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Biomedical subjects

L A Silva

Publications and source records attributed to L A Silva.

At least 55 records · Page 3Linked to original sources
PubMed1983

Hemodynamic effects of intravenous administration of amiodarone in congestive heart failure from chronic Chagas' disease.

Fourteen patients with congestive heart failure due to chronic Chagas' disease had hemodynamic studies before and 20, 40 and 60 minutes and 24 hours after intravenous amiodarone. Amiodarone was given initially as a bolus (5 mg/kg); after 1 hour a continuous infusion was maintained for 24 hours (total dose 900 to 1,050 mg). During the first hour of observation, heart rate and cardiac index decreased and mean right atrial, left ventricular end-diastolic pressures and pulmonary and systemic vascular resistances increased. Except for heart rate and mean right atrial pressure, all hemodynamic variables returned to control values at 24 hours. Thus, myocardial depression occurred with a dose of 5 mg/kg within the first hour of intravenous administration. Amiodarone must be cautiously administered by bolus, especially in patients with cardiac failure.

Adult↗
PubMed1980

Abnormal atrioventricular nodal response patterns in patients with long-term Chagas' disease.

Thirty-two volunteers with positive serologic tests for Chagas' disease were submitted to electrophysiologic studies. No one had documented tachyarrhythmias, heart failure, PR interval shorter than 0.12 or longer than 0.20 msec, pre-excitation or cardiac enlargement. The atrioventricular (AV) nodal function study under programmed atrial stimulation revealed abnormal AV nodal function in nine (28.1 percent) with long-term Chagas' disease. Due to the high incidence of the longitudinal dissociation in this disease, and based on previously reported histopathologic findings that demonstrate the involvement of the right side of the AV node and His bundle, this study suggests that the abnormal AV nodal responses may be secondary to the organic alterations produced by Chagas' disease.

Adult↗
PubMed1978

Double ventricular response to an extrastimulus in a patient with triple atrioventricular pathways.

A patient with the Wolff-Parkinson-White Syndrome was studied through recordings of the intracardiac potentials and programmed atrial stimulation. During programmed atrial stimulation at progressively shorter coupling intervals (A1-A2 intervals), the His deflection was always recorded after the ventricular complex. Thus, at coupling intervals between 295 and 250 msec, there was a double ventricular response, one through the accessory pathway (QRS complex of the Wolff-Parkinson-White morphologic pattern) and the other by the normal atrioventricular pathway (normal QRS complex or with pattern of left bundle-branch block). At a coupling interval of 295 msec, the atrio-His (A-H) interval increased from 200 to 350 msec. This fact and the presence of two distinct A2-H2 intervals are suggestive of the existence of dual atrioventricular pathways, coexisting functionally with a lateral accessory bypass (Kent's bundle).

Bundle of His↗