The effect of hypertension and left ventricular hypertrophy on the lower range of coronary autoregulation.

Abstract

These studies were performed to test the hypothesis that left ventricular hypertrophy arising as a complication of chronic hypertension is associated with impaired coronary autoregulation. Twelve

ACE-inhibitor therapy with spirapril increases nocturnal hypotensive episodes in elderly hypertensive patients

“…Moreover, in hypertensive patients also coronary autoregulation in the subendocardium is shifted toward higher pressure, probably owing to Journal of Human Hypertension left ventricular hypertrophy and functional and structural alterations in the small coronary vessels. 3,5,18,19 The relationship between CBF and MAP has been established by invasive BP measurements. 1,20 In general, the non-invasive approach tends, when compared with the invasive approach, to underestimate SBP and overestimate DBP, 21 but the differences are small.…”

“…[3][4][5] Pierdomenico et al 6 found nocturnal ischaemia significantly more frequently in non-dippers than in dippers and overdippers among untreated hypertensive patients with coronary artery disease. Drug therapy significantly reduced nocturnal ischaemia in non-dippers, had no significant effect in dippers and significantly increased night time ischaemia in overdippers.…”

Normalization of impaired coronary circulation in hypertrophied rat hearts.

“…1 In the subendocardium of hypertrophied hearts with hypertension, autoregulation is impaired in the lower range of coronary perfusion pressure. 2 Furthermore, coronary flow reserve estimated with adenosine, dipyridamole, or flow increases during stress or after ischemia is also decreased in hypertrophied hearts. 3 -23 In previous studies, 24 - 25 we reported that the maximal coronary flow rate during reactive hyperemia decreased in cardiac hypertrophy, but the decreased flow normalized after relief of pressure overload.…”

ST segment depression elicited by dipyridamole infusion in asymptomatic hypertensive patients.

“…Another contributing mechanism can be arterial hypotension. Harrison et al 26 showed that left ventricular hypertrophy can profoundly impair the lower range of autoregulation in the subendocardial myocardium of hypertensive dogs. As suggested by Pepi et al, 34 it is entirely possible that the high blood pressure becomes a physiological requirement in the myocardium of hypertensive patients so that adequate coronary perfusion pressure and blood flow can be maintained.…”