LEFT-VENTRICULAR ARTERIAL COUPLING IN SYSTEMIC HYPERTENSION - ANALYSIS BY MEANS OF ARTERIAL EFFECTIVE AND LEFT-VENTRICULAR ELASTANCES

Objective: To clarify the spectrum of the left ventricular responses i n hypertension in man by means of coupled analysis of elastances. In t he present study we analysed the 'functional' coupling of the left ven tricle and the arterial system in terms of the arterial effective elas tance (E(a)) divided by a value of end-systolic left ventricular elast ance approximated by the end-systolic pressure-volume ratio (E(Iv)). M ethods: Twenty-five normotensive and 19 hypertensive males without hea rt failure underwent a haemodynamic and angiographic study. The hypert ensives were divided into three subgroups: group 1 had normal ejection fraction, group 2 had ejection fraction >70% and group 3 had ejection fraction 50-58%. Results: The ejection fraction was similar in hypert ensives and controls and E(Iv) was significantly increased in the hype rtensives. E(a) was identical in the three hypertensive subgroups, whi ch differed only for E(Iv). Hypertensives with a normal ejection fract ion (n=8) had a normal E(a)/E(Iv) ratio and end-systolic stress, and a significantly increased E(Iv), related mainly to an increase in the l eft ventricular mass divided by the end-diastolic volume (m/V-ED) with normal systolic function of the left ventricular muscle. The signific antly increased systolic pump function of group 2 (n=5) seems to be re lated to a significant increase in both m/V-ED and left ventricular mu scle contractility. Group 3 (n=6) was more heterogeneous, some patient s having insufficient hypertrophy and others impaired muscle function. Conclusions: The left ventricle and the arterial system remain correc tly coupled in hypertensives overall, but with marked heterogeneity of the systolic pump (and sometimes muscle) function and mainly of the g eometry of the left ventricle. Regarding the relatively unequivocal ch anges in E(a), the differences in ejection fraction and in left ventri cular-arterial coupling in hypertensives are related mainly to changes in the left ventricular systolic pump function.