Above-normal left ventricular systolic performance during exercise in young subjects with mild hypertension

Abstract

Debate continues on whether left ventricular (LV) systolic function during exercise is abnormal in young subjects with mild hypertension and on whether the abnormal blood pressure (BP) trend observed in hypertensives during prolonged exercise is due to impaired LV function. LV function was measured by means of M-mode echocardiography during prolonged exercise in 13 physically trained, young, mild hypertensives and 12 age-matched, trained normotensives with similar working capacity. Systolic BP/end-systolic volume (SBP/ESV) and end-systolic stress/ESV at rest were greater in the hypertensives (P < 0.0001 and P = 0.034), while LV filling was impaired (P = 0.05). BP changes during the first 20 min of exercise were similar in the two groups, but thereafter the between-group BP difference tended to decline progressively. LV diastolic dimension was similar at rest. During exercise it slightly increased in the normotensives and slightly decreased in the hypertensives (P = 0.032). Exercise ejection fraction (P = 0.018), SBP/ESV (P < 0.0001) and stress/ESV (P = 0.027) were greater in the hypertensives throughout the test. SBP/ESV normalized for LV wall thickness (P < 0.0001) and the changes in SBP/ESV from rest to exercise were also greater in the hypertensives (P = 0.002). Stroke volume increased to a lower extent in the hypertensives, but the between-group difference was not statistically significant. The increase in SBP/ESV from rest to exercise was related to the concentric remodelling of the ventricle in the hypertensives (P < 0.0001) and the subjects grouped together (P < 0.0001), but not in the normotensives. In conclusion, increased LV systolic performance is present early in hypertension not only at rest but also during vigorous exercise. It is partly due to concentric remodelling of the left ventricle and partly to enhanced inotropic state.

Exercise capacity in young adults with hypertension and systolic blood pressure difference between right arm and leg after repair of coarctation of the aorta

“…This is confirmed by findings in other studies which reported an enhanced systolic function for patients after surgery with a moderate resting systolic blood pressure difference between the right arm and leg (Borow et al 1985;Moskowitz et al 1990;Tantengco et al 1997). An increased (above normal) left ventricular systolic performance during exercise has been reported in young subjects with mild hypertension (Palatini et al 1995). Overcompensation of a slight increase in aortic resistance can contribute to a slight cardiac hypertrophy, as seen in athletes (Sharma et al 2002), increasing stroke volume and muscle perfusion.…”

Left ventricular contractile performance in the early stage of hypertension in humans

“…A preliminary cycle ergometer test to exhaustion in a 30% gradient semi-supine position served to evaluate _ V O 2max and anaerobic threshold (Wasserman and McIlroy 1964) using the procedure reported elsewhere (Palatini et al 1995). Expired gas was continuously analysed for percentage of oxygen and carbon dioxide using a Datex O 2 -CO 2 fast response analyser.…”

“…During the ®rst 10 min of exercise, the intensity was progressively increased to attain the level previously reached at the anaerobic threshold, then the subjects continued pedalling to exhaustion. M-mode echocardiograms were performed using a SPR 8000 (Hitachi, mod EUP 121, Tokyo, Japan) under two-dimensional guidance (Palatini et al 1995). LV images were obtained at end-expiration.…”

“…Doppler measurements of transmitral¯ow were obtained from all subjects at rest (Palatini et al 1995). The sampling volume was positioned at the centre of the mitral anulus, 1 cm below the anulus plane using the apical four-chamber view.…”

“…More recently, it has been documented that increased indices of LV ejection performance in hypertension may be present not only at rest but also during prolonged strenuous exercise (Palatini et al 1995). However, some authors claimed that LV pump function indices measured at the endocardium do not provide a reliable measure of myocardial contractility, especially when wall thickness is increased by hypertrophy (Shimizu et al 1991;De Simone et al 1994).…”