system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
All the above loud S1 caused by
assistant
The correct answer is  Ref Harrison 19 th ed pg 1447 The intensity of S1 is determined by the distance over which the ante- rior leaflet of the mitral valve must travel to return to its annular plane, leaflet mobility, left ventricular contractility, and the PR interval. S1 is classically loud in the early phases of rheumatic mitral stenosis (MS) and in patients with hyperkinetic circulatory states or sho PR inter- vals