Acute Coronary Syndromes
STEMI, NSTEMI, Unstable Angina — Time-critical management with reperfusion strategies, antiplatelet & anticoagulation therapy.
Lethal Arrhythmias
VF, Pulseless VT, Torsades de Pointes, Complete Heart Block — Immediate defibrillation, antiarrhythmics & pacing.
Cardiac Arrest (ACLS)
High-quality CPR, ACLS algorithms, reversible causes (H's & T's), post-cardiac arrest care & targeted temperature management.
Classification of Cardiac Emergencies
| Category | Conditions | Urgency | Key Intervention |
|---|---|---|---|
| ACS | STEMI, NSTEMI, UA | IMMEDIATE | PCI / Thrombolysis |
| Arrhythmias | VF, VT, SVT, Bradycardia, Heart Block | IMMEDIATE | Defibrillation / Pacing / Drugs |
| Cardiac Arrest | Asystole, PEA, VF, Pulseless VT | IMMEDIATE | CPR + ACLS Algorithm |
| Acute HF | Cardiogenic Shock, Flash Pulmonary Edema | URGENT | Diuretics / Vasodilators / Inotropes |
| Tamponade | Pericardial Effusion with Hemodynamic Compromise | IMMEDIATE | Pericardiocentesis |
| Aortic Dissection | Type A & Type B (Stanford) | IMMEDIATE | BP Control / Surgery (Type A) |
Acute Coronary Syndromes (ACS)
ACS Spectrum
STEMI
- • ST elevation ≥1mm in ≥2 contiguous leads
- • New LBBB with clinical suspicion
- • Complete occlusion of coronary artery
- • Troponin: Elevated
- • Tx: Emergent PCI or Thrombolysis
NSTEMI
- • ST depression, T-wave inversion or normal ECG
- • Partial occlusion / thrombus
- • Troponin: Elevated
- • Risk stratify with GRACE/TIMI score
- • Tx: Early invasive vs. conservative
Unstable Angina
- • Ischemic symptoms at rest or crescendo pattern
- • ECG may show ST/T changes
- • Troponin: Normal
- • High-risk plaque but no necrosis yet
- • Tx: Antiplatelet + anticoagulation
STEMI Management Algorithm
Initial Assessment (0-10 min)
12-lead ECG within 10 min of first medical contact • Focused H&P • IV access • Continuous monitoring • O₂ if SpO₂ < 90%
Immediate Pharmacotherapy
MONA+ — Morphine (if pain persists) • Oxygen (if hypoxic) • Nitroglycerin SL/IV (avoid in RV infarct, SBP<90, PDE5i use) • Aspirin 325mg chewed • P2Y12 inhibitor (Ticagrelor 180mg or Clopidogrel 600mg) • Heparin (UFH or Enoxaparin)
Reperfusion Strategy Decision
PCI-capable facility (Door-to-Balloon <90 min): Primary PCI
Non-PCI facility (Door-to-Needle <30 min): Fibrinolysis (Tenecteplase/Alteplase/Streptokinase) → Transfer for rescue PCI if no reperfusion in 60-90 min
Post-Reperfusion / ICU Care
Continuous telemetry • Serial ECG & Troponins • Echo for LV function • Beta-blocker (if hemodynamically stable) • ACE inhibitor/ARB (within 24h if anterior MI or EF<40%) • High-intensity statin • Monitor for complications: arrhythmia, cardiogenic shock, mechanical complications
⚠ Contraindications to Fibrinolysis
Absolute
- • Prior intracranial hemorrhage
- • Known intracranial neoplasm / AVM
- • Active internal bleeding (excl. menses)
- • Suspected aortic dissection
- • Ischemic stroke within 3 months
- • Significant head/facial trauma within 3 months
Relative
- • Severe uncontrolled HTN (>180/110)
- • Current anticoagulant use (INR >2)
- • Traumatic/prolonged CPR (>10 min)
- • Major surgery within 3 weeks
- • Pregnancy or 1 week postpartum
- • Non-compressible vascular puncture
Life-Threatening Arrhythmias
Tachyarrhythmias (HR > 100 bpm)
ECG: Chaotic, irregular waveforms; no identifiable P, QRS, or T waves
Hemodynamics: No cardiac output → Pulseless → Cardiac arrest
Treatment:
- • Immediate unsynchronized defibrillation — Biphasic 120-200J, Monophasic 360J
- • Resume CPR immediately for 2 min after each shock
- • Epinephrine 1mg IV/IO every 3-5 min
- • Amiodarone 300mg IV bolus → 150mg repeat
- • Consider Lidocaine 1-1.5 mg/kg if Amiodarone unavailable
- • Address reversible causes (H's & T's)
ECG: Wide complex tachycardia (QRS >120ms), regular rhythm, rate 150-250 bpm
Types: Monomorphic VT (stable QRS) vs Polymorphic VT (varying QRS morphology)
Treatment — Stable:
- • Amiodarone 150mg IV over 10 min → infusion 1mg/min for 6h
- • Procainamide 20-50mg/min until arrhythmia suppressed
- • Sotalol IV if above fail
Treatment — Unstable (hypotension, AMS, chest pain):
- • Synchronized cardioversion — 100J → 200J → 300J → 360J
- • Sedation with Midazolam/Etomidate if conscious
ECG: Narrow complex (QRS <120ms), regular, rate 150-250 bpm, P waves often hidden
Treatment:
- • Vagal maneuvers — Valsalva (modified), carotid sinus massage, cold water immersion
- • Adenosine — 6mg rapid IV push → 12mg → 12mg (with saline flush)
- • If refractory: Verapamil 2.5-5mg IV or Diltiazem 15-20mg IV
- • Unstable: Synchronized cardioversion 50-100J
ECG: Polymorphic VT with "twisting of the points" around baseline, preceded by prolonged QT
Causes: Drug-induced QT prolongation (antiarrhythmics, antibiotics, antipsychotics), hypokalemia, hypomagnesemia
Treatment:
- • Magnesium Sulfate 2g IV over 5-10 min (first-line regardless of Mg level)
- • Overdrive pacing (temporary transvenous) at 100-120 bpm
- • Isoproterenol infusion if pacing unavailable
- • Correct K⁺ to >4.0 mEq/L
- • AVOID: Amiodarone, Procainamide (worsen QT prolongation)
Bradyarrhythmias (HR < 60 bpm)
Symptomatic Bradycardia Algorithm
1. Assess adequacy of perfusion — Hypotension? Altered mental status? Signs of shock? Chest pain? Acute HF?
2. Atropine — 1mg IV every 3-5 min (max 3mg) — first-line for symptomatic bradycardia
3. If Atropine ineffective:
- • Transcutaneous pacing — Set rate 60-80, increase mA until capture
- • Dopamine 5-20 mcg/kg/min infusion
- • Epinephrine 2-10 mcg/min infusion
4. Prepare for transvenous pacing if refractory
⚠ Note: Atropine is INEFFECTIVE in infranodal blocks (Mobitz Type II, Complete Heart Block) — proceed directly to pacing
1st Degree AVB
PR >200ms, all P waves conducted. Usually benign — observe.
2nd Degree Type I (Wenckebach)
Progressive PR prolongation → dropped beat. Usually at AV node. Often benign.
2nd Degree Type II / 3rd Degree (CHB)
Sudden dropped beats without PR change (Mobitz II) or complete AV dissociation (CHB). Requires pacing.
Cardiac Arrest & ACLS
High-Quality CPR — The Foundation
ACLS Cardiac Arrest Algorithm
Shockable (VF / Pulseless VT)
- 1. CPR → Rhythm check → SHOCK (Biphasic 120-200J)
- 2. CPR 2 min → Rhythm check → SHOCK
- 3. Epinephrine 1mg IV/IO (then q3-5min)
- 4. CPR 2 min → Rhythm check → SHOCK
- 5. Amiodarone 300mg IV (then 150mg)
- 6. Continue cycle — CPR → Check → Shock → Drugs
Non-Shockable (Asystole / PEA)
- 1. CPR immediately (no shock indicated)
- 2. Epinephrine 1mg IV/IO ASAP (then q3-5min)
- 3. CPR 2 min → Rhythm check
- 4. If rhythm changes to shockable → switch algorithm
- 5. Aggressively search for reversible causes
- 6. Consider advanced airway, waveform capnography
Reversible Causes — The H's & T's
5 H's
- Hypovolemia — IV fluids, blood products, stop bleeding
- Hypoxia — Advanced airway, 100% O₂, confirm placement
- Hydrogen ion (Acidosis) — Sodium bicarbonate, ventilation
- Hypo/Hyperkalemia — Calcium, insulin+glucose, kayexalate / IV KCl
- Hypothermia — Active rewarming (core temp monitoring)
5 T's
- Tension Pneumothorax — Needle decompression → Chest tube
- Tamponade (Cardiac) — Pericardiocentesis / Thoracotomy
- Toxins — Specific antidotes (Naloxone, Flumazenil, Digibind, Lipid emulsion)
- Thrombosis (Coronary) — PCI / Fibrinolysis during CPR
- Thrombosis (Pulmonary) — Systemic thrombolysis (Alteplase 50mg IV)
Acute Decompensated Heart Failure
Forrester / Nohria-Stevenson Classification
Profile A — Warm & Dry
Adequate perfusion, no congestion
CI >2.2, PCWP <18
Tx: Optimize oral meds
Profile B — Warm & Wet
Adequate perfusion, congested
CI >2.2, PCWP >18
Tx: IV Diuretics ± Vasodilators
Profile L — Cold & Dry
Low perfusion, no congestion
CI <2.2, PCWP <18
Tx: Cautious fluids ± Inotropes
Profile C — Cold & Wet
Low perfusion + congested
CI <2.2, PCWP >18
Tx: Inotropes + Diuretics ± MCS
🚨 Cardiogenic Shock
Definition: SBP <90 (or vasopressors needed) + CI <2.2 + PCWP >15 + End-organ hypoperfusion
Diagnosis: SCAI Shock Classification Stages A–E
Management Ladder:
- 1. IV Fluids (cautious 250ml bolus if not volume overloaded)
- 2. Norepinephrine (vasopressor of choice per SOAP II trial)
- 3. Dobutamine 2.5-20 mcg/kg/min (inotrope) or Milrinone
- 4. IABP (Intra-Aortic Balloon Pump) — routine use not recommended (IABP-SHOCK II)
- 5. Impella / ECMO for refractory shock
- 6. Emergent revascularization if ACS-related
Flash Pulmonary Edema — Acute Management
Mnemonic: LMNOP
40-80mg IV
2-4mg IV (caution)
SL/IV infusion
CPAP or BiPAP
Upright / Legs down
Key: NIV (CPAP/BiPAP) reduces intubation rates by 50% (3CPO Trial). Start early!
Tamponade, Dissection & Other Emergencies
Cardiac Tamponade
Beck's Triad: Hypotension + Muffled heart sounds + JVD (present in ~30% of acute tamponade)
Additional Signs: Pulsus paradoxus (>10 mmHg drop in SBP on inspiration), tachycardia, electrical alternans on ECG, low-voltage QRS
Diagnosis: Bedside Echo — RA/RV diastolic collapse, IVC plethora, respiratory variation in mitral/tricuspid inflow
Emergency Management
- • Pericardiocentesis — Subxiphoid approach, echo-guided preferred, 18G spinal needle
- • IV fluid bolus (250-500ml NS) as bridge to maintain preload
- • Avoid positive pressure ventilation (decreases venous return)
- • Avoid diuretics & vasodilators (worsen hemodynamics)
- • Surgical pericardial window if recurrent or traumatic
Acute Aortic Dissection
Type A (Ascending Aorta)
- • Involves ascending aorta ± arch
- • Mortality: 1-2% per hour untreated
- • Treatment: EMERGENT SURGERY
- • Complications: AI, tamponade, coronary malperfusion, stroke
Type B (Descending Aorta)
- • Distal to L. subclavian artery
- • Often managed medically if uncomplicated
- • Treatment: BP & HR Control
- • TEVAR if complicated (malperfusion, rupture)
Medical Management (All Types):
- • Target: HR <60, SBP 100-120 mmHg
- • 1st: IV Esmolol or Labetalol (reduce dP/dt)
- • 2nd: Add Nitroprusside or Nicardipine if BP still high (ONLY after beta-blockade)
- • Pain control: IV Morphine/Fentanyl
- • CT Angiography or TEE for diagnosis
Hypertensive Emergency
Definition: BP >180/120 with acute end-organ damage (encephalopathy, AKI, retinopathy, aortic dissection, acute HF, eclampsia)
| Scenario | Preferred Agent | BP Target |
|---|---|---|
| Aortic Dissection | Esmolol + Nitroprusside | SBP <120 in 20 min |
| Acute Pulmonary Edema | NTG IV + Furosemide | 25% reduction in 1h |
| ACS | NTG IV + Esmolol | 25% reduction in 1h |
| Eclampsia | Labetalol / Hydralazine + MgSO4 | <160/110 |
| Pheochromocytoma | Phentolamine (α-blocker first) | Gradual reduction |
Massive Pulmonary Embolism
Definition: PE causing hemodynamic instability (SBP <90 for >15 min, or requiring vasopressors, or cardiac arrest)
Diagnosis: CTPA (gold standard) or bedside Echo (RV dilation, McConnell's sign, D-shaped septum)
Treatment:
- • Systemic Thrombolysis: Alteplase 100mg IV over 2h (or 50mg bolus in cardiac arrest)
- • Anticoagulation: UFH bolus 80 U/kg → 18 U/kg/h infusion
- • Hemodynamic support: IV fluids (cautious), Norepinephrine, Dobutamine
- • If thrombolysis contraindicated: Catheter-directed therapy or Surgical embolectomy
- • ECMO as bridge in refractory cases