Which one of the following statements is true to Stockcs-Adam attack -

Stokes-Adams syndrome is a periodic fainting spell in which there is a periodic onset and offset of blockage of hea due to disorder of hea rhythm that may last for seconds, hours, days, or even weeks before the conduction returns. It is characterised by decrease in cardiac output and loss of consciousness due to a transient arrhythmia; for example, bradycardia due to complete hea block The attacks are caused by any temporary lack of cardiac output. This in turn could be due to any number of causes, including antimony poisoning, cardiac asystole, hea block, Lev's disease or ventricular fibrillation. Paroxysmal supraventricular tachycardia or atrial fibrillation is the underlying cause in up to 5% of patients. The resulting lack of blood flow to the brain is responsible for the faint Stokes-Adams attacks may be diagnosed from the history, with paleness prior to the attack and flushing after it paicularly characteristic. The ECG will show asystole, an AV block, or ventricular fibrillation during the attacks. Ref Harrison 20th edition pg 1437