Changes of Left Ventricular Function , Left Atrial Function , and Pulmonary Venous Flow Patterns in Patients with Acute Myocardial Infarction

Kim, Bok Kun; Joo, Seung Jae; Bae, Young Hwan; Park, Sun Mi; Choi, Jin; Choi, Hwi; Yoon, Byung Chul; Oh, Won Sub; Koo, Yang Hwun; Hong, Sung Jun; Kim, Jin; Park, Neung Hwa; Cha, Tae Joon; Lee, Jae Woo

Abstract

OBJECTIVES
Acute myocardial infarction decreases left ventricular systolic and diastolic function. Left ventricular diastolic function is usually assessed with the left ventricular filling patterns. Abnormal left ventricular tilling patterns after acute myocardial infarction can be classified as relaxation abnormality, pseudonormalization, and restriction, but sometimes the differentiation between pseudonormalization and the normal pattern is difficult. To assess left ventricular systolic and diastolic function, and left atrial function after acute myocardial infarction, M-mode, two-dimensional, pulsed Doppler, and automated border detection echocardiography were performed. To complement the information obtainable from the mitral flow patterns, pulmonary venous flow patterns were also analysed to assess the left ventricular filling patterns.
METHODS
Twenty six patients (mean age 60+/-10) underwent echocardiographic examination 7 to 14 days after acute myocardial infarction. Twenty healthy persons(mean age 57+/-12) were served as a control group. Various indexes were obtained with M-mode, two-dimensional, pulsed Doppler, and automated border detection echocardiography
RESULTS
1) Mean age, sex ratio, heart rate, body mass index were not different between patient and control groups. There were five patients with hypertension in patient group. Left ventricular mass index of patient group was greater than that of control group (163+/-43g/m2 vs. 109+/-22g/m2, P<0.0D1). 2) Patients had decreased cardiac index(2.35+/-0.53L/min/m2 vs. 3.02+/-0.70L/min/m2, P<0.05) and left ventricular ejection fraction(55+/-12% vs. 62+/- 0.4%). There was a negative correlation between left ventricular regional wall motion score and ejection fraction(r=-0.71; P<0.001). 3) In patients, peak mitral flow velocity at atrial contraction(A) was higher(73+/-11cm/sec vs. 63+/-13 cm/sec; P<0.01), E/A ratio was lower(0.77+/-0.28 vs. 1.01+/-0.25; P<0.01), and left ventricular isovolumic relaxation time was longer(126+/-34msec vs. 97+/-21msec; P<0.005). 4) Patients had smaller systolic time-velocity integral(13.0+/-3.30cm vs. 14.8+/-2.83cm, P=0.056) and diastolic time-velocity integral(9.18+/-2.21cm vs. 11.2+/-2.77cm, P<0.01). 5) Relaxation abnormality of left ventricular filling patterns, which was classified by E/A ratio of less than 1, was more frequently founded in patients than in controls(45%). Four patients had E/A ratio of greater than 1; SV/DV ratio was greater than 1 in two and less than 1 in others. 6) End-diastolic area of left atrium(minimal area) was larger in patients(11+/-1.9cm2 vs. 9.6+1.4cm2, P<0.01). Therefore, patients showed decreased atrial emptying index and expansion index. Patients had a greater extent of left atrial area decrease resulting from atrial contraction.
CONCLUSION
Patients with acute myocardial infarction showed a decreased left ventricular systolic function and a relaxation abnormality 7 to 14 days after attack, Minimal area of left atrium increased and left atrial function decreased.