Echocardiographic correlates of left ventricular outflow obstruction and systolic anterior motion following mitral valve repair.

BACKGROUND AND AIM OF THE STUDY: Systolic anterior motion (SAM) of the mitral valve resulting in left ventricular outflow obstruction is a well-recognized complication of repair of the degenerative myxomatous mitral valve. A precise mechanism is unknown. A current approach consists of sliding annuloplasty of the posterior leaflet. It was postulated that excess tissue of the anterior mitral leaflet (AML) was as equally (or more) important as the excess posterior mitral leaflet (PML) tissue in the development of SAM subsequent to valve repair. METHODS: Thirty-two patients without post-repair SAM (No-SAM group) were compared with eight patients with SAM (SAM group). The AML and PML heights and the mitral annulus diameter were measured by TEE using mid-esophageal four-chamber and long-axis planes. RESULTS: Pre-repair TEE showed the AML height to be greater in the SAM group (p = 0.04), and that of the posterior leaflet tended to be greater (p = 0.08), whilst the annular dimensions were similar in both groups. In the post-repair status, the AML height was markedly greater (p = 0.005) and the annulus markedly smaller (p = 0.001) in the SAM group. Post-repair assessment showed the relative difference between AML height and annular dimension (AML - Ann) as well as the difference between combined leaflet heights and annular dimension (AML + PML - Ann) to be strikingly greater in the SAM group as compared with the No-SAM group (p = 0.001). CONCLUSION: A disparity between dimension of the annulus following mitral valve repair and combined heights of the two leaflets explains post-repair SAM. The AML height is a more important factor in the development of SAM. Thus, surgical techniques to reduce AML heights should be considered in patients with disproportionately large anterior leaflets in order to prevent SAM. Selection of size of the annuloplasty ring should take into consideration the height of the AML.

The 'Pomeroy procedure': a new method to correct post-mitral valve repair systolic anterior motion.

Systolic anterior motion (SAM), a recognized complication of mitral valve repair, is often associated with left ventricular outflow gradient and mitral regurgitation. Current surgery to prevent these conditions is to perform sliding annuloplasty to reduce the posterior mitral leaflet (PML) height and to oversize the annuloplasty ring. However, these techniques do not consistently eliminate post-repair SAM, and removal of excess tissue and reduction of anterior mitral leaflet (AML) height may be more effective; this is the 'Pomeroy procedure'. Here, we report a patient in whom all standard procedures to prevent SAM were performed, but the condition still developed. This was corrected on a second pump run, using the Pomeroy procedure.

Multiplane transesophageal echocardiography: a roadmap for mitral valve repair.

Multiplane transesophageal echocardiography (TEE) is useful in providing a detailed anatomic map for successful mitral valve repair. This report describes an approach, developed over the past two to three years, which helps to delineate valve anatomy in specific detail. Mid-esophageal views are selected to view different segments of the valve leaflets. When correlated with surgical anatomy, this approach is found to be both practical and useful.

Temporary extracorporeal support of the right ventricle.

Six patients having severe right ventricular failure after cardiac surgical procedures were treated temporarily with an extracorporeal pump to bypass the right ventricle. The initial operative procedures included coronary artery bypass procedures with and without concomitant valvular and aortic replacement. A Biomedicus centrifugal pump was used as the right ventricular assist device in most cases. The assist period ranged from 3 to 96 hours, and an intra-aortic balloon pump was used in five of the six patients. All patients initially responded to the right ventricular assist device, four were successfully weaned, and one patient is a long-term survivor. The use of a right ventricular assist device is not difficult or complicated and can be lifesaving for those patients having potentially reversible profound right ventricular failure.

Distant heart procurement for human transplantation. Ultrastructural studies.

The paucity of donor hearts for human transplantation can be remedied by distant heart procurement. In the present study, 12 donor hearts obtained at distant locatins were preserved by infusion with 500 ml of cardioplegic solution at 4 degrees C at 150 mm Hg and immersion in 4 degrees C saline for rapid transmural cooling. They were transported in ice-cold saline. Maximal ischemic times were 110-182 minutes. Septal biopsies before coronary reperfusion showed normal mitochondria (11 and 12), normal nuclei (seven of 12), myofibrillar I-bands (six of 12), and capillary endothelial swelling (12 of 12). Septal biopsies 30 minutes after reperfusion showed mitochondrial swelling (six of 10), nuclear damage (10 of 10), myofibrillar contraction (10 of 10), and endothelial swelling (eight of 10). All grafts functioned satisfactorily. Eight of the 12 patients were alive 6-15 months later; four patients died (one of pulmonary hypertension and three of infection). We concluded that (1) human hearts show significant ultrastructural changes after 3 hours of ischemia, but (2) these worsen after reperfusion, and (3) distant heart procurement is feasible for human transplantation.

Hepatitis risk in cardiac surgery patients receiving factor IX concentrates.

Experience with the clinical use and hepatitis risks of factor IX concentrate (Proplex) in cardiac surgical patients is presented in this report. Seventy-five patients received the concentrate for severe intraoperative or postoperative hemorrhage and 75 patients constituted matched controls. The incidence of probable type B viral hepatitis in patients receiving factor IX concentrate was 13.8 percent (four of 29) versus zero percent (zero of 29) in control patients (difference not significant). However, there was a greater incidence (p less than 0.05) of anti-HBs in patients receiving factor IX concentrate as compared to control subjects. No hepatitis-associated deaths or major morbidity were noted in these patients. It is confirmed that factor IX concentrate carries an associated significant risk of hepatitis. However, its use is justified in certain severe, acquired coagulopathies in which conventional platelet and fresh-frozen plasma therapy is inadequate.

Distant heart procurement for transplantation.

Between January 1, 1977, and September 15, 1978, 39 cardiac transplants were performed on 38 patients. Twenty donor hearts were removed at Stanford University Hospital, and 19 donor hearts were removed at distant hospitals. The characteristics of recipients and donors in both groups were similar. The only significant difference between donor hearts was the mean ischemia time (154 +/- 30 minutes in distant hearts and 52 +/- 12 minutes in local hearts, P less than 0.001). As of February 1, 1979, the total mortality rate was 32% for the distant heart donors and 40% for the local heart donors. No difference between the two groups was present in immediate myocardial function, the need for postoperative inotropic support, the mortality rate within the first 90 days after operation, the mean maximum serum enzyme levels, the occurrence of rejection or infection, and the histological appearance of the hearts, both early and late. The results of cardiac transplantation when hearts are removed at distant hospitals are entirely comparable to the results with hearts removed on site with a minimum ishchemic time. Distant heart procurement provides an expanded donor pool for potential cardiac recipients.

Diagnosis and treatment of acute cardiac allograft rejection.

Integration of data derived from immunologic monitoring techniques and endomyocardial biopsy currently permits more precise administration of immunosuppressive medications for the treatment of acute cardiac allograft rejection than was formerly possible, resulting in a substantially improved outlook for long-term survival. Indeed, the probability of survival for 5 years postoperatively of 50% exceeds that for several categories of cardiac patients currently undergoing other more common forms of heart surgery. The continuing demonstration of the potential for cardiac transplantation clearly warrants further application of this procedure for the treatment of appropriate patients with end-stage cardiac disease.