Abstract 13517: Transient Right Ventricular Pressure Overload Causes Vulnerability to Lethal Arrhythmias; Comparison of Pneumonectomy with Monocrotaline-Induced Rat Pulmonary Hypertension Model
Peumonectomy sometimes causes arrhythmias, although the precise mechanisms are not understood. To study if pneumonectomy-induced (PI) pulmonary hypertension (PH) produces right ventricular (RV) arryhythmogenic vulnerability, we serially performed optical mapping analysis (OMP) with electrophysiological study (EPS) to the heart excised from pneumonectomy and monocrotaline-induced (MCTi) PH rats. RV pressure was measured by telemetry before excision. PI-PH transiently sustained from day 1 to 2 weeks after pneumonectomy. OMP revealed abnormal RV conduction delay and pattern (36/42 rats, 87%), and also abnormal action potential dispersion (APd) accompanying ventricular fibrillation/tachycardia (VF/VT) induction by EPS while all MCTi-PH rats showed both abnormal RV conduction, APd and VF/VT induction (Table/Figure). Conclusions; Similar to MCTi-PH, transiently sustained PH itself can cause lethal arrhythmias possibly due to conduction disturbance in RV. These findings give us new insights in understanding the mechanisms for lethal arrhythmias in pneumonectomy and/or acute pulmonary embolism.
- © 2011 by American Heart Association, Inc.