In this article, we will discuss the Etiology of Cardiac Arrest. So, let’s get started.
Etiology of Cardiac Arrest
Cardiac arrest may be due to:
• Ventricular fibrillation
• Pulseless ventricular tachycardia
• Electromechanical dissociation
Ventricular fibrillation (VF) and pulseless ventricular tachycardia: This is most common and most easily treatable cause of sudden death. It is characterised by uncoordinated rapid, bizarre ventricular contractions which are ineffective to produce a pulse. The ECG shows rapid irregular ventricular rhythm with no identifiable complexes. Ventricular tachycardia may also cause loss of cardiac output (pulseless VT) and may further degenerate into VF.
Ventricular asystole: It is characterised by no electrical activity of the ventricles producing more or less straight line on ECG. It is usually due to failure of the conducting tissue or massive ventricular damage complicating MI. A sudden blow to the chest (precordial thump) or cardiac massage can sometimes restore the cardiac activity. An artificial pacemaker may be needed to prevent further attacks.
Electromechanical dissociation: There is dissociation between electrical activity (it is normal or near normal) and mechanical events (no effective cardiac output). It is mostly due to extraneous causes such as hypovolaemia tension pneumothorax, cardiac rupture or massive pulmonary embolism. It carries poor prognosis.