Robert O. Brandenburg

The natural history of idiopathic dilated cardiomyopathy

Between 1960 and 1973, a total of 104 patients at the Mayo Clinic had a diagnosis of idiopathic dilated cardiomyopathy on the basis of clinical and angiographic criteria; these patients were followed up for 6 to 20 years. Twenty-one percent of the patients had a history of excessive consumption of alcohol, 20 percent had had a severe influenza-like syndrome within 60 days before the appearance of cardiac manifestations and 8 percent had had rheumatic fever without involvement of cardiac valves several years before; thus, possible etiologic risk factors of infectious-immunologic type may be important. Eighty patients (77 percent) had an accelerated course to death, with two thirds of the deaths occurring within the first 2 years. Twenty-four patients (23 percent) survived, and 18 of them had clinical improvement and a normal or reduced heart size. Univariate analysis at the time of diagnosis revealed three factors that were highly predictive (p less than 0.01) of the clinical course: age, cardiothoracic ratio on chest roentgenography and cardiac index. Systemic emboli occurred in 18 percent of the patients who did not receive anticoagulant therapy and in none of those who did; thus, anticoagulant agents should probably be prescribed unless their use is contraindicated.

Significance of calcification of the coronary arteries

Abstract The frequency of and association between calcification and occlusive disease of the coronary arteries were determined by roentgenographic and pathologic study of 200 human hearts obtained at autopsy of persons more than 30 years old. Calcification was present in 69 percent of the hearts, most frequently in the left anterior descending branch in men, and it occurred more frequently than significant narrowing, regardless of age, sex or presence of cardiac disease. The greater the degree of calcification, the more likely was the presence of significant narrowing. Absence of calcification indicated persons least likely to have significant narrowing. The presence of myocardial infarction associated with coronary artery calcification but without complete occlusion suggests that the advanced sclerosis of these vessels made them relatively insufficient to meet the needs of the myocardium.

Accuracy of 2-dimensional echocardiographic diagnosis of congenitally bicuspid aortic valve: Echocardiographic-anatomic correlation in 115 patients

The preoperative 2-dimensional (2-D) echocardiograms of all patients less than 50 years of age in whom the aortic valve had been directly inspected by the surgeon or the pathologist or both were reviewed. From June 1977 to June 1981, 283 patients aged less than or equal to 50 years had aortic valve surgery at the Mayo Clinic: 115 (aged 1 to 50 years [mean 32]) had 2-D examinations preoperatively. The echocardiograms were reviewed blindly, and the aortic valve structure was categorized as bicuspid, tricuspid, or indeterminate. On the basis of combined surgical and pathologic inspection, 50 aortic valves were congenitally bicuspid, 60 were tricuspid, 4 were unicommissural, and 1 was quadricuspid. By 2-D echocardiography, the number of cusps was indeterminate in 29 patients (25%). When these patients were excluded, the sensitivity, specificity, and diagnostic accuracy of 2-D echocardiography for bicuspid aortic valve were 78,96, and 93%, respectively. Thus, with adequate 2-D images, echocardiography is a sensitive and highly specific technique for the diagnosis of bicuspid aortic valve.

The Clinical, Hemodynamic, and Pathologic Diagnosis of Muscular Subvalvular Aortic Stenosis

Muscular obstruction to left ventricular outflow is a rare but serious occurrence. Eight cases in which this disease was anatomically proved are presented. The commonest symptoms are angina, dyspnea, and palpitations. Not uncommonly a family history of heart disease may be elicited. A systolic murmur along the left sternal border is the most characteristic physical finding, but a normal aortic second sound, the presence of third and fourth heart sounds, splitting of the second sound, and the absence of a diastolic murmur are all helpful clinical guides. Withdrawal pressures from the left ventricle reveal a characteristic infundibular pressure zone. Other hemodynamic findings include an anacrotic notch on the left ventricular pressure tracing, a rapidly ascending bisferious aortic pulse and a small compensatory beat after extrasystoles. Necropsy specimens reveal a grossly thickened interventricular septum as compared with normal and hypertrophied control hearts. Microscopic alterations are minimal. The etiology remains obscure but familial and developmental factors, either or both, appear to be implicated.

Factors Affecting Thromboembolism Associated with Prosthetic Heart Valves

The incidence of thromboembolism after insertion of prosthetic cardiac valves is related to the type of prosthesis and in the cases reviewed here was highest for the ball-valve prosthesis.The risk of thromboembolism was studied by constructing actuarial curves showing the proportion of patients with embolism at increasing time intervals postoperatively. Such curves for the patients studied suggest that the risk of thromboembolism diminishes with time, particularly by the third postoperative year. The risk was remarkably similar for patients having aortic, mitral, and multiplevalve replacements, being 15% for the first 6 postoperative months, another 8% for the next 6 months, and another 20% for the next 2 years.Emboli lodged in cerebral, coronary, renal, and other sites in these patients in diminishing frequency. The risk of fatality averaged 15%. None of the nonfatal embolisms resulted in significant continuing disability, save for 7% of the cerebral embolisms.A beneficial effect of anticoagulation was demonstrated for patients having replacement of the aortic valve with a ball-valve prosthesis, particularly when this treatment was carefully controlled. In the latter group, the risk of thromboembolism was less than 5% 2 years postoperatively.

Pregnancy and Open-Heart Surgery

During pregnancy, when surgically reparable heart disease can no longer be medically manged, open- or closed-heart surgery is the procedure of choice without prior therapeutic abortion. Cyanotic congenital heart disease in a pregnant patient when completely correctable surgically may be an indication for surgery in itself. Available data suggest that pregnancy per se does not increase the maternal risk of heart surgery with use of extracorporeal circulation. Fetal mortality in our series was 33%.

The Electrocardiogram of Patients with Atrioventricular Cushion Defects (Defects of the Atrioventricular Canal)

Abstract The electrocardiogram is the most important single item in alerting the physician to the diagnosis of congenital cardiac anomalies stemming from defective formation of the atrioventricular canal. It is characterized by left axis deviation with the early manifest frontal vector characteristically in the 0 ° to −60 ° zone. The tracings usually show evidence of enlargement of the right ventricle, particularly an rSR configuration in right precordial leads, the picture of volume overloading of the right ventricle. Different hemodynamic profiles (for instance, the amount of shunting at the atrial and ventricular levels, the degree of mitral insufficiency and the pulmonary hypertensive level) will be additively reflected in the basic electrocardiographic pattern. The typical electrocardiogram may be encountered occasionally in other types of congenital heart disease, particularly ventricular septal defects located posteriorly under the septal tricuspid leaflet. It is believed that the electrocardiographic pattern is related to a congenital aberration of the left bundle branch system.

Infective endocarditis—A 25 year overview of diagnosis and therapy

Diagnosis and management of infective endocarditis have significantly changed in the past 25 years. Improved bacteriologic techniques have allowed detection of cases of infective endocarditis caused by unusual organisms. Bactericidal therapy has become available for patients with gram-negative endocarditis and antimicrobial therapy has improved. Echocardiography has become an important diagnostic and management aid, and cardiac valve replacement has dramatically improved the outlook for many patients.

Clinical follow-up study of paroxysmal supraventricular tachyarrhythmias after operative repair of a secundum type atrial septal defect in adults

Adults with isolated secundum atrial septal defect (ASD) may present with paroxysmal atrial tachyarrhythmias. The clinical course of these rhythmic disturbances after correction of the ASD is unknown. Of 188 patients aged 44 years old or older with isolated ASD, 27 (14%) (mean age 52.7 years, range 44 to 71) had documented paroxysmal atrial tachyarrhythmias preoperatively: 16 had paroxysmal atrial fibrillation, 2 had atrial flutter, and 9 had supraventricular tachycardia. Among these 3 groups, there were no differences in age, sex, New York Heart Association class, duration of preoperative symptoms, mean right atrial and pulmonary arterial pressures, shunt size, atrial size, or follow-up period. After operative repair, follow-up data were available in all patients for a mean of 12 years (range 1.5 to 25). Of the 16 patients with preoperative paroxysmal atrial fibrillation, 14 (88%) continued to have increasingly frequent paroxysmal atrial fibrillation, culminating in sustained atrial fibrillation. In 1 of the 2 patients with paroxysmal atrial flutter, sustained atrial fibrillation developed. Of the 9 patients with preoperative paroxysmal supraventricular tachycardia, 5 had no further episodes of this arrhythmia postoperatively.

Traumatic rupture of the chordae tendineae of the tricuspid valve: Successful repair twenty-four years later

Abstract A unique case of traumatic rupture of the chordae tendineae of the tricuspid valve with associated intense cyanosis and successful repair 24 years later has been reported. The clinical findings, hemodynamic and angiographic data, details of the surgical correction, and a year and a half follow-up of the patient have been included.