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Biomedical subjects

J M van der Bel-Kahn

Publications and source records attributed to J M van der Bel-Kahn.

6 recordsLinked to original sources
PubMed1983

Transcutaneous cardiac pacing: determination of myocardial injury in a canine model.

Transcutaneous cardiac pacing holds promise as the initial cardiac pacing technique for emergency patients. Determination of the extent of myocardial injury associated with the use of commercial transcutaneous pacemaker devices has been limited. This study was undertaken to document electrocardiographic, enzymatic, and histologic changes following transcutaneous pacing. Ten mongrel dogs were paced with a transcutaneous cardiac pacemaker for 30 minutes. Electrical pulses of 100 mA lasting 20 ms each were delivered at a rate of 80/min via cutaneous electrodes on the anterior and posterior thorax. Myocardial damage was assessed by serial electrocardiograms (ECGs), serial creatine kinase (CK) determinations with myocardial band (MB) fractionation, and gross and microscopic pathologic examination. Double blind reading of the ECGs showed no significant changes after pacing. CK levels peaked an average of 78 units over baseline levels at 4 hours; however, there was no rise in the CK MB fraction. Pathologic examination revealed micro-infarcts adjacent to intramural vessels in 5 animals, but no clinically significant myocardial injury in the 10 dogs. The absence of enzymatic, cardiographic, and clinically significant pathologic findings was statistically significant (P less than .05). Transcutaneous pacing at low currents and for short periods appears to be a safe technique. This pacing technique deserves further evaluation, and may hold promise as a clinical tool during resuscitation.

Animals↗
PubMed1981

Circulating Charcot-Leyden crystals in the hypereosinophilic syndrome.

A patient who had malignant melanoma associated with the hypereosinophilic syndrome died of cardiovascular thrombotic lesions. Widespread tissue eosinophilia was accompanied by numerous Charcot-Leyden crystals in the tumor as well as in various organs, including the renal tubules. A unique observation, not previously described, is the finding of Charcot-Leyden crystals in the thrombi and vessels, including the renal glomeruli. While little is known of the significance of Charcot-Leyden crystals, it is speculated that the circulating crystals injure the endothelium and trigger intravascular coagulation, resulting in thrombosis. A search for the crystals in blood and/or urine may be of additional aid in the evaluation of the extent of the thrombotic process. A special staining method is proposed to facilitate recognition of the crystals, since these are virtually not visualized by routine stain. With the use of such a staining method, future observations in other cases of the hypereosinophilic syndrome may elucidate the role of Charcot-Leyden crystals in the pathogenesis of the thrombotic cardiovascular lesions of this syndrome.

Adult↗
PubMed1979

Indications for surgical replacement of the mitral valve. With particular reference to common and uncommon causes of mitral regurgitation.

Mitral valve replacement is considered when there is severe mitral stenosis, severe mitral insufficiency or a combination of the two. Ordinarily, surgical replacement is considered only for patients who are in functional classes III or IV and do not respond to medical management. Patients with symptomatic mitral stenosis should be treated with mitral commissurotomy whenever possible. Patients selected for commissurotomy should have a pliable valve, no other major valve dysfunction, sinus rhythm, no systemic embolism and good left ventricular function. Early operation is not ordinarily required. Mitral insufficiency may require mitral valve replacement in six rather common settings: rheumatic disease, rupture of mitral chordae tendineae, postinfarction rupture of a papillary muscle, intractable infective endocarditis, floppy mitral valve and malfunction of a prosthetic valve. Rupture of mitral chordae tendineae can usually be recognized from the history, physical examination, echocardiogram and angiocardiogram. Severe left ventricular papillary muscle dysfunction is usually due to cardiac infarction, and occurs within the first 9 days of infarction. When only a papillary muscle tip is ruptured the patient may survive long enough for a mitral valve replacement. In infective endocarditis, operation is more often needed because of congestive heart failure than because of refractory infection. Evidence of mitral stenosis or insufficiency in a patient with a previously implanted prosthetic valve usually indicates an urgent need for study and early operation. Uncommon causes of mitral incompetence that may require valve replacement are endocardial fibroelastosis, Marfan's syndrome, calcified mitral anulus, osteogenesis imperfecta, methysergide-induced heart disease and carcinoid heart disease.

Adult↗
PubMed1978

Chlamydia trachomatis endocarditis.

A case of infective endocarditis due to Chlamydia trachomatis immunotype F is reported. Multiple negative blood cultures were a major deterrant from the initial clinical diagnosis of infective endocarditis. Postmortem ultrastructural identification of Chlamydia in the aortic valve vegetation led to an intensive retrospective study of retrieved serum samples utilizing microimmunofluorescent tests. Likewise an unusual echocardiographic finding was discovered to be the ultrasonic visualization of an aortic ring abscess. No similar case could be found in the literature. Clinicopathologic correlations are presented.

Adult↗