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 (beta = 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.

The Effect of Metabolic Syndrome on Myocardial Contractile Reserve during Exercise in Non-Diabetic Hypertensive Subjects

BACKGROUND: Metabolic syndrome (MS) is associated with increased left ventricular (LV) mass and diastolic dysfunction. This study uses relatively load-independent Doppler tissue echocardiography to examine whether MS is associated with decreased longitudinal contractile reserve during dynamic exercise. METHODS: A total of 112 patients with relatively well-controlled, treated hypertension who complained of exertional dyspnea were enrolled (average age: 56.7 +/- 10.5 years). Fifty-six were non-diabetic patients with MS (Group 1), and 56 were age-sex matched hypertensive patients without MS (Group 2). Exercise stress echo was performed using a symptom-limited, multistage, supine bicycle exercise test. Multiple Doppler parameters were obtained at baseline, at each stage of exercise, and during recovery. RESULTS: There was no significant difference between the two groups in terms of age, gender, and hemodynamic variables. E/E', an index of LV filling pressure, was significantly higher in the MS group at rest and during exercise. The longitudinal contractile reserve, the change in S' (longitudinal tissue velocity) from baseline to peak exercise, was significantly lower in the MS group (2.00 +/- 1.65 vs. 2.90 +/- 1.66, p = 0.015). Multiple regression analysis showed independent association of MS with longitudinal contractile reserve when controlled for confounding factors, such as LV mass index, gender, blood pressure, and age (beta = -0.235, p = 0.035). CONCLUSION: Longitudinal contractile reserve was reduced in MS patients compared to others, although both groups demonstrated similar longitudinal contractile function at rest. We present the first demonstration that metabolic syndrome is independently associated with LV systolic dysfunction during exercise in hypertensive patients.

The Effect of Metabolic Syndrome on Myocardial Contractile Reserve during Exercise in Non-Diabetic Hypertensive Subjects

OBJECTIVE: Metabolic syndrome (MS) is associated with increased left ventricular (LV) mass and diastolic dysfunction. This study uses relatively load-independent Doppler tissue echocardiography to examine whether MS is associated with decreased longitudinal contractile reserve during dynamic exercise. METHODS: A total of 112 patients with relatively well-controlled, treated hypertension who complained of exertional dyspnea were enrolled (average age, 56.7+/-10.5 years). Fifty-six were non-diabetic patients with MS (group 1), and 56 were age-sex matched hypertensive patients without MS (group 2). Exercise stress echo was performed using a symptom-limited, multistage, supine bicycle exercise test. Multiple Doppler parameters were obtained at baseline, at each stage of exercise. RESULTS: There was no significant difference between the two groups in terms of age, gender, and hemodynamic variables. E/E', an index of LV filling pressure, was significantly higher in the MS group at rest and during exercise. The longitudinal contractile reserve, the change in S' (longitudinal tissue velocity) from baseline to peak exercise, was significantly lower in the MS group (2.00+/-1.65 vs. 2.90+/-1.66, P=0.015). Multiple regression analysis showed independent association of MS with longitudinal contractile reserve when controlled for confounding factors, such as LV mass index, gender, blood pressure, and age (beta=-0.235, P=0.035). CONCLUSION: Longitudinal contractile reserve was reduced in MS patients compared to others, although both groups demonstrated similar longitudinal contractile function at rest. We present the first demonstration that metabolic syndrome is independently associated with LV systolic dysfunction during exercise in hypertensive patients.