Systematic auscultation and JVP analysis approach:
Clinical data: generalized weakness, breathing difficulty, mid-diastolic murmur, prominent wave (JVP a-wave).
Mid-diastolic murmur differential:
- Mitral stenosis (MS): left-sided, apex, opening snap, associated with AF and left atrial enlargement.
- Tricuspid stenosis (TS): right-sided, left lower sternal border, louder on inspiration.
- Austin Flint murmur (aortic regurgitation): rumbling mid-diastolic at apex, no opening snap.
The discriminating finding -- prominent a-wave:
JVP a-wave represents right atrial contraction. In TS, blood cannot cross the stenosed tricuspid valve easily, so the right atrium contracts forcefully, producing a giant a-wave in the JVP. This is the classical distinguishing feature of TS vs MS.
Other features of TS:
- Carvallo's sign: murmur increases on inspiration (right-sided murmur rule)
- Hepatomegaly and ascites (right heart failure)
- Etiology: rheumatic fever (MC), carcinoid syndrome
Therefore, the answer is Tricuspid Stenosis (TS).
\[\boxed{\text{Tricuspid Stenosis (TS)}}\]