[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.

[Heart size and left ventricular function in coronary artery disease: I. Heart size, exercise tolerance, cardiac output and filling pressures (author's transl)]

The possible relationship between the cardiac volume, as determined radiologically in the supine position in 119 patients with angiographically proven coronary artery disease, and the results of ergometry and balloon catheterization was investigated. There was no relationship between the heart size on the one side and the maximum exercise tolerance and the maximum cardiac output on the other, except for the fact, that these parameters tended to decrease with increasing heart size. This was especially true in patients with angina. The maximum cardiac output of patients with angina was always below the value of patients without angina but comparable heart size. Reduced cardiac output under exercise (exertional cardiac insufficiency) was present in 50% of patients with enlarged hearts but already in 22% of patients with heart volumes in the lower range of normal. The diastolic pulmonary artery pressure, determined under exercise, was the only parameter with a significant relationship to the heart size: The larger the heart size, the higher the diastolic pulmonary artery pressure. On the other hand: the diastolic pulmonary artery pressure at rest was abnormal with significant frequency only, when the heart was enlarged. Our data suggest, that the hemodynamics are determined by 2 factors: Myocardial scarring secondary to infarction and coronary insufficiency (ischemia). Of these two factors only the former influences cardiac size. Therefore, determination of the heart volume helps evaluating the respective role of these two factors in individual cases.

[The importance of heterologous implants in cardiovascular surgery (author's transl)]

The importance of heterologous transplants in the substitution of heart valves in cardiac surgery and the substitution or bypassing of displaced arteries of the thigh in vascular surgery is discussed with reference to some results and developmental considerations. In addition to the alloplastic valve material, heterologous bioprosthesis from glutaraldehyde-fixed pig's valves has proved useful to an increasing extent for the substitution of diseased and functionally impaired heart valves. The results of followup examinations show equally favorable results in comparison with the alloplastic prosthesis. In vascular surgery, the calf collagen prosthesis has proved a real alternative to the alloplastic Dacron prosthesis at the level of the thigh.

Myocardial oxygen consumption and substrate uptake in man during physiological and pathological volume load

It is shown in trained and untrained healthy individuals that the energy requirement of the physiologically hypertrophied heart is lower at rest and even more pronounced during submaximal heavy exercise compared to the non-hypertrophied state. This difference exceeds the changes which could have been anticipated by deviations in hemodynamics and total heart weight. In patients with mild or moderate aortic insufficiency the energy expenditure of the pathologically hypertrophied heart per unit tissue mass is comparable to the non-hypertrophied state at rest or during exercise. It is increased in severe aortic regurgitation or additional myocarditis. The transition from compensation to failure may be associated with a steep decreased of the metabolic and flow reserve of the whole heart.

Studies on the regulation of myocardial blood flow in man. I.: Training effects on blood flow and metabolism of the healthy heart at rest and during standardized heavy exercise

In a comparative study 11 athletes and 11 untrained students were investigated at rest, of these 6 trained and 5 untrained individuals during exercise as well. Myocardial blood flow was measured by the argon method. Myocardial oxygen consumption, myocardial substrate uptake of glucose, lactate, and free fatty acids and cardiac output were determined by the direct Fick principle. Exercise was standardized according to 65% of an individual's maximal oxygen uptake (delta VO2 max). Coronary flow reserve was determined by dipyridamole injections. All measurements were made during hemodynamic and respiratory steady-state conditions with the subject in a supine position. At rest, myocardial blood flow and myocardial oxygen consumption were significantly lower in trained subjects compared to the untrained ones. These differences were more pronounced during heavy exercise. They cannot be explained completely by hemodynamic parameters. - During exercise, myocardial substrate uptake shifted to a predominant lactate uptake of almost 90% of total substrate uptake. Total substrate uptake as well as lactate uptake correlated significantly with myocardial oxygen. - Coronary flow reserve was lower in the trained group. It is concluded that the heart muscle of a trained individual requires less energy at a given work load than in the untrained state.

[Substitution of the aortic value in florid bacterial endocarditis and severe aortic valvular insufficiency (author's transl)]

Urgent operation for replacement of the aortic valve for the correction of a severe, increasing hemodynamic impairment of the output of the heart and for the removal of the septic focus in florid bacterial aortic endocarditis must be carefully thought over. 3 of our own 7 patients died. The indication is to be made largely on hemodynamic grounds when the clinical symptoms are quite clear without preoperative catheter diagnosis. Preliminary specific treatment with antibiotics and intensive follow-up treatment is necessary. Preoperative identification of bacteria in the blood, just like identification of bacteria on the excised valve, is only possible in some of the cases.

[Clinical and hemodynamic aspects of myocardial diseases (author's transl)]

Definition, arrangement into primary and secondary forms and classification of myocardial diseases are used irregularly in the literature. The great variety of clinical and hemodynamic parameters are shown with reference to our own patients and an attempt is made to arrange them in individual types. Followup examinations show that signs of congestive failure, heart size and other clinical and hemodynamic parameters may be considerably altered. For this reason it is proposed to describe myocardial diseases accoridng to clinical and hemodynamic parameters in order to obtain a closer insight into the pathomechanism of these diseases.