ABSTRACT
BACKGROUND: The strength of each heart beat and the stiffness of large arteries contribute to blood pressure (BP). When the large arteries are stiff and their resistance greater, the afterload increases and this may change the function of the heart. However, the relation between common carotid artery stiffness and heart function in hypertensive patients has not been clarified. METHODS: Two hundred and twenty hypertensive patients underwent transthoracic and carotid echocardiography. Measurements of local arterial stiffness were taken at the right common carotid artery level and stiffness parameter (ß), pressure-strain elasticity modulus and intima-media thickness were calculated. Brachial cuff BP was measured just before starting the carotid study. The patients with any cardiovascular disease, diabetes mellitus, stroke, transient ischemic attack, or carotid stenosis were excluded. RESULTS: Carotid artery stiffness parameter (ß) was correlated with age and left ventricular mass index (p < 0.005). Even though ß was not correlated with LV systolic function, it was inversely correlated with diastolic function as measured by early mitral annular velocity. When the artery was stiffer, early mitral annular velocity (e') decreased (p < 0.001) and the index of left atrial (LA) pressure (early diastolic mitral inflow E velocity/e') increased (p = 0.001). In logistic regression, diastolic dysfunction was affected by age (beta -0.385, p = 0.001), LA volume index (beta 0.175, p = 0.013) and ß (beta -0.273, p = 0.019). CONCLUSION: In hypertensive patients, changes in carotid artery stiffness can affect the diastolic function, independent of age and LA volume index. Therefore, measurements and control of carotid stiffness can play an important role in the prevention of diastolic heart failure.
ABSTRACT
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 (ß = 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.
