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To investigate the mechanism and time of onset of ventricular dysfunction after mitral valve replacement, 18 patients with pure, severe mitral regurgitation (of whom 10 underwent mitral valve repair and 8 standard mitral valve replacement with papillary muscle excision) were studied by intraoperative two-dimensional echocardiography immediately before and immediately after the operative procedure. No patient sustained a perioperative myocardial infarction or had any residual mitral regurgitation. Although preoperative hemodynamics were similar, postoperatively the patients with valve repair had a lower pulmonary capillary wedge pressure than did the patients with valve replacement (8.6 +/- 1.9 versus 14.4 +/- 7.5 mm Hg, p less than 0.04). Although intraoperative echocardiographic ejection fraction fell significantly after mitral valve replacement (0.64 +/- 0.11 to 0.40 +/- 0.09, p less than 0.0001), it was maintained after valve repair (0.44 +/- 0.20 to 0.49 +/- 0.16, p = NS). Additionally, regional myocardial contractile abnormalities in the anterior and posterior septum were detected immediately after the procedure by intraoperative echocardiography in the patients with valve replacement, but not in those with repair. These postoperative regional contractile abnormalities after papillary muscle resection have not been described previously. Resection of the papillary muscles may disrupt the muscle bundle alignment and induce contractile abnormalities remote from the excised muscle. This study demonstrated that significant global and regional ventricular dysfunction develops immediately after removal of the papillary muscles, whereas myocardial contractility is preserved in patients undergoing mitral valve repair. Therefore, with intraoperative echocardiography to assure minimal residual regurgitation, surgeons should attempt to preserve ventricular function by performing mitral valve reconstruction in patients with mitral regurgitation.

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Systolic anterior motion (SAM) of the mitral valve, once considered to be pathognomonic of hypertrophic cardiomyopathy, has been reported in the absence of asymmetric septal hypertrophy. Of the 1,000 open heart operations performed with intraoperative two-dimensional epicardial echocardiography monitoring, four patients developed intraoperative dynamic left ventricular outflow obstruction associated with systolic anterior motion of the mitral valve that was not present preoperatively: three cases of mitral valve annuloplasty with Carpentier ring insertion and one of coronary artery bypass grafting. Though no patient had asymmetric septal hypertrophy or echocardiographic evidence of outflow obstruction by either preoperative cardiac catheterization or echocardiography, intraoperative two-dimensional epicardial echocardiography revealed SAM, and hyperdynamic left ventricles with three of these patients having documented left ventricular outflow tract gradients causing hemodynamic compromise. (Case 4 was hemodynamically stable following mitral valve repair, but had SAM and significant residual mitral regurgitation [MR] requiring reinstitution of cardiopulmonary bypass and re-repair). Measurement of mitral annular dimension demonstrated a normal decrease in size from diastole to systole in control operative subjects but not in the patients who developed outflow obstruction. The pathophysiology, treatment, and role of intraoperative echocardiography of dynamic left ventricular outflow tract obstruction are discussed.

Ascending (type I) aortic dissection carries a high morbidity and mortality. Proper identification of the proximal origin of the dissection and determination of concomitant aortic valve involvement significantly facilitate surgical repair, which may improve survival. In this case, intraoperative two-dimensional echocardiography with contrast injections was used to image the heart and great vessels before and after cardiopulmonary bypass. The proximal origin of the intimal flap of a type I dissection was identified, and primary aortic valve disease was excluded. Postprocedure intraoperative echocardiography demonstrated that the site of repair was imaged and that aortic regurgitation was absent. Intraoperative contrast two-dimensional echocardiography may be a valuable new tool to provide information otherwise unavailable by routine techniques.

Comparison of phenotyping (PT) and genotyping (GT) of lymphoid neoplasms was performed on 51 specimens including lymph nodes, bone marrows, and body fluids. PT was performed with a flow cytometer using a large monoclonal antibody panel. GT included the testing for gene rearrangements of heavy chain, kappa and lambda light chains, and T-cell receptor beta-chain genes with DNA probes. The results obtained from these two techniques were generally compatible in terms of clonality and cell lineage. Only one case of B-cell lymphoma was not diagnosed by PT but showed gene rearrangement. For T-cell lymphoma, GT offers a more definitive diagnosis than does PT. Biclonality was demonstrated in one case of hairy cell leukemia by GT only. The rearranged band also offers a definitive clonal identification based on electrophoretic mobility. GT can detect a monoclonal population as small as 5% and can be performed on old or fresh specimens. PT requires 20% abnormal cells and a fresh specimen. It is concluded that GT is superior to PT for lymphoid tumor diagnosis, but it should be reserved as a supplementary test at this stage because of its technical complexity.

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