Doppler Echocardiographic Evaluation of the Correlation Between Left Ventricular Compliance Impairment and Left Atrial Systolic Time Intervals

The left atrial (LA) ejection (AET), preejection (APET) and corrected preejection (APETc) time as well as the early (E) peak and Iate (A) peak diastolic velocity, A to E ratio (A/E), the atrial flow volume to transmitral flow volume ratio (AFV/TFV) values were obtained using continuous Doppler echocardiography in 18 patients with essential hypertension (HT) and a phonocardiographically affirmed fourth heart sound (S4) who were compared to 32 hypertensive and 25 normotensive subjects (NT) without a S4. Left ventricular wall thickness (LVWT) and its ratio to end-diastolic diameter (LVWT/Dd) were determined with M-mode echocardiography. AET was longer in the S4 (+) group than the S4 (-) group (p<0.0005), but APETc was shorter in the S4 (+)group than S4 (-)group (p<0.0005). LVWT/Dd correlated with AET (r:0.45, p<0.001), APETc (r:- 0.45, p<0.001), APET/AET (r:-0.40, p<0.001) and APETc/AET (r:-0.52, p<0.001). In addition, LVWT and A to E ratio correlated with left atrial systolic time intervals (LASTI). There were no statistically significant correlations between age and the variables of LASTI. LASTI displayed important changes pointing to a reduced LV compliance in patients with essential hypertension, compared to normotensive controls.These changes become even more striking in the presence of a fourth heart sound which can therefore be accepted as an important sign of a decrease in compliance in a patient with hypertension. Since LASTI were not affected by age and showed significant correlation with the A to E ratio and LV dimensions, they can be regarded as reliable indicators of LV compliance.