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Biomedical subjects

A J Zinner

Publications and source records attributed to A J Zinner.

4 recordsLinked to original sources

Clinical predictors of defibrillation energy requirements in patients treated with a nonthoracotomy defibrillator system. The ResQ Investigators.

Many factors can influence defibrillation energy requirements (DER) in patients with a nonthoracotomy defibrillator. No large studies, however, have correlated clinical characteristics with the DER. In this study, 124 patients underwent the same DER protocol with the identical biphasic waveform, nonthoracotomy lead system, and lead configuration. These patients were 63 +/- 12 years old (mean +/- SD); 99 were men; the ejection fraction was 0.32 +/- 0.13, and 36 were taking an antiarrhythmic medication. New York Heart Association congestive heart failure class I was present in 28, class II in 70, and class III in 26 patients. Male sex (454 +/- 94 V vs 406 +/- 91 V for female sex) was associated with a significantly higher DER (p = 0.02) and an increased risk of a DER > 550 V (p = 0.047). No other clinical variable was associated with the DER or a DER > 550 V. In conclusion, women tend to have lower DERs than men.

Anti-Arrhythmia Agents↗

Effect of ouabain on the anterograde effective refractory period of accessory atrioventricular connections in children.

The anterograde effective refractory period of the accessory connection was determined before and after the administration of ouabain (0.015 mg/kg intravenously) during electrophysiologic studies in 21 patients with Wolff-Parkinson-White syndrome. The mean age (+/- standard deviation) was 10 +/- 2 years (range 1 month to 31 years). Each patient had stopped taking all cardiac drugs for more than 36 hours. Determination of the anterograde effective refractory period of the accessory connection was made using the atrial extrastimulus technique. A change in the anterograde refractory period of the accessory connection was defined as an increase or decrease of greater than 10 ms from the value before ouabain administration. The post-ouabain anterograde effective refractory period of the accessory connection increased in 2 (9%) of the 21 patients, decreased in 9 (43%) and was unchanged in 10 (48%). This study demonstrated a decrease in the anterograde effective refractory period of the accessory connection of 43% of patients with Wolff-Parkinson-White syndrome after the administration of ouabain.

Adolescent↗