[Heart size and left ventricular function in coronary artery disease. II. Heart volume, coronary morphology and laevocardiogram (author's transl)].

We have investigated the possible relationship between the radiogically determined cardiac volume and the coronary angiogram and laevocardiogram. There was no relationship between cardiac size and coronary angiogram. Independently from the number of coronary vessels involved, we found normal sized hearts in patients without ECG-evidence of myocardial infarction, and enlarged hearts in patients with ECG-evidence of myocardial infarction. There was a significant, though loose relationship between the cardiac volume and the endsystolic and enddiastolic volumes (r=0.73 and 0.55 respectively) and the ejection fraction (r=0.69) as determined by laevocardiography. The critical value of the cardiac size, about which one encounters an increased number of abnormal volume parameters, was the upper boundary of 1-SD. Using this value we found a specifity of 81% and a sensitivity of 74% for the heart volume as a predictor of a pathological ejection fraction. On the other hand, using the upper boundary of 2-SD as a critical value, there was a sensitivity of only 58%, but a specificity of 92%. Only 11% of the patients with a cardiac size in the lower range of normal or below had an ejection fraction below 50%. Therefore the radiologically determined heart size is a simple, in daily practive acceptable method to assess and follow up left ventricular function in coronary patients.