[Thallium-201 myocardial scintigraphy in patients with normal coronary arteries and normal left ventriculogram - comparison with hemodynamics, metabolic and morphologic findings (author's transl)]. / Thallium-201-Myokardszintigraphie bei Patienten mit normalen Koronararterien und normalem AVentrikulogramm - Vergeich mit hämodynamischen, metabolischen und morphologischen Befunden.

36 consecutive patients with chest pain and/or severe ventricular dysrhythmias, but normal coronary arteries and normal left ventriculogram, underwent thallium-201 myocardial imaging at rest and during exercise. The myocardial scintigram was abnormal in 27 patients (group A) and normal in only 9 patients patients (group B). To answer the question, whether the scintigram was false positive or a correct expression of a myocardial disorder not detectable with angiocardiographic methods, we compared the scintigraphic results with the findings of resting and exercise ECG (n = 36), mean pulmonary artery pressure during exercise (n = 27), myocardial lactate extraction during highrate atrial pacing (n = 14) and light- and electronmicropic examination of right ventricular endomyocardial biopsies (n = 14). The resting ECG was abnormal in 7 of 27 patients of group A and 1 of 9 patients of group B, the exercise ECG in 20 of 27 patients of group A and 1 of 9 patient B. An abnormally elevated exercise pulmonary artery pressure was measured in 10 of 21 patients of group A and 1 of 6 patients of group B. High rate atrial pacing induced an abnormal myocardial lactate extraction in 3 of 13 patients of group A, but not in the single investigated patient of group B. All 12 examined patients of group A and 1 of 2 patients of group B had abnormal biopsy findings. The high incidence of abnormal findings in group A compared to the rare incidence in group B suggests, that the abnormal myocardial scintigrams in patients with chest pain and normal coronary arteries is likely not false positive but reflects a myocardial disorder not being recognized on angiography.

[Hemodynamic effects of medical and surgical therapy of hypertrophic obstructive cardiomyopathy (author's transl)]. / Hämodynamische Auswirkungen konservativer und operativer Therapie bei hypertrophischer obstruktiver Kardiomyopathie.

In order to assess the hemodynamic effects of medical (propranolol) and surgical (transaortal subvalvular myectomy) therapy, we determined in 20 patients with hypertrophic obstructive cardiomyopathy the following circulatory parameters at rest and during maximal exercise before and after therapy: heart rate, stroke volume, cardiac output, and pulmonary artery pressure. 9 patients were re-investigated after medical therapy of 3.5 weeks to 7 months (averaging 3 months) with a daily dose of 120 to 360 mg (mean 198 +/- 80 mg) propranolol, 11 patients 1 week to 28 months (averaging 7.5 months) after operation. Propranolol induced a significant reduction of heart rate and cardiac output averaging 20.9% and 20.3%, respectively (p in both cases < 0.0001) at equal exercise levels, no change in stroke volume, and a slight increase in the pathologically elevated exercise mean pulmonary artery pressure, with the pulmonary vascular resistance remaining unchanged. Although 3 of the 9 patients reported a slight subjective improvement, exercise capacity did not change significantly from a mean of 66.7 to 69.4 watts. Myectomy, on the other hand, induced no change in heart rate, but a significant increase in exercise stroke volume by 14.9% (p < 0.025) and a distinct increase in cardiac output by an average of 11.2% (not significant), whereas the pathologically elevated exercise mean pulmonary artery pressure fell significantly by 23.8% from a mean of 45.0 to 34.3 mm Hg (p < 0.025). 10 of the 11 surgically treated patients reported a usually marked subjective improvement, and the exercise capacity increased from an average of 61.4 to 81.8 watts (p < 0.01). Thus, the clinical and functional result of surgical therapy was significantly better than that of medical therapy and included, in contrast to medical therapy, a significant hemodynamic improvement and increase in exercise capacity.

Circulating platelet aggregates and thrombocytopenia induced by intravenous infusions of arachidonic and lauric acids in guinea pigs.

Slow intravenous infusion of Na laurate (NaL) into guinea pigs caused a rapid appearance of platelet aggregates in the arterial blood and a precipitous fall in platelet counts. During the infusion of Na arachidonate (NaA) thrombocytopenia developed slowly, and few and smaller platelet aggregates appeared in the arterial blood. Considerably more guinea pigs died during or after the NaA infusion than after administration of NaL. The possibility that arachidonic acid and other long-chain fatty acids may play a role in the development of thrombosis and thromboembolism is discussed.