🚨 Cardiology emergencies can deteriorate rapidly through myocardial ischaemia, arrhythmia, shock, pulmonary oedema, aortic catastrophe, tamponade or cardiac arrest. The safest first step is ABCDE assessment, continuous ECG monitoring, 12-lead ECG, IV access, bloods including troponin/U&E/Mg, oxygen only if hypoxaemic or shocked, and early senior/cardiology/ICU involvement when unstable.

🚩 Cardiology Red Flags

🩺 Ongoing chest pain with ECG changes or haemodynamic instability.
📉 Hypotension, syncope, shock or altered consciousness.
⚡ Sustained VT, VF, complete heart block or unstable bradycardia.
🫁 Severe breathlessness, pulmonary oedema or hypoxia.
🩸 Tearing chest/back pain, pulse deficit or neurological symptoms - consider aortic dissection.
🫀 Raised JVP with hypotension - consider tamponade, massive PE or right ventricular infarction.
🧠 Chest pain with stroke-like symptoms - consider dissection or embolic event.
💊 Recent overdose or rate-limiting drugs: beta-blockers, calcium-channel blockers, digoxin.

🚑 Immediate Generic Approach

🔄 Use an ABCDE approach.
📈 Attach continuous ECG monitoring and obtain a 12-lead ECG within 10 minutes where ACS or arrhythmia is suspected.
💉 Insert IV access and take bloods: FBC, U&E, Mg, LFT, clotting, glucose, troponin, CRP and group & save if bleeding/procedure likely.
🫁 Give oxygen if SpO₂ is low, patient is shocked, in cardiac arrest, or has severe respiratory distress. Do not give routine oxygen to normoxic ACS patients.
🩻 Chest X-ray if pulmonary oedema, pneumothorax, pneumonia, widened mediastinum or alternative chest pain cause is suspected.
🫀 Bedside echo is very useful in shock, tamponade, massive PE, severe LV failure or suspected mechanical complication after MI.
📞 Escalate early to cardiology, ICU, anaesthetics, vascular surgery or interventional radiology depending on the suspected emergency.

📊 Cardiology Emergencies

Cardiological Emergency	Clinical Presentation	Investigations	Immediate Management
🫀 Acute STEMI / Acute Myocardial Infarction	Central crushing chest pain, pressure or tightness. Radiation to left/right arm, neck, jaw, back or epigastrium. Sweating, nausea, vomiting, breathlessness or collapse. May be atypical in older adults, women, diabetes and CKD.	12-lead ECG: ST elevation, new posterior MI pattern, or STEMI equivalent. Troponin supports diagnosis, but do not delay reperfusion in clear STEMI. U&E, FBC, glucose, lipids/HbA1c later. Echo if shock, murmur, heart failure or diagnostic uncertainty.	Immediate cardiology/cath-lab pathway for primary PCI if eligible. Aspirin loading unless contraindicated. Second antiplatelet and anticoagulation according to local ACS/PCI protocol. GTN for pain if BP allows and no contraindication. Morphine/antiemetic if severe pain. Oxygen only if hypoxaemic/shocked. High-intensity statin and secondary prevention after acute stabilisation.
🩺 NSTEMI / Unstable Angina	Chest pain at rest, new-onset severe angina, or crescendo angina. May have dyspnoea, diaphoresis, nausea or syncope. NSTEMI has troponin rise; unstable angina does not.	ECG: ST depression, T-wave inversion or may be normal. Serial high-sensitivity troponins and dynamic change. Risk stratification using GRACE or local pathway. Echo if heart failure, murmur or LV function assessment needed.	Aspirin loading unless contraindicated. Anticoagulation and second antiplatelet according to cardiology/local pathway. GTN for pain if BP allows. High-intensity statin. Early invasive angiography for high-risk features, recurrent pain, dynamic ECG changes, heart failure or instability.
💧 Cardiac Tamponade	Hypotension, raised JVP and muffled heart sounds: Beck’s triad. Tachycardia, dyspnoea, pulsus paradoxus. May follow malignancy, pericarditis, trauma, cardiac procedure or post-MI rupture. Can cause obstructive shock or PEA arrest.	Urgent bedside echocardiography: pericardial effusion with chamber collapse. ECG: low voltage or electrical alternans may occur. CXR may show enlarged globular heart in chronic effusion. Do not delay treatment in peri-arrest tamponade.	Urgent cardiology/cardiothoracic/ICU involvement. IV fluids may temporarily support preload. Avoid unnecessary positive-pressure ventilation if possible before drainage, as it may worsen preload. Urgent pericardiocentesis or surgical drainage depending on cause and stability. Treat underlying cause.
🩸 Aortic Dissection	Sudden severe tearing chest, back or interscapular pain. Pain may migrate. Pulse deficit, BP difference between arms, syncope or neurological deficit. Risk factors: hypertension, Marfan/Ehlers-Danlos, bicuspid aortic valve, pregnancy, cocaine, known aneurysm.	CT angiography aorta is first-line if stable. TEE if unstable or CT unsuitable. ECG/troponin may mislead if coronary involvement. CXR may show widened mediastinum but can be normal.	Immediate senior/cardiothoracic/vascular discussion. Analgesia and controlled BP/heart rate reduction. IV beta-blocker first-line to reduce shear stress if no contraindication. Add vasodilator only after rate control if needed. Type A dissection = emergency surgery. Complicated Type B may need endovascular/surgical intervention; uncomplicated Type B often medical management.
🫁 Massive / High-Risk Pulmonary Embolism	Sudden dyspnoea, pleuritic chest pain, syncope or collapse. Hypotension, shock, tachycardia and hypoxia. May have signs of DVT. Raised JVP/right heart strain in massive PE.	CTPA if stable enough. Bedside echo may show RV dilatation/strain in unstable patients. ECG: sinus tachycardia common; S1Q3T3 is uncommon. Troponin/BNP may support risk stratification.	ABCDE, oxygen if hypoxaemic, IV access and ICU/cardiology input. Anticoagulation if no contraindication. Systemic thrombolysis for PE with haemodynamic instability unless contraindicated. Consider catheter-directed therapy or surgical embolectomy if thrombolysis contraindicated or unsuccessful.
⚡ Ventricular Tachycardia	Palpitations, dizziness, chest pain, syncope or cardiac arrest. Broad-complex regular tachycardia, usually >120 bpm. Assume broad-complex tachycardia is VT until proven otherwise, especially with structural heart disease.	12-lead ECG if stable. Check potassium, magnesium, calcium, troponin and drug causes. Echo after stabilisation to assess structural disease.	Unstable VT: synchronised DC cardioversion. Pulseless VT: defibrillation and ALS cardiac arrest algorithm. Stable VT: IV amiodarone according to ALS/local protocol. Correct hypokalaemia/hypomagnesaemia and treat ischaemia. ICD assessment if recurrent/sustained VT or high-risk structural disease.
🫀 Acute Heart Failure / Pulmonary Oedema	Severe breathlessness, orthopnoea and paroxysmal nocturnal dyspnoea. Crackles, hypoxia, pink frothy sputum. Raised JVP, peripheral oedema or cool peripheries. May be triggered by ACS, arrhythmia, hypertension, valve disease or fluid overload.	CXR: pulmonary oedema, pleural effusions, cardiomegaly. ECG and troponin if ACS suspected. BNP/NT-proBNP supports heart failure diagnosis. Echo to assess LV function, valves and complications. ABG/VBG if severe respiratory distress.	Sit upright. Oxygen if hypoxaemic. CPAP/NIV if severe respiratory distress or persistent hypoxia. IV nitrates if hypertensive and BP allows. IV diuretics if fluid overloaded. Treat trigger: ACS, arrhythmia, hypertensive emergency, valve disease or renal failure. Inotropes/vasopressors only with senior/ICU/cardiology input if cardiogenic shock.
📈 Hypertensive Emergency	Severe hypertension with acute end-organ damage. Symptoms may include chest pain, dyspnoea, headache, confusion, visual symptoms or neurological deficit. Complications: ACS, pulmonary oedema, aortic dissection, stroke, encephalopathy, AKI, papilloedema.	Confirm BP using correct cuff and repeat measurements. ECG, U&E/creatinine, urinalysis, troponin if chest pain. CXR if pulmonary oedema. CT head if neurological symptoms. Fundoscopy if hypertensive encephalopathy suspected.	Admit for monitored BP reduction. Use IV antihypertensive therapy according to the emergency and local policy. Avoid rapid excessive BP reduction except in specific conditions such as aortic dissection. Treat the organ injury: ACS, pulmonary oedema, stroke, AKI or dissection. Seek specialist input for pregnancy, dissection, stroke, phaeochromocytoma or renal failure.
🐢 Unstable Bradycardia / High-Grade AV Block	Bradycardia with hypotension, syncope, shock, heart failure or chest pain. May be caused by inferior MI, complete heart block, hyperkalaemia, hypothermia, beta-blockers, calcium-channel blockers or digoxin. ECG may show sinus bradycardia, Mobitz II, complete heart block or slow AF.	12-lead ECG. U&E including potassium, magnesium and calcium. Glucose, troponin if ACS suspected. Drug levels if digoxin/toxicity suspected.	Follow ALS bradycardia algorithm. Atropine if symptomatic bradycardia. If ineffective or high-risk features: transcutaneous pacing, isoprenaline/adrenaline infusion or temporary pacing depending on local protocol. Treat reversible causes: hyperkalaemia, hypoxia, drug toxicity, MI. Permanent pacemaker may be required for persistent high-grade block.
💓 Fast Atrial Fibrillation / SVT with Instability	Palpitations, breathlessness, chest pain, dizziness or syncope. Unstable signs: shock, syncope, myocardial ischaemia or heart failure. AF is irregularly irregular; SVT usually regular narrow-complex tachycardia.	12-lead ECG. U&E, Mg, thyroid function later if new AF. Troponin if chest pain/ischaemia suspected. Echo if structural disease or heart failure.	Unstable tachyarrhythmia: synchronised DC cardioversion. Stable SVT: vagal manoeuvres then adenosine if appropriate. Stable AF: rate control with beta-blocker/diltiazem/digoxin depending on LV function and context. Consider anticoagulation according to stroke/bleeding risk and duration/onset. Treat triggers: sepsis, PE, thyrotoxicosis, alcohol, electrolyte disturbance.
🧱 Cardiogenic Shock	Hypotension with poor tissue perfusion due to cardiac pump failure. Cold clammy peripheries, oliguria, confusion, raised lactate. May follow large MI, mechanical complication, severe valve disease, myocarditis or arrhythmia.	ECG and troponin. Bedside echo: LV/RV function, valves, tamponade, VSD, MR. ABG/VBG lactate, U&E, LFT, FBC, clotting. CXR for pulmonary oedema.	Urgent cardiology and ICU involvement. Treat cause: PCI for MI, cardioversion for arrhythmia, surgery for mechanical complication. Careful fluids only if hypovolaemia/RV infarct suspected. Vasopressors/inotropes under ICU/cardiology guidance. Consider mechanical circulatory support in selected cases.

📊 Quick Pattern Recognition

Presentation	Think Of	Immediate Action
Crushing chest pain + ST elevation	STEMI	Aspirin, cath lab/PCI pathway, analgesia, oxygen only if hypoxic.
Tearing chest/back pain + pulse deficit	Aortic dissection	CTA, analgesia, IV beta-blockade, surgical/vascular call.
Hypotension + raised JVP + muffled heart sounds	Cardiac tamponade	Urgent echo and pericardial drainage.
Broad-complex tachycardia + shock	Unstable VT	Synchronised DC cardioversion.
Bradycardia + hypotension/syncope	Unstable bradycardia/high-grade block	Atropine, pacing, treat reversible causes.
Severe dyspnoea + crackles + hypertension	Acute pulmonary oedema	Sit up, oxygen if hypoxic, nitrates, NIV, diuretics if overloaded.
Syncope/shock + pleuritic pain + RV strain	Massive PE	Anticoagulation, thrombolysis if unstable, ICU/cardiology.

🚫 Common Pitfalls

❌ Giving routine oxygen to normoxic ACS patients.
❌ Waiting for troponin before activating PCI in clear STEMI.
❌ Treating aortic dissection as ACS with anticoagulation before considering dissection red flags.
❌ Delaying decompression/drainage in tamponade with shock.
❌ Assuming all broad-complex tachycardia is SVT with aberrancy - treat as VT until proven otherwise.
❌ Giving nitrates in hypotension, right ventricular infarction or severe aortic stenosis.
❌ Reducing BP too rapidly in hypertensive emergency without considering the underlying condition.
❌ Missing hyperkalaemia or drug toxicity as a reversible cause of bradycardia.

📝 Exam Pearls

🫀 STEMI = reperfusion emergency; troponin should not delay PCI.
🩸 Aortic dissection pain is sudden, severe, tearing and may migrate.
💧 Tamponade causes obstructive shock: raised JVP + hypotension.
⚡ Unstable tachyarrhythmia = synchronised cardioversion.
🐢 Unstable bradycardia = atropine, pacing and reversible causes.
🫁 Pulmonary oedema: sit up, nitrates if hypertensive, NIV if severe.
🧱 Cardiogenic shock needs cause-specific treatment, not just fluids.

🧠 Teaching Note

Cardiology emergencies are easiest to understand by asking whether the problem is pump, pipe, rhythm, valve or pressure. ACS and cardiogenic shock are pump/ischaemia problems; dissection is a pipe catastrophe; VT and heart block are rhythm problems; acute MR/VSD are structural complications; pulmonary oedema often reflects pump failure plus pressure overload. The ECG tells you electrical risk, the blood pressure tells you perfusion, and bedside echo often reveals the mechanical problem. That is why unstable rhythm, shock, pulmonary oedema and persistent ischaemic pain should trigger immediate escalation.

📚 References & UK Resources

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Cardiological Emergencies: Revision ✅