Cardiovascular Anatomy, Physiology, and Pathology
Core concepts
This domain supplies the structural and functional background for everything else. Know coronary anatomy: left main bifurcates into LAD and circumflex; the LAD supplies the anterior wall and septum; the circumflex supplies the lateral wall; the right coronary artery supplies the inferior wall and, in most people, the SA and AV nodes. Coronary dominance is defined by which artery gives rise to the posterior descending artery.
Understand the cardiac cycle: systole and diastole, the Wiggers diagram, isovolumetric contraction and relaxation, and how valve events map to pressure waveforms. Know the Frank-Starling relationship-stroke volume rises with preload up to a point-and the determinants of myocardial oxygen demand (heart rate, contractility, wall stress).
Pathology concepts tested include atherosclerosis and plaque rupture, stable versus acute coronary syndrome, valvular stenosis and regurgitation, cardiomyopathies, pericardial disease, and congenital lesions such as ASD, VSD, and PDA. Connect lesions to physiology: aortic stenosis causes a systolic murmur and concentric hypertrophy; mitral stenosis causes elevated left atrial pressure and pulmonary congestion.
Traps
Questions mix up which artery supplies which wall, or which lesion produces which murmur and hemodynamic signature. Do not assume the LAD always supplies the inferior wall. Remember that the right coronary artery more often supplies the AV node, so inferior infarcts carry higher bradyarrhythmia risk. Distinguish preload, afterload, and contractility when asked what changes stroke volume.
Rule of thumb
Map artery to territory: LAD = anterior/septal, circumflex = lateral, RCA = inferior and often nodal. Map lesion to physiology before answering.