(2) Accelerated idioventricular rhythm
An accelerated idioventricular rhythm is seen in as many as 20% of patients who have an AMI. This pattern is defined as a ventricular rhythm characterized by a wide QRS complex with a regular escape rate faster than the atrial rate, but less than 100 bpm. AV dissociation is frequent. Slow, nonconducted P waves are seen; these are unrelated to the fast, wide QRS rhythm. Most episodes are short and terminate spontaneously. They occur with equal frequency in anterior and inferior infarctions (Ashok et al. 2011).
This arrhythmia results from either (1) Failure or structural damage of the SA or AV nodal pacemaker or enhanced vagal tone leading to depres-sion of nodal automaticity and function and an escape …show more content…
Monomorphic ventricular tachycardia is most likely to be caused by a myocardial scar, whereas polymorphic ventricular tachycardia may be most responsive to measures directed against ischemia. Sustained polymor-phic ventricular tachycardia after an AMI is associated with a hospital mor-tality rate of 20% (Ashok et al. 2011).
In polymorphic ventricular tachycardia, the QRS morphology and RR intervals are variable during each episode, while in monomorphic ventricu-lar tachycardia, the QRS complexes are uniform and the RR intervals are fairly un form, although slight variability may be present (Tofler et al., 1987).
Emergency treatment of sustained ventricular tachycardia is mandato-ry because of its hemodynamic effects and because it frequently deteriorates into ventricular fibrillation. Rapid polymorphic ventricular tachycardia (rate >150 bpm) associated with hemodynamic instability should be treated with immediate direct-current unsynchronized cardioversion of 200 J (or biphasic energy equivalent). Monomorphic ventricular tachycardia should be treated with a synchronized discharge of 100 J (or biphasic energy equivalent) (Ashok et al.
An accelerated idioventricular rhythm is seen in as many as 20% of patients who have an AMI. This pattern is defined as a ventricular rhythm characterized by a wide QRS complex with a regular escape rate faster than the atrial rate, but less than 100 bpm. AV dissociation is frequent. Slow, nonconducted P waves are seen; these are unrelated to the fast, wide QRS rhythm. Most episodes are short and terminate spontaneously. They occur with equal frequency in anterior and inferior infarctions (Ashok et al. 2011).
This arrhythmia results from either (1) Failure or structural damage of the SA or AV nodal pacemaker or enhanced vagal tone leading to depres-sion of nodal automaticity and function and an escape …show more content…
Monomorphic ventricular tachycardia is most likely to be caused by a myocardial scar, whereas polymorphic ventricular tachycardia may be most responsive to measures directed against ischemia. Sustained polymor-phic ventricular tachycardia after an AMI is associated with a hospital mor-tality rate of 20% (Ashok et al. 2011).
In polymorphic ventricular tachycardia, the QRS morphology and RR intervals are variable during each episode, while in monomorphic ventricu-lar tachycardia, the QRS complexes are uniform and the RR intervals are fairly un form, although slight variability may be present (Tofler et al., 1987).
Emergency treatment of sustained ventricular tachycardia is mandato-ry because of its hemodynamic effects and because it frequently deteriorates into ventricular fibrillation. Rapid polymorphic ventricular tachycardia (rate >150 bpm) associated with hemodynamic instability should be treated with immediate direct-current unsynchronized cardioversion of 200 J (or biphasic energy equivalent). Monomorphic ventricular tachycardia should be treated with a synchronized discharge of 100 J (or biphasic energy equivalent) (Ashok et al.