Papers Published

1. Li, H. and Malkin, R. A., Defibrillation and the upper limit of vulnerability to fibrillation in a transthoracic guinea pig model., J Electrocardiol, vol. 32 no. 2 (April, 1999), pp. 159--166 [10338034] .
   (last updated on 2010/05/26)

   Abstract:
   Recent studies have shown sustained tachyarrhythmias in guinea pigs. We hypothesized that guinea pigs could be used as a model of ventricular fibrillation, focusing on defibrillation waveform efficacy and the upper limit of vulnerability to fibrillation. In 10 male guinea pigs, an esophageal/apical pacing electrode configuration was used. The electrocardiogram (ECG) and arterial blood pressure were continuously monitored. T-wave and defibrillation shocks were applied transthoracically. A modified up-down protocol was used. After up-down testing was completed, a tachyarrhythmia was induced without electrical termination. All animals died of a sustained tachyarrhythmia. The monophasic DFT50 (the 50\% successful defibrillation voltage, 496 +/-176 V) was larger than the biphasic DFT50 (364+/-94 V, P < .005). The upper limit of vulnerability to fibrillation (ULV50) (the 50\% successful induction voltage) was correlated with the DFT50 for both monophasic (r = .82, P < .005) and biphasic shocks (r = .88, P < .005). Its low cost and ease of handling may make the guinea pig a preferred model for some fibrillation and defibrillation studies.

   Keywords:
   Animals • Data Interpretation, Statistical • Disease Models, Animal • Electric Countershock • Electrocardiography • Guinea Pigs • Male • Models, Cardiovascular • Ventricular Fibrillation