Ventricular standstill is a state of no cardiac electrical activity, hence no contractions of the myocardium and no cardiac output or blood flow.
Asystole, is an absence of ventricular complexes (called QRS) measured on an electrocardiogram (ECG), or absence of ventricular activity (electrical-mechanical dissociation). Electrical-mechanical dissociation is when there is a recorded ECG cardiac rhythm (P–QRS–T), but no effective cardiac output or palpable femoral pulse (the pulse of the artery in the inner thigh).
This condition leads to cardiac arrest and irreversible brain injury if the ventricular rhythm is not restored within 3-4 minutes. This condition results due to severe sinoatrial block or arrest or by third-degree atrioventicular (AV) block without a junctional or ventricular escape rhythm.
Symptoms of ventricular standstill are
Severe systemic illness or cardiac disease in many patients
Other cardiac arrhythmias in some
Cardiac arrest (the heart stops momentarily)