Imperial College London

Dr Fu Siong Ng

Faculty of MedicineNational Heart & Lung Institute

Clinical Senior Lecturer in Cardiac Electrophysiology



+44 (0)20 7594 Website




ICTEM buildingHammersmith Campus






BibTex format

author = {Handa, B and Lawal, S and Wright, IJ and Li, X and Cabello, Garcia J and Mansfield, C and Chowdhury, R and Peters, N and Ng, FS},
doi = {10.3389/fcvm.2019.00034},
journal = {Frontiers in Cardiovascular Medicine},
title = {Interventricular differences in action potential duration restitution contribute to dissimilar ventricular rhythms in ex vivo perfused hearts},
url = {},
volume = {6},
year = {2019}

RIS format (EndNote, RefMan)

AB - Background: Dissimilar ventricular rhythms refer to the occurrence of different ventricular tachyarrhythmias in the right and left ventricles or different rates of the same tachyarrhythmia in the two ventricles.Objective: We investigated the inducibility of dissimilar ventricular rhythms, their underlying mechanisms, and the impact of anti-arrhythmic drugs (lidocaine and amiodarone) on their occurrence.Methods: Ventricular tachyarrhythmias were induced with burst pacing in 28 Langendorff-perfused Sprague Dawley rat hearts (14 control, 8 lidocaine, 6 amiodarone) and bipolar electrograms recorded from the right and left ventricles. Fourteen (6 control, 4 lidocaine, 4 amiodarone) further hearts underwent optical mapping of transmembrane voltage to study interventricular electrophysiological differences and mechanisms of dissimilar rhythms.Results: In control hearts, dissimilar ventricular rhythms developed in 8/14 hearts (57%). In lidocaine treated hearts, there was a lower cycle length threshold for developing dissimilar rhythms, with 8/8 (100%) hearts developing dissimilar rhythms in comparison to 0/6 in the amiodarone group. Dissimilar ventricular tachycardia (VT) rates occurred at longer cycle lengths with lidocaine vs. control (57.1 ± 7.9 vs. 36.6 ± 8.4 ms, p < 0.001). The ratio of LV:RV VT rate was greater in the lidocaine group than control (1.91 ± 0.30 vs. 1.76 ± 0.36, p < 0.001). The gradient of the action potential duration (APD) restitution curve was shallower in the RV compared with LV (Control - LV: 0.12 ± 0.03 vs RV: 0.002 ± 0.03, p = 0.015), leading to LV-to-RV conduction block during VT.Conclusion: Interventricular differences in APD restitution properties likely contribute to the occurrence of dissimilar rhythms. Sodium channel blockade with lidocaine increases the likelihood of dissimilar ventricular rhythms.
AU - Handa,B
AU - Lawal,S
AU - Wright,IJ
AU - Li,X
AU - Cabello,Garcia J
AU - Mansfield,C
AU - Chowdhury,R
AU - Peters,N
AU - Ng,FS
DO - 10.3389/fcvm.2019.00034
PY - 2019///
SN - 2297-055X
TI - Interventricular differences in action potential duration restitution contribute to dissimilar ventricular rhythms in ex vivo perfused hearts
T2 - Frontiers in Cardiovascular Medicine
UR -
UR -
VL - 6
ER -