Heart Failure
HFrEF vs HFpEF
| Feature | HFrEF (Systolic) | HFpEF (Diastolic) |
|---|---|---|
| EF | <40% | ≥50% (HFmrEF 41–49%) |
| Mechanism | Impaired contractility → reduced SV and CO | Impaired relaxation/compliance → elevated filling pressures despite normal EF |
| Causes | Ischemia (CAD/MI), DCM, myocarditis, alcohol, chemotherapy (anthracyclines), viral | HTN (#1), obesity, DM, hypertrophic CMP, aging, AF |
| Pathophysiology | Neurohormonal activation: RAAS, SNS → Na/H2O retention → volume overload; cardiac remodeling | Impaired lusitropy → elevated LVEDP → pulmonary congestion with normal systolic function |
| Treatment | ACE-I/ARB or ARNi (sacubitril/valsartan), Beta-blocker (carvedilol, metoprolol succinate, bisoprolol), MRA (spironolactone), SGLT-2 inhibitor (dapagliflozin/empagliflozin) = GDMT | Diuretics for symptoms; SGLT-2 inhibitors (only proven mortality benefit); treat underlying HTN, AF, obesity; no ACE-I/beta-blocker survival benefit proven |
NYHA Classification
| Class | Symptoms |
|---|---|
| I | No limitation; ordinary activity does not cause symptoms |
| II | Slight limitation; comfortable at rest; ordinary activity causes symptoms |
| III | Marked limitation; comfortable at rest; less than ordinary activity causes symptoms |
| IV | Symptoms at rest; inability to carry on any activity without discomfort |
🧠 Mnemonic — HFrEF GDMT: ABCDACE-I/ARB/ARNi · Beta-blocker · Cardiac device (ICD if EF <35%) · Diuretics (symptom management) + SGLT-2 inhibitors
🎯 Boards PearlBNP/NT-proBNP: elevated in HF (BNP >100 pg/mL or NT-proBNP >300 pg/mL suggests HF; BNP <100 pg/mL makes HF very unlikely). ICD indicated for EF ≤35% despite ≥3 months GDMT. CRT indicated for EF ≤35% + LBBB with QRS >150ms. Furosemide is NOT a life-prolonging drug — treat for symptoms only.
Acute Coronary Syndromes
Pathophysiology
ACS results from plaque rupture or erosion in a coronary artery → platelet aggregation and thrombus formation → partial or complete occlusion → myocardial ischemia/infarction. Plaque vulnerability depends on lipid core size, fibrous cap thickness, and inflammatory activity.
ACS Spectrum
| Type | Occlusion | ECG | Troponin | Key Action |
|---|---|---|---|---|
| Unstable Angina (UA) | Partial; no infarction | ST depression or T-wave changes (or normal) | Negative | Antiplatelet + anticoagulation; early cath |
| NSTEMI | Partial; subendocardial infarction | ST depression, T-wave inversion (or normal) | Elevated | Same as UA + troponin elevated = NSTEMI |
| STEMI | Complete transmural infarction | ST elevation ≥1mm in ≥2 contiguous leads (or LBBB) | Elevated | EMERGENT reperfusion: PCI within 90 min (door-to-balloon); fibrinolytics if PCI unavailable within 120 min |
ECG Localization of MI
| Territory | Leads | Artery |
|---|---|---|
| Anterior | V1–V4 | LAD |
| Lateral | I, aVL, V5–V6 | LCx |
| Inferior | II, III, aVF | RCA (80%) or LCx (20%) |
| Posterior | ST depression V1–V3 (reciprocal); tall R waves V1–V2 | RCA or LCx |
| RV infarct | ST elevation in V4R; occurs with inferior MI | Proximal RCA |
Complications of MI
🧠 Mnemonic — MI Complications by Timeline: DREADDay 1–2: Death (arrhythmia, VF) · Reperfusion arrhythmias · 2–5 days: Extension, Embolism · Days 3–5: Aneurysm, papillary muscle rupture (MR), free wall rupture, VSD · Days 5–10: Dressler syndrome (weeks later)
🏥 Post-MI Management (MONA + BATMAN)Morphine (pain, preload), Oxygen (if SaO2 <90%), Nitrates (angina relief), Aspirin 325mg; then: Beta-blocker (reduce remodeling, arrhythmia), ACE-I (reduce remodeling, especially anterior MI), Thrombus management (anticoagulation), Aldosterone antagonist (EF <40% + HF/DM), Statin (high-intensity: atorvastatin 80mg), New platelet inhibitor (clopidogrel or ticagrelor or prasugrel for 12 months).
Arrhythmias
| Arrhythmia | Mechanism | ECG | Treatment |
|---|---|---|---|
| Atrial Fibrillation | Chaotic atrial depolarizations from multiple re-entrant wavelets; most common sustained arrhythmia | Irregularly irregular, absent P waves, wavy baseline, narrow QRS | Rate control (beta-blocker, diltiazem, digoxin); rhythm control (amiodarone, flecainide, cardioversion); anticoagulation (CHA₂DS₂-VASc ≥2 men, ≥3 women) |
| Atrial Flutter | Single re-entrant circuit in RA; atrial rate ~300 bpm | Sawtooth flutter waves (best in II, III, aVF); 2:1, 3:1, or 4:1 block; ventricular rate ~150 bpm (2:1) | Rate control; cardioversion; ablation (highly effective in flutter) |
| SVT (AVNRT) | Re-entrant circuit within or near AV node; retrograde P waves buried in or just after QRS | Narrow QRS tachycardia ~150–250 bpm; P waves not visible or retrograde | Vagal maneuvers; adenosine (drug of choice); verapamil/diltiazem; ablation for recurrent |
| Ventricular Tachycardia | Re-entrant circuit or automaticity in ventricle; associated with structural heart disease, ischemia, cardiomyopathy | Wide QRS (>0.12s) tachycardia ≥3 beats; AV dissociation, fusion beats, capture beats | Stable: amiodarone, lidocaine; Unstable: synchronized cardioversion; Pulseless: defibrillation; ICD for recurrent sustained VT |
| Ventricular Fibrillation | Completely chaotic ventricular depolarization; no effective cardiac output | Coarse or fine irregular waveforms; no organized QRS | Immediate defibrillation; ACLS; epinephrine, amiodarone |
| Complete Heart Block (3rd°) | No conduction from atria to ventricles; independent atrial and ventricular rates | AV dissociation; atrial rate > ventricular rate (junctional ~40–60, ventricular ~20–40 bpm) | Atropine (temporary); transcutaneous pacing; permanent pacemaker |
🎯 Boards Pearl — AF AnticoagulationCHA₂DS₂-VASc score: Congestive HF (1) · HTN (1) · Age ≥75 (2) · Diabetes (1) · Stroke/TIA history (2) · Vascular disease (1) · Age 65–74 (1) · Sex category female (1). Anticoagulate with score ≥2 (men) or ≥3 (women). DOACs preferred over warfarin. Hold anticoagulation if CrCl <15 or on dialysis (check agent-specific thresholds).
Valvular Disease
| Lesion | Mechanism | Murmur | Key Features | Treatment |
|---|---|---|---|---|
| Aortic Stenosis | Progressive calcification/fibrosis of aortic valve leaflets; congenital bicuspid aortic valve | Harsh crescendo-decrescendo systolic murmur at RUSB; radiates to neck; paradoxical splitting of S2 | Triad: Angina, Syncope, CHF (SAD); EF may be preserved until late; AS = most common valvular disease in adults | Symptomatic: TAVR or surgical AVR; NO vasodilators (will cause decompensation) |
| Aortic Regurgitation | Aortic root dilation (Marfan's, HTN, syphilitic aortitis) or valve disease (endocarditis, bicuspid, rheumatic) | Diastolic decrescendo blowing murmur at LUSB; Austin Flint murmur (apical rumble) | Wide pulse pressure; Corrigan's pulse (water-hammer); de Musset's sign; Quincke's pulses | Acute severe: emergency surgery. Chronic: surgery when EF <55% or symptomatic; vasodilators (nifedipine, ACE-I) |
| Mitral Stenosis | Rheumatic fever → leaflet thickening and fusion, commissural fusion, chordal shortening | Diastolic rumble at apex; opening snap; loud S1 | LA enlargement → AF, emboli; pulmonary congestion; hemoptysis; opening snap moves closer to S2 as severity increases | Diuretics; rate control for AF; anticoagulation; percutaneous mitral balloon valvotomy (PMBV) or valve replacement |
| Mitral Regurgitation | MVP (most common), ischemic papillary muscle rupture, rheumatic, endocarditis, dilated CMP | Holosystolic blowing murmur at apex; radiates to axilla; soft S1 | LV volume overload → LV dilation; eccentric hypertrophy; LA enlargement → AF | Acute severe: emergency surgery. Chronic: surgery when EF <60% or LVESD >40mm; vasodilators; no proven benefit of medical therapy in chronic |
🧠 Mnemonic — Murmur LocationsRUSB (2nd R intercostal) = Aortic stenosis · LUSB = Aortic regurgitation, Pulmonary stenosis/regurgitation · LSB (3rd–4th intercostal) = VSD, HCM, TR · Apex = Mitral stenosis (diastolic), Mitral regurgitation (systolic)