In this report clinical and angiographic data on three patients with total occlusion of the left main coronary artery is presented. Two of our cases demonstrated rich collateralization with good preservation of left ventricular (LV) function. The third case, with initial subtotal occlusion and no collaterals, sustained a severe anterolateral myocardial infarction (MI) responding to the use of the intra-aortic balloon pump (IABP). This report is consistent with the findings of others who suggest the possible beneficial effect of collaterals in preserving myocardial contractility in this unusual situation. We suggest that the IABP may be of benefit in patients with total occlusion of the left main coronary artery and sparse collaterals who remain unstable and cannot be operated on immediately.

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While the very low thrombogenicity without anticoagulant therapy and generally good durability of the lonescu-Shiley bioprosthesis has been demonstrated, further hemodynamic assessment is necessary. The present study assessed cardiac function and heterograft performance during right and left heart catheterization at rest and exercise (three to six months postoperation) of eight patients with severe mitral stenosis and/or regurgitation prior to surgery. We found, comparing pre- and postoperative resting values, that mean pulmonary artery pressure decreased (32 +/- 2.7 to 22 +/- 3.5 mm Hg; P < 0.02), cardiac index increased (2.1 +/- 0.09 to 2.5 +/- 0.13 liters/min/m2; P < 0.01), pulmonary wedge pressure decreased (21 +/- 2.3 to 13 +/- 1.8 mm Hg; P < 0.01), and the clinical status (NYHA) improved markedly. Mean diastolic gradient across the pericardial xenograft was 6.1 +/- 1.1 mm Hg at rest and 14.6 +/- 2.3 mm Hg on exercise. The calculated xenograft surface area was 1.7 cm2 at rest and 2.0 cm2 during exercise. No regurgitation was detected in seven of eight patients. Thus, mitral lonescu-Shiley bioprosthesis provide excellent heterograft function.