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Biomedical subjects

V Parsonnet

Publications and source records attributed to V Parsonnet.

At least 109 records · Page 6Linked to original sources
PubMed1987

Techniques for implantation of antitachyarrhythmia devices.

Implantation of ATDs is similar surgically to transpericardial implantation of conventional antibradycardia pacemakers, but considerable special expertise is involved in choosing the appropriate device and deciding how it should be programmed. Experience has reinforced our view that ATD implantation should be performed in what is essentially an operating-room setting, by a qualified team possessing the necessary surgical, electrophysiologic, and technical skills. ATD follow-up is different from that of conventional pacemakers and, particularly in the case of AIDS and AICDs, requires additional specialized instrumentation and more flexibility in scheduling.

Electric Countershock↗
PubMed1986

Usefulness of an implantable antitachycardia pacemaker system for supraventricular or ventricular tachycardia.

The Cordis Omni-Orthocor model 234A, an implantable antitachycardia system, was evaluated in 13 patients. Two patients had recurrent sustained supraventricular tachycardia (SVT) and 11 had ventricular tachycardia (VT). The system was used for SVT or VT termination (group 1: SVT, 2 patients; VT, 4 patients) or for demand pacing and noninvasive electrophysiologic studies for tachycardia induction and serial electrophysiologic testing alone (group 2: VT, 7 patients). The overdriver was used successfully in 4 of 6 patients in group 1 for repeated tachycardia termination (SVT and VT) during a mean follow-up period of 18 months. One patient had 1 sustained VT episode unresponsive to pacing and 1 patient had no recurrence of tachycardia. Tachycardia termination zones varied when using the system in 2 patients receiving long-term amiodarone therapy. Eighteen noninvasive electrophysiologic studies for serial drug testing were performed, 4 in group 1 and 14 in group 2. Clinical tachycardia was induced and successfully terminated by use of the overdriver in 12 studies. It is concluded that implantable antitachycardia systems can be used successfully for noninvasive tachycardia induction and termination and for reliable serial electrophysiologic studies. Such systems provide improved patient safety and acceptability and are reasonable in cost.

Aged↗
PubMed1986

Pulmonary inactivation of vasopressors following cardiac operations.

Vasoactive drugs were infused through catheters in the right atrium and then the left atrium of 34 patients who required either vasopressor or vasodilator support following cardiac operation to determine if the route of infusion affected the aortic blood concentration of these agents. Drugs were given through the right atrium for one hour and then the left atrium for an hour. Both central aortic and pulmonary arterial blood were assayed for drug concentrations, and hemodynamic measurements were made. Sixteen patients receiving dopamine hydrochloride through the left atrium had a 36 +/- 12% (+/- standard error of the mean) increase in aortic concentration of the drug (p less than 0.005) and a 37 +/- 14% increase in cardiac index (p less than 0.005) compared with administration through the right atrium. Seven patients receiving epinephrine showed a 59 +/- 21% increase in aortic concentration (p less than 0.05) and a 21 +/- 10% increase in cardiac index (p greater than 0.05, not significant). Eleven patients receiving sodium nitroprusside achieved a 99 +/- 25% increase in aortic concentration (p less than 0.005) and a 20 +/- 7% increase in cardiac index (p less than 0.05). In all instances, significantly higher central aortic blood concentrations were achieved during left atrial (LA) versus right atrial (RA) infusions. Changes in blood concentration of the drug between the pulmonary artery and the aorta during RA infusion suggest removal or inactivation of these drugs in the pulmonary vasculature.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

Long-term efficacy of subendocardial resection in refractory ventricular tachycardia: relationship to site of arrhythmia origin.

Subendocardial resection is performed in patients with ventricular tachycardia (VT), but its efficacy as related to the site of origin of VT is problematic. We analyzed the efficacy of subendocardial resection in 24 patients with coronary artery disease and VT. All patients underwent preoperative and intraoperative mapping before subendocardial resection. Postoperative electrophysiologic studies were performed in the drug-free state 7 to 14 days after subendocardial resection. Group 1 (n = 14) had anterior, septal, or lateral sites of origin, and Group 2 (n = 10) had inferior or posterior sites of origin. Localization of presystolic electrical activity during VT by preoperative and intraoperative mapping was comparable in both groups (100%). Resectability of the site of origin was higher in Group 1. Induction of VT during a postoperative electrophysiological study was higher in Group 2. Perioperative mortality was comparable. Postoperative antiarrhythmic therapy was instituted more frequently in Group 2. Actuarial survival analysis showed improved patient survival at one year after subendocardial resection for both groups. The efficacy of subendocardial resection is related to site of origin of VT: Subendocardial resection is less efficacious in VT with inferior or posterior sites of origin because of nonresectability of the arrhythmogenic area.

Adolescent↗
PubMed1986

Computer-assisted measurements in pacemaker follow-up.

The application of increasingly sophisticated engineering techniques to cardiac pacemaker design has resulted in substantially greater complexity of follow-up which requires that more complicated measurements be made and interpreted. A feasibility study was conducted in which microcomputer software was designed to permit direct electronic communication between the computer and a commercial follow-up measurement device. This technique eliminates human error in reading or copying measurement data, and facilitates the application of computerized error-trapping, predictive interpretation of measurements, and database-management methods to pacemaker follow-up.

Computers↗