HMOX1 and atrial fibrillation: The allelic frequencies of GT repeats in the HO-1 gene promoter were screened in 205 random individuals who underwent catheter ablation for drug refractory AF.In the patients who received catheter ablation, those with AF recurrence had fewer GT repeats (53.4±7.1 vs. 56.1±6.5, p = 0.004), a lower incidence of hyperlipidemia, more non-paroxysmal AF, and a larger left atrial diameter.