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Biomedical subjects

R L Click

Publications and source records attributed to R L Click.

27 records · Page 2Linked to original sources

Complement activation from protamine sulfate administration after coronary angiography.

The cause of hypotension after reversal of heparin by protamine has not been well defined. In this study we evaluated complement activation (C3a and C4a) by the heparin-protamine complex in 46 consecutive patients (40 received protamine sulfate to reverse heparin, and six did not) during and after coronary angiography. In patients receiving protamine sulfate, there was a significant increase in C3a over the value before protamine sulfate administration (P less than .001) or in patients who did not receive protamine sulfate (P less than .05): 807 +/- 100 ng/ml vs. 274 +/- 75 ng/ml. There were no significant changes in C4a after protamine sulfate administration. These results indicate that the alternate complement pathway is activated when protamine sulfate is administered after coronary angiography. This may induce hypotension as well as platelet aggregation and thrombus formation and may contribute to coronary instability. Therefore, in unstable patients, heparin reversal by protamine should not be done routinely.

Anaphylatoxins↗

Chest pain in a young woman.

Chest pain in a young person is often caused by chest wall tenderness, associated with mitral valve prolapse, or attributed to psychologic factors. Ischemic cardiac pain may be overlooked because of its rare occurrence in this age group. A 35-year-old woman complained of substernal chest pressure precipitated by exertion and relieved by rest. The symptom had been noted for 15 years. Worsening of the symptom during dancing prompted her to seek medical advice. She had no other illnesses, was taking no medications, was a nonsmoker, and had no family history of coronary disease. Physical examination disclosed a grade 1 (on the basis of 1 to 6) systolic ejection murmur, an ejection click, and a grade 2 diastolic murmur. An exercise test produced symptoms at 4 minutes. Coronary arteriography showed the absence of a left coronary ostium and filling of the entire coronary system from the right ostial injection through collateral vessels from the right coronary artery. Surgical repair was recommended. Operative intervention showed a dysplastic bicuspid aortic valve with a membrane that covered the left coronary ostium. Excision of the membrane reestablished antegrade blood flow to the left coronary system. A follow-up exercise test revealed normal findings. Because chest pain in a young person is rarely ischemic in origin, benign or noncardiac causes are usually considered; however, if the history suggests ischemic pain, the possible presence of unusual cardiovascular abnormalities should not be disregarded.

Adult↗

Role of invasive electrophysiologic testing in patients with symptomatic bundle branch block.

Electrophysiologic testing was performed in 112 symptomatic patients with bundle branch block. Abnormalities included HV interval 70 ms or longer (35 patients), infra-Hisian block with atrial pacing (6 patients) and sinus node dysfunction (23 patients). Inducible ventricular tachycardia occurred in 47 patients (42%). Therapy was based on the electrophysiologic test result: group I--16 patients with no therapy (normal study results); group II--34 patients with permanent pacing alone; group III--39 patients with antiarrhythmic therapy alone; and group IV--21 patients with both antiarrhythmic therapy and permanent pacing. Cumulative 4-year survival rates were 83% in group I, 84% in group II, 63% in group III and 84% in group IV (mean follow-up 2.5 years). Recurrent syncope occurred in 19% of group I, 6% of group II, 33% of group III and 19% of group IV. In symptomatic patients with bundle branch block and normal electrophysiologic test results, prognosis is good without treatment. In patients undergoing permanent pacing based on electrophysiologic testing, survival is good and rate of symptom recurrence is low. Electrophysiologic testing identifies patients with inducible ventricular tachycardia for whom antiarrhythmic therapy is indicated but who nevertheless have a poor prognosis.

Adult↗

Paraneoplastic digital thrombosis: a case report.

Persistent digital ischemia is an uncommon paraneoplastic syndrome. We describe a 71-year-old man whose only manifestation of an underlying adenocarcinoma was digital ischemia. His symptoms responded dramatically to bilateral dorsal sympathectomies. A thorough search for the mechanism producing the ischemia failed to provide an explanation. We assume that unknown neurohumoral factors produced by the tumor were responsible.

Adenocarcinoma↗

Reactivity of gomerular afferent and efferent arterioles in renal hypertension.

Renal tissue from neonatal hamsters was grafted into the cheek pouch of adult hamsters. Renal hypertension was induced in 28 hamsters, and sham operation was performed in 27. When blood pressure became elevated in hypertensive hamsters (10 to 12 days), the renal microcirculation of both groups was evaluated by direct microscopy. Wall and luminal diameter and vascular responses to norepinephrine (NE) and angiotensin II (AII) were determined on glomerular afferent and efferent arterioles and on the corresponding cheek pouch arterioles. In the hypertensive hamsters, the luminal diameter of the afferent arteriole increased, as did the wall/lumen ratio of the efferent arteriole. Although all vessels responded to direct application of NE and AII in both groups, the response of the afferent to AII and the response of the efferent to both NE and AII was greater in the hypertensive hamsters as compared to the sham-operated hamsters. These results indicate that during the development of renal hypertension structural alterations of glomerular vessels and the selective vascular responses to vasoactive agents would lead to an increased glomerular capillary pressure.

Angiotensin II↗

Congenital absence of the pericardium: echocardiography as a diagnostic tool.

Between 1982 and 1992, 10 patients who underwent echocardiography at the Mayo Clinic were found to have congenital absence of the pericardium. Clinical, electrocardiographic, chest roentgenographic, echocardiographic, computed tomographic, and magnetic resonance imaging features were reviewed in this patient group. The characteristic features of this entity are reviewed. The echocardiographic features in order of frequency are (1) unusual echocardiographic windows, seen in all 10 patients, (2) cardiac hypermobility in nine patients, (3) abnormal ventricular septal motion in eight patients, and (4) abnormal swinging motion of the heart in seven patients.

Adolescent↗