Increased afterload following myocardial infarction promotes conduction-dependent arrhythmias that are unmasked by hypokalemia.

Although the pathophysiological significance of resistant hypertension in post-myocardial infarction (MI) patients is established, mechanisms by which increased afterload in that setting worsens outcome are unclear. With regards to sudden cardiac death, whether increased afterload alters the electrophysiological substrate following MI is unknown. We established a new large animal model of chronic post-MI remodeling with increased afterload which exhibits widespread deposition of fibrosis in remote areas from the anterior MI, mimicking the disease phenotype of patients with advanced ischemic heart disease. We identified the mode-of-initiation and mechanism of arrhythmias which were consistently unmasked by hypokalemia in this clinically-relevant model.