Hub / Organ Systems / Cardiovascular Medicine

COMLEX Level 1 • Level 2-CE • COMAT • 14–18% Blueprint Weight

Cardiovascular Medicine Command Center

High-yield cardiovascular pathophysiology, ACS biomarker kinetics, 12-lead ECG localization, physical exam maneuver dynamics on murmurs, GDMT heart failure guidelines, and pediatric congenital cyanotic defect matrices.

Drill 15-Q Cardio Block

Ischemic Heart Disease Spectrum

Acute Coronary Syndromes (ACS) Triad

ECG • Biomarkers • Plaque Pathology

Incomplete Occlusion No Necrosis

Unstable Angina (UA)

New-onset angina at rest, worsening frequency/duration, or post-infarction angina. Subtotal thrombotic occlusion over ruptured atheromatous plaque.

ECG: Normal or transient ST depression / T-wave inversion

Troponin: Negative

Management: Medical anti-ischemic + DAPT

Subendocardial Infarct Partial Occlusion

NSTEMI

Persistent ischemia causing subendocardial myocyte necrosis without transmural ST elevations. Subendocardium is most vulnerable to ischemic hypoperfusion.

ECG: ST depression (>0.5 mm) or T-wave inversion

Troponin: Positive (Elevated)

Management: DAPT, Heparin, early invasive angiography (<24h)

Transmural Infarct Full Occlusion

STEMI

Complete, acute thrombotic occlusion of epicardial coronary artery leading to full-thickness transmural necrosis of myocardium. Immediate time-critical emergency!

ECG: Convex-up ST elevation ≥1 mm in ≥2 contiguous leads (or new LBBB)

Troponin: Markedly Elevated

Target Door-to-Balloon: ≤90 minutes (or tPA ≤30 min if no PCI facility)

Coronary Angiography • 12-Lead Map

Coronary Territory & Infarction Localization

LAD • LCx • RCA • Reciprocal Shifts

Infarct Location	ECG Leads with ST Elevation	Occluded Coronary Artery	Reciprocal ST Depression	Key Board Exam Correlates
Anteroseptal	V1, V2	LAD (Proximal / Septal Branches)	None or minimal II, III, aVF	Supplies IV septum and Bundle of His; high risk of Mobitz II and complete AV block.
Anteroapical	V3, V4	LAD (Distal)	Inferior leads (II, III, aVF)	Most common STEMI location. Risk of true left ventricular apical aneurysm and mural thrombus.
Anterolateral / Extensive Anterior	V1–V6, I, aVL	LAD Mainstem ("Widowmaker")	Inferior leads (II, III, aVF)	Massive anterior wall necrosis; severe cardiogenic shock; acute pulmonary edema.
Lateral	I, aVL, V5, V6	LCx (Left Circumflex Artery)	Inferior leads (II, III, aVF)	Supplies lateral left ventricle; perfused from diagonal or obtuse marginal branches.
Inferior	II, III, aVF	RCA (Right Coronary Artery) in 90%	Leads I and aVL	Supplies AV node in right-dominant circulation; risk of sinus bradycardia, Wenckebach AV block. Contraindicated: Nitrates/Morphine if RV involvement!
Right Ventricular (RV)	V4R (Right-sided leads), V1	RCA (Acute Marginal Branches)	Varies	Clinical Triad: Hypotension, Clear lung fields, Elevated JVP. Highly preload-dependent → treat with IV Normal Saline boluses, avoid nitrates/diuretics.
Posterior	V7–V9 (≥0.5 mm STE)	PDA (from RCA or LCx)	Tall R waves & ST depression in V1–V3	Mirror-image changes in standard V1–V3 leads (horizontal ST depression, upright tall T waves, tall R waves).

Clinical 12-Lead Diagnostic Exhibits

Anterior STEMI ("Tombstone") vs. Inferior STEMI

12-Lead Strip Verification

LAD Occlusion • Anteroseptal

Anterior STEMI: Massive "Tombstone" ST Elevations

Anterior STEMI Tombstone ST Elevations 12-Lead ECG

Marked convex-up ST elevations spanning V1–V4 with hyperacute T waves ("tombstoning"). Indicates proximal LAD occlusion with massive anterior wall necrosis.

RCA Occlusion • Diaphragmatic Wall

Inferior STEMI: Leads II, III, aVF with Reciprocal Changes

Inferior STEMI Leads II III aVF 12-Lead ECG

Prominent ST elevation in inferior leads (II, III, aVF) paired with classic reciprocal ST depression in high lateral leads (I, aVL). Indicates RCA occlusion.

High-Yield Board Pathology Timeline

Post-Myocardial Infarction Complications Timeline

0 Hours to >2 Weeks

0–24 Hours

Lethal Arrhythmias & Heart Failure

Ventricular Fibrillation (VF) and Ventricular Tachycardia (VT) from electrical re-entry around ischemic margins. Primary cause of pre-hospital death.

Histology: Early waviness of myofibers (0–4h), contraction bands (reperfusion), early coagulation necrosis, and edema.

1–3 Days

Fibrinous Pericarditis

Localized inflammation over transmural infarct area. Pleuritic chest pain worse supine, relieved sitting forward. Audible pericardial friction rub.

Histology: Dense neutrophil infiltration with extensive coagulation necrosis and loss of myocyte nuclei.

3–14 Days

Mechanical Rupture Triad

• Free Wall Rupture: Hemopericardium → rapid Cardiac Tamponade (Beck's triad).

• Papillary Muscle Rupture: Posteromedial papillary muscle (single blood supply from PDA) → acute severe Mitral Regurgitation & pulmonary edema.

• Interventricular Septum Rupture: Macrophage lysis of IV septum → left-to-right shunt with harsh new holosystolic murmur at LLSB.

Histology: Macrophage phagocytosis of necrotic tissue, granulation tissue formation, and neo-vascularization. Wall is softest and most vulnerable!

>2 Weeks

Dressler Syndrome & Aneurysm

Dressler Syndrome: Autoimmune pericarditis (Type III/IV hypersensitivity to exposed cardiac antigens) weeks after MI. Fever, pleurisy, leukocytosis. Treated with NSAIDs/colchicine.

Ventricular Aneurysm: Thin, fibrous scar bulges outward during systole (dyskinesis). Persistent ST elevation months post-MI; risk of mural thrombus and embolic stroke.

Hemodynamic Mechano-Pathology • 2K Atlas

Left Ventricular PV Loops in Valvular Lesions

AS • AR • MS • MR

Left Ventricular PV Loops in Valvular Disease 2K Master Plate

Mechanical phase shifts across Aortic Stenosis (increased peak LV systolic pressure), Aortic Regurgitation (increased stroke volume and wide pulse pressure), Mitral Stenosis (decreased LV filling and end-diastolic volume), and Mitral Regurgitation (loss of true isovolumetric phases with regurgitation into low-pressure left atrium).

Bedside Auscultation Dynamics

Physical Examination Maneuvers on Cardiac Murmurs

Preload • Afterload • SVR Modulations

Bedside Maneuver	Hemodynamic Mechanism	Murmurs That INCREASE (↑)	Murmurs That DECREASE (↓)	Key Board Rule of Thumb
Inspiration	↓ Intrathoracic pressure → ↑ venous return to right heart	ALL Right-Sided Murmurs (TR, TS, PR, PS)	Left-Sided Murmurs (AS, MR, MS, AR)	Carvallo Sign: Tricuspid Regurgitation increases with inspiration; Mitral Regurgitation does not.
Expiration	↑ Intrathoracic pressure → ↑ blood flow from pulmonary veins to left heart	ALL Left-Sided Murmurs (AS, MR, MS, AR)	Right-Sided Murmurs	Left-sided sounds (e.g. S3, S4, Aortic stenosis) are best heard at end-expiration.
Valsalva (Strain phase) / Standing	↓ Venous return → ↓ Preload (smaller LV chamber)	HOCM & MVP (Click occurs earlier)	ALL Other Murmurs (AS, MR, VSD, AR)	THE GOLDEN EXCEPTION: Only HOCM and MVP get louder with decreased preload!
Squatting / Passive Leg Raise	↑ Venous return & ↑ SVR → ↑ Preload & ↑ Afterload	AS, MR, VSD, AR	HOCM & MVP (Click occurs later)	Increased LV volume pushes anterior mitral leaflet away from hypertrophied septum in HOCM → softens murmur.
Handgrip (Isometric Clench)	↑ Systemic Vascular Resistance (SVR) → ↑ Afterload	MR, AR, VSD (Backward Flow)	AS, HOCM (Forward Flow)	Differentiates AS from MR: Handgrip softens AS (decreased forward pressure gradient) but intensifies MR.
Amyl Nitrite Inhalation	Potent arteriolar vasodilator → ↓ Afterload	AS, HOCM, PS (Forward Flow)	MR, AR, VSD (Backward Flow)	Opposite of Handgrip: Promotes forward ejection, reducing regurgitant backward leaks.

High-Yield Systolic Murmurs

Between S1 and S2

Aortic Stenosis (AS)

Crescendo-decrescendo systolic ejection murmur best heard at right 2nd intercostal space; radiates to both carotids. Pulsus parvus et tardus (slow-rising, delayed carotid pulse), paradoxically split S2.

Mitral Regurgitation (MR)

Blowing holosystolic murmur loudest at apex; radiates to left axilla. High-pitched, plateau intensity. Post-MI papillary muscle dysfunction or rheumatic heart disease.

Mitral Valve Prolapse (MVP)

Midsystolic click followed by late systolic murmur. Caused by myxomatous valve degeneration (Marfan, Ehlers-Danlos). Click moves earlier with Valsalva; later with squatting.

Hypertrophic Cardiomyopathy (HOCM)

Harsh systolic crescendo-decrescendo murmur at left lower sternal border without carotid radiation. Asymmetric septal hypertrophy with systolic anterior motion (SAM) of mitral valve.

High-Yield Diastolic Murmurs

Between S2 and S1 • ALWAYS PATHOLOGIC!

Aortic Regurgitation (AR)

Early blowing, high-pitched decrescendo diastolic murmur heard best at left sternal border with patient leaning forward in full expiration. Hyperdynamic circulation: Wide pulse pressure, Corrigan water-hammer pulse, head bobbing (de Musset sign), capillary pulsations in nail beds (Quincke sign).

Mitral Stenosis (MS)

Follows S2 with a high-pitched Opening Snap (OS) due to abrupt halting of tensed leaflet excursion, followed by a low-pitched mid-diastolic decrescendo rumble with presystolic accentuation. Shorter A2-OS interval = MORE SEVERE stenosis! Sequela of Rheumatic Fever.

Patent Ductus Arteriosus (PDA)

Continuous "machine-like" murmur heard throughout systole and diastole with maximal intensity at S2. Loudest at left infraclavicular region. Associated with congenital rubella.

Cardiovascular Medicine Command Center

Acute Coronary Syndromes (ACS) Triad

Unstable Angina (UA)

NSTEMI

STEMI

Coronary Territory & Infarction Localization

Anterior STEMI ("Tombstone") vs. Inferior STEMI

Anterior STEMI: Massive "Tombstone" ST Elevations

Inferior STEMI: Leads II, III, aVF with Reciprocal Changes

Post-Myocardial Infarction Complications Timeline

Lethal Arrhythmias & Heart Failure

Fibrinous Pericarditis

Mechanical Rupture Triad

Dressler Syndrome & Aneurysm

Left Ventricular PV Loops in Valvular Lesions

Physical Examination Maneuvers on Cardiac Murmurs

High-Yield Systolic Murmurs

High-Yield Diastolic Murmurs

Atrioventricular (AV) Blocks Master Decoder

Constant Prolonged PR

Wenckebach Periodic Dropping

Sudden Dropped QRS

Total AV Dissociation

Supraventricular Tachycardias (SVT)

Ventricular Arrhythmias & Electrolytes

High-Yield Rhythm Strips Gallery

The 4 Pillars of GDMT in HFrEF (Mortality Reduction)

ARNI / ACEi / ARB

Evidence-Based Beta-Blockers

MRA (Spironolactone / Eplerenone)

Dapagliflozin / Empagliflozin

Cardiomyopathies: Dilated vs. Hypertrophic vs. Restrictive

Eccentric Hypertrophy • Systolic Failure

Asymmetric Septal Hypertrophy

Stiff Ventricles • Diastolic Failure

Congenital Heart Defects (Cyanotic vs. Acyanotic)

Cyanotic Heart Defects (Right-to-Left Shunt: "The 5 T's")

Acyanotic Heart Defects (Left-to-Right Shunt & Obstructive)

Acute Aortic Dissection

Pericarditis vs. Cardiac Tamponade

Active-Recall Cardiovascular Case Solver