Assessment of Hypertrophied Left Ventricular Function in Patients with Essential Hypertension Using New Noninvasive Index, E' max/V 100 : Comparison between non-hypertrophied and hypertrophied hearts with and without ST-T changes

In forty-one essential hypertensive (EHT) patients with and without left ventricular hypertrophy (LVH), the left ventricular (LV) contractile performance was determined noninvasively using echocardiography. Classification was made with respect to the LVH, as measured by the sum of end-diatolic posterior wall thickness and interventricular septal thickness, and the presence of ST-T changes on electrocardiogram. Patients who had neither LVH nor ST-T changes formed Hl-subgroup (H1; n=22), those who had LVH without ST-T changes served as HZ-subgroup (H2; n =8), and those with LVH accompanied by ST-T changes constituted HS-subgroup (H3; n = 11), Sixteen normal volunteers served as normal control (N).

LV systolic phase indices such as ejection fraction (EF), mean velocity of circumferential fiber shortening (mVcf) and end-systolic wall stress (ESWS), and diastolic indices such as isovolumic relaxation time (IVRT) and PR-AC interval were compared among each subgroup and normal subjects. All systolic and diastolic indices showed a depressed LV function in H3. Of these variables, the only IVRT could separate H2 from H1, suggesting deteriorated diastolic function at an early stage of hypertrophy.

By altering LV systolic loading, peak systolic pressure-end-systolic volume relation, E’ max, and E' max-volume intercept at 100 mmHg peak systolic pressure ratio, E' max/V 100, were designated and these indices were used for the expression of the myocardial contractile state. E' max and E’ max/V 100 were significantly lower in H2 and H3 than in the control group, indicating depressed myocardial contractility. The value of these variables in Hl did not differ from N, indicating a normal level of inotropic state. E’ max/V 100 in H3, 0.13±0.04 mmHg/ml2, was significantly less than in H2, 0.23±0.05 (p<0.01), and the value in H2 was significantly lower than that in H1, 0.36 ±0.07 (p< 0.01), indicating a validity of E' max/V 100 to differentiate each EHT subgroup.

It is concluded that in patients with LVH induced by pressure overload the LV function is declined, furthermore, LV contractile performance is more impaired when LVH is accompanied by ST-T changes. E’ max/V 100 is highly sensitive in identifying the presence of LV contractile impairment and may be a useful approach to the quantitation of LV. performance.