N. Baubion

Treatment of severe mitral regurgitation caused by ischemic papillary muscle dysfunction: Indications for coronary angioplasty

The aim of this study was to evaluate the prognosis and functional outcome of mitral regurgitation caused by ischemic papillary muscle dysfunction with respect to treatment, and to determine the role of coronary angioplasty in this context. Thirty patients with severe ischemic mitral regurgitation were followed up for 33 +/- 3 months. Thirteen patients were treated medically (group I) and 17 patients underwent surgery or angioplasty (group II). The 3-year survival was 59.5% (45.6% in group I and 70.2% in group II). Angioplasty was only used in paroxysmal mitral regurgitation caused by papillary muscle ischemia. This technique resulted in spectacular immediate results in three patients with pulmonary edema caused by mitral regurgitation during myocardial ischemia. Surgical correction of mitral regurgitation should be considered without delay if angioplasty is not feasible or if the regurgitation is permanent or severe. Widening the indications of surgery or angioplasty should result in an improvement of the prognosis of these high-risk patients.

Assessment of reversible dyssynergic segments after acute myocardial infarction : Dobutamine echocardiography versus thallium-201 single photon emission computed tomography

Only a moderate degree of concordance has been reported between stress-redistribution-reinjection thallium-201 single photon emission computed tomography (SPECT) and dobutamine echocardiography for the identification of myocardial viability after acute myocardial infarction. SPECT with rest-reinjection performed 4 hours after exercise testing and digitized two-dimensional (2-D) ultrasound reconstruction of the left ventricle at baseline and after low-dose dobutamine (5 to 10 microg/kg/min) infusion were compared in 50 patients > or = 8 days (12 +/- 7 days) after acute myocardial infarction. Five patients were excluded because of technically inadequate echocardiograms. Both SPECT and dobutamine echocardiography were assessed in a 16-segment model and interpreted in the remaining 45 patients. Digitized 2-D reconstruction of the left ventricle in each wall motion was scored from 1 (normal) to 4 (dyskinesia). Myocardial viability was identified on ultrasound wall-motion improvement of one or more grades from baseline to echocardiography performed > or = 30 days (60 +/- 41 days) after systematic revascularization procedure of the infarct-related artery. Reversible defect under thallium-201 SPECT and wall-motion improvement under dobutamine echocardiography were concordant in 163 (69 percent) of the 235 baseline dyssynergic segments and in 30 (67 percent) patients. Myocardial viability was identified after angioplasty (n=37) or surgery (n=8) in 29 patients and 109 segments. Positive and negative predictive values per patient in the diagnosis of myocardial viability were 86 percent and 57 percent, respectively, for stress thallium-201 SPECT with reinjection, and 100 percent and 62 percent for dobutamine echocardiography. Positive and negative predictive values per segment were 80 percent and 69 percent for the isotopic method and 91 percent and 70 percent for dobutamine echocardiography. We conclude that dobutamine echocardiography and stress thallium-201 SPECT with reinjection have similar accuracies to identify myocardial viability after acute myocardial infarction, with excellent positive but relatively low negative predictive values.