Clinical, Hemodynamic and Angiographic Aspects of Inferior and Anterior Myocardial Infarctions in Patients with Angina Pectoris

Abstract Clinical, hemodynamic and angiographic findings were reviewed in 82 patients with isolated inferior, 55 patients with isolated anterior and 27 with combined inferior and anterior myocardial infarction and were compared with findings in 100 patients without electrocardiographic evidence of a prior transmural myocardial infarction. All of the 264 patients were referred and evaluated because of angina pectoris and found, on selective coronary angiography, to have coronary artery disease. There was no significant difference in the ages of the patients in each group studied. A history of heart failure, audible gallops and cardiomegaly were more prevalent in the two groups with anterior infarction (isolated and combined with inferior infarction) than in the other two groups. The mean left ventricular hemodynamic measurements (end-diastolic pressure, end-diastolic volume and ejection fraction) in the groups of patients with a normal QRS or an isolated inferior myocardial infarction were not significantly different from those of patients with a normal left ventricle. Patients with isolated anterior myocardia infarction had abnormal end-diastolic pressure (68 percent), end-diastolic volume (51 percent) and ejection fraction (67 percent). Similarly, the group with multiple infarctions had abnormal hemodynamic measurements, with 81 percent having an abnormal ejection fraction. For the entire group of patients studied, an abnormal end-diastolic volume was always associated with an abnormal ejection fraction. Cardiomegaly on X-ray film was associated with an abnormal end-diastolic volume and ejection fraction. An abnormal contractile pattern (asynergy) was noted in 42 percent of the patients with a normal QRS; inferior asynergy was observed in 88 percent with inferior infarction, and anterior or apical asynergy, or both, was found in 90 percent with anterior infarction. All the patients with multiple infarctions had asynergy. The right coronary artery was significantly involved in 90 percent of the patients with inferior infarction, while all the patients with anterio infarction had significant disease of the left anterior descending artery. More than 80 percent of the patients with an infarction pattern on electrocardiogram had double or triple vessel disease, as compared with 68 percent of the patients with a normal QRS pattern. This study represents a select group of patients referred because of angina pectoris and cannot be extended to the asymptomatic patient with coronary artery disease. The observations made on these patients indicate that an anterior infarction (isolated or combined with inferior) in patients referred because of angina pectoris is accompanied by significant impairment of left ventricular function, whereas an inferior infarction (isolated), although accompanied by asynergy, is usually associated with normal hemodynamics. The electrocardiogram is not sensitive enough to predict reliably in the individual patient the extent and severity of the coronary artery disease.