Cardiac Arrest — Causes, Survival and Prevention in Hyderabad
Cardiac arrest is when the heart suddenly and unexpectedly stops beating — causing immediate loss of consciousness, cessation of breathing, and absence of pulse. Without immediate resuscitation, brain death begins within 4 to 6 minutes. Cardiac arrest is distinct from a heart attack — though a heart attack is one of the most common causes of cardiac arrest. Survival depends critically on how quickly CPR and defibrillation are delivered.
Cardiac arrest vs heart attack — the key difference
| Heart attack (myocardial infarction) | A blocked coronary artery starving the heart muscle of blood. The patient is conscious, in pain, and breathing. A medical emergency requiring urgent angioplasty — but not necessarily immediately life-threatening if treated promptly. |
| Cardiac arrest | The heart stops pumping entirely — from a lethal arrhythmia such as ventricular fibrillation. The patient is unconscious, not breathing, and pulseless. Immediate CPR and defibrillation are required. Death occurs within minutes without resuscitation. |
Most cardiac arrests are caused by ventricular fibrillation
Ventricular fibrillation (VF) — a chaotic, disorganised electrical rhythm that causes the heart to quiver rather than pump — is responsible for 80% of out-of-hospital cardiac arrests. VF is treatable with an electric shock (defibrillation) — but only within the first few minutes. For every minute without defibrillation, survival decreases by 7 to 10%.
Common causes of cardiac arrest
- Coronary artery disease and heart attack — the most common cause. Acute ischaemia destabilises the heart's electrical system, triggering ventricular fibrillation (VF).
- Hypertrophic cardiomyopathy (HCM) — the leading cause of sudden cardiac death in young athletes.
- Arrhythmogenic cardiomyopathy (ARVC) — right ventricular disease predisposing to VF during exercise.
- Severe heart failure with very low ejection fraction — chronic risk of sustained ventricular tachycardia and VF.
- Long QT syndrome, Brugada syndrome, WPW syndrome — inherited electrical abnormalities.
- Pulmonary embolism — massive PE can cause cardiac arrest from acute right heart failure.
- Hyperkalaemia, severe hypothermia, drug toxicity — metabolic and toxic causes.
Immediate response — the chain of survival
- 1 — Recognise cardiac arrest: unresponsive, not breathing normally, no pulse. Call for help immediately.
- 2 — Call emergency services: call +91-9000352998 (AIG Hospitals) or 108. Put the phone on speaker.
- 3 — Start CPR immediately: 30 chest compressions (hard and fast — 5–6 cm depth, 100–120 per minute) followed by 2 rescue breaths. Continue without interruption.
- 4 — Defibrillation: if an automated external defibrillator (AED) is available, attach it and follow voice instructions. AEDs are safe for untrained users — they will only shock if ventricular fibrillation (VF) is detected.
- 5 — Advanced care: :contentReference[oaicite:0]{index=0} provides 24/7 advanced resuscitation, ECMO for refractory cardiac arrest (ECPR), and immediate coronary angiogram for post-arrest patients with suspected myocardial infarction.