Lockhart B. McGuire

Assessment of preoperative left ventricular function in patients with mitral regurgitation: value of the end-systolic wall stress-end-systolic volume ratio.

Twenty-one patients with symptomatic, chronic, severe mitral regurgitation (MR) but without other valvular heart disease or coronary disease were evaluated to determine which hemodynamic and angiographic factors might be prognostic of surgical outcome. Sixteen patients were in New York Heart Association functional classes I or II postoperatively and formed group A. One patient remained in class III postoperatively and four patients died perioperatively; they constitute group B. End-diastolic volume index (EDVI) was less for group A than for group B, 119 ± 25 ml/m2 vs 170 ± 28 ml/m2 (p < 0.001). End-systolic volume index (ESVI) was also lower in group A, 39 ± 19 ml/m2 vs 72 ± 32 ml/m2 for group B (p < 0.01).The ratio of end-systolic wall stress to end-systolic volume index (ESWS/ESVI) was examined in normal persons and in groups A and B. This ratio was significantly lower in both groups than in normal persons, indicating relatively greater end-systolic volume at a given wall stress, suggesting left ventricular dysfunction. The ESWS/ESVI ratio in group B, 2.2 ± 0.2, was significantly less than in group A, 3.3 ± 0.4 (p < 0.001). The variables of age, pulmonary capillary wedge pressure, EDVI, ESVI, ejection fraction and the ESWS/ESVI ratio were subjected to stepwise discriminant multivariate analysis to determine if any were independent predictors of outcome. The only independent predictor determined by this method was the ESWS/ESVI ratio (p < 0.001). We conclude that the ESWS/ESVI ratio may be helpful in evaluating left ventricular function and operative risk in patients with chronic, symptomatic MR.

The management of anticoagulation during noncardiac operations in patients with prosthetic heart valves

Based on previous thromboembolic complications associated with the interruption of anticoagulation during subsequent noncardiac operations in patients with nonbiological mitral prostheses, a protocol was developed for this high risk group. We report the successful management of 26 such operations in which anticoagulation was interrupted for 12 hours and then rapidly restored by means of heparin in the postoperative period. Since an earlier study suggested no adverse effect from the interruption of chronic anticoagulants for three to five days among patients with isolated aortic valve prostheses, simple interruption was again employed during 16 subsequent noncardiac operative procedures in this group with no complications. There were three episodes of hemorrhage observed in patients receiving therapeutic doses of heparin postoperatively, but only one required blood replacement.

Living with prosthetic heart valves. Subsequent noncardiac operations and the risk of thromboembolism or hemorrhage.

A total of 111 survivors of prosthetic valve insertion were followed an average of 4 years to assess the risk of thromboembolism or hemorrhage. Non-cloth-covered ball and/or disc valve prostheses were used, and all patients received long-term anticoagulant therapy. During the follow-up period the patients with mitral or combined valve replacement suffered four times more thromboembolic episodes and had a poorer survival rate than the patients with isolated aortic valve replacement. The management of anticoagulation and the complications resulting from 44 subsequent noncardiac operations were analyzed. Anticoagulation was discontinued before 25 noncardiac operations in patients with isolated aortic valve prostheses and there were no perioperative thromboemboli. Ten operations were performed on patients with mitral or combined valve prostheses with cessation of anticoagulation prior to surgery and there were two deaths due to perioperative thromboemboli. Unanticipated hemorrhage was encountered in four of nine patients in whom anticoagulation was maintained during surgery. Cessation of anticoagulation for 3 to 5 days appears safe in patients with aortic prostheses who require subsequent noncardiac operations. The incidence of thromboembolism in patients after mitral or combined valve replacement is high and constitutes a major risk whether or not a subsequent operation is required.

THE PULMONARY BLOOD VOLUME IN MAN

The measurement of blood volume in the pulmonary vascular bed during life became theoretically feasible with the introduction of indicator dilution methods by Stewart (1) and Hamilton, Moore, Kinsman and Spurling (2). The principles and formulas set forth by these investigators have since undergone extensive scrutiny by theoretical analysis, in circulation models, and in vivo. As a result of these studies, there exists now general agreement that the introduction of an indicator substance into the central circulation, either directly or by peripheral venous injection, and downstream recording of its concentration change with time during the first transit permits the determination of three important circulatory parameters: 1) the cardiac output, 2) the mean transit time from injection to sampling site, and 3) by multiplication of cardiac output and mean transit time, the circulating volume of blood between injection and sampling sites, including all temporally equidistant points in the vascular bed. Practically speaking, then, the measurement of pulmonary blood volume in vivo requires determination of the mean transit time of an indicator from the pulmonary artery to the left atrium together with cardiac output. The development of right and left heart catheterization has made the pulmonary artery and left atrium accessible as injection and sampling sites in man. Injection of an indicator through a

COR TRIATRIATUM AS A PROBLEM OF ADULT HEART DISEASE.

The occurrence of severe pulmonary venous obstruction due to the congenital anomaly known as cor triatriatum in a 19-year-old furniture mover is described. Relentless and massive hemoptysis led to pulmonary edema, and an attempt at surgical correction under unfavorable conditions was not successful.Seven other cases of cor triatriatum in adults are reviewed. The hemodynamic abnormalities closely resemble mitral stenosis, except that pressures in the true left atrium were normal in the presence of elevated pulmonary capillary pressures. The availability of flow across the obstructing membrane during systole as well as diastole is probably the major element in the surprisingly good tolerance of severe degrees of anatomic obstruction for long periods of time. Slow increase in the degree of obstruction could also be a factor.The clinical picture in these patients very closely resembles mitral stenosis. Hemoptysis appeared to be more frequent in cor triatriatum. Features suggestive of the correct diagnosis would include the absence of an opening snap, the absence of a typical murmur of mitral stenosis, regular rhythm, and lesser evidence of left atrial enlargement in the presence of obvious pulmonary hypertension. Five of these patients have undergone successful correction of their disease by operation.Representative films from the first knownangiograms in this condition in an adult are reproduced and discussed.

Mitral stenosis associated with partial anomalous pulmonary venous return (with intact atrial septum). An unsolved question.

Abstract In a patient with severe mitral stenosis, intact atrial septum and venous drainage of the left lung into the left innominate vein, increased values for pulmonary capillary wedge pressure and flow in the abnormally draining left lung equaled those found in the normally draining right lung. The possible mechanisms for this discrepancy are discussed. Total surgical correction of these lesions was successful.

Impaired left ventricular systolic and diastolic function without left ventricular dilatation associated with papillary muscle calcification in hypertrophic cardiomyopathy

Abstract Impairment of left ventricular (LV) systolic function in hypertrophie cardiomyopathy (HC) is unusual, and when it occurs the LV cavity often dilates. 1 This report describes a patient with chronic severe impairment in LV contractility associated with congestive heart failure (CHF) but without LV dilatation.

Just Beyond the Next Bend in the River: Reflections on a Medical Career

Vignettes or anecdotes often lack the authority of objective, analytic forms of writing. Nevertheless, we physicians sometimes feel compelled to offer these kinds of stories from our experience. Al...

Relation of therapeutic response to nifedipine to coronary anatomy and motion of S-T segment during unstable angina pectoris

Of 77 patients hospitalized for unstable angina pectoris and failure of oral, dermal, or intravenous nitrates and/or beta blockade, 81 percent with negligible or single-vessel disease and 55 percent with two- or three-vessel disease showed response (p less than 0.05) to nifedipine therapy. Patients with either S-T elevation or no change during pain responded better (31 of 45) than those with any S-T depression (16 of 32; p less than 0.05). Patients with negligible or single-vessel disease had a higher prevalence of S-T elevation (13 of 16) than patients with two- or three-vessel disease (15 of 31; p = 0.004). S-T motion did not predict response in patients with two- or three-vessel disease, but did predict response in patients with negligible or single-vessel disease. On follow-up study at 9 +/- 8 (range one to 33) months, 39 of 42 who had shown response were free from pain. Three died from infarction without unstable angina. (range one to 33) months, 39 of 42 who had shown response were free from pain. Three died from infarction without unstable angina. Five who showed response had elective bypass surgery. The addition of nifedipine abolished or reduced pain episodes by more than 50 percent in 61 percent of patients with refractory unstable angina pectoris. Patients with negligible or single-vessel disease with S-T elevation benefit most. In patients with two- or three-vessel disease, the type of S-T motion did not predict response. Follow-up of all those with response indicated sustained amelioration by nifedipine therapy. Failure of nifedipine therapy should not be accepted until a dose of 120 mg per day has been achieved, or until intolerable side effects appear.

Left ventricular ejection fraction and results of cardiac surgery.

The results of prosthetic valve replacement in 64 patients and coronary revascularization or aneurysmectomy in 58 patients were analyzed 1 year after the operation. 24 early and late deaths were found