STRAIN RATE ECHOCARDIOGRAPHY IN ASSESSMENT OF CLINICAL CARDIAC STATUS IN HYPERTENSIVE PATIENTS

Objective: Strain Rate Echocardiography (SRE) measures rate of change of contraction (LS) of cardiac fibres, the major component of overall cardiac contractility. Cardiac end organ involvement in Hypertension is omnipotent. We assessed utility of SRI in identifying clinical dysfunction of myocardial contractility in Hypertensives subjects. Design and method: We looked at Colour Doppler and Strain Rate Echocardiography data of 523 patients, with sequential Blood Pressure measurements(Thrice over 10 minutes). Hypertensives (n=136) constituted patients with average BP >130/80. Rest were designated as Normotensives(n=387). Left Ventricular Mass (LVM), Left Atrial Volume (LAV), Mitral E/e‘ ratio as surrogate for LV end diastolic pressure (LVEDP), were analysed for comparison. Unpaired Chi square test determined statistical significance. Results: Ejection Fraction were similar (56%+/-0.41 vs 58%+/-0.11). Normotensives showed positive correlation between LS and Systolic BP. However, negative correlation was observed in Hypertensives. In bothgroups, moderate inverse correlation between LVM, LVEDP versus GLS was observed. In both groups,LS was reduced in patients with high LVMi(p<0.0001), high LVEDP(p<0.003), increased LAV(p<0.01). The difference was statistically, highly significant. Difference in LS between Dippers (n=227) and Non-Dippers(n=296) was statistically not significant. However, LVM, LVEDP and LAV were higher in Non-Dippers. (p<0.001,p<0.03,p<0.02 respectively) Conclusions: LS measures longitudinally arranged cardiac fiber's function (predominantly sub-endocardial region) Present study showed, increased LVM and High LVEDP depresses their contractility, may lead to heart failure in future. Efforts to reduce intracardiac pressures and LV mass and Blood pressure will preserve cardiac function in hypertensives. Thus, LS estimation can identify subset who will respond to aggressive afterload reduction in hypertensives.