Accelerated idioventricular rhythms (AIVRs) are a type of irregular heart rhythms characterized by an increased rate of electrical activity in the ventricles of the heart. "Accelerated" refers to the higher than normal heart rate, "idioventricular" indicates that the electrical signals originate within the ventricles themselves, and "rhythms" refers to the irregular pattern of these electrical signals.
In AIVRs, the electrical impulses that control the heart's contractions originate from a different part of the heart than the usual natural pacemaker, the sinoatrial node. Instead, they arise from a lower area of the heart known as the ventricular conduction system. This abnormal electrical activity is often a result of various underlying conditions or events, such as heart disease, a myocardial infarction (heart attack), electrolyte imbalances, or certain medications.
During accelerated idioventricular rhythms, the ventricles contract at a faster rate than during normal heart rhythms. However, the heart rate is still generally slower than the normal sinus rhythm. The irregular electrical signals in AIVRs usually result in a characteristic pattern on an electrocardiogram (ECG) recording, showing wide QRS complexes with distinctive T-waves.
While accelerated idioventricular rhythms themselves are not typically considered dangerous or life-threatening, they can sometimes be an indicator of an underlying heart condition that requires medical attention. Treatment may vary depending on the cause and symptoms but can include addressing the underlying condition, discontinuing medications that may contribute to the arrhythmia, or in some cases, the insertion of a pacemaker.
