Hypertension and atrial fibrillation: Evidence of progressive atrial remodeling with electrostructural correlate in a conscious chronically instrumented ovine model

BackgroundHypertension accounts for more atrial fibrillation (AF) than any other predisposing factor.ObjectiveThe purpose of this study was to characterize the time course, extent, and electrostructural correlation of atrial remodeling in chronic hypertension.MethodsThirty-two sheep were studied: 21 with induced "one-kidney, one-clip" hypertension and 11 controls. Sequential closed-chest electrophysiologic studies were performed in 12 conscious animals (6 hypertensive, 6 controls) to evaluate progressive remodeling over 15 weeks. Additional atrial structural/functional analyses were performed in 5 controls and at 5, 10, and 15 weeks of hypertension (five per time point) via histology/cardiac magnetic resonance imaging to correlate with open-chest electrophysiologic parameters.ResultsThe hypertensive group developed a progressive increase in mean arterial pressure (P ConclusionHypertension is associated with early and progressive changes in atrial remodeling. Atrial remodeling occurs at different time domains in chronic hypertension with significant electrostructural correlation of the remodeling cascade. Early institution of antihypertensive treatment may prevent formation of substrate capable of maintaining AF.Dennis H. Lau, Lorraine Mackenzie, Darren J. Kelly, Peter J. Psaltis, Anthony G. Brooks, Michael Worthington, Arumuga Rajendram, Douglas R. Kelly, Yuan Zhang, Pawel Kuklik, Adam J. Nelson, Christopher X. Wong, Stephen G. Worthley, Mohan Rao, Randall J. Faull, James Edwards, David A. Saint, Prashanthan Sander