Hallermann, Franz J.

In each of 12 mongrel dogs, data for end-diastolic volume, end-systolic volume, and stroke volume of the left ventricle were obtained by two independent methods: the indicator dilution method and a radiographic method. While the values for stroke volume showed good agreement between the two methods, a significant and directionally constant difference was found between values for end-diastolic volume and end-systolic volume calculated by the two different methods. This was observed in dogs with fast heart rates (exceeding 150 beats/min), as well as in dogs with heart rates of about 100 beats/min. The findings strongly suggest that a fundamental error is present in estimations of volume based on the washout of an indicator dye.

Left ventricular hemodynamics at rest and during supine exercise were studied before and 1 year after internal mammary artery implantation in 24 patients with severe coronary artery disease and angina pectoris and in five similar patients before and after 1 year of medical treatment. In the surgical group, 14 had evidence of one or more implants providing collaterals to coronary arteries, and 10 had no evidence of collaterals from the implant. Only two patients, both with functioning implants, showed a return to normal of left ventricular end-diastolic pressure at rest and during exercise. There was no correlation between clinical improvement and hemodynamics at the time of the postoperative study. It is concluded that left ventricular hemodynamics may return to normal after internal mammary artery implantation but this was uncommon in the present study.

Simultaneously recorded standard electrocardiograms (ECG) and Frank vectorcardiograms (VCG) were correlated with the coronary arteriograms and the left ventriculograms of 210 patients. Quantitative criteria were applied to ECG measurements made by manual technics and to VCG measurements obtained by computer technics. As the extent of significant arteriographic disease increased, the frequency of ECG and VCG evidence of "definite" myocardial infarction (MI) increased. The VCG was diagnostic of MI in a greater number of patients than the ECG (50 versus 39, P < 0.01) and excelled in the detection of multiple areas of infarction in a greater number of patients (13 versus six, P < 0.05). This increased sensitivity was gained in anterior, inferior, and true posterior infarcts. Excluding patients with myocardiopathy, all MIs diagnosed from the VCG and all but one from the ECG were associated with significant arteriographic disease in the distribution of the predicted nutrient artery. Quantitative VCG analysis appears superior to the usual ECG analysis in the accurate detection of MI. When MI is diagnosed by either technic, significant associated coronary artery disease can be anticipated in a predictable anatomic distribution.

Left ventricular (LV) performance was studied during mild exercise (100 kg-m/min for 3 minutes) in 19 cases of coronary artery disease (CAD). Each patient suffered from a severe anginal syndrome. None had ventricular aneurysm, cardiomegaly, or clinical heart failure. Mean resting values follow: LV end-diastolic pressure (LVEDP), 19 ± 7 mm Hg; LV systolic pressure (LVSP), 150 ± 16 mm Hg; stroke volume index (SVI), 48 ± 10 ml/beat/m 2 ; and LV stroke work index (LVSWI), 81 ± 19 g-m/m 2 . During exercise LVEDP rose to 30 ± 8 mm Hg ( P ≤0.001) and LVS to 160 ± 20 (not significant [NS]); SVI diminished to 46 ± 11 (NS) and LVSWI, to 76 ± 24 (NS). Patients with decreased or asynchronous areas of LV myocardium identified on cine left ventriculograms had higher mean LVEDPs during exercise than did those with normal ventriculograms (34 ± 10 versus 26 ± 4 mm Hg; P ≤0.05). The difference between responses to exercise of patients who experienced angina during the study and of those who did not was NS. Administration of nitroglycerin reduced the increase in LVEDP during exercise. An abnormality in LV performance-a significant rise in LVEDP without a significant increase in SVI or LVSWI-was observed in 13 of 19 cases of CAD.