Abstract 200: Pressure Overload Causes Right Ventricular Lethal Arrhythmias: Analysis by Optical Mapping in Pulmonary Artery Banding and Pneumonectomy Model
Right ventricular (RV) pressure overload due to severe pulmonary hypertension (svr-PH > 40 mmHg) sometimes causes lethal arrhythmias, although the mechanisms are unclear. To investigate if RV pressure overload produces RV arryhythmogenic vulnerability, we serially performed optical mapping analysis (OMP) with electrophysiological study (EPS) to the heart excised from pneumonectomy-induced (LP+H) and/or pulmonary artery banding-induced (PBI) svr-PH rats. In PBI-svr-PH, experiments were only conducted for 2 hours after PB because PBI-svr-PH was lethal. Action potential duration dispersion (APDd) and connexin43 (Cx43) expression were measured in RV. LP+H-svr-PH transiently sustained. OMP revealed abnormal RV conduction and increased APDd accompanying ventricular fibrillation/tachycardia (VF/VT) induction by EPS with normal Cx-43 in LP+H -svr-PH while PBI-svr-PH showed abnormal RV conduction and nonsustained VF/VT induction, but not increased APDd and without Cx-43 abnormality.
Conclusions: Transiently sustained (>24-hours) svr-PH can cause lethal arrhythmias possibly due to the mechanoelectric transduction not including Cx43degradation.
- © 2013 by American Heart Association, Inc.