Clinical Evaluation in Patients with Acute Myocardial Infarction with or without Significant Coronary Artery Stenosis

BACKGROUND: It has been recognized for many years that myocardial infarction is almost invariably associated with significant narrowing of one or more coronary arteries. However, the widespread use of selective coronary angiography has resulted in an increasing number of reports of patients with proved infarction and patent coronary arteries. The purpose of this study was to analyze whether any clinical features distinguishes patients with these findings from those having coronary arterial lesions. METHODS: The clinical association of myocardial infarction with no significant stenosis of major coronary artery on cineangiogram was analysed retrospectively. The findings on the 13 patients in this group was compared with those of myocardial infartion with significant coronary artery stenosis. RESULTS: There were no significant differences in risk factors, hemodynamic findings of cardiac catheterization and the site of infarction between both groups. However, the patients with no significant stenosis of coronary artery had fewer complications during hospitalization and lesser ST segment change during exercise test before discharge. CONCLUSION: It could be concluded that the acute myocardial infarction with no significant stenosis of coronary arteries would have the better prognosis. The mechanism of the acute myocardial infarction with no significant stenosis of coronary arteries might be studied in the aspect of the coronary artery spasm and the alternation of function of endothelial cell.

Clinical and Coronary Angiographic Findings in Patients with Postinfarction Angina

To determine the incidence, clinical characteristics and coronary angiographic findings of postinfarction angina, clinical course and coronary angiogram were studied in 45 patients with acute myocardial infarction. During a mean follow-up period of 12 weeks, 17 patients(37.8%) developed angina. Of 5 patients with postinfarction angina within 1 week of infarction, 2 patients died during hospitalization, whereas all 12 patients with postinfarction angina which occured more than 1 week after acute myocardial infarction were discharge alive. The frequency of stenosis over 90% and multivessel disease by coronary angiography were 51.7% and 64.7% respectively in patients with postinfarction angina, and 25%, 28.5% respectively in patients without postinfarction angina.

Assessment of Mitral Blood Flow by Exercise Doppler Echocardiography in the Diagnosis of Coronary Artery Disease

BACKGROUND: The pattern of left ventricular filling as depicted by Doppler echocardiographic transmitrial flow velocities has been used to left ventricular diastolic properties. Especially, altered transmitral flow by abnormal myocardial wall motion and left ventricular function in ischemic heart disease, was predicted during exercise test. METHODS: To determine the effects of exercise on Doppler echocardiographic measures of left ventricular diastolic filling, we studied 15 angina pectoris patients and 20 normal control subjects. Transmitral flow measurements comprised peak and integrated early passive(E) and late atrial(A) filling velocities and diastolic filling period. RESULTS: Heart rate in negative exercise treadmill test group was 70/min at rest, 111/min just after exercise, and 86/min at 5 minutes after exercise. Positive exercise treadmill test group was 69/min, 109/min and 82/min, respectively. DFP and E duration were also significantly decreased after exercise in group with negative treadmill exercise test. In positive treadmill exercise group, peak A was significantly increased from 0.57+/-0.15m/sec to 0.75+/-0.20m/sec at just after exercise(p<0.01), 0.67+/-0.12m/sec at 5 minuties after exercise. DFP and E duration were also significantly decreased after exercise. CONCLUSION: Doppler echocardiographic transmitral flow was altered by abnormal regional wall motion and left ventricular dysfunction in ischemic heart disease during exercise test. The use of Doppler echocardiography for this purpose is limited, however, because a number of variables may influence transmitral flow patterns, including age, preload, afterload and systolic function.

Effects of Nifedipine on Left Ventricular Diastolic Function in Hypertensive Patients by Assessment with Doppler Echocardiography

It is well known that hypertension is associated with left ventricular diastolic dysfunction which frequently precede systolic dysfunction. To determine whether nifedipine could improve left ventricular diastolic function in hypertensive patients, we studied 15 hypertensive patients and 15 normotensive subjects matched for sex, age with Doppler echocardiography. After oral administration of 10mg of nifedipine, there were no significant changes in Doppler-derived transmitral diastolic filling indexes of normotensive subjects. On the other hand, although peak flow velocity in atrial systole(PFVA), time velocity integral in atrial systole(TVIA) did not change significantly after nifedipine, nifedipine significantly increased peak flow velocity in early diastole(PFVE) from 40.2+/-6.4cm/sec to 46.5+/-10.9cm/sec(p<0.005), time velocity integral in early diastole(TVIE) from 5.24+/-1.2cm to 5.97+/-1.43cm(p<0.001), the ratio of PFVE/PFVA from 0.69+/-0.11 to 0.76+/-0.12(p<0.05), the ratio of TVIE/TVIA from 1.18+/-0.21 to 1.29+/-0.24(p<0.05), deceleration slope(DS) from 244.9+/-51.9cm/sec2 to 289.9+/-49.1cm/sec2 (p<0.001) and decreased isovolumic relaxation time(IVRT) from 132.3+/-10.3msec to 117.2+/-13.5msec(p<0.001), deceleration time(DT) from 168.8+/-30.3msec to 154.9+/-29.8msec(p<0.05) in hypertensive patients. These fimdings indicated that nifedipine improves Doppler-derived early diastolic filling indexes in hypertensive patients and may be related to improvement of active relaxation of left ventricle in early diastole.