Stephen C. Achuff

Exercise thallium-201 myocardial imaging in left main coronary artery disease: Sensitive but not specific

To determine the usefulness of thallium-201 scintigraphy for identifying left main coronary artery disease, the results of scintigraphy at rest and during exercise were compared in 24 patients with 50 percent or greater narrowing of the left main coronary artery and 80 patients with 50 percent or greater narrowing of one or more of the major coronary arteries but without left main coronary involvement. By segmental analysis of the scintigrams, perfusion defects were assigned to the left anterior descending, left circumflex or right coronary artery, singly or in combination, and the pattern of simultaneous left anterior descending and circumflex arterial defects was used to identify left main coronary artery disease. Of the 24 patients with left main coronary artery disease, 22 (92 percent) had abnormal exercise scintigrams. Despite this high sensitivity, the pattern of perfusion defects was not specific; the left main pattern was found in 3 patients (13 percent) with left main coronary artery disease but also in 3 (33 percent) of 9 patients with combined left anterior descending and left circumflex arterial disease, 4 (19 percent) of 21 patients with three vessel disease and 3 (6 percent) of 50 patients with one or two vessel disease but excluding the group with left anterior descending plus left circumflex arterial disease. The pattern of perfusion defects in the patients with left main coronary artery disease was determined by the location and severity of narrowings in the coronary arteries downstream from the left main arterial lesion. Concomitant lesions in other arteries were found in all patients with left main coronary disease (one vessel in 1 patient, two vessels in 7 patients and three vessels in 16). For this reason, it is unlikely that even with improvements in radiopharmaceutical agents and imaging techniques, myocardial perfusion scintigraphy will be sufficiently specific for definitive identification of left main coronary artery disease.

Coronary Spasm With Ventricular Fibrillation During Thyrotoxicosis: Response to Attaining Euthyroid State

Although myocardial ischemia may occur in thyrotoxic patients with normal coronary arteries, the mechanism remains unclear. This report describes a woman with hyperthyroidism who had ventricular fibrillation during an apisode of myocardial ischemia. The event was documented with continuous ambulatory electrocardiography. Subsequent angiography revealed normal coronary anatomy with spasm of the right coronary artery that disappeared after ingestion of one sublingual nitroglycerin tablet. The angina, electrocardiographic evidence of myocardial ischemia, ventricular arrhythmias and the patients need for nitroglycerin were eliminated after she became euthyroid. These findings suggest that coronary spasm may be associated with myocardial ischemia and arrhythmias in a hyperthyroid patient.

Prognostic cardiac catheterization variables in survivors of acute myocardial infarction: A five year prospective study

The prognostic variables from predischarge coronary angiography and left ventriculography in survivors of acute myocardial infarction during the years 1974 to 1978 were evaluated in 143 patients (less than or equal to 66 years of age) with documented myocardial infarction who were then followed up prospectively for 5 years. One half of the study population had triple vessel coronary disease (greater than or equal to 50% stenosis). However, only 7% of patients had severely depressed left ventricular function with an ejection fraction less than or equal to 29%. Evaluation of the contribution of many clinical and angiographic variables to a first cardiac event (death, nonfatal reinfarction or coronary artery bypass surgery) was considered with Kaplan-Meier actuarial curves and multivariate Coxs hazard function analysis. A risk segment was defined as an area of contracting myocardium supplied by a coronary artery with a greater than 50% stenosis. Multivariate analysis demonstrated that right plus left anterior descending coronary artery stenoses (p less than 0.01), ejection fraction (p less than 0.01) and the presence of risk segments (p less than 0.05) were significant predictors of outcome. Furthermore, on separate multivariate analyses, the angiographic variables added significantly to the clinical variables to predict cardiac events over 5 years of follow-up. Therefore, in survivors of acute myocardial infarction who undergo cardiac catheterization, additive prognostic information is obtained that can be used to stratify risk over 5 years.

Recurrent cardiac tamponade and large pericardial effusions: Management with an indwelling pericardial catheter

A new technique, using an atraumatic indwelling catheter, has been developed for short-term management of large or rapidly reaccumulating pericardial effusions. This technique (1) permits continuous pericardial fluid drainage, obviating repeated aspirations; (2) provides a convenient route for intrapericardial instillation of chemotherapeutic agents; and (3) enables one to await the results of diagnostic studies without subjecting a patient to thoracotomy. Experience in three patients suggests that in some cases the use of this catheter may eliminate the need for surgery; in others, it may serve as a valuable temporary measure to achieve stabilization of the patients condition.

The "angina-producing" myocardial segment: An approach to the interpretation of results of coronary bypass surgery.

The first 153 cases of saphenous vein aortocoronary bypass surgery performed at The Johns Hopkins Hospital were reviewed. Eighty-eight percent of the 140 late survivors reported significant symptomatic improvement. Seventy-one unselected patients consented to complete reevaluation at a mean interval of 6.1 months postoperatively. Vein bypass patency in this group was 66 percent. Eighty-two percent of these 71 patients had improved performance on electrocardiographic stress testing. There were no significant differences between hemodynamic status on pre- and postoperative studies regardless of the status of vein bypass patency. Repeat coronary angiography revealed a 30 percent incidence of new total occlusions of the intrinsic coronary circulation. Segmental wall motion on ventriculography was improved in 12 percent, unchanged in 50 percent and decreased in 38 percent of the segments analyzed. Localized electrocardiographic changes compatible with myocardial damage developed in the immediate postoperative period in 45 of these patients (63 percent); in 38 of the 45, these changes corresponded to new angiographic abnormalities. Physiologic mechanisms underlying symptomatic improvement were sought by identification of an angina-producing myocardial segment. In most instances, alleviation of angina could be related to either: (1) a patent bypass graft into an unchanged intrinsic coronary artery with presumed increased blood flow to the distal coronary segment, or (2) occlusion of the bypass graft and the corresponding coronary artery with probable infarction of previously ischemic myocardium. Current criteria for the selection of patients undergoing coronary bypass surgery are reviewed in the light of these findings. It is concluded that relief of disabling angina is the major indication for surgery. Prevention of myocardial infarction and improvement in left ventricular function are at present less reliable objectives.

Histologic predictors of acute cardiac rejection in human endomyocardial biopsies: A multivariate analysis

To identify specific histologic abnormalities that could predict early cardiac rejection before the development of myocyte necrosis, 167 consecutive endomyocardial biopsy samples from 18 cardiac transplant recipients were retrospectively analyzed and 17 histologic variables were semiquantitatively graded from 0 to 3. Forty-five biopsy samples contained foci of myocyte necrosis and were labeled Rejectors. The two samples immediately preceding Rejector biopsies were labeled Predictors (n = 44). All remaining samples were labeled Others (n = 78). Endocardial and interstitial infiltrates, interstitial mononuclear cells, pyroninophilic mononuclear cells, polymorphonuclear leukocytes and other cells (eosinophils and plasma cells) were significantly increased in graded severity in Rejector biopsy samples as compared with Predictors or Others (p less than 0.001, ANOVA testing). These variables cannot distinguish Predictor biopsy specimens from Others. On the other hand, interstitial edema, perivascular karyorrhexis and perivascular infiltrate with intermyocyte extension are histologic abnormalities that can distinguish Predictor biopsy samples from Others (p less than 0.001, ANOVA testing). Multiple logistic regression analysis indicates that the relative risk of developing myocyte necrosis when a biopsy sample contains interstitial edema is 8.1. With perivascular infiltrate with intermyocyte extension in addition, the relative risk is 41.4. In summary, three histologic abnormalities have been identified that help predict the future development of myocyte necrosis within the next two endomyocardial biopsies. Biopsy specimens with these abnormalities probably represent early cardiac rejection before the development of myocyte necrosis.

Operative Intervention for Postinfarction Angina

Thirty-four patients (26 men and 8 women) underwent myocardial revascularization following myocardial infarction (MI) at the Johns Hopkins Hospital during 1980 through 1982. Average age was 59 years. Of the 33 patients with unstable angina, 61% had ischemia in the infarct zone and 39% had ischemia at a distance. Mean time from MI to operation was 16 days. The MIs were equally divided between a transmural and a subendocardial location. Eleven patients had a history of congestive heart failure. Intraaortic balloon pumping was used preoperatively for anginal stabilization in 14 patients. Mean ejection fraction for the group was 52%. There were 3 operative deaths, all 3 due to myocardial failure. Late follow-up (mean, 13.7 months; range, 6 to 35 months) is complete for 28 patients. There was 1 late death, secondary to cardiac failure. There were no late MIs. Angina had recurred in 5 patients, but only 2 were taking antianginal medication. At the time of follow-up, 52% of patients were in New York Heart Association Functional Class I. This experience suggests that operative intervention for postinfarction angina can be accomplished with an acceptable mortality and thereby increase survival, reduce the later occurrence of MI, and relieve angina in this high-risk group.

Multiple coronary thromboses in previously normal coronary arteries: a rare cause of acute myocardial infarction

This report describes an unusual form of myocardial infarction in a 44-year-old woman who was found to have two proximal coronary artery thrombi with otherwise normal coronary arteries. An interesting feature of her history was that the coronary events occurred in association with thrombocytopenia and heparin treatment. Two other clinical reports of patients who developed thrombocytopenia and myocardial infarction while receiving heparin have been identified, and the possibility that these thrombi were secondary to a coagulation abnormality associated with heparin is considered.

Late False Aneurysm Following Replacement of Ascending Aorta: The Problem of the Teflon Graft in Combination with a Silk Suture Anastomosis

Two patients underwent resection and replacement of the ascending aorta using a low-porosity Teflon graft anastomosed with silk suture. In both patients false aneurysms developed that required operation 13 and 23 years postoperatively. The clinical courses of these patients, along with data from the literature, suggest that the combination of a low-porosity Teflon graft and a silk suture anastomosis presents a major potential hazard for the development of anastomotic false aneurysm.

Coronary artery aneurysm producing right ventricular outflow obstruction

Abstract We report clinical, echocardiographic and morphologic findings in a patient with an aneurysm of the right coronary artery, which produced right ventricular (RV) outflow obstruction, myocardial infarction, and subsequent fatal intrapericardial rupture and cardiac tamponade.