ABIM Cardiology cheat sheet

Reperfusion in STEMI: primary PCI within 90 minutes of first medical contact (120 minutes if transfer is required); fibrinolysis within 30 minutes door-to-needle only when PCI cannot be achieved in time and symptoms began under 12 hours ago.

High-sensitivity troponin: myocardial injury requires a rise or fall with at least one value above the 99th percentile upper reference limit; myocardial infarction additionally requires clinical evidence of ischemia (symptoms, ECG change, imaging, or angiographic thrombus).

NSTE-ACS invasiveness: refractory ischemia, hemodynamic or electrical instability, or mechanical complications warrant angiography within 2 hours; GRACE score above 140, troponin rise, or dynamic ST changes warrant an early invasive strategy within 24 hours.

DAPT after ACS: aspirin plus a P2Y12 inhibitor for 12 months; ticagrelor or prasugrel preferred over clopidogrel unless bleeding risk is high, in which case 6 months may be used, followed by aspirin indefinitely.

Secondary prevention: high-intensity statin to LDL below 70 mg/dL (below 55 mg/dL for very high risk), add ezetimibe then a PCSK9 inhibitor; beta-blocker and ACE inhibitor or ARB after MI; mineralocorticoid antagonist when EF is 40% or lower with heart failure or diabetes.

Revascularization choice: CABG preferred for left main disease, three-vessel disease with high SYNTAX score, and multivessel disease with diabetes; PCI preferred for limited anatomy or high surgical risk; heart team discussion for complex cases.

Stable angina pathway: pretest probability determines testing; coronary CT angiography suits lower-risk patients, stress imaging suits intermediate-to-high risk; antianginal therapy starts with a beta-blocker, adding a calcium channel blocker or long-acting nitrate.

MINOCA: angiography showing less than 50% stenosis requires investigation for plaque disruption, spontaneous coronary artery dissection, vasospasm, and embolism, including intravascular imaging and cardiac MRI.

Vasospastic angina: resting or nocturnal angina with transient ST elevation, provoked by acetylcholine or ergonovine at angiography, treated with calcium channel blockers and smoking cessation; beta-blockers may worsen it.

Ejection fraction categories: HFrEF 40% or lower, HFmrEF 41-49%, HFpEF 50% or higher; HFmrEF and HFpEF diagnoses require evidence of elevated filling pressures or natriuretic peptide elevation.

Four pillars for HFrEF, each with mortality benefit: ARNI (preferred) or ACE inhibitor/ARB, evidence-based beta-blocker (bisoprolol, carvedilol, metoprolol succinate), mineralocorticoid receptor antagonist, and SGLT2 inhibitor; initiate early and titrate to target doses.

Add-on therapy: ivabradine when sinus rate is 70 bpm or higher on maximally tolerated beta-blocker; vericiguat after a worsening heart failure event; hydralazine plus isosorbide dinitrate in self-identified Black patients; digoxin for symptom control only.

Loop diuretics relieve congestion but have no mortality benefit; use the lowest effective dose and monitor creatinine, potassium, and magnesium.

Primary prevention ICD: EF 35% or lower despite at least 3 months of guideline-directed therapy, NYHA class II or III symptoms, and expected survival beyond 1 year; ICD is not indicated when life expectancy is under 1 year or revascularization is imminent.

CRT indications: LBBB with QRS 150 ms or more and EF 35% or lower is class I; LBBB with QRS 120-149 ms or non-LBBB with QRS 150 ms or more and EF 35% or lower is reasonable.

Acute decompensated heart failure: profile patients by congestion and perfusion; intravenous loop diuretic for congestion, noninvasive ventilation for pulmonary edema, inotropes only for hypoperfusion, and avoid nitrates or diuretics in hypotension.

Cardiogenic shock: graded by SCAI stages A through E; urgent revascularization in acute MI, vasopressors plus inotropes, and temporary mechanical circulatory support in selected patients; routine intra-aortic balloon pumping does not reduce mortality.

Hypertrophic cardiomyopathy: LVOT gradient of 30 mmHg or more with symptoms warrants septal reduction (surgical myectomy preferred); avoid volume depletion and vasodilators; ICD for prior arrest, sustained VT, or high-risk features.

Atrial fibrillation anticoagulation: CHA2DS2-VASc 2 or higher in men and 3 or higher in women supports anticoagulation; DOACs are preferred except with mechanical valves or moderate-to-severe mitral stenosis, where warfarin is required.

Bleeding risk scores identify modifiable risk factors and should not by themselves be used to withhold anticoagulation from a patient who meets a stroke-risk threshold.

Rate control: beta-blocker or non-dihydropyridine calcium channel blocker first line; a lenient resting target below 110 bpm is acceptable when asymptomatic and LV function is preserved; digoxin is an alternative.

Cardioversion of AF lasting over 48 hours or of unknown duration requires 3 weeks of therapeutic anticoagulation or a negative transesophageal echo before the shock, followed by at least 4 weeks of anticoagulation afterward.

Supraventricular tachycardia: vagal maneuvers first, then adenosine 6 mg rapid push, then 12 mg; use caution in severe asthma; unstable patients receive synchronized cardioversion.

Pre-excited atrial fibrillation (WPW): AV nodal blockers including adenosine, verapamil, diltiazem, and digoxin are contraindicated; use ibutilide, procainamide, or synchronized cardioversion.

Wide-complex tachycardia is treated as VT: pulseless → defibrillation; unstable → synchronized cardioversion; stable monomorphic → procainamide or amiodarone; polymorphic → magnesium, electrolyte correction, and overdrive pacing for torsades.

Permanent pacing indications: symptomatic sinus node dysfunction, Mobitz II second-degree block, complete heart block, and alternating bundle branch block, regardless of symptoms in some settings.

Long QT syndrome: QTc above 500 ms markedly raises torsades risk; avoid QT-prolonging drugs, correct potassium and magnesium, use beta-blockers, and consider ICD after cardiac arrest.

Severe aortic stenosis: peak velocity 4 m/s or higher, mean gradient 40 mmHg or higher, or valve area 1.0 cm² or less (indexed 0.6 cm²/m² or less); any symptom (angina, syncope, dyspnea) with severe AS warrants aortic valve replacement.

Low-flow low-gradient AS: dobutamine stress echocardiography distinguishes true severe from pseudosevere disease; when contractile reserve is absent, aortic valve calcium scoring by CT helps confirm severity.

Aortic regurgitation: severe when vena contracta is 0.6 cm or more, regurgitant volume 60 mL or more, or regurgitant fraction 50% or more; surgery for symptoms or when EF falls to 55% or less or end-systolic dimension exceeds 50 mm.

Primary mitral regurgitation: surgery for symptoms or when EF is 60% or less, end-systolic dimension is 40 mm or more, or pulmonary hypertension or atrial fibrillation develops; valve repair is preferred over replacement.

Secondary mitral regurgitation: treat the ventricle with guideline-directed medical therapy and resynchronization; transcatheter edge-to-edge repair is reserved for persistent symptoms despite optimized therapy.

Rheumatic mitral stenosis: severe when valve area is 1.5 cm² or less; percutaneous balloon commissurotomy is preferred when morphology is favorable, there is no left atrial thrombus, and mitral regurgitation is less than moderate.

Prosthetic valves: mechanical valves need lifelong warfarin (INR 2.0-3.0 aortic, 2.5-3.5 mitral) plus low-dose aspirin; bioprostheses need aspirin, with 3 months of warfarin after surgery in selected patients.

Endocarditis prophylaxis before high-risk dental procedures: prosthetic valve or prosthetic material, prior infective endocarditis, unrepaired cyanotic congenital heart disease, and cardiac transplant with valvulopathy.

Auscultation anchors: AS is a crescendo-decrescendo systolic murmur radiating to the carotids; MR is holosystolic at the apex radiating to the axilla; AR is an early diastolic decrescendo murmur; MS produces an opening snap and diastolic rumble.

Acute pericarditis is diagnosed by at least 2 of 4 criteria: characteristic sharp pleuritic chest pain improved by leaning forward, pericardial friction rub, new widespread ST elevation or PR depression, and a new or enlarging pericardial effusion.

First-line pericarditis therapy is a nonsteroidal anti-inflammatory drug plus colchicine for 3 months, with exercise restriction; corticosteroids are reserved for contraindications or systemic disease because they raise recurrence risk.

High-risk pericarditis features requiring admission: fever above 38°C, subacute course, large effusion or tamponade, immunosuppression, trauma, and oral anticoagulation.

Cardiac tamponade: hypotension, elevated jugular venous pressure, muffled heart sounds, pulsus paradoxus over 10 mmHg, and electrical alternans; treatment is urgent pericardiocentesis or surgical drainage, with avoidance of diuretics and vasodilators.

Constrictive pericarditis: pericardial knock, septal bounce, annulus reversus, and respirophasic septal shift on echocardiography; pericardiectomy is definitive when symptoms persist after medical therapy.

Myocarditis: cardiac MRI with Lake Louise criteria (nonischemic late gadolinium enhancement plus edema) supports diagnosis; treat heart failure, avoid strenuous exercise for 3-6 months, and use mechanical support in fulminant cases.

Cardiac amyloidosis: low-voltage ECG, thickened walls with apical sparing strain pattern, and elevated troponin or natriuretic peptides; bone scintigraphy is diagnostic for ATTR, but serum protein electrophoresis with free light chains is mandatory to exclude AL amyloidosis.

Takotsubo syndrome: postmenopausal women after emotional or physical stress with apical ballooning and no obstructive coronary disease; management is supportive, and recurrence occurs in a small minority.

Peripartum cardiomyopathy: heart failure with EF below 45% between late pregnancy and 5 months postpartum; treat with standard heart failure therapy, and recovery of function is common with guideline-directed care.

ACC/AHA blood pressure categories: normal below 120/80 mmHg, elevated 120-129/under 80, stage 1 130-139/80-89, and stage 2 at 140/90 mmHg or above; treatment target is generally below 130/80.

Hypertensive emergency: blood pressure 180/120 mmHg or higher with end-organ damage; lower mean arterial pressure by no more than 25% in the first hour, except in aortic dissection, where systolic pressure is rapidly brought below 120 mmHg.

Resistant hypertension: blood pressure above goal on three agents including a diuretic at maximally tolerated doses; add spironolactone as the fourth drug and screen for primary aldosteronism with an aldosterone-to-renin ratio.

Secondary hypertension clues: onset before age 30 or after 55, hypokalemia, resistant pressure, abdominal bruit, paroxysmal headache with palpitations, and worsening renal function after an ACE inhibitor.

Aortic dissection: type A is a surgical emergency; type B is managed medically with intravenous beta-blockade before vasodilatation, targeting heart rate below 60 bpm and systolic pressure near 100-120 mmHg.

Peripheral artery disease: ankle-brachial index of 0.90 or less is diagnostic; claudication is treated with supervised exercise, statin, antiplatelet therapy, and cilostazol; an index above 1.40 indicates noncompressible calcified vessels.

Abdominal aortic aneurysm: repair when diameter is 5.5 cm or more in men or 5.0 cm or more in women, or with rapid growth; one-time ultrasound screening for men aged 65-75 who have ever smoked.

Carotid stenosis: carotid endarterectomy for symptomatic stenosis of 50-99% (ideally performed within 2 weeks of the event), with intensive medical therapy for asymptomatic disease.

Venous thromboembolism: direct oral anticoagulants are first line for most patients; 3 months is the minimum duration, with extended therapy for unprovoked or recurrent events when bleeding risk is acceptable.

Pulmonary hypertension is defined by mean pulmonary artery pressure above 20 mmHg at rest on right heart catheterization; precapillary disease additionally requires pulmonary vascular resistance of 3 Wood units or more and wedge pressure of 15 mmHg or less.

WHO groups: 1 pulmonary arterial hypertension, 2 left heart disease, 3 lung disease or hypoxia, 4 chronic thromboembolic disease, and 5 multifactorial mechanisms.

Group 1 therapy: perform vasoreactivity testing; only responders may receive calcium channel blockers; otherwise use endothelin receptor antagonists, phosphodiesterase-5 inhibitors, or prostacyclin pathway agents, with combination therapy for high-risk patients.

Groups 2 and 3 do not benefit from pulmonary arterial hypertension-specific drugs; treat the underlying left heart or lung disease, and oxygen for hypoxemia.

Chronic thromboembolic pulmonary hypertension: ventilation-perfusion scanning is the screening test of choice; pulmonary endarterectomy is curative for accessible disease, with riociguat or balloon pulmonary angioplasty as alternatives.

Pulmonary embolism diagnosis: pretest probability by Wells score, age-adjusted D-dimer for low or intermediate probability, and CT pulmonary angiography for confirmation; V/Q scan when contrast is contraindicated.

High-risk pulmonary embolism with hypotension or shock requires systemic thrombolysis or catheter-directed therapy; intermediate-high-risk patients are watched closely for deterioration on anticoagulation alone.

Acute right ventricular failure: avoid volume overload, maintain systemic perfusion with vasopressors, and consider inhaled pulmonary vasodilators or mechanical support in refractory cases.

Atrial septal defect: fixed split second heart sound and a systolic pulmonary flow murmur; closure is indicated when the pulmonary-to-systemic flow ratio exceeds 1.5 with right ventricular enlargement; closure is contraindicated in Eisenmenger physiology.

Ventricular septal defect: small muscular defects often close spontaneously; large defects cause heart failure and failure to thrive, prompting surgical repair before pulmonary vascular disease develops.

Patent ductus arteriosus: indomethacin, ibuprofen, or acetaminophen promotes closure in preterm infants; persistent defects are closed percutaneously or surgically.

Tetralogy of Fallot: cyanosis with a systolic ejection murmur and squatting; hypercyanotic spells are treated with knee-chest position, oxygen, morphine, intravenous fluids, phenylephrine, and beta-blockade, with repair at 3-6 months of age.

Transposition of the great arteries: prostaglandin E1 maintains ductal patency, balloon atrial septostomy improves mixing, and the arterial switch operation is definitive in the first weeks of life.

Coarctation of the aorta: upper extremity hypertension with a systolic gradient between arms and legs, rib notching on chest radiograph, and an associated bicuspid aortic valve in a majority; treat with surgical or catheter repair.

Eisenmenger syndrome: pulmonary vascular disease reverses a left-to-right shunt; pregnancy and systemic vasodilators are contraindicated, and pulmonary vasodilators plus supplemental oxygen may be used.

Endocarditis prophylaxis applies to unrepaired cyanotic lesions, prosthetic material within the first 6 months, and residual defects after repair; not to simple repaired defects after endothelialization.

Genetic associations: trisomy 21 with atrioventricular septal defects, 22q11 deletion with conotruncal anomalies, and Turner syndrome with coarctation and bicuspid aortic valve.

The pooled cohort equations estimate 10-year ASCVD risk from age, sex, race, total and HDL cholesterol, systolic blood pressure, antihypertensive use, diabetes, and smoking; thresholds are below 5% low, 5-7.5% borderline, 7.5-20% intermediate, and above 20% high.

Statin strategy: high-intensity statin for clinical ASCVD, diabetes aged 40-75, or 10-year risk above 20%; moderate-intensity statin with shared decision-making for intermediate risk, especially with risk-enhancing factors.

Risk enhancers include family history of premature ASCVD, persistently elevated LDL above 160 mg/dL, metabolic syndrome, chronic kidney disease, chronic inflammatory disease, high-risk ethnicity, elevated lipoprotein(a), and hsCRP of 2 mg/L or more.

Coronary artery calcium scoring: a score of 0 in an intermediate-risk patient supports withholding statin therapy (except in smokers or diabetics), while a score of 100 or more favors statin initiation.

LDL targets: below 70 mg/dL for very high risk and below 55 mg/dL for extreme risk, adding ezetimibe and then a PCSK9 inhibitor when targets are not achieved.

Aspirin is not recommended for routine primary prevention; it may be considered in selected adults aged 40-70 at higher ASCVD risk who are at low bleeding risk.

Smoking cessation: varenicline combined with behavioral counseling is the most effective monotherapy, with combination nicotine replacement as an alternative; e-cigarettes are not first-line therapy.

Lifestyle prescription: at least 150 minutes per week of moderate-intensity aerobic activity, reduced sodium intake, a Mediterranean-style diet, weight loss, and limited alcohol.

Diabetes and cardiovascular risk: SGLT2 inhibitors and GLP-1 receptor agonists reduce major adverse cardiovascular events in patients with established ASCVD or high risk, independent of glycemic control.

Revised Cardiac Risk Index predictors: high-risk surgery, history of ischemic heart disease, heart failure, cerebrovascular disease, insulin-dependent diabetes, and serum creatinine above 2.0 mg/dL; 3 or more predictors marks elevated risk.

Perioperative beta-blockade: continue chronic beta-blockers through surgery; do not start beta-blockers on the day of surgery, because this increases bradycardia, hypotension, and stroke.

Dual antiplatelet therapy before elective surgery: defer at least 6 months after drug-eluting stent implantation and 1 month after bare-metal stent implantation when clinically feasible; never stop aspirin without cardiology input after recent stenting.

Preoperative testing is indicated only when it will change management; a functional capacity of 4 METs or more allows most patients to proceed to surgery without stress testing.

Perioperative myocardial infarction is most often type 2 from supply-demand imbalance; check troponin in symptomatic patients, treat anemia, hypotension, tachycardia, and pain, and reserve coronary angiography for ST-elevation or clear instability.

Adult cardiac arrest: compressions 100-120 per minute at 5-6 cm depth with full recoil, 30:2 compression-ventilation ratio without an advanced airway; epinephrine 1 mg every 3-5 minutes and amiodarone 300 mg then 150 mg for shock-refractory VF or pulseless VT.

Post-arrest care: targeted temperature management, avoidance of fever, treatment of the cause, and delayed neuroprognostication at least 72 hours after return of spontaneous circulation.

Cardiogenic shock: SCAI stages A-E; norepinephrine is the first-line vasopressor, and mechanical circulatory support is considered for refractory shock, with early revascularization in acute MI.

Septic shock: 30 mL/kg crystalloid within the first 3 hours, norepinephrine as the first-line vasopressor with a mean arterial pressure target of 65 mmHg, and lactate-guided resuscitation.