Jan 14, 2026 · Atrial fibrillation (AFib) is a heart rhythm disorder. In a typical heart, a group of cells called the sinus node sends electrical signals that start each heartbeat. The signals go across the upper.
Jan 14, 2026 · Atrial fibrillation (AFib) is a heart rhythm disorder. In a typical heart, a group of cells called the sinus node sends electrical signals that start each heartbeat. The signals go across the upper.
