ABSTRACT:
Cardiac arrhythmic disorders are defined as bradycardia or tachycardia on the basis of ventricular response that is less than 60 beats/minute for bradyarrhythmias and more than 100 beats/minute for tachyarrhythmias. Arrhythmias are a common cause of syncope and must be considered in all patients in whom syncope occurs, particularly when cardiac disease is present. Either extreme of ventricular rate, bradycardia or tachycardia, can depress cardiac output to the point of critical hypotension and syncope. Pulse rates outside this range may reduce cerebral circulation. The most common arrhythmias producing syncope or presyncope are profound sinus bradycardia, high-grade atrioventricular (AV) block, supraventricular tachycardia (SVTs), ventricular tachycardia, pacemaker malfunction, pacemaker induced arrhythmias, and pacemaker syndrome. The supraventricular tachycardias (SVTs) are sinus tachycardia, atrial tachycardia, AV-nodal re-entrant tachycardia, and tachycardia due to accessory pathways. It is essential to evaluate the arrhythmia history, to perform a good physical examination, and to accurately analyze the 12-lead electrocardiogram. In ventricular tachycardia there are broad QRS complexes (QRS width > 0.12 s). For acute management of arrhythmia there may be a new concept of the five 'A' strategy, which refers to “Adenosine, Adrenaline, Ajmaline, Amiodarone, and Atropine”. The five 'A' concept may revolutionise the treatment and effective management of all bradycardias, tachycardias, SVT, VT.