HY lecture notes:
What is a parasternal heave? –> a parasternal heave means the heartbeat can be felt (or sometimes seen) along the left sternal border, usually due to RVH (since the RV is most anterior) –> RVH can be seen in ventricular septal defect (VSD), so parasternal heave can be seen in VSD.
What is a palpable thrill? –> a palpable thrill is merely a palpable murmur; it carries no additional diagnostic significance; a thrill is seen in grades 4-6 of the heart sounds.
What are the 6 grades of heart sounds? (not asked on USMLE, but just for your own knowledge with respect to this document) –>
- Very faint; not heard in all positions (“cardiologist only”);
- Faint; heard in all positions;
- Loud, with no thrill;
- Loud with palpable thrill;
- Loud with palpable thrill + can be heard with stethoscope partially off chest;
- Loud with palpable thrill + can be heard with the stethoscope completely off the chest.
Which murmurs are holosystolic (aka pansystolic)? –> mitral regurgitation (mitral insufficiency; MR) + tricuspid regurgitation (tricuspid insufficiency; TR); ventricular septal defect (VSD).
Which murmurs are mid-systolic (crescendo-decrescendo systolic) –> aortic stenosis (AS) + hypertrophic obstructive cardiomyopathy (HOCM) + pulmonic stenosis (PS).
Which murmur has a diastolic opening snap? –> mitral stenosis (MS) à has diastolic opening snap, followed by a mid-late decrescendo diastolic murmur.
Which murmur has a mid-systolic click? –> mitral valve prolapse (MVP).
Which murmur can also be described as a late-peaking systolic murmur with an ejection click? –> aortic stenosis.
Which murmur is continuous machinery-like? –> patent ductus arteriosus (PDA).
Which murmur is pansystolic-pandiastolic? –> PDA (same as continuous machinery-like).
Which murmur is to-and-fro? –> PDA; outrageous, but it’s on NBME 6 for 2CK and relies on you knowing this description to get it right; every student gets this Q wrong and then says “wtf is to-and-fro.” (my students of course will say, “got that one right because of you”).
Which murmur is fixed splitting of S2? –> atrial septal defect (ASD).
Which murmurs are holodiastolic (pandiastolic)? –> aortic regurgitation (aortic insufficiency; AR) + pulmonic regurgitation (pulmonic insufficiency; PR).
Which murmur is pandiastolic and loudest in early-diastole? –> classically AR (decrescendo holodiastolic murmur).
Young child + hypocalcemia + harsh systolic murmur at left sternal border; Dx? –> DiGeorge syndrome associated with tetralogy of Fallot –> on the USMLE, you should essentially think of ToF and DiGeorge syndrome as interchangeable –> you can by all means get other heart defects in DiGeorge, e.g., truncus arteriosus, but I can’t emphasize enough that ToF is almost always seen in DiGeorge on USMLE.
Important initial principle regarding heart murmurs –> all will get worse / more prominent with more volume in the heart, however MVP and HOCM are the odd ones out; they’ll get worse with less volume in the heart.
What does VSD sound like? –> USMLE will describe it two ways: 1) holosystolic murmur (aka pansystolic) at the left sternal border (or lower left sternal border) with a parasternal heave or thrill; 2) holosystolic murmur at the left sternal border with a diastolic rumble (weird, but in NBME Qs and possibly an effect from movement across the valve even during the diastolic filling stage).
Most common congenital heart defect? –> VSD.
If you patch/repair a VSD, what will happen to pressure in the LV, RV, and LA? (up or down arrows) à repairing a VSD will cause up LV, down RV, down LA à the down always confuses people –> repair of VSD means less blood entering RV –> less blood going back through the lungs to the LA.
Who gets AVSD (atrioventricular septal defect)? –> Down syndrome (aka endocardial cushion defect).
What does ASD sound like and why? –> as discussed earlier, fixed splitting of S2 –> when you’ve got an ASD, blood is constantly moving L –> R from LA –> RA (pressure is always greater on the left side). So the effects of inhalation/exhalation are minimized in terms of the A2-P2 split bc you’ll always have relatively constant LA –> RA flow (and resultant steady RA preload) irrespective of inspiration. The sound can also be described as “wide, fixed splitting” bc of increased RV preload à delayed closure of P2 relative to A2 –> slight widening, but it’s still fixed for the reasons explained above.
