A medium-pitched harsh mid-systolic murmur heard at the right second ICS suggests which diagnosis?

A medium-pitched harsh mid-systolic murmur heard at the right second intercostal space (ICS) is indicative of aortic stenosis. This positioning aligns with the pathophysiology of aortic stenosis, where the murmur occurs due to turbulent blood flow across a narrowed aortic valve during systole.

In the case of aortic stenosis, the murmur typically starts after the first heart sound (S1) and can be characterized by its medium pitch and harsh quality, often described as a "crescendo-decrescendo" type. The right second ICS is the standard auscultation site for heart murmurs associated with aortic lesions, as it is directly over the aortic valve.

The clinical significance of identifying this murmur lies in the potential progression of aortic stenosis to serious cardiovascular complications, including heart failure and syncope, and helps guide appropriate further evaluation and management.

In contrast, murmurs associated with pulmonic stenosis would generally be best heard over the left second ICS, and those related to aortic regurgitation would be diastolic rather than systolic. Mitral stenosis typically produces a mid-diastolic murmur rather than a systolic one. Understanding these