Under certain circumstances, the SA node fails to initiate an impulse at the expected time in the cardiac cycle. In the absence of an impulse from the SA node, neither the atria nor the ventricles are stimulated and thus an entire PQRST complex drops out for 1 beat(or more). This is called<unk>  (SA)<unk> . In other instances the impulse is initiated normally but is blocked within the SA Node and never reaches the atria and ventricles. This is called sinus exit block or<unk>  block. Sinus<unk>  is one of several variants of sinus node dysfunction.  The word sinus pause is used to indicate a pause in the generation of QRS complexes for 3 seconds or less. If the delay is longer than this, then the term sinus<unk>  is used.  If there is a markedly prolonged or permanent cessation of P wave and QRS complexes, then the term asystole is applied.
Sinoatrial arrest
Atrioventricular dissociation
Fascicular VT
Ventricular escape beat
Supraventricular arrhythmias
Junctional tachycardia
Respiratory sinus arrhythmia
Ventricular fibrillation