The Relationship Between Left Ventricular Filling Shortly After an Uncomplicated Myocardial Infarction and Subsequent Exercise Capacity

Resting measurement of only left ventricular systolic function, is not enough sufficient parameter that predicts exercise capacity in patients with cardiac disease. Therefore, left ventricular filling shortly after an acute myocardial infarction (AMI) was prospectively studied to determine whether it could predict subsequent exercise time. Consecutive AMI patients underwent Doppler and two-dimensional echocardiography within 48 hours of infarction. The study group consisted of 63 participants: 33 patients with an uncomplicated AMI who had undergone symptom-limited stress testing during recovery and 30 healthy subjects. Systolic function was evaluated by wall motion score index (WMSI), and diastolic one was assessed by the peak transmitral Doppler velocity in early diastole (E) and atrial systole (A), then by their ratio (E/A), normalized E/A ratio, and by diastolic filling period (DFP). Myocardial infarction (MI) size was measured electrocardiographically, using Selvester’s QRS scoring system (QRSSI) and then expressed in percentages. Healthy participants and patients were compared, through common parameters. The patients receiving BB treatment at the time of exercise testing, had a lower resting pulse, and achieved a lower maximal pulse, yet their exercise time was similar incomparison to that of the group not receiving BB therapy. Our results have shown a strong positive correlation between exercise time and WMSI (r = 0.77, p < 0.001) DFP (r = 0.56, p < 0,001), respectively weak negative correlation with QRSSI (r = –0.17, p < 0.001) and better negative correlation with normalized E/A ratio (r = –0.56, p < 0.001). This correlation was not influenced by beta-blokers (BB) at the time of stress testing. Normalized E/A ratio and DFP are the only diastolic function parameters, which predict exercise capacity during recovery, measured soon after an uncomplicated AMI