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Biomedical subjects

A J Burger

Publications and source records attributed to A J Burger.

53 records · Page 3Linked to original sources
PubMed1991

Late potentials in mitral valve prolapse.

To determine the incidence and significance of late potentials in patients with mitral valve prolapse, we performed surface signal-averaged electrocardiography and 24-hour ambulatory electrocardiographic (ECG) monitoring in 41 patients with moderate to severe mitral valve prolapse on two-dimensional echocardiograms. Late potentials were defined as the presence of either a root mean square voltage of the last 40 msec of the QRS (RMS-40) of less than 20 mu v or a low-amplitude signal duration (LAS-40) of greater than 39 msec. Despite the absence of clinically significant ventricular tachycardia by history and on ambulatory ECG monitoring, 12 patients had late potentials on their signal-averaged electrocardiograms. Clinical characteristics could not differentiate patients with from patients without late potentials, and all patients were doing well at a mean follow-up of 34 months except for one noncardiac death. We conclude that late potentials on the surface signal-averaged electrocardiogram are a common and benign finding in patients with mitral valve prolapse and their clinical significance should be determined only in the presence of other findings.

Adult↗
PubMed1991

Modulation of orocaecal transit time by hypnosis.

The ability of hypnosis to modulate the orocaecal transit time of 10 g lactulose was tested in six healthy volunteers. Orocaecal transit time was measured by the hydrogen breath test during three periods in random order. During the control period the subjects remained throughout the test in a semirecumbent position without moving. During the hypnotic relaxation period subjects were hypnotised before lactulose ingestion and were instructed to experience relaxation till the orocaecal transit time had elapsed. During the acceleration suggestion period subjects were hypnotised before lactulose ingestion and were repeatedly instructed to imagine the acceleration of lactulose through the intestine until transit time had elapsed. The mean orocaecal transit time was significantly longer during the hypnotic relaxation period (mean (SEM) 133 (8) min) than during the control period (93 (13) min). The mean orocaecal transit time during the acceleration suggestion period was 105 (26) minutes and was not significantly different from the mean transit time during the control period. The individual values during the acceleration suggestion period were scattered. We conclude that lactulose orocaecal transit time is delayed during hypnotic relaxation.

Adult↗
PubMed1991

The acute and chronic effects of G-lasing on femoral vein grafts in dogs.

Each year, 5% of all coronary artery bypass operations are repeat procedures, and 15%-30% of coronary artery vein grafts occlude within the first eighteen months postoperatively. To evaluate the macroscopic and histologic effects of G-lasing on vein grafts and their patency, femoral veins were used to bypass bilaterally induced stenoses of femoral arteries in 10 dogs. The left vein grafts were G-lased with a 1.5 mm, hot-tipped argon laser at 5 watts for ninety seconds, while the right grafts were used as the controls. Acutely, each vein graft demonstrated no evidence of charring or perforation. The percentage of endothelium present in the G-lased vein grafts was consistently less than 5%, whereas the control vein grafts had an average of 70%. After ten weeks, the animals were sacrificed, and the vein grafts were evaluated for histologic changes and patency. There were no significant microscopic differences between the G-lased and control vein grafts. A statistically significant difference in graft patency was not achieved between G-Lased and control vein grafts at 10 weeks, but only a small number of grafts were studied. Further studies will be needed to evaluate the effects of G-lasing on the long-term patency of vein grafts.

Angioplasty, Laser↗
PubMed1991

The role of two-dimensional echocardiology in the diagnosis of infective endocarditis [corrected].

Two-dimensional echocardiography has had a significant impact on and is considered the technique of choice for the diagnosis and management of infective endocarditis. Over a thirty-six month period, 106 patients were evaluated by echocardiography for the possibility of endocarditis. The diagnosis of endocarditis was determined by strict clinical and laboratory criteria. All clinical histories, blood cultures, echocardiograms, and autopsy results were reviewed. Five echocardiograms were technically inadequate, resulting in a study population of 101 patients. The age of the patients ranged from forty-five days to eighty-eight years (mean fifty-seven years). The clinical manifestations of endocarditis included fever (83%), chills (60%), congestive heart failure (25%), and splenomegaly (18%). Twelve patients had preexisting valvular or congenital heart disease. Gram-positive cocci were the most common microorganisms. Complications included mitral regurgitation, subarachnoid hemorrhage, renal infarction, stroke, and a pulmonary embolus. The patients were divided into two groups: Group I consisted of 36 patients with definite vegetations by echocardiography, and Group II had 65 patients with no vegetations. In Group I, acute infective endocarditis was present in 35 patients, whereas only 4 patients had endocarditis in Group II. The sensitivity of two-dimensional echocardiography for detecting endocarditis was 90%. The specificity was 98%. The predictive accuracy for a positive test was 97%, and the predictive accuracy for a negative test was 94%. Thus, two-dimensional echocardiography appears to have a high sensitivity, specificity, and predictive value in the evaluation of patients with suspected endocarditis.

Aneurysm, Infected↗
PubMed1991

Late variation in ventricular function after myocardial infarction.

To assess the possible role of variables not related to early infarct artery reperfusion in predicting late changes in ventricular function after infarction, paired early (mean 6.6 +/- 3.5 days after admission) and late (12.7 +/- 7.0 months later) cross-sectional echocardiograms from 54 infarction survivors were retrospectively reviewed. Ejection fraction was calculated from digitized biapical echocardiographic views on a graphics tablet. Changes of 0.10 or more in LVEF were correlated with 23 clinical variables. By stepwise regression analysis, Q-wave infarction and low early LVEF independently predicted late improvement in function. Early high LVEF and interval infarction were the only independent predictors of late declines in function. Overall, when patients were indexed by early left ventricular systolic function, a pronounced late "regression to the mean" was noted with initially high values tending to fall and low values to rise (r = -0.44, p less than 0.001). This effect must be accounted for in any acute intervention trial in myocardial infarction. The occurrence of Q-wave infarction does not exclude late improvement in ventricular function.

Echocardiography↗
PubMed1991

Benign pleural effusions in long-standing diabetes mellitus.

We studied intractable pleural effusions in five patients with long-standing diabetes mellitus and an additional 40 patients with left ventricular systolic dysfunction to determine whether the frequency of pleural effusions is increased in diabetic patients and, if so, the relation of pleural effusions to left ventricular dysfunction. In our initial observations, effusions were benign, were not always associated with congestive heart failure (CHF), and reaccumulated following thoracentesis. Effusions associated with CHF persisted despite medical treatment and improvement of CHF. In our study of 40 patients with similar degrees of left ventricular dysfunction, the incidence of pleural effusions in diabetic patients was 83 percent and in our nondiabetic patients was 14 percent (p less than 0.001). We conclude that pleural effusions occur more commonly in diabetic than nondiabetic patients and may be related to left ventricular dysfunction and possibly other factors leading to increased effusion.

Aged↗
PubMed1989

Left ventricular pseudoaneurysm after myocardial infarction.

As is evident from our case and others, post-myocardial infarction pericarditis with the formation of pericardial adhesions creates a suitable milieu for left ventricular pseudoaneurysm. Although the conditions for pseudoaneurysm formation are rarely met, the clinician should be aware of this diagnosis, even long after myocardial infarction, because of its associated mortality and also because it is surgically curable.

Heart Aneurysm↗
PubMed1984

Mycotic aneurysm of the sinus of Valsalva due to Eikenella corrodens bacterial endocarditis.

A patient with a left sinus of Valsalva aneurysm secondary to bacterial endocarditis involving an unusual pathogen, Eikenella corrodens, is presented. This case and a review of previous reports on mycotic sinus of Valsalva aneurysm are analyzed. The distinctive M-mode and two-dimensional echocardiographic patterns of a sinus of Valsalva aneurysm as well as the usefulness and limitations of echocardiography in this condition are discussed. This rare complication of bacterial endocarditis can be diagnosed and clinically followed by serial echocardiographic studies, and its presence alone does not necessitate surgical intervention.

Adult↗