Abstract 3611: Abnormal Longitudinal Myocardial Functional Reserve in Hypertensive Patients with Vascular-Ventricular Uncoupling During Exercise
Background: Vascular stiffening is a common feature in hypertensive patients and is also accompanied by left ventricular (LV) end-systolic chamber stiffness. Uncoupling between heart and vessel may affect cardiovascular reserve function especially during exercise. We hypothesized the augmentation of LV longitudinal contraction and relaxation during exercise would be blunted in hypertensive patients with uncoupled vascular ventricular interaction (VVI). The purpose of this study was to evaluate resting LV longitudinal function and functional reserve during exercise in hypertensive patient according to VVI change during exercise using mitral annular velocities by tissue Doppler echocardiography.
Methods: Doppler echo parameters and BP were measured at rest and during supine bicycle exercise (25W, 3 minutes increments) in 87 hypertensive patients older than 50 years (35 male, mean age 62±8 years). Arterial elastance (Ea), end-systolic ventricular elastance (Ees) and VVI index (Ea/Ees) were calculated at rest and peak exercise. The patients were divided two groups; Group I (n=64): normal VVI response during exercise; Group II (n=23): abnormal VVI response during exercise. Abnormal VVI response during exercise was defined as increased VVI index at peak exercise compared with at rest.
Results: There were no significant differences in conventional echo parameters and mitral inflow velocities at rest between the two groups. S’ and E’ at rest were also similar between the groups. However, E’ during peak exercise (8.7±2.0 vs. 6.9±1.7 cm/s, p=0.003) and the magnitude of change of E’ (3.4±1.7 vs. 1.9 ±1.4 cm/s, p=0.003) and S’ (2.1±1.9 vs. 1.5 ± 1.6 cm/s, p=0.040) with exercise were significantly smaller in Group II. The Ea (2.4±0.6 vs. 3.0± 0.7 mmHg/ml, p<0.001) at peak exercise was significantly higher and Ees (5.2 ±1.9 vs. 4.2±1.3 mmHg/ml, p=0.015) at peak exercise was significantly smaller in Group II.
Conclusions: Vascular stiffening and abnormal VVI during exercise were associated with subclinical myocardial systolic and diastolic dysfunction in hypertensive patients. We speculate that vascular-ventricular uncoupling during exercise was associated with the pathophysiology of subclinical heart failure in hypertensive patients.