower maximum and mean transprosthetic gradient than the other valve groups (P = .001). One year after operation there was a significant reduction in left ventricular mass for all patient groups (P < .01), but mass did not reach normal values (P = .05). Although the rate of regression in the interventricular septum and posterior wall thickness differed slightly among groups, their values at follow-up were comparable and still higher than control values (P = .002). The ratio between interventricular septum and posterior wall and the ratio between wall thickness and chamber radius did not change significantly at follow-up. CONCLUSIONS: Because the number of patients was relatively small, we could not use left ventricular mass regression after I year to distinguish among patients undergoing aortic valve replacement for aortic stenosis by means of valve prostheses with different hemodynamic performances.     

Sudden cardiac death in patients with arterial hypertension and left ventricular hypertrophy on antihypertensive therapy

The hypertrophy of the left ventricle in patients with arterial hypertension is an independent risk factor which increases c 9 times the probability of sudden cardiac death. Despite the fact that the incidence of sudden cardiac death in patients with arterial hypertension is low, regarding the high occurrence of hypertension it represents a significant medical problem. The therapy of arterial hypertension is able to decrease the general and cardiovascular mortalities with significant interspecies characteristics of individual antihypertensive drugs, as well as to promote the regression of hypertrophy of the left ventricle. The therapy per se can however increase the risk of cardiovascular complications: until now the complication of the therapy by diuretics rich in potassium and beta-blockers are best distinguished. Calcium antagonists are effective antihypertensive drugs but they do not decrease the total mortality. ACE inhibitors have a marked antihypertensive effect and few adverse effects, but until now there is not a sufficient number of large prospective studies which would definitely confirm the preliminary promising findings. Despite the presented problems the cured patients with arterial hypertension have a substantially better prognosis than patients that are not being cured.     

Latent impairment of left ventricular filling in hypertension without left ventricular hypertrophy and improvement by dipyridamole treatment: pulsed Doppler echocardiography study

Left ventricular (LV) filling impairment in patients with hypertension (HT) not necessarily associated with LV hypertrophy has not been sufficiently investigated. Therefore, we examined the response of LV filling to isometric exercise in patients with HT without LV hypertrophy and LV filling abnormality at rest. We studied 25 patients (aged 40 to 66 years, mean 51 +/- 7 years) and 13 age-matched normal subjects. The HT patients were selected by the following criteria: 1) systolic blood pressure (sBP) over 160 mmHg and/or diastolic BP over 90 mmHg was observed at least three times during the last 6 months, 2) LV wall thickness was under 11 mm, and 3) the ratio of peak atrial LV inflow velocity (A) to peak early diastolic LV inflow velocity (E) was within the mean +/- SD of normal subjects. LV inflow was measured by pulsed Doppler flowmetry before and during handgrip exercise (50% maximal effort for one minute and a half) in the patients before [HT-D (-)] and after [HT-D (+)] dipyridamole (D) administration (0.28 mg/kg/4 min) and in the normal subjects (N). Doppler-derived indices were A, E, A/E, DR (the deceleration rate from peak to half of the early diastolic inflow velocity), % delta A/E (% change in A/E from baseline), and % delta DR (% change in DR from baseline). There was no significant difference in LV wall thickness between the HT and N groups. There was also no significant difference in A/E at rest between the three groups. Increase of sBP and heart rate were similar in all groups during handgrip exercise.(ABSTRACT TRUNCATED AT 250 WORDS)     

Influence of the angiotensin II antagonist valsartan on left ventricular hypertrophy in patients with essential hypertension

BACKGROUND: Left ventricular hypertrophy (LVH) represents an independent risk factor in patients with essential hypertension. Because reversal of LVH may be associated with an improvement of prognosis, the influence of new antihypertensive compounds, such as angiotensin II AT1 receptor antagonists, on LVH should be determined. METHODS AND RESULTS: In a randomized, double-blind trial, 69 predominantly previously untreated hypertensive patients with echocardiographically proven LVH, ie, left ventricular mass index (LVMI) >134 g/m2 in men and >110 g/m2 in women and/or end-diastolic septal thickness >12 mm, received either the angiotensin II antagonist valsartan or atenolol for 8 months. Echocardiographic data of 58 patients were available. After 8 months of valsartan treatment (n=29), LVMI decreased from 127+/-23 to 106+/-25 g/m2 (ratio [R]=0.83; 95% CI, 0.79 to 0.87; P<0.0001 versus baseline). Under atenolol (n=29), LVMI decreased to a smaller extent, from 127+/-25 to 117+/-27 g/m2 (R=0.92; 95% CI, 0.86 to 0.98; P=0.0082 versus baseline). The mean reduction of LVMI came to 21 g/m2 under valsartan and only to 10 g/m2 under atenolol (R=0.91; 90% CI, 0.85 to 0.97 versus atenolol). Baseline mean blood pressure values were determined to be 163+/-12/101+/-6 mm Hg before treatment with valsartan and 160+/-14/103+/-6 mm Hg before atenolol treatment. After 8 months of treatment, mean blood pressure decreased to 146+/-13/90+/-7 mm Hg with valsartan and to 147+/-18/90+/-7 mm Hg with atenolol. Nine patients in the valsartan group and 8 patients in the atenolol group required additional medication with hydrochlorothiazide. CONCLUSIONS: Antihypertensive treatment with the angiotensin II antagonist valsartan for 8 months produced a significant regression of LVH in predominantly previously untreated patients with essential hypertension. The drug may be safely administered in this subset of hypertensive patients; however, the long-term benefit in terms of risk reduction has still to be evaluated in further trials.     

Left ventricular hypertrophy in patients with nephrogenic arterial hypertension

Incidence and geometric peculiarities of hypertrophy of the left ventricle of the heart (HLVH) were studied on the basis of findings from the echocardiographic investigation done in 86 patients with chronic glomerulonephritis (ChGN) with arterial hypertension (AH), with the renal function being preserved and at the early stages of renal insufficiency. HLVH was detected in 30.2% of the patients, in 80.8% of whom it was concentric, and in 19.2% eccentric, in 76%--symmetric and in 23.1%--asymmetric. Incidence of HLVH did not correlate with sex, clinical variant of ChGN, renal function status, and increased with the degree and duration of AH. There was no difference in geometric peculiarities between sexes, clinical variants of ChGN, and no association with degree and duration of AH as well as with functional state of the kidneys.     

Reversal of left ventricular hypertrophy in essential hypertension. A meta-analysis of randomized double-blind studies

OBJECTIVE: To determine the ability of various antihypertensive agents to reduce left ventricular hypertrophy, a strong, blood pressure-independent cardiovascular risk factor, in persons with essential hypertension. DATA SOURCES: MEDLINE, DIMDI, RINGDOC, ADES, EMBASE, and review articles through July 1995 (English-language and full articles only). STUDY SELECTION: Meta-analysis of all published articles including only double-blind, randomized, controlled clinical studies with parallel-group design. DATA EXTRACTION: Intensive literature search and data extraction according to a prefixed scheme performed independently by 2 investigators. Reduction of left ventricular mass index after antihypertensive therapy with placebos, diuretics, beta-blockers, calcium channel blockers, or angiotensin-converting enzyme (ACE) inhibitors was the principal parameter. DATA SYNTHESIS: Of 471 identified references describing the effects of antihypertensive drugs on left ventricular hypertrophy, only 39 clinical trials fulfilled the inclusion criteria of our study. We found that the decrease in left ventricular mass index was more marked the greater was the decline in blood pressure (systolic r=0.46, P<.001; diastolic r=0.21, P=.08) and the longer was the duration of therapy (r=0.38, P<.01). After adjustment for different durations of treatment (mean duration of treatment, 25 weeks), left ventricular mass decreased 13% with ACE inhibitors, 9% with calcium channel blockers, 6% with beta-blockers, and 7% with diuretics. There was a significant difference between drug classes (P<.01): ACE inhibitors reduced left ventricular mass more than beta-blockers (significant, P<.05) and diuretics (tendency, P=.08). Similar differences between drug classes were found with regard to effect on left ventricular wall thickness (P<.05). CONCLUSIONS: The database of articles published through July 1995 is small and incomplete, and most of the articles are of poor scientific quality. In this first meta-analysis including only double-blind, randomized, controlled clinical studies, decline in blood pressure, duration of drug treatment, and drug class determined the reductions in left ventricular mass index. The ACE inhibitors seemed to be more potent than beta-blockers and diuretics in the reduction of left ventricular mass index; calcium channel blockers were somewhat in the intermediate range. The ACE inhibitors and, to a lesser extent, calcium channel blockers emerged as first-line candidates to reduce the risk associated with left ventricular hypertrophy.     

Regression of left ventricular hypertrophy prevents ischemia-induced lethal arrhythmias. Beneficial effect of angiotensin II blockade

To evaluate the preventive effect of regression of left ventricular hypertrophy (LVH) on sudden cardiac death (SCD), the incidence of ventricular tachycardia or ventricular fibrillation (VT/Vf) after left coronary artery occlusion in Langendorff preparations was studied in the following five groups: (1) spontaneously hypertensive rats (SHR) without treatment (SHR-N), (2) SHR treated with captopril (SHR-C), (3) SHR treated with the angiotensin II receptor antagonist TCV-116 (SHR-A), (4) SHR treated with hydralazine (SHR-H), and (5) Wistar-Kyoto (WKY) rats. Although blood pressure was equally lowered in all treated groups, SHR-C and SHR-A but not SHR-H showed regression of LVH. The incidence of VT/Vf was 5% in WKY rats, 63% in SHR-N (P < .005 versus WKY rats), 0% in SHR-C, 10% in SHR-A, and 45% in SHR-H (P < .05 versus WKY rats). Further evaluation of the effect of TCV-116 revealed that SHR treated with a low dose of TCV-116 (1 mg/kg per day) showed a decrease in left ventricular mass with only a little decrease in blood pressure and that the incidence of VT/Vf was reduced in association with the degree of regression of LVH. Electrophysiological study using microelectrode techniques revealed that in the LVH groups (SHR-N and SHR-H), the action potential duration (APD) of the left ventricular papillary muscle was more prolonged than in WKY rats, whereas APD shortened to a greater extent during superfusion with a hypoxia/no-glucose solution. APD showed no difference in the regression groups (SHR-C and SHR-A) compared with the WKY group.(ABSTRACT TRUNCATED AT 250 WORDS)     

Left ventricular contractile performance, ventriculoarterial coupling, and left ventricular efficiency in hypertensive patients with left ventricular hypertrophy

Contractile performance of hypertrophied left ventricle may be depressed in arterial hypertension. Ventriculoarterial coupling is impaired when myocardial contractile performance is reduced and when afterload is increased. The left ventricular contractile performance and the ventriculoarterial coupling were evaluated in 30 hypertensive patients with moderate left ventricular hypertrophy and 20 control subjects. Left ventricular angiography coupled with the simultaneous recording of pressures with a micromanometer were used to determine end-systolic stress/volume index, the slope of end-systolic pressure-volume relationship, ie, end-systolic elastance, effective arterial elastance, external work, and pressure-volume area. In hypertensive patients, left ventricular contractile performance, as assessed by end-systolic elastance/ 100 g myocardial mass, was depressed (4.35 +/- 1.13 v 5.21 +/- 1.89 mm Hg/mL/100 g in control subjects P < .02), when end-systolic stress-to-volume ratio was comparable in the two groups (3.85 +/- 0.99 g/cm2/mL in hypertensive patients versus 3.51 +/- 0.77 g/cm2/mL in control subjects). Ventriculoarterial coupling, evaluated through effective arterial elastance/end-systolic elastance ratio, was slightly higher in hypertensive patients (0.53 +/- 0.08 v 0.48 +/- 0.09 mm Hg/mL in control subjects, P < .05), and work efficiency (external work/pressure-volume area) was similar in the two groups (0.78 +/- 0.04 mm Hg/mL in hypertensive patients versus 0.80 +/- 0.03 mm Hg/mL in control subjects). This study shows that despite a slight depression of left ventricular contractile performance, work efficiency is preserved and ventriculoarterial coupling is almost normal in hypertensive patients with left ventricular hypertrophy. Thus, it appears that left ventricular hypertrophy might be a useful means of preserving the match between left ventricle and arterial receptor with minimal energy cost.     

Centralized echocardiogram quality control in a multicenter study of regression of left ventricular hypertrophy in hypertension

Deep skin wounds in the adult mammal close spontaneously by epithelialization, wound contraction, and scar synthesis. In previous wound healing studies, it has been unsuccessfully attempted to separate from each other the natural processes that close wounds. In this study, we attempted to isolate skin regeneration from spontaneous processes of wound closure using "island" grafts. A porous analog of the extracellular matrix, composed of a graft copolymer of type I collagen and chondroitin 6-sulfate, was seeded with uncultured autologous keratinocytes and served to induce regeneration of the dermis and the epidermis. Grafts of the copolymer, measuring 1 x 2 cm, were placed in the center of 5 x 6-cm wounds in guinea pigs. By day 14, the edges of the island grafts were clearly separated from the host epidermis and dermis by a distinct bed of granulation tissue. Histologic study of island grafts on day 14 showed that the copolymer grafts had largely degraded and that a new epidermis and dermis had been synthesized in its place. The thickness of the new epidermis increased as the density of cells seeded into the graft increased. No synthesis of epidermis or dermis was observed in the granulation tissue outside the perimeter of the island grafts. We conclude that island grafting allows the study of early events in skin regeneration in isolation from epithelialization, contraction, and scar synthesis.     

Dispersion of ventricular repolarization in left ventricular hypertrophy: influence of afterload and dofetilide

INTRODUCTION: Increased dispersion of ventricular repolarization is observed in cardiac hypertrophy and is associated with sudden cardiac death. At present, there is little information about the effects of cardiac hemodynamics and antiarrhythmic drugs on dispersion of repolarization in disease states. We compared the effects of increasing afterload and the Class III antiarrhythmic drug, dofetilide, on dispersion of ventricular repolarization in hypertrophied rabbit hearts to normal rabbit hearts. METHODS AND RESULTS: Cardiac hypertrophy was induced in rabbits by abdominal aortic banding. Isolated hearts were studied 49+/-4 days postsurgery in the working heart mode using a blood-buffer perfusate. The action potential duration (APD) was measured from eight sites on the epicardium of the heart at low (50+/-7 mmHg) afterload and high afterload (97+/-12 mmHg) at baseline and during dofetilide perfusion. APD dispersion, determined as the difference between the maximal and minimal APD, was greater in hypertrophied hearts (42+/-8 msec) compared with control hearts (26+/-8 msec, P < 0.05) at baseline and low afterload. Increasing afterload caused a decrease in APD dispersion in hypertrophied hearts (P < 0.05) but not in control hearts, and APD dispersion was similar in hypertrophied hearts (31+/-9 msec) compared with control hearts (30+/-9 msec, P = NS). During dofetilide perfusion, APD dispersion remained greater in hypertrophied hearts (60+/-39 msec) compared with control hearts (30+/-13 msec, P < 0.05) at low afterload but not high afterload. Increasing afterload caused shortening of the APD in most regions of the control hearts, whereas APD did not shorten significantly in hypertrophied hearts at baseline and tended to increase during dofetilide perfusion. During dofetilide perfusion, the maximal change in APD recorded from the posterior wall of the left ventricle following an increase in afterload was -18+/-21 msec in control hearts and 7+/-21 ms in hypertrophied hearts (P < 0.05). CONCLUSION: Epicardial APD dispersion decreases in hypertrophied hearts following an increase in afterload, and this response is mediated in part by the absence of afterload-induced shortening of the APD. This effect may be due in part to altered responses of the delayed rectifying current to cardiac loading conditions in the setting of cardiac hypertrophy.     

Reduced epicardial coronary vasodilator capacity in patients with left ventricular hypertrophy

BACKGROUND: Enlargement of the epicardial coronary arteries occurs in left ventricular (LV) hypertrophy as an adaptation to the increased coronary blood flow. METHODS AND RESULTS: Vasodilator capacity of the epicardial coronary arteries was determined in 44 patients. The dose-response relation of intracoronary nitroglycerin was assessed in 14 patients (7 control subjects and 7 patients with aortic stenosis [study A]) using quantitative coronary angiography. In a second study (B), vasodilator capacity of the epicardial coronary arteries was determined in 15 control subjects and 15 patients with valvular heart disease. In study A, a curvilinear dose-response relation with maximal vasodilation after 90 micrograms intracoronary nitroglycerin was found in both control subjects and patients with aortic stenosis. Vasodilator capacity was reduced in those with aortic stenosis, although sensitivity to nitroglycerin was similar in both groups. In study B, coronary circumferential length at baseline was larger in those with LV hypertrophy (12.2 +/- 2.2 mm) than in control subjects (8.6 +/- 1.5 mm; P < .001); after 100 micrograms intracoronary nitroglycerin, it increased to 12.9 +/- 2.2 mm (6 +/- 5%) in those with LV hypertrophy and to 10.3 +/- 1.5 mm (21 +/- 8%; P < .001) in control subjects. An inverse relation between baseline circumferential length and its percent increase after nitroglycerin was found (r = -.71, P < .001). CONCLUSIONS: Vasodilator capacity of the epicardial coronary arteries is reduced in patients with LV hypertrophy, although sensitivity to nitroglycerin is normal. This may be due to a flow-mediated decrease in coronary vasomotor tone and/or the occurrence of vascular remodeling with an enlargement of the coronary arteries.