Cardio| S2 Splitting

1.08 S2 Splitting Cardiovascular system review for the USMLE Step 1 exam S2 splitting is a phenomenon where the closure of the aortic and pulmonic valves occur at different times, resulting in two heart sounds heard at what is normally S2. Four types of splitting: physiologic or normal splitting, wide splitting, fixed splitting, and paradoxical splitting. Physiologic splitting is normal and occurs when a person takes a deep breath and the difference between the closure of the aortic and pulmonic valves can be heard. Wide splitting is a symptom that is not normal and is associated with diseases that delay right ventricle emptying, such as right bundle branch block and pulmonary stenosis. It gets worse with inhalation. Wide split, worsened by inhalation Fixed splitting is similar to wide splitting, but it is not made worse when the patient inhales. It is seen in patients with an atrial septal defect. Fixed split, fixed in place Paradoxical splitting is a wide split that is fixed by inspiration and is caused by diseases that delay aortic valve closure, such as aortic stenosis and left bundle branch block. Paradoxially fixded by inspiration