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Most cardiac tumors are benign, whereas up to 50 % of the diagnosed cases are histologically myxomas. The common clinical signs are rhythm disturbances, myocardial ischemia, pulmonary edema, syncope and cardiac arrest. They do normally lead to the diagnostic hypothesis of an intracardiac mass. The primary modality for imaging is echocardiography which usually confirms the suspected diagnosis. But in rare cases there are masses which cannot be exactly identified by this technique. Here we present a patient with an atypical echocardiography of an unusual intracardiac tumor.

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From 10 cultures of manipulated Escherichia coli bacteria expressing the class I heparin-binding growth factor polypeptide alpha-endothelial cell growth factor, 11.2 +/- 0.7 mg alpha-endothelial cell growth factor was eluted by heparin-sepharose affinity chromatography. Analysis of molecular weight (17,000 kD) was done by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and purification of the growth factor was done by high-performance liquid chromatography. The harvested alpha-endothelial cell growth factor was proved by protein blotting. To assess the growth-promoting activity, we did an endothelial cell growth assay by comparing adult human endothelial cell control cultures, without adding growth factor to the culture medium, with adult human endothelial cell cultures with 0.02 to 20.0 ng/ml alpha-endothelial cell growth factor and 1.0 ng/ml heparin and with adult human endothelial cell cultures with alpha-endothelial cell growth factor but without heparin. Tritiated thymidine counts proved the significant growth-promoting activity of alpha-endothelial cell growth factor. In 10 experimental animals modified fibrin glue containing 1 microgram alpha-endothelial cell growth factor was implanted between the aorta and the myocardium of the left ventricle and results were compared with those in five control animals that received normal fibrin glue without growth factor. After 9 weeks of implantation, angiography and histologic investigation showed newly grown vascular structures between the aorta and the myocardium in all experimental animals, but none in the control animals. Our study proved the feasibility of initiating site-directed formation of new blood vessel structures to the heart by a modified fibrin glue implant containing angiogenic growth factor alpha-endothelial cell growth factor.

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The efficacy of the human angiogenetic heparin-binding growth factor I (HBGF-I) to initiate site-directed growth of new blood vessels from the aorta into the myocardium was studied. First, manipulated Escherichia coli bacteria, which had received the human mRNA-transcript for HBGF I into their genetic material, were cultivated. The growth factor derived was purified using heparin-Sepharose affinity chromatography. The separation and characterization of biologically active alpha- and beta-chains was carried out using high pressure liquid chromatography (HPLC) of dialyzed and lyophilized samples from the heparin-Sepharose column. One microgram HBGF I (alpha-ECGF) was bound to polytetrafluoroethylene (PTFE) sponges, precoated with collagen type I, and implanted between the aorta and the myocardium of the left ventricle in experimental rats. Twelve growth factor implants in the experimental group were compared to six controls receiving uncoated PTFE sponges for 9 weeks. Digitized computed angiography showed new blood vessels between the aorta and the myocardium in 11 of the 12 experimental animals, and retrograde coronary perfusion by these "new" vascular structures could be seen. Histology showed no specific structures in the control group (without HBGF I). In the experimental group (with HBGF I) individual vessels with highly differentiated endothelial and smooth muscle cell layers were evident. Our experiments proved the feasibility of induced, site-directed angiogenesis. It is possible to initiate in vivo growth of new "coronary" vascular structures between the aorta and the myocardium.

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The incidence of perioperative complications after coronary artery surgery was investigated by a retrospective study of all 502 patients undergoing coronary artery bypass graft (CABG) surgery in our Department between January 1st and December 31st of last year (1990). Furthermore, the influence of obesity on the early results of surgery was assessed and the effect of preoperative weight reduction on perioperative complication rates examined. Obese patients had a greater incidence of left-stem coronary artery stenosis (p less than 0.001), hyperlipidaemia (p less than 0.05), hypertension (p less than 0.05), diabetes mellitus (p less than 0.02), and were in general younger at the time of operation (57.9 +/- 8.4 vs. 60.8 +/- 8.5 years). There were no differences in the surgery performed and in operative mortality, but there were some in perioperative morbidity. Obese patients had higher rates of infection (p less than 0.02), sternal dehiscence (p less than 0.02), arrhythmias (p less than 0.02) and myocardial infarction (p less than 0.02). No significant differences were identified in obese patients with or without preoperative weight reduction, although there was a trend of better postoperative recovery and results in patients having undergone preoperative weight reduction. Analysis of our results demonstrated obesity to be an independent risk factor for perioperative complications, hospital morbidity, and length of hospitalization.

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This study reports our results with vitro endothelialization of fresh nonpreserved homograft valve leaflets compared with mild alternatively preserved valves and valves treated by preservation procedures commonly used for commercially available tissue valves. In vitro lining of biological heart valves with cultured autologous endothelial cells might help prevent the detrimental effects of degeneration on valve durability. To investigate the growth characteristics of endothelial cells on valve bioprostheses, three different methods of storage and preservation were compared. After precoating with fibronectin and seeding of 4.4 x 10(4) endothelial cells/cm2 onto the different leaflet surfaces, primary adherence, growth kinetics, morphology, and maintenance of monolayer integrity were studied over a period of 10 days. On valve leaflet surfaces of group 1 (fresh nonpreserved homograft valve leaflets) and group 2 (mild alternatively preserved valves), endothelial cells grew to persistent monolayers between days 6 and 10. In contrast, endothelial cell proliferation with monolayer growth could not be achieved on the group 3 leaflets (preserved like commercially available biological valve prostheses). In that group, no viable endothelial cells could be found on the valve surfaces 2 days after seeding. These results demonstrate the theoretical feasibility of endothelializing biological heart valve leaflets in vitro if they are not preserved and stored according to commonly used procedures. Provided such an endothelium can withstand the mechanical forces after implantation in vivo, in vitro endothelialization might contribute either to the development of new biological heart valves for modern cardiac surgery or to the improvement of clinical results with homograft valve transplants.

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