Cardiac arrest

Cardiac arrest is a sudden state of circulatory failure due to a loss of cardiac systolic function.

The most common shockable rhythms associated with cardiac arrest are pulseless ventricular tachycardia and ventricular fibrillation.

The most common underlying causes are ischaemic heart disease and myocardial infarction. In some settings, cardiac arrest is the result of respiratory arrest triggered by opioid toxicity.

Presentation is usually sudden and manifests as loss of consciousness but can be preceded by chest pain or dyspnoea.

Treatment is through implementing the algorithms for basic and advanced cardiac life support, depending on the provider’s level of training.

The overall survival from cardiac arrest, especially unwitnessed, is poor and, among early survivors, is fraught with complications of many organ systems due to ischaemic injury (i.e., multisystem organ failure).

This topic covers cardiac arrest in adults. Sudden cardiac arrest is a sudden state of circulatory failure due to a loss of cardiac systolic function. It is the result of 4 specific cardiac rhythm disturbances: ventricular fibrillation, pulseless ventricular tachycardia (VT), pulseless electrical activity, and asystole. Torsades de pointes is a sub-group of polymorphic VT in patients with an underlying prolonged QT interval, sometimes related to hypomagnesaemia.[Figure caption and citation for the preceding image starts]: Monomorphic ventricular tachycardiaFrom the personal collections of Dr A. Askari and Dr A. Krishnaswamy; used with permission [Citation ends].[Figure caption and citation for the preceding image starts]: Torsades de pointesFrom the personal collection of Dr A. Askari; used with permission [Citation ends].