Ventricular remodelling in rabbits with sustained high-fat diet.
AIM
Excess weight gain and obesity are one of the most serious health problems in the western societies. These conditions enhance risk of cardiac disease and have been linked with increased prevalence for cardiac arrhythmias and sudden death. Our goal was to study the ventricular remodelling occurring in rabbits fed with high-fat diet (HFD) and its potential arrhythmogenic mechanisms.


METHODS
We used 15 NZW rabbits that were randomly assigned to a control (n = 7) or HFD group (n = 8) for 18 weeks. In vivo studies included blood glucose, electrocardiographic, and echocardiographic measurements. Optical mapping was performed in Langendorff-perfused isolated hearts.


RESULTS
Body weight (3.69 ± 0.31 vs. 2.94 ± 0.18 kg, P < 0.001) and blood glucose levels (230 ± 61 vs. 141 ± 14 mg dL(-1) , P < 0.05) were higher in the HFD group vs. controls. The rate-corrected QT interval and its dispersion were increased in HFD rabbits vs. controls (169 ± 10 vs. 146 ± 13 ms and 37 ± 11 vs. 9 ± 2 ms, respectively; P < 0.05). Echocardiographic analysis showed morphological and functional alterations in HFD rabbits indicative of left ventricle (LV) hypertrophy. Isolated heart studies revealed no changes in repolarization and propagation properties under conditions of normal extracellular K(+) , suggesting that extrinsic factors could underlie those electrocardiographic modifications. There were no differences in the dynamics of ventricular fibrillation (frequency, wave breaks) in the presence of isoproterenol. However, HFD rabbits showed a small reduction in action potential duration and an increased incidence of arrhythmias during hyperkalaemia.


CONCLUSION
High-fat feeding during 18 weeks in rabbits induced a type II diabetes phenotype, LV hypertrophy, abnormalities in repolarization and susceptibility to arrhythmias during hyperkalaemia.
['Zarzoso|M|M|', 'Mironov|S|S|', 'Guerrero-Serna|G|G|', 'Willis|B Cicero|BC|', 'Pandit|S V|SV|']
D000200:Action Potentials D000818:Animals D001145:Arrhythmias, Cardiac D001786:Blood Glucose D003924:Diabetes Mellitus, Type 2 D059305:Diet, High-Fat D004562:Electrocardiography D006321:Heart D017379:Hypertrophy, Left Ventricular D008297:Male D011817:Rabbits D020257:Ventricular Remodeling D015430:Weight Gain
high-fat diet ventricle structure and electrophysiology