Ventricular Rhythms ECG Interpretation #315

Introduction Part 1

• Rhythms are often named according to the origin of the electrical activity in the heart or the structure where the problem is occurring.
• Ventricular Rhythms are aptly named due to the locus of stimulation being the ventricles (Purkinje network).
• Dysrhythmias in this category occur as a result of either a failure of the higher (faster) pacemakers within the heart or an abnormal locus of stimulation within the ventricles is occurring at a faster rate than the other pacemaker sites and thus takes over as the pacemaker of the heart.
• Remember, the fastest electricity in the heart (regardless of location) will dictate the heart rate.

Introduction Part 2

• Each rhythm in this category will share unique morphologic features which separate them from other rhythms.
• Other than Asystole and Ventricular Fibrillation which are unique even within this category, the remaining ventricular rhythms typically present without P waves and will display a wide, bizarre QRS complex (measuring 0.12 seconds or greater).
• After learning the unique features just described, it is simply a matter of recalling the heart rate range associated with the dysrhythmia.

Chart of Types

Ventricular Rhythms

(no P wave, wide - bizarre QRS if present)

Rhythm	Rate
Asystole	0
Agonal	less than 20 bpm
Idioventricular	20-40 bpm
Accelerated Idioventricular	40-100 bpm
*Ventricular Tachycardia	> 100 bpm
*Ventricular Fibrillation	Electrical Chaos

*Only two rhythms that are treated with defibrillation.