Simultaneous determinations of systolic time intervals (preejection period index [PEPI], left ventricular ejection time index [LVETI] and ratio of preejection period to left ventricular ejection time [PEP/LVET]) and echographic measures of left ventricular performance (percent change in minor axis diameter [%ΔD], circumferential shortening rate [Vcf] and end diastolic diameter [Dd]) were obtained in 25 normal subjects and 37 patients with previously documented transmural myocardial infarction. The group with previous infarction demonstrated significant (P<0.001) differences from the normal group in each of the noninvasive measures. PEP/LVET and %ΔD were the most sensitive measures of left ventricular dysfunction. Deviation from the normal range in these measures occurred, respectively, in 70 and 65 percent of patients without dyspnea or fatigability (20 patients) and in 85% of those without angina pectoris (13 patients). Abnormalities in systolic time interval and echocardiographic measures were related to the severity of dyspnea and fatigability but not to that of angina. Neither the presence of phonocardiographically documented third or fourth sound gallops nor an abnormal cardiothoracic ratio by chest roentgenogram reliably detected patients with abnormal left ventricular performance. The range of abnormality in left ventricular performance did not differ between patients with prior anterior or diaphragmatic myocardial infarction. The frequency of abnormal performance was greatest among patients with combined sites of prior infarction. Among 26 patients studied by coronary arteriography, abnormal left ventricular performance as determined by values for PEP/LVET and %ΔD occurred in fewer than 30 percent of those with 70 percent or greater obstruction of one coronary artery and in more than 80 percent of those with two or three vessel involvement. There was a high correlation between systolic time intervals, %ΔD and Vcf, the closest correlation occurring between PEP/LVET and %ΔD (r = -0.93). These data document the sensitivity of the noninvasive systolic time intervals and echographic measures and their superiority over current clinical bedside methods in evaluating left ventricular performance in patients with prior myocardial infarction.
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine