Article Content

Determine the following:

Rhythm: _______________________________________

Figure. No caption a... - Click to enlarge in new windowFigure. No caption available.

Rate: ___________________________________________


P waves: _______________________________________


PR interval: ____________________________________


QRS complex: __________________________________


What's your interpretation?

(Answers on next page)


Name that strip: Answers

Rhythm: Regular


Rate: 41 beats/minute


P waves: Absent


PR interval: Not measurable


QRS complex: 0.22 to 0.24 second.


Idioventricular rhythm (IVR) may occur intermittently or as a continuous dysrhythmia. Intermittent IVR often occurs in short runs of three or more consecutive ventricular beats and is usually related to increased vagal effect on the sinoatrial node, allowing a ventricular focus to take control for a temporary period. Treatment is usually unnecessary.


Continuous IVR usually occurs in patients with advanced heart disease and is commonly the dysrhythmia present just before the appearance of ventricular standstill (asystole). Continuous IVR is generally symptomatic because of the slow rate and the loss of the atrial kick. Symptomatic IVR must be treated promptly following the protocols for symptomatic bradycardia with a pulse (atropine, transcutaneous pacing, and vasopressors). However, treatment is rarely successful.


If the rate of IVR falls below 20 beats/minute and the QRS complexes deteriorate into irregular, wide, indistinguishable waveforms, the rhythm is commonly referred to as an agonal rhythm or "dying heart." Treatment is usually ineffective at this point.


Idioventricular rhythm: Identifying ECG features

Rhythm: Regular


Rate: 30 to 40 bpm (sometimes less)


P waves: Absent


PR interval: Not measurable


QRS complex: Wide (0.12 second or greater)