Persistent thallium-201 defect: can clinical, electrocardiographic and exercise hemodynamic variables predict defect normalization with reinjection?

This study was designed to assess the contribution of clinical, electrocardiographic and exercise hemodynamic variables to the prediction of normalization on resting reinjection scintigraphy of persistent thallium-201 (201Tl) myocardial perfusion defects seen with exercise and 2- to 4-hour delayed (redistribution) imaging. To evaluate this contribution, we studied 159 consecutive patients with persistent 201Tl myocardial perfusion defects on routine exercise and 2- to 4-hour-delayed scintigrams at the University of Rochester Medical Center who were classified as having moderate or greater ischemic normalization (group 1, n = 76) or minimal to no ischemic normalization (group 2, n = 83) by reinjection scintigraphy. Multiple logistic regression analysis with backward elimination was used to model the effects of clinical, electrocardiographic and exercise hemodynamic data on the odds ratio of a normalized defect. No difference was observed in the two groups with regard to gender, angina on exertion, rate-pressure product, exercise duration, resting or exertional ischemic ST changes on electrocardiogram, presence of Q waves or left ventricular hypertrophy on baseline electrocardiogram, or total number of stress thallium defects (2.8 +/- 1.5 segments). No single variable or combination of variables discriminated between groups 1 and 2 by logistic regression analysis. We conclude that defect normalization seen on resting 201Tl myocardial perfusion scintigraphy is prevalent in patients with persistent defects on routine exercise and delayed myocardial perfusion scintigraphy, and was not predictable from available clinical, electrocardiographic and exercise hemodynamic variables.

Giant right coronary artery aneurysm with fistulous connection to the coronary sinus: diagnosis and management.

This report describes the case of a giant aneurysmal right coronary artery connecting to the coronary sinus near its opening into the right atrium in a 70-year-old woman who presented with a recent onset of congestive heart failure. By coincidence, a secundum atrial septal defect was also present. The diagnosis and surgical management of this uncommon pathology are described.

Infective endocarditis due to Fusobacterium nucleatum: case report and review of the literature.

Endocarditis caused by Fusobacterium nucleatum is exceedingly rare. We report a case of F. nucleatum right-sided endocarditis in a patient with no known intravenous drug abuse. A detailed computer and manual search of the literature using Med-Line and Index Medicus, respectively, revealed a total of five cases of endocarditis due to this species. The clinical characteristics and the patient's hospital course are summarized and reviewed.

Mitral valve replacement in idiopathic hypereosinophilic syndrome.

Idiopathic hypereosinophilic syndrome is an eosinophil-mediated tissue injury causing multiple organ failure. Cardiac manifestations include subendocardial fibrosis, thrombus leading to peripheral emboli, restrictive cardiomyopathy, and valvar dysfunction. This article describes a patient with the syndrome and reviews surgical experience with valve replacement and long-term prognosis.

Permanent pacemakers in centenarians.

We have described six centenarians who have benefited from permanent pacemakers. In all of these patients, their initial symptoms of syncope, presyncope, dyspnea, and transient cerebral ischemic attacks resolved promptly after pacemaker implantation. In most of these patients quality of life, as measured by lifestyle and independence, improved after pacemaker implantation. None of these patients exhibited evidence of ischemic heart disease or cardiac failure. Because of increasing longevity and age-related degenerative and destructive changes in the conduction system and the sinus node, we expect that the number of patients requiring pacemakers in this age group will continue to grow. Ischemic heart disease as an underlying pathology necessitating pacemaker implantation appears to be rare in this age group.

Comparison of antianginal efficacies and exercise hemodynamic effects of nifedipine and diltiazem in stable angina pectoris.

The antianginal efficacies of nifedipine (40 to 120 mg/day) and diltiazem (120 to 360 mg/day) were studied in 21 normotensive patients with chronic stable angina pectoris, using a randomized, double-blind, crossover design. Patients received each agent titrated to maximum tolerated doses for 6 weeks, after a 2-week placebo baseline period. The maximum tolerated dose for nifedipine was 72 +/- 8 (standard error) mg/day and for diltiazem 297 +/- 20 mg/day. Two patients discontinued nifedipine early because of side effects. Duration of symptom-limited treadmill exercise was longer during the nifedipine (556 +/- 43 seconds) and diltiazem periods (546 +/- 39 seconds) compared with placebo baseline (474 +/- 41 seconds, p less than 0.02). Compared with placebo, nifedipine caused a significant increase in heart rate both at rest standing and at peak exercise. Nifedipine decreased resting systolic blood pressure but had no effect at peak exercise. In contrast, diltiazem caused a significant decrease in heart rate at rest but had no effect on blood pressure at rest or at peak exercise. Thus, nifedipine and diltiazem have differential effects on heart rate and systolic blood pressure suggesting different modes of action. However, despite the increase in exercise duration, neither nifedipine nor diltiazem increased the heart rate-systolic pressure product during maximum exercise. This suggests that the antianginal effects of the 2 agents probably are mediated via reduction of myocardial oxygen demand at submaximal exercise. In addition, diltiazem appears to be better tolerated than nifedipine.

The 20 alpha-hydroxysteroid dehydrogenase of Streptomyces hydrogenans.

In addition to the well-known 3 alpha,20 beta-hydroxysteroid dehydrogenase ('cortisone reductase'), Streptomyces hydrogenans produces a relatively stable, NAD-dependent 20 alpha-hydroxysteroid dehydrogenase of molecular mass approximately 48 kDa. This enzyme catalyzes the transfer of hydrogen from the 4-pro-S position of NADH.

Proctitis and fatal septicemia caused by Plesiomonas shigelloides in a bisexual man.

A case of proctitis and fatal septicemia caused by Plesiomonas shigelloides in a 42-year-old bisexual male is reported. The medical history of the patient was significant for an aortic valve replacement 3 years before but was otherwise unremarkable. A serum specimen obtained at autopsy was negative for antibody to human immunodeficiency virus by Western blot (immunoblot) analysis. P. shigelloides isolated from blood was susceptible to all antibiotics tested, agglutinated in Shigella group D antiserum, possessed a greater than 100-megadalton plasmid, and was noninvasive in a HeLa cell invasion assay. The previous reports of Plesiomonas bacteremic infections are reviewed, and possible pathogenic mechanisms are discussed.

Delayed appearance of left-to-right shunt following aortic valvular replacement. Report of two cases.

Two cases are presented in which a left-to-right shunt occurred late following aortic valvular replacement. In one patient a fistula was found between the aortic root and the right atrium and ventricle. In the second patient a defect developed in the membranous septum, allowing shunting from the left ventricle to both the right atrium and right ventricle.

Acute valvular insufficiency complicating hypertrophic obstructive cardiomyopathy.

This report describes a patient with hypertrophic obstructive cardiomyopathy complicated by acute aortic and probably mitral valvular incompetence caused by endocarditis due to Staphylococcus aureus. Following the onset of valvular insufficiency, this patient developed hypotension and pulmonary edema and eventually underwent cardiac surgery in an attempt to control these complications. We review the unique pathophysiology of hypertrophic obstructive cardiomyopathy and its alterations in the presence of acute valvular incompetence and analyze the limitations of medical management of cardiac decompensation in patients with this combination of cardiac abnormalities. The possible need for early surgery in such patients is examined.