Measurement of left atrial systolic time intervals in hypertensive patients using Doppler echocardiography: Relation to fourth heart sound and left ventricular wall thickness

Abstract

The concept of left atrial systolic time intervals anil Doppler echocardiography were used in a quantitative assessment of left atrial function in relation to the presence or absence of a fourth heart sound and to left ventricular hypertrophy in 47 patients with hypertension. Left atrial systolic time interval indexes included atrial pre-ejection period (the time between the onset of an electrocardipgraphic P wave and the onset of left ventricular inflow during atrial systole [A wave]), corrected atrial pre-ejcctlon period (the airial pre-ejection period divided by the duration of the P wave), and atrial ejection time (the time between the onset and cessation of the A wave).Twenty-one patients with a fourth heart sound on the phonocardiogram had a shorter atrial pre-ejection period (81 ± 10 versus 89 ± 14 ms p < 0.05) and a corrected atrial pre-ejection period (66 ± 17 versus 83 ± 18 ms, p < 0.01), as well as a longer atrial ejection time (147 ± 15 versus 126 ± 13 ms, p < 0.001) than did 26 patients without a fourth heart sound. The ratio of atrial pre-ejection period to atrial ejection time and that of corrected atrial pre-ejection period to atrial ejection time was smaller in patients with than in patients without a fourth heart sound (0.56 ± 0.08 versus 0.71 ± 0.11, p < 0.001; 0.46 ± 0.16 ms−1versus 0.67 ± 0.17 ms−1, p < 0.001, respectively). Left ventricular wall thickness (the sum of interventricular septal thickness and left ventricular posterior wall thickness) evaluated by two-dimensional echocardiography correlated positively with left atrial ejection time (r = 0.42, p < 0.01) and negatively with corrected atrial pre-ejection period (r = −0.34, p < 0.02), the ratio of atrial pre-ejection period to atrial ejection time (r = − 0.35, p < 0.02) and the ratio of corrected atrial pre-ejection period to atrial ejection time (r = −0.40, p < 0.01).It is concluded that quantitative evaluation of left atrial function obtained by left atrial systolic time intervals correlates with the presence of a fourth heart sound and with left ventricular wall thickness.