HEART SIZE AND 10-YEAR SURVIVAL AFTER UNCOMPLICATED MYOCARDIAL INFARCTION

One hundred and five men, 30 to 69 years of age, who survived myocardial infarction by at least 3 months and were free of congestive failure, hypertension, and conditions influencing heart size or survival were selected. Heart size was determined by ECG, fluoroscopy, and chest x-ray measurements of the cardiothoracic ratio, transverse cardiac diameter, and frontal cardiac area. ECG failed to reveal any cardiac enlargement. By fluoroscopy or x-ray about 35 per cent of the patients, especially the older ones, did have enlargement of slight to moderate degree. This suggests that the enlargement was due to cardiac dilatation rather than to gross hypertrophy. In comparison with the patients having normal heart size, the ECG in those with fluoroscopic enlargement did not differ in site of infarction but showed more ventricular premature beats. The patients with cardiomegaly were similar to the other patients in regard to fasting serum lipids, lipoproteins and uric acid, fasting blood sugars, socioeconomic class, physical activity, diet, and use of alcohol and tobacco. Survival of patients with cardiomegaly was consistently and significantly lower than those with normal heart size: at 5 years, 43 versus 78 per cent (p < 0.001); at 10 years, 29 versus 50 per cent (p < 0.005). Fluoroscopy gave a better indication of prognosis than did the x-ray measurements. In conclusion, modest cardiac enlargement is demonstrated by fluoroscopy and x-ray, but not by ECG, in one third of patients with uncomplicated myocardial infarction and it adversely influences long-term survival. © 1969.