Alcohol‐Induced Electrical Remodeling: Effects of Sustained Short‐Term Ethanol Infusion on Ion Currents in Rabbit Atrium

Background: In some patients, above‐average alcohol consumption before occurrence of atrial fibrillation (AF) in terms of a “holiday heart syndrome” (HHS) can be determined. There is evidence that long before development of apparent alcohol‐induced cardiomyopathy, above‐average alcohol consumption generates an arrhythmogenic substrate which abets the onset of AF. Changes of atrial current densities in terms of an electrical remodeling after sustained short‐term ethanol infusion in rabbits as a potential part of HHS pathophysiology were examined in this study. Methods: Rabbits of the ethanol group (EG) received sustained short‐term intravenous alcohol infusion for 120 hours (during infusion period, blood alcohol level did not fall below 158 mg/dl), whereas NaCl 0.9% was infused in the placebo group (PG). Using patch clamp technique in whole‐cell mode, atrial current densities were measured and compared between both groups. Results: Ethanol infusion did not alter current densities of I to [58.7 ± 5.0 pA/pF (PG, n = 20 cells) vs. 53.9 ± 5.0 pA/pF (EG, n = 24)], I sus [11.3 ± 1.4 pA/pF (PG, n = 20) vs. 10.2 ± 1.0 pA/pF (EG, n = 24)], and I K1 [−1.6 ± 0.3 pA/pF (PG, n = 17) vs. −2.0 ± 0.3 pA/pF (EG, n = 22)]. However, alcohol infusion resulted in a remarkable reduction of I Ca,L current densities [−28.4 ± 1.8 pA/pF (PG, n = 20) vs. −15.2 ± 1.4 pA/pF (EG, n = 22)] and I Na [−75.4 ± 3.6 pA/pF (PG, n = 17) vs. −35.4 ± 4.4 pA/pF (EG, n = 21)], respectively. Conclusion: Sustained short‐term ethanol infusion in rabbits alters atrial current densities. HHS might be favored by alcohol‐induced atrial electrical remodeling.