AKT-0171

A 53-year-old woman presents to the clinic with increasing shortness of breath. She enjoys walking her dog but has noticed a decrease in exercise tolerance. She reports experiencing fast, irregular palpitations at various times throughout the day.

During the examination, you observe flushed cheeks, a blood pressure reading of 140/95, and a raised JVP. You suspect the presence of a diastolic murmur. In a subsequent communication from the cardiologist, they describe a loud first heart sound, an opening snap, and a mid-diastolic rumble that is best heard at the apex.

What is the most probable diagnosis?