HY lecture notes:
Who gets pulmonic stenosis and what does it sound like? –> sounds like aortic stenosis (midsystolic murmur) but increases in intensity with inspiration because it’s right-sided; classically seen as part of tetralogy of Fallot in DiGeorge syndrome; also seen classically in Noonan syndrome (USMLE will not ask you about Noonan syndrome).
Who gets pulmonic regurg and what does it sound like? –> sounds like aortic regurg (holodiastolic) but increases with inspiration; rare, but can be seen in endocarditis in IV drug users.
Who gets tricuspid regurg and what does it sound like? –> same as mitral regurg (holosystolic murmur) but gets louder with inspiration; seen in IV drug user endocarditis; also seen in carcinoid syndrome (small bowel, appendiceal, or bronchial neuroendocrine tumor that secretes serotonin, leading to diaphoresis, tachycardia, diarrhea, and tricuspid regurg; Dx with urinary 5-hydroxyindole acetic acid [5-HIAA]); 2CK NBMEs love pulmonary hypertension causing TR (i.e., you’ll have cor pulmonale with TR and be like “huh? Why is there TR? What am I missing here?” But once again it can be seen in PH).
Who gets tricuspid stenosis and what does it sound like? –> sounds like mitral stenosis presumably (diastolic rumbling murmur, with or without opening snap); very rare; I’ve never seen this in any USMLE question.
28M IV drug user + 2/6 holosystolic murmur at left sternal border + fever; most likely characteristic of valvular lesion? –> “large, friable, floppy vegetation” –> bacterial endocarditis (probably tricuspid regurg in this case bc IV drug user).
How to Tx AF? –> we have to consider both arms of management: blood thinning + treating the actual AF. For blood thinning, CHADS2 score is standard in terms of evaluating risk (there are variants, but the USMLE won’t ever be borderline with how this plays into a question; they’ll either give you a full-blown obvious high-risk patient where all are positive, or they’ll make it clear that the patient is low-risk and merely just has AF alone).
- CHADS2 = CHF, HTN, Age 75+, Diabetes, Stroke/TIA (latter is 2 points; the rest are 1 point).
- If 0 or 1 points, give aspirin (anti-platelet therapy).
- If 2+ points, give warfarin (anti-coagulation therapy).
- If valvular AF (i.e., AF in someone with a mitral or aortic valve lesion), answer = warfarin.
- If non-valvular AF, can give other agents (e.g., dabigatran, apixaban).
For the actual Tx of the AF, we do rate control before rhythm control (the management is actually heavily involved, but for the USMLE know the following):
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- Rate control: beta-blocker first-line (metoprolol). If beta-blocker avoided (i.e., severe or psychotic depression, sexual dysfunction, COPD, Hx of asthma requiring oxygen or hospitalization, 2nd/3rd-degree heart block), verapamil is the next choice. If rate control fails, go to rhythm control.
- Rhythm control: Flecainide (type-Ic Na channel blocker) first-line in those without any structural (i.e., LVH or valvular problems) or coronary artery disease (any symptomatology of CVD or PVD means patient has coronary artery disease). In those who cannot receive flecainide, other anti-arrhythmics like amiodarone, dronedarone, and dofetilide may be used.
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