History
History is helpful for identifying the underlying etiology for accelerated idioventricular rhythm (AIVR). The AIVR per se is often detected as an asymptomatic finding on review of ECG monitoring. The presence of the following conditions supports a potential diagnosis of AIVR:
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Most patients with AIVR have chest pain or shortness of breath, symptoms related to myocardial ischemia. They often have recent history of myocardial reperfusion with drugs or coronary artery interventions. [26]
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Some patients with AIVR have chest discomfort, shortness of breath, peripheral edema, cyanosis, clubbing, symptoms related to cardiomyopathy, myocarditis, and congenital heart diseases.
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Occasionally, patients with AIVR have a history of using digoxin, some anesthetic agents, or illicit drugs such as cocaine.
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Rarely, AIVR can occur in people without apparent heart disease and no identifiable triggers.
Physical Examination
There are no specific physical findings for accelerated idioventricular rhythm (AIVR). The following physical signs may be present:
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Slow (< 55 bpm) or fast (>100 bpm) pulse rate.
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Variable heart sound intensity and cannon A waves related to atrioventricular dissociation.
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Some irregularity of heart rate/pulse rate due to competing sinus rhythm and AIVR.
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Rarely, hypotension related to either AV asynchrony or relatively rapid ventricular heart rate during AIVR.
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Accelerated Idioventricular Rhythm. AIVR and sinus rhythm: AIVR starts and terminates gradually, competing with sinus rhythm. A possible ventricular fusion beat (arrow) and isoarrhythmic AV dissociation (arrowheads: sinus P waves) are present. During AIVR, ectopic ventricular rate is just faster than sinus rate. AIVR has a wide QRS morphology different from the QRS morphology in sinus rhythm.
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Accelerated Idioventricular Rhythm. AIVR in atrial fibrillation: AIVR starts and terminates gradually, competing with the ventricular capture beats (arrow) from atrial fibrillation. Ventricular fusion beat (arrowhead) is present. AIVR has a wide QRS morphology different from the QRS morphology of ventricular capture beats.
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Accelerated Idioventricular Rhythm. Complete heart block with escaped junctional rhythm: The AV dissociation in complete heart block is not isoarrhythmic AV dissociation, because the atrial rate is much faster than the escaped junctional ventricular rate.
