In a patient with palpitations and a midsystolic click, what is the most likely diagnosis?

The presence of palpitations combined with a midsystolic click strongly suggests mitral valve prolapse (MVP). Mitral valve prolapse is characterized by the abnormal displacement of one or both leaflets of the mitral valve into the left atrium during systole. This condition can lead to various symptoms, including palpitations, which are often due to arrhythmias resulting from changes in the heart’s structure and function.

The midsystolic click is a distinctive auscultation finding associated with MVP, as it reflects the sudden tensing of the chordae tendineae and valve leaflets during early to mid-systole. The click is typically followed by a late systolic murmur if there is associated mitral regurgitation.

Other conditions listed have different clinical presentations and auscultatory findings. Aortic stenosis is typically associated with a triad of symptoms including exertional dyspnea, angina, and syncope, and it produces a systolic ejection murmur rather than a click. Atrial septal defect often presents with a fixed split S2 and may lead to right heart volume overload rather than the described symptoms. Pulmonic stenosis features a systolic ejection murmur and does not typically