Ohio State University Wexner Medical Center May 15 2025 For decades, doctors and researchers have puzzled over a basic heart rhythm mystery: Why do women tend to have faster heartbeats while men are more likely to develop irregular rhythms like atrial fibrillation (AFib)? Now a new study from The Ohio State University Wexner Medical Center provides some insight. The research shows that the sinoatrial node (SAN) - a small but powerful structure in the human heart that serves as its natural