[Cardiac myxoma in 13 patients]. / Myxoma cordis bij 13 patiënten.

OBJECTIVE: To gain insight into the occurrence, the manifestation and the treatment of cardiac myxoma. DESIGN: Retrospective. SETTING: The departments of Cardiology and Cardiac Surgery of Middelheim General Hospital, Antwerp, Belgium. PATIENTS AND RESULTS: Thirteen patients in the period 1985-1995 were subjected to surgical resection of a cardiac myxoma. In accordance with earlier studies, most patients were middle-aged and female. The site of predilection was the left atrium. Cardiac auscultation suggested mitral valve stenosis and insufficiency in three and five patients, respectively; in only one case was the specific 'tumour plop' heard. Cardiac symptoms were atypical thoracic pain (4 times), syncopes (3) and effort dyspnoea (7). Although embolism is described in the literature in 20-70% of the cases, it occurred in only three patients of this group. General symptoms were observed in only seven patients, as against 90% in earlier studies: they were elevated sedimentation rate in five (one also polycythaemia and leucocytosis) and abnormal fatigue in two (one also anorexia) patients. In all 13, the diagnosis of 'intracardiac mass' was made on the basis of ultrasonography. In six of 11 patients who subsequently underwent coronary roentgenography, neovascularization was visualized. All 13 tumours were resected successfully, after which in ten cases a dacron patch was implanted at the level of the interatrial septum. In addition, two patients underwent coronary bypass surgery. Postoperatively, atrial flutter (two patients), atrial fibrillation (one) and fatal cerebral bleeding (one) were observed. The other patients suffered no recurrences. CONCLUSION: Cardiac myxoma is a rare tumour which in general can be accurately diagnosed on the basis of ultrasonography and which almost always can be cured by surgical excision.

Foam cell replication and smooth muscle cell apoptosis in human saphenous vein grafts.

Occlusion of saphenous vein grafts is a major problem after coronary artery bypass grafting. Segments of occluded and suboccluded implanted aortocoronary grafts were obtained during re-intervention bypass grafting in 47 patients yielding a total of 80 vein grafts. The grafts were studied by immunohistochemistry for smooth muscle cells (alpha-SMC actin), macrophages (HAM56), cell replication (PCNA, Ki-67) and transmission and scanning electronmicroscopy (TEM, SEM). In 81% of the examined grafts the (sub)occlusion was due to a myo-intimal thickening and an associated luminal accumulation of foam cells and mural thrombi. The foam cells were constantly found at the luminal site of the myo-intimal thickening and within the luminal part of adherent thrombi. Transmission electronmicroscopy demonstrated phagocytosis of platelets and platelet fragments by the foam cells. A significant fraction of the foam cells demonstrated nuclear immunoreactivity for Ki-67 and PCNA. The myo-intimal thickening of the vein grafts was composed of smooth muscle cells lying in a fibrous tissue matrix. The smooth muscle cells were surrounded by prominent basal lamina and showed ultrastructural features of apoptosis. Our results support the hypothesis that phagocytosis of lipid rich platelets by monocytes set up a mechanism for foam cell formation and replication in human saphenous vein grafts. The transformation of a smooth muscle cell rich myointimal thickening towards a fibrous, cell poor intimal thickening could be induced by progressive smooth muscle cell loss through apoptosis.

Influence of the breathing mode on the time course and amplitude of the cyclic inter-atrial pressure reversal in postoperative coronary bypass surgery patients.

The haemodynamic basis for paradoxical embolization in patients with stroke and decompression sickness has not yet been fully elucidated. Therefore right and left atrial pressures were measured simultaneously with peroperatively placed catheters after coronary artery bypass grafting in 17 patients with sinus rhythm and normal left ventricular function. Recordings were made both during spontaneous breathing and positive pressure ventilation. A cyclic pressure reversal in which right atrial pressure exceeded left atrial pressure was reproducibly recorded. It started on average 215 +/- 5 ms (mean +/- SEM) after the onset of the electrocardiographic P-wave, lasted on average 179 +/- 14 ms and had a maximal amplitude of on average 4.1 +/- 0.3 mmHg. During the expiration phase of spontaneous breathing and inspiration phase of positive pressure ventilation, the onset of the pressure reversal occurred later, its duration was shorter and its amplitude smaller. These observations demonstrate the presence of a cyclic inter-atrial pressure reversal and illustrate the importance of the breathing mode for the time course and amplitude of this reversal.

The modulation of smooth muscle cell phenotype is an early event in human aorto-coronary saphenous vein grafts.

The morphological changes in human vein grafts occurring in the first days after a coronary bypass operation (CBP) are rarely reported in the literature. Sections of aorto-coronary vein grafts from 11 patients who died during the first 10 days after a CBP were obtained at autopsy. The number of vein grafts per patient ranged from 1 to 4, yielding a total of 28 vein grafts. The early changes in the vein grafts have been studied by light microscopy, immunohistochemistry, transmission and scanning electron microscopy. The study demonstrates that soon after grafting, the vein wall is infiltrated by polymorphonuclear leucocytes (PMN). At 24 h the endothelium shows extensive desquamation. The massive migration of PMN through the venous wall occurs simultaneously with the endothelial damage. The circular layer of the media is severely damaged, resulting in a loss of smooth muscle cells (SMC). The remaining SMC in this layer show a change toward the synthetic phenotype and a reduced expression of alpha-smooth muscle actin. These early changes in the SMC function may initiate the process of fibrosis in the intima and the media of the vein grafts.

Fusarium endocarditis involving aortic valve following coronary artery surgery.

This article describes a case of infective aortic valve endocarditis due to Fusarium oxysporum occurring 4 years after coronary artery bypass grafting. It is the first reported case of endocarditis caused by Fusarium.

Myxoma with a left-to-left shunt and fistula.

We present the case of a 68-year-old man with a peculiar coincidence of cardiac pathologic findings: a huge left atrial myxoma, mitral insufficiency, a high degree atrioventricular block and three-vessel disease. The myxoma was vascularized from a dilated sinus arteriosus branch, giving rise to neovascularization at the base of the tumor. Blood from the neovascularization gathered into a large cavern which fistulated into the left atrium, responsible for a left-to-left cardiac shunt.

Acute traumatic disruption of the thoracic aorta.

Rapid diagnosis of traumatic aortic rupture is life saving. Initial findings are often misleading and multiple organ injuries add to the diagnostic complexity. Increasing awareness of the diagnosis and rapid performing of aortography together with improved surgical techniques will improve the outcome of these patients.