Ventricular Tachycardia

Structural heart disease (most commonly a chronic phase of MI); predictor of sudden cardiac death after MI.

Most common cause of mortality with CHF.

Cardiomyopathies, both hypertrophic and dilated, are assoc with VTach.

Seen in genetic syndromes such as long QT syndrome, Brugada syndrome, and arrhythmogenic right ventricular dysplasia.

Endogenous or exogenous catecholamines trigger VTach in susceptible pts.

Central venous, pulm artery cath and intubation can trigger VTach.

Hyperventilation may decrease serum K ⁺ .

Precipitation of polymorphic VTach with agents that alter QT interval.

Decreased vital organ perfusion related to low cardiac output

Possible effect of antiarrhythmics on cardiac and pulm function

Periop ventricular dysfunction and/or ischemia

Progression of VTach to VFIB

Reduction of left ventricular function due to IV antiarrhythmic

Defined as 3 or more consecutive ventricular beats (usually at a rate >100 bpm).

Sustained VTach persists for >30 sec or requires an intervention for termination.

VTach storm is 3 or more separate episodes of sustained VTach within 24 h requiring intervention.

Nonsustained VTach is ≤6 consecutive beats terminating spontaneously within 30 sec.

Possible signs of VTach include a wide QRS (>140 ms), presence of fusion beat, AV dissociation, and LBBB morphology.

Must rule out SVT with aberrant conduction or preexisting bundle branch block.

Torsades de pointes refers to VTach characterized by polymorphic QRS complexes that undulate in a regular fashion about baseline. Often associated with prolonged QT interval.