Echocardiographic diagnosis of left ventricular outflow tract obstruction caused by an acquired subaortic membrane after mitral valve replacement.

Although an acquired subaortic membrane has been reported as a cause of left ventricular outflow tract (LVOT) obstruction in various clinical settings, it previously has not been reported after mitral valve surgery. We describe 3 cases of acquired LVOT obstruction that resulted from development of a subaortic membrane after mitral valve replacement. This report emphasizes the role of an acquired subaortic membrane in LVOT obstruction after mitral valve replacement, the use of echocardiography in diagnosing this condition, and the importance of early intervention.

Factors influencing immediate results, complications, and short-term follow-up status after Inoue balloon mitral valvotomy: a North American multicenter study.

Clinical trials with the Inoue mitral valvotomy balloon have recently begun in the United States. We assessed the effects of 17 demographic, echocardiographic, procedural, and hemodynamic variables on the immediate results, complications, and short-term follow-up of 200 patients in 15 centers undergoing valvotomy with this device. The study population had a mean age +/- SD of 53 +/- 15 years, and the total echocardiographic score was 7.2 +/- 2.4. Valvotomy was technically successful in 96.5% of procedures and increased the mean mitral valve area from 1.0 +/- 0.3 to 1.8 +/- 0.7 cm2 (p less than 0.001); 72% had an increase in valve area greater than or equal to 50%, and 67% had a final area greater than or equal to 1.5 cm2. Major procedural complications included cardiac tamponade during transseptal puncture (1.0%), systemic embolism (1.5%), and severe mitral regurgitation (2.4%); there were no procedural deaths and one hospital death. Multivariate analysis identified the absence of prior surgical commissurotomy and younger age as significant predictors of the gain in mitral valve area, but the correlation coefficients were low. Although the absence of subvalvular disease on echocardiograms was a predictor of a final valve area greater than or equal to 1.5 cm2, the total echocardiographic score did not correlate well with the immediate outcome (r = 0.01, p = NS). No variable was identified as predictive of restenosis, which occurred according to echocardiographic criteria in 14 of 66 (21%) patients evaluated 6 months after valvotomy. Good hemodynamic results with valvotomy were achieved in the majority of patients with low complication rates by many investigators with the use of the Inoue balloon device.(ABSTRACT TRUNCATED AT 250 WORDS)

A new manifestation and treatment alternative for heparin-induced thrombosis.

We treated a coronary artery bypass patient whose postoperative course was complicated by heparin-induced thrombocytopenia and resultant pulmonary artery and saphenous vein graft thromboses. The pulmonary thromboemboli were found first, and pulmonary blood flow was restored with intravenously administered tissue plasminogen activator (tPA). A short time later, the vein grafts were found to be occluded, and we subsequently performed multivessel percutaneous transluminal coronary angioplasty (PTCA) using tPA as an adjuvant to oral warfarin sodium therapy with excellent results. We conclude that heparin-induced thromboses in the pulmonary arteries are amenable to thrombolytic therapy, including tPA, whereas this regimen appears to have little effect on saphenous vein grafts. We also found that a combination of warfarin and thrombolytic therapy is an alternative regimen for heparin-intolerant patients who require PTCA.

Collateral circulation in coronary artery disease.

The coronary arteriograms and left ventriculograms of 202 consecutive patients were reviewed. All had at least 75% diameter reduction of 1 or more major coronary arteries. In 127 patients (63%), at least 1 major branch was totally occluded. Collateral circulation was seen in 125 of these 127 patients (190 of 192 totally occluded arteries). Of the 75 patients without total occlusion, only 2 with 99% (or near-total) occlusion had demonstrable collateral circulation (2 of 208 arteries). In no patient with 75 to 98% diameter narrowing was collateral circulation demonstrated (0 of 164 arteries). An analysis was made of the relation between left ventricular (LV) segmental wall motion and the quality of collateral circulation in 190 totally occluded arteries among 125 patients. Of 126 arteries with good collateral circulation, LV contraction was normal in 21%, hypokinetic in 48% and akinetic/dyskinetic in 29%. Of 64 arteries with poor collateral circulation, LV contraction was normal in 23%, hypokinetic in 55% and akinetic/dyskinetic in 20%. There was no statistically significant difference between the effect of good or poor collateral circulation on LV function. These data indicate that collateral circulation cannot be seen angiographically unless there is total or near-total occlusion, and that the presence of collateral circulation does not correlate with LV wall motion abnormalities, i.e., akinetic area, despite good collateral flow or normal wall motion despite absent or poor collateral flow.

Intravascular microaggregation and in vitro platelet aggregation in coronary artery disease.

To investigate in vivo and in vitro microaggregation in coronary artery disease, we obtained blood samples from the coronary sinus (CS), pulmonary artery (PA), and aorta (AO) in patients undergoing cardiac catheterization. An electronic particle size analyzer was used to quantify microaggregates 13 to 81 mu in diameter in blood. In the first group of 58 patients, preformed circulating microaggregates and platelet responsiveness to ADP were assessed in AO and PA blood only. The coronary artery disease patients did not have significantly higher volumes of preformed in vivo aggregates in either AO or PA blood. However, the mean aggregate size in response to 0.2 microM ADP in vitro was larger in both AO and PA blood in patients with coronary disease [12.4 +/- 0.9 vs. 9.4 +/- 1.4 X 10(3) mu3 (AO); 12.5 +/- 0.9 vs. 8.3 +/- 0.7 0.7 X 10(3) mu3 (PA)]. In a second group of 46 patients, CS, AO and PA samples were compared using the same methods. The volume of microaggregates preformed in vivo was significantly greater in CS blood than in PA or AO blood in patients with and without coronary disease. The volume and mean size of aggregates induced by ADP in vitro were smaller in CS blood compared to PA. In conclusion, the volume of in vivo microaggregates is increased in CS blood, independent of coronary disease, but significant volumes are not found in PA or AO blood. Patients with coronary disease have more reactive platelets to in vitro aggregatory agents in AO and PA samples of similar hematocrit.

Total occlusion of the left main coronary artery: report of seven cases from 5312 cardiac catheterizations and review of the literature.

Of the 5312 cardiac catheterizations performed at the Clayton Foundation for Research Cardiovascular Laboratories from 1974 to early 1981, seven patients (0.13%) had total occlusion of the left main coronary artery. All seven had a history of myocardial infarction, and were markedly symptomatic (New York Heart Association, Classes III and IV), with anginal pain that had existed from 2 to 13 years. Left ventricular end-diastolic pressure was notably elevated in all patients, and ejection fractions ranged from 16% to 69%. In all patients, there was significant collateral circulatory flow to the left coronary system from the right coronary artery and its branches. Six underwent coronary artery bypass at our institution, and one was operated on at another hospital. The six patients operated on in our institution were markedly improved after the operation. Our results support previously reported findings about patients with total occlusion of the left main coronary artery in that (1) no definitive clinical pattern leads to simple diagnosis, (2) the anomaly is rarely encountered during cardiac catheterization, and (3) myocardial revascularization alleviates symptoms and prolongs life.