Cardiovascular

~11% of blueprint

Highest-yield system. ACS, HF, arrhythmias, valvular disease.

Disease Profiles

Region: Within the myocardium, from the right atrium to the ventricles.
Key Structures: SA node (RA) → AV node → Bundle of His → R/L bundle branches → Purkinje fibers.
Clinical Correlation: SA node = dominant pacemaker; AV nodal delay = PR interval; block at His/branches → bundle branch & heart block.

High-Yield Pearl

SA node is the pacemaker; the AV node is the gatekeeper that delays conduction so the atria empty first.

Region: Epicardial surface of the heart, arising from the aortic root.
Key Structures: LAD & LCx (from left main), RCA; RCA → PDA in ~85% (right-dominant).
Clinical Correlation: LAD occlusion → anterior MI (V1–V4); RCA → inferior MI (II, III, aVF); LCx → lateral MI (I, aVL, V5–V6).

High-Yield Pearl

RCA supplies the SA node in ~60% — inferior MI → watch for bradyarrhythmias & AV block.

Region: Anchored to the fibrous cardiac skeleton at the AV and outflow junctions.
Key Structures: AV valves: tricuspid (R), mitral/bicuspid (L). Semilunar: pulmonic (R), aortic (L).
Clinical Correlation: Auscultation: Aortic (R 2nd ICS), Pulmonic (L 2nd ICS), Tricuspid (L lower sternal), Mitral (apex).

High-Yield Pearl

“APT M” — All Physicians Take Money — Aortic → Pulmonic → Tricuspid → Mitral auscultation sites.

Region: Fibroserous sac enclosing the heart and great-vessel roots.
Key Structures: Fibrous pericardium + serous (parietal & visceral/epicardium) layers; pericardial space (~15–50 mL fluid).
Clinical Correlation: Inflammation → pericarditis (friction rub, diffuse ST elevation); fluid → effusion → tamponade.

High-Yield Pearl

Beck’s triad = hypotension + JVD + muffled heart sounds → cardiac tamponade (a clinical emergency).