STEMI

ST-elevation myocardial infarction · complete reference · all trials · full doses + brand names · Full Card

Symptoms / Associated Sx

• Severe substernal pressure, crushing, or squeezing ± radiation to left arm, jaw, neck, shoulder, or back; diaphoresis (most specific associated sign — more specific than chest pain quality); dyspnea; nausea/vomiting; palpitations; syncope (vasovagal or arrhythmia); profound sense of impending doom

• Inferior STEMI (RCA territory): nausea/vomiting predominant; bradycardia + hypotension (Bezold-Jarisch vagal reflex); ± RV MI (JVD + clear lungs + hypotension — preload-dependent; NTG → cardiac arrest)

• Anterior STEMI (LAD territory): largest territory → highest risk cardiogenic shock; signs of reduced CO (cool extremities, AMS, narrow pulse pressure, oliguria)

• RV MI (complicates 30–50% of inferior STEMI): classic triad — JVD + clear lungs + hypotension; check V4R routinely on all inferior STEMI; NTG absolutely contraindicated; aggressive IV fluid loading required

• Atypical presentations (up to 30% in elderly, diabetics, women): epigastric pain mistaken for GI illness; isolated dyspnea; fatigue; syncope; arm pain; jaw pain — these delay presentation and worsen outcomes; STEMI should be in the differential for any of these in appropriate risk context

Neg

• Pt denies tearing/ripping quality chest pain radiating between shoulder blades with BP differential >20 mmHg between arms and widened mediastinum on CXR — argues against aortic dissection (RCA ostium involvement in type A dissection produces classic inferior STEMI pattern on ECG; giving thrombolytics to a dissection = fatal aortic hemorrhage; brief 30-second clinical screen for tearing quality + BP differential before fibrinolysis is mandatory)

• Pt denies diffuse saddle-shaped ST elevation in ALL leads including lateral leads without territorial reciprocal changes, with PR segment depression — argues against pericarditis (STEMI has focal territorial STE + reciprocal ST depression in mirror leads; pericarditis has diffuse STE in virtually all leads, no reciprocal changes except aVR, and PR depression; no focal wall motion abnormality on echo in pericarditis)

• Pt denies pleuritic chest pain worsening with inspiration + acute hypoxia + RV dilation without LV dysfunction on echo + tachycardia out of proportion — argues against massive PE producing RV strain pattern (PE: S1Q3T3 on ECG; RV dilation with preserved LV on echo; McConnell sign [apical RV hyperkinesis]; CT-PA confirms)

• Pt denies known pre-existing Brugada pattern or LV aneurysm STE on prior ECGs — argues against non-ischemic STE pattern (always compare to prior ECG; Brugada: coved STE V1–V2 without inferior changes; LV aneurysm: persistent STE weeks after MI with deep Q-waves, no acute changes; dynamic ECG changes confirm acute STEMI)

Social History (SHx)

• Exact symptom onset time (determines reperfusion window — PCI most effective <12h; lytics most effective <3h; late PCI [12–48h] still beneficial for ongoing ischemia or hemodynamic instability); prior CAD (stent type, vessel, date — prior stent occlusion vs new territory); prior CABG (graft anatomy affects PCI approach)

• Tobacco, HTN, hyperlipidemia, DM, cocaine/stimulants; family history premature CAD (M <55, F <65); current antiplatelet/anticoag regimen (missed DAPT doses); last meal time (sedation for PCI); contrast allergy history; baseline renal function (contrast nephropathy risk stratification)

Main Etiology

• Plaque rupture (~75%): lipid-rich atherosclerotic plaque with thin fibrous cap → mechanical stress → plaque fissuring → subendothelial collagen exposure → platelet adhesion → thrombus formation → complete coronary occlusion; typically occurs in intermediate stenoses (30–70%), not necessarily the most severe lesion on angiography

• Plaque erosion (~25%): usually younger patients, women, smokers; erosion of endothelial surface without plaque rupture → thrombus on intact plaque; OCT-guided management possible (conservative thrombus aspiration without stenting)

• SCAD (spontaneous coronary artery dissection): young women, peripartum; intramural hematoma; avoid thrombolytics; careful angiography (avoid occlusive wiring); conservative preferred if stable

• Other: coronary embolism (AF, endocarditis, paradoxical from PFO); cocaine-induced vasospasm + thrombosis; post-PCI (stent thrombosis, no-reflow); coronary vasospasm (Prinzmetal — STE during spasm, normalizes after NTG)

RF

• Modifiable: tobacco (strongest — ↑plaque vulnerability + vasospasm + thrombosis), HTN, hyperlipidemia (LDL drives plaque growth), DM (↑plaque burden + microvascular disease + silent ischemia), obesity, cocaine/stimulants (vasospasm + catecholamine surge + thrombosis), physical inactivity

• Non-modifiable: age (M ≥45, F ≥55 — estrogen-protective pre-menopause), male sex, family history of premature CAD (M <55, F <65 in first-degree relative), prior ACS/PCI/CABG (↑vulnerable plaque burden)

• Emerging: Lp(a) (>50 mg/dL — independent RF; not reduced by statins; PCSK9i ↓Lp(a) ~25%; inclisiran [Leqvio] + pelacarsen emerging), CKD (uremic toxins → ↑endothelial dysfunction + accelerated atherosclerosis), chronic inflammatory states (RA/SLE/HIV), OSA (nocturnal hypoxemia + HTN + sympathetic surge)

Data

• ECG ≤10 minutes — diagnosis is ECG-based, NOT troponin-based (STE ≥1 mm in ≥2 contiguous limb leads OR ≥2 mm in V1–V4 [men] / ≥1.5 mm in V2–V3 [women] = STEMI; activate cath lab immediately; do NOT await troponin — diagnosis is clinical + ECG; STEMI equivalents: new LBBB + Sgarbossa ≥5 points; de Winter T-waves [LAD occlusion]; posterior STEMI [V1–V3 ST↓ with upright T → check V7–V9]; aVR STE ≥1 mm + diffuse ST↓ = left main/proximal LAD; reciprocal ST↓ in mirror leads confirms ischemic STE vs pericarditis)

• Right-sided leads V3R and V4R (mandatory in ALL inferior STEMI) (V4R STE ≥0.5 mm = RV MI in 30–50% of inferior STEMI; highest-risk inferior STEMI; NTG absolutely contraindicated; fluids required; early reperfusion critical)

• Posterior leads V7–V9 (if V1–V3 show ST↓ + tall upright T-waves) (posterior STEMI: STE ≥0.5 mm in V7–V9 = posterior MI; mirror image of anterior STEMI; circumflex territory most common; commonly missed without posterior leads)

• Troponin I/T serial q6h (confirms diagnosis post-cath; peak correlates with infarct size; re-elevation after initial decline = reinfarction or stent thrombosis; do NOT delay cath lab for first troponin result)

• BMP (K+ — target ≥4.0 mEq/L to reduce VF risk; hypokalemia ↑reperfusion VF; Cr — contrast nephropathy risk [peaks Days 2–3 post-procedure]; glucose — hyperglycemia ↑post-MI mortality [target <180 mg/dL]; Na+ — prognosis if HF develops)

• CBC (Hgb — anemia ↑ischemic burden; platelets — ≥70,000 for DAPT; WBC — stress leukocytosis; eosinophilia post-MI [Dressler syndrome at Days 2–6])

• Coagulation studies + T&S (baseline INR/PTT before anticoag; 2 units pRBC on hold if large anterior MI + hemodynamic compromise; anti-Xa level if on LMWH)

• Echo (portable bedside) — if diagnosis uncertain or hemodynamically unstable (regional WMA confirms ischemic territory; EF — Killip class ≥3; RV MI — dilated/hypokinetic RV with preserved apex [McConnell sign]; papillary muscle dysfunction — MR; LV thrombus in anterior MI [risk highest at 24–72h]; pericardial effusion — free wall rupture risk; tamponade)

• CXR portable (widened mediastinum — aortic dissection screen BEFORE fibrinolysis; pulmonary edema Killip ≥2; cardiomegaly; pleural effusion — do NOT delay cath lab for CXR; obtain simultaneously)

DDx

Aortic dissection (tearing back pain + BP differential >20 mmHg + widened mediastinum; RCA ostium dissection = inferior STEMI pattern; CTA BEFORE any anticoag or thrombolytics; giving lytics to dissection = fatal hemorrhage) · Pericarditis (diffuse saddle ST↑ all leads + PR↓ + pleuritic + friction rub; no territorial pattern; no focal WMA on echo; troponin mild elevation only in myopericarditis) · PE (pleuritic CP + hypoxia + RV dilation on echo without LV WMA; S1Q3T3; CT-PA; McConnell sign distinguishes from RV MI) · Takotsubo CM (stressor + older women + apical ballooning; transient anterior STE possible; normal coronaries — post-cath diagnosis; EF recovers) · Myocarditis (young + viral prodrome + diffuse non-territorial STE; cardiac MRI LGE non-ischemic; no occlusion on cath) · Early repolarization (young athlete; concave STE; J-point notching; dynamic with HR; benign variant — compare to old ECG) · Hyperkalemia (broad STEMI-mimicking pattern + peaked T-waves + K+ >6.5; check K+ stat if atypical broad ECG changes)

Home Meds

• Give immediately: aspirin (Bayer) 325 mg PO chewed ×1; P2Y12 loading dose (ticagrelor [Brilinta] 180 mg or prasugrel [Effient] 60 mg or clopidogrel [Plavix] 600 mg); UFH per protocol

• Hold: PDE5 inhibitors (sildenafil [Viagra] ×24h, tadalafil [Cialis] ×48h — severe hypotension with NTG; use fentanyl [Sublimaze] for pain relief); metformin (Glucophage) — hold before contrast (restart 48h post if Cr stable); NSAIDs (ibuprofen [Advil]/naproxen [Aleve]/celecoxib [Celebrex]) — avoid indefinitely post-ACS

• NTG absolutely contraindicated: suspected or confirmed RV MI (V4R STE); SBP <90 mmHg; PDE5i use within 24–48h; inferior STEMI with hypotension + JVD + clear lungs — always check V4R in inferior STEMI before giving NTG

• Continue: BB (carvedilol [Coreg]/metoprolol succinate [Toprol-XL]) — do NOT stop; rebound ischemia with abrupt discontinuation; statins — continue or initiate atorvastatin (Lipitor) 80 mg immediately

Plan

• STEP 1 — Activate cath lab ON ECG DIAGNOSIS (do not await troponin):

  • Notify cath lab team simultaneously while initiating dual antiplatelet + anticoag; every minute of door-to-balloon delay ↑mortality; goal door-to-balloon ≤90 minutes at PCI-capable center

  • Obtain IV ×2; continuous telemetry; O2 only if SpO2 <90%; 12-lead + right-sided leads (V3R/V4R) + posterior leads (V7–V9) if inferior MI

  • Brief screening for aortic dissection (tearing quality? BP differential? widened CXR mediastinum?) — if dissection possible → CTA before ANY thrombolytics or anticoag (30-second screen; do not delay definitive STEMI treatment for low-probability dissection)

• STEP 2 — Dual antiplatelet loading (simultaneous with cath lab activation):

  • Aspirin (Bayer/Ecotrin) 325 mg PO chewed ×1 — immediately; in ambulance, ED, floor — wherever STEMI is identified

  • Ticagrelor (Brilinta) 180 mg PO ×1 (preferred in STEMI — PLATO 2009: ↓CV death/MI/stroke 16% vs clopidogrel [Plavix]; give pre-cath in STEMI unlike NSTEMI); OR prasugrel (Effient) 60 mg PO ×1 (TRITON-TIMI 38: superior to clopidogrel [Plavix] in STEMI PCI setting; avoid age ≥75, weight <60 kg, prior stroke/TIA); OR clopidogrel (Plavix) 600 mg PO ×1 if ticagrelor/prasugrel contraindicated

  • GPIIb/IIIa inhibitors (eptifibatide [Integrilin]/tirofiban [Aggrastat]/abciximab [ReoPro]) — reserved for bail-out high thrombus burden at cath lab per interventionalist; not routine upstream

• STEP 3 — Anticoagulation:

  • UFH 60 units/kg IV bolus (max 4,000 units) → 12 units/kg/hr (max 1,000 units/hr; aPTT 50–70 sec; preferred for STEMI — rapid onset, reversible with protamine sulfate, predictable at cath lab); continue until post-PCI

  • Bivalirudin (Angiomax) 0.75 mg/kg IV bolus → 1.75 mg/kg/hr: alternative used at cath lab (HORIZONS-AMI: ↓major bleeding vs heparin + GPIIb/IIIa; slight ↑acute stent thrombosis within 24h; some centers prefer)

  • Enoxaparin (Lovenox): if already administered pre-hospital, do NOT give UFH at cath lab (↑bleeding from anticoag stacking); notify interventionalist of last dose and timing

• STEP 4 — Anti-ischemic measures (en route to cath lab):

  • Nitroglycerin (NTG SL) 0.4 mg q5 min ×3 (HOLD if: SBP <90; inferior MI + hypotension + JVD = RV MI; PDE5i ×24–48h; RV MI confirmed by V4R STE)

  • IV NTG (Nitro-Bid) 5–200 mcg/min: ongoing ischemic pain + SBP >100 + no RV MI

  • IV fentanyl (Sublimaze) 25–50 mcg q15 min PRN for pain — preferred over morphine (MSIR) in STEMI (morphine ↓P2Y12 absorption; ↑residual platelet reactivity)

  • O2 only if SpO2 <90% — avoid routine O2 in normoxic patients (↑oxidative stress + ↑coronary vascular resistance)

  • Metoprolol tartrate (Lopressor) 5 mg IV q5 min ×3 (max 15 mg IV) if: HR >100, SBP >120, no HF, no bronchospasm, no AV block — hold for any of these; do NOT give BB in cardiogenic shock

• Fibrinolytic therapy (if primary PCI unavailable AND symptom onset <12h AND first medical contact-to-balloon >120 min):

  • Tenecteplase (TNKase) single IV weight-based bolus: <60 kg = 30 mg; 60–69 kg = 35 mg; 70–79 kg = 40 mg; 80–89 kg = 45 mg; ≥90 kg = 50 mg (maximum) — easiest to administer correctly

  • Alteplase (Activase/tPA): 15 mg IV bolus → 0.75 mg/kg over 30 min (max 50 mg) → 0.5 mg/kg over 60 min (max 35 mg); total maximum 100 mg

  • Reteplase (Retavase): 10 units IV over 2 min → repeat 10 units IV at 30 min

  • Absolute contraindications: prior ICH (ever); ischemic stroke <3 months; known intracranial neoplasm/AVM/aneurysm; active internal bleeding; suspected aortic dissection; significant closed head trauma <3 months; SBP >185 or DBP >110 (relative)

  • Adjunct anticoag with lytics: UFH for alteplase/reteplase; enoxaparin (Lovenox) 30 mg IV bolus → 1 mg/kg SQ q12h (reduce if age ≥75: no bolus, 0.75 mg/kg SQ q12h; max 100 mg/dose) for tenecteplase (TNKase)

  • Pharmaco-invasive strategy: successful reperfusion (STE resolution >50% + pain relief + reperfusion arrhythmia) → routine cath 3–24h post-lytic; failed reperfusion (STE resolution <50% at 60–90 min) → immediate rescue PCI

• RV MI management (inferior STE + V4R STE ≥0.5 mm):

  • NTG absolutely contraindicated (↓RV preload → ↓CO → hemodynamic collapse → VF → cardiac arrest)

  • IV fluids: NS 250–500 mL bolus → reassess; RV requires high preload to maintain CO through failing RV; avoid aggressive diuresis

  • Avoid diuretics; avoid morphine (↓preload); avoid ACEi/ARB initially (↓afterload → ↓RV-PA gradient)

  • AF + RV MI: cardioversion immediately (loss of atrial kick → hemodynamic collapse in RV MI)

  • AV block + RV MI: temporary pacing if hemodynamically unstable (AV sequential pacing preferred — atrial kick 25% of CO in RV MI); usually reversible with reperfusion

  • Early reperfusion (primary PCI of RCA) is the only definitive treatment; RV function usually recovers within days with successful reperfusion

• Post-PCI care (CCU/step-down):

  • Aspirin (Bayer) 81 mg PO daily indefinitely + ticagrelor (Brilinta) 90 mg PO BID ×12 months (or prasugrel [Effient] 10 mg PO daily or clopidogrel [Plavix] 75 mg PO daily)

  • Metoprolol tartrate (Lopressor) 25–50 mg PO q6h → transition to metoprolol succinate (Toprol-XL) 25–200 mg PO daily (target HR 55–65; ↓reinfarction, ↓VF in post-MI period; COMMIT/CCS-2: oral BB ↓mortality; IV BB in cardiogenic shock: CONTRAINDICATED)

  • Atorvastatin (Lipitor) 80 mg PO daily immediately (PROVE-IT 2004: intensive statin ↓CV events; target LDL <70 mg/dL; <55 mg/dL if recurrent ACS; add ezetimibe [Zetia] 10 mg PO daily if above goal; add evolocumab [Repatha] 140 mg SQ q2 weeks or alirocumab [Praluent] 75–150 mg SQ q2 weeks if still above goal)

  • ACEi: lisinopril (Zestril) 2.5→10–20 mg PO daily (GISSI-3, ISIS-4: ↓30-day mortality; indicate in EF ≤40%, HTN, DM, anterior MI; start within 24h if hemodynamically stable)

  • Eplerenone (Inspra) 25→50 mg PO daily starting at Day 3 post-MI if EF ≤40% + HF symptoms or DM (EPHESUS 2003: ↓CV death 15%, ↓SCD 21%; hold if K+ >5.0 or Cr >2.5M/>2.0F; check K+ 1 week after initiation)

• Mechanical complications (Days 3–7 post-STEMI — free wall rupture/VSD/papillary muscle rupture):

  • Papillary muscle rupture: sudden severe dyspnea + new holosystolic murmur radiating to axilla + pulmonary edema (posterior > anterior papillary; posterior papillary has single blood supply via RCA; emergency echo + IABP bridge + emergent MV repair/replacement)

  • VSD: new harsh holosystolic murmur at left sternal border + biventricular failure + step-up in O2 saturation from RA to RV on Swan; IABP bridge + emergent surgical repair (higher mortality with percutaneous closure)

  • Free wall rupture: sudden hemodynamic collapse + tamponade physiology on echo (electrical-mechanical dissociation); emergent pericardiocentesis or surgical repair; >90% mortality without surgery

• PT/OT eval and treat — ambulate post-PCI Day 1 if hemodynamically stable; cardiac rehab referral (NACR: ↓mortality 26%; Class I for STEMI post-PCI); functional capacity assessment; psychological support (post-MI depression in 20–30% — ↑mortality)

• Trend daily: troponin q6h ×24h (serial peak then plateau; re-elevation after initial decline = reinfarction or stent thrombosis → urgent repeat cath); ECG daily + with any symptom; BMP (K+ ≥4.0 + Mg2+ ≥2.0 to ↓arrhythmia risk; Cr — contrast nephropathy peaks Days 2–3; glucose target <180 mg/dL); CBC; LFTs at 1 week (statin monitoring); echo at 24–48h post-PCI (EF, wall motion recovery, MR, pericardial effusion, LV thrombus — highest risk at 24–72h in anterior MI); fever curve — Days 2–6 = Dressler pericarditis (aspirin [Bayer] + colchicine [Colcrys]); Days 5+ = infection/drug fever

• Escalation triggers: cardiogenic shock (SBP <90 + cool extremities + ↓UO + lactate >2) → CCU + early PCI (SHOCK trial: revascularization ↓1-year mortality; NNT 8 at 1 year) + Impella CP (Abiomed) pre-PCI (IABP-SHOCK II: IABP no mortality benefit over medical Rx alone; Impella preferred per current guidelines) · VF/VT → immediate defibrillation 200–360 J + amiodarone (Pacerone) 300 mg IV push (VF arrest) or 150 mg IV over 10 min (stable VT) → 1 mg/min ×6h; reperfusion VT/VF in first 48h does NOT mandate ICD (usually resolves) · AV block (inferior MI) → atropine 0.5–1 mg IV; if inadequate → transcutaneous pacing; transvenous pacing if 3rd-degree AV block (usually transient — reversible with reperfusion); permanent pacemaker rarely needed for inferior MI AV block · new systolic murmur → immediate bedside echo → papillary muscle rupture or VSD → surgical emergency + IABP bridge immediately · troponin re-elevation after initial decline → stent thrombosis/reinfarction → urgent repeat PCI · pericarditis (Dressler syndrome — Days 2–6) → aspirin (Bayer) 650 mg PO q4–6h ×2 weeks + colchicine (Colcrys) 0.5 mg PO BID ×3 months; avoid NSAIDs and steroids post-MI (↑scar thinning → rupture risk)

• Discharge: aspirin (Bayer) 81 mg PO daily indefinitely + ticagrelor (Brilinta) 90 mg PO BID ×12 months (PLATO NNT 54; keep aspirin ≤100 mg); metoprolol succinate (Toprol-XL) titrated to HR 55–65 bpm; lisinopril (Zestril) 10–20 mg PO daily (or valsartan [Diovan] 160 mg BID if ACEi intolerant — VALIANT: equivalent to ACEi); atorvastatin (Lipitor) 80 mg PO daily ± ezetimibe (Zetia) 10 mg PO daily ± evolocumab (Repatha) 140 mg SQ q2 weeks (target LDL <55 mg/dL in STEMI — most aggressive lipid target); eplerenone (Inspra) 50 mg PO daily if EF ≤40% + HF sx or DM (EPHESUS); nitroglycerin (NTG SL) 0.4 mg q5 min ×3 PRN (return if >3 doses needed or no relief after 1); cardiac rehab (Class I — NACR: ↓mortality 26%); ICD evaluation at 40 days if EF ≤35% after GDMT (MADIT-II, SCD-HeFT); LV thrombus on echo → apixaban (Eliquis) 5 mg PO BID ×3–6 months; no driving ×4 weeks if EF impaired or arrhythmia; smoking cessation (varenicline [Chantix] most effective); dietary counseling (Mediterranean diet, <2 g Na+/day); return precautions: recurrent CP + dyspnea + palpitations + syncope → call 911; cardiology f/u 1–2 weeks post-discharge

⚠ Red Flags

• Cardiogenic shock (SBP <90, cool/clammy, ↓UO, AMS, lactate >2) complicating STEMI — mortality 40–50% without early revascularization; SHOCK trial: early PCI ↓1-year mortality (NNT 8); Impella CP (Abiomed) preferred MCS (IABP-SHOCK II: IABP no mortality benefit); CULPRIT-SHOCK: PCI culprit vessel only in multivessel STEMI + shock (staged non-culprit PCI later); CCU immediately

• RV MI (inferior STE + V4R STE) — NTG absolutely contraindicated; NTG → ↓RV preload → complete hemodynamic collapse → VF → cardiac arrest; check V4R in ALL inferior STEMI before giving NTG; classic triad JVD + clear lungs + hypotension = RV failure; requires IV fluid loading (opposite of LV MI)

• Fibrinolytic therapy in aortic dissection — RCA ostium involvement in type A dissection produces exact inferior STEMI pattern; giving thrombolytics = massive aortic hemorrhage + death; 30-second clinical screen (tearing quality, BP differential) before fibrinolysis is mandatory; if ANY suspicion of dissection → CTA first; this is the most catastrophic error in STEMI management

• Mechanical complications (Days 3–7): papillary muscle rupture (acute severe MR → flash APE + new holosystolic murmur → emergent MV surgery); VSD (harsh holosystolic murmur at LLSB + biventricular failure → emergent surgery); free wall rupture (sudden tamponade → PEA arrest → surgical emergency >90% mortality without repair); each carries 50–90% in-hospital mortality without surgical intervention

• Reperfusion arrhythmias (first 24–48h post-PCI): accelerated idioventricular rhythm (AIVR — reperfusion sign; benign; no treatment); VF — immediate defibrillation; sustained VT — amiodarone (Pacerone) 150 mg IV + consider cardioversion; VT/VF in first 48h does NOT mandate ICD (transient reperfusion arrhythmia); ICD at 40 days only if persistent EF ≤35%

• Missed posterior STEMI (circumflex territory): presents with isolated ST↓ in V1–V3 with tall upright T-waves; often mismanaged as NSTEMI; check V7–V9 whenever V1–V3 show ST↓ + upright T; posterior STE ≥0.5 mm in V7–V9 = STEMI → cath lab; circumflex territory is the blind spot of the standard 12-lead

• Dressler syndrome (Days 2–6 post-MI) — aspirin (Bayer) + colchicine (Colcrys); avoid NSAIDs and corticosteroids (↑scar thinning → ↑free wall rupture risk; NSAIDs contraindicated indefinitely post-MI)

Senior IM Resident Pearls

• Time = myocardium: each 30-minute delay in door-to-balloon ↑1-year mortality 7.5%; 1.9 million cardiomyocytes lost per minute of coronary occlusion; NNT to save one life with primary PCI ≤2h = 10; mortality doubles beyond 4h; make the cath lab call simultaneously with examination — never sequential

• STEMI equivalents — know them all: new LBBB + Sgarbossa criteria ≥5 points (concordant STE ≥1 mm = +5; concordant ST↓ V1–V3 ≥1 mm = +3; discordant STE ≥5 mm = +2); de Winter T-waves (upsloping ST↓ + tall peaked T V1–V4 = LAD occlusion); posterior STEMI (ST↓ V1–V3 + tall upright T = check V7–V9); aVR STE ≥1 mm + 8-lead ST↓ = left main or proximal LAD; missing these = cath lab delay = avoidable deaths

• RV MI — most dangerous inferior STEMI variant: always check V3R and V4R in ALL inferior STEMI; V4R STE ≥0.5 mm = RV MI; NTG contraindicated (→ cardiac arrest); IV fluids required (opposite of LV MI); diuretics worsen; AF cardioversion urgently; pacing if AV block; NTG in RV MI = most dangerous drug error in STEMI management

• SHOCK trial (1999, NEJM): early revascularization (PCI or CABG) vs intensive medical therapy in STEMI + cardiogenic shock → ↓1-year mortality 46.7% vs 63.1% (NNT 8); early PCI is the intervention that saves lives in cardiogenic shock; IABP-SHOCK II: IABP does NOT ↓30-day mortality vs medical therapy alone; Impella CP (Abiomed) preferred MCS based on hemodynamic data and current guidelines

• PLATO (2009, NEJM) in STEMI: ticagrelor (Brilinta) 180 mg → 90 mg BID vs clopidogrel (Plavix) 600 mg → 75 mg → ↓CV death/MI/stroke 16% (NNT 54); ↓CV death 21%; faster onset than clopidogrel; GIVE PRE-CATH in STEMI (unlike NSTEMI where anatomy must be confirmed first); keep ASA ≤100 mg/day

• Fibrinolysis checklist — the 30-second screen before giving lytics: (1) Is this actually dissection? Tearing quality? BP differential? Widened CXR mediastinum? → if yes: CTA immediately; (2) Absolute contraindications (prior ICH, ischemic stroke <3 months, intracranial tumor, active bleeding, dissection); (3) Symptom onset <12h; (4) First medical contact-to-balloon >120 min; all 4 must be addressed; tenecteplase (TNKase) single weight-based bolus is easiest and lowest error rate

• Mechanical complications — Days 3–7 (most feared post-STEMI): new systolic murmur at ANY time post-STEMI = emergency echo; papillary muscle rupture (posterior papillary — single RCA blood supply; acute severe MR → pulmonary edema + shock → emergent MV surgery; IABP bridge); VSD (harsh holosystolic murmur + right heart failure + O2 step-up RA→RV → emergent surgical repair; percutaneous closure inferior results); free wall rupture (PEA + tamponade → surgical emergency >90% mortality without repair)

• Common mistake — giving NTG in inferior STEMI without checking V4R: inferior STEMI + RV MI (V4R STE) → NTG → ↓preload → ↓RV filling → ↓CO → hemodynamic collapse → VF → cardiac arrest; always obtain V3R + V4R before ANY vasoactive agent in inferior STEMI; this remains a repeated fatal error in community hospitals