More Pronounced Diastolic Left Ventricular Dysfunction in Patients with Accelerated Idioventricular Rhythm After Reperfusion by Primary Percutaneous Coronary Intervention

Objective. Reperfusion-induced accelerated idioventricular rhythm (AIVR) during primary percutaneous coronary intervention (pPCI) may be a sign of left Ventricular (LV) dysfunction. We compared LV dynamic effects of reperfusion between patients with and without reperfusion-induced AIVR during pPCI for ST-elevation myocardial infarction (STEMI). Methods. We studied 15 consecutive patients, who presented with their first acute anterior STEMI within 6 hours after onset of symptoms, and in whom LV pressure-volume (PV) loops were directly obtained during pPCI. Immediate effects of pPCI on LV function were compared between patients with (n = 5) and without (n = 10) occurrence of AIVR after reperfusion, as well as the direct effects of AIVR on LV function compared to sinus rhythm. Results. Patients with reperfusion-induced AIVR showed more pronounced diastolic LV dysfunction before the onset of the arrhythmia, i.e., a delayed active relaxation expressed by Tau (53 +/- 15 vs. 39 +/- 6 ms; p = 0.03), a worse compliance curve (p = 0.01), and a higher end-diastolic stiffness (p = 0.07). At the end of the procedure, AIVR patients showed less improvement in diastolic LV function, indicated by a downward shift of the compliance curve (-3.1 +/- 2.3 vs. -7.5 +/- 1.4 mmHg; p = 0.001), a decrease in end-diastolic stiffness (13 +/- 18 vs. 34 +/- 15%; p = 0.03) and end-diastolic pressure (12 +/- 8 vs. 29 +/- 19%; p = 0.07). Conclusion. STEMI patients with reperfusion-induced AIVR after pPCI showed more pronounced diastolic LV dysfunction before and after AIVR than patients without AIVR, which suggests that diastolic LV dysfunction contributes to the occurrence of AIVR and that AIVR is a sign of diastolic LV dysfunction