Reperfusion-Induced Tachyarrhythmias Resolve With Intracoronary Verapamil
Results of a study conducted in Japan confirm that the intracoronary use of verapamil can safely and immediately terminate reperfusion-induced ventricular tachyarrhythmias (VT) with no evidence for resumption of arrhythmias after treatment.
Intracoronary verapamil, however, is not effective in terminating reperfusion-induced ventricular fibrillation (VF), investigators report in the September issue of Chest. This suggests that the underlying mechanism of VF in the ischemic reperfused heart is different from that of VT, they write.
Restoring coronary blood flow after transient ischemia immediately induces life-threatening VT, the authors note in the paper. And while most of these arrhythmias resolve spontaneously, some induce “serious hemodynamic changes.”
Dr. Masaya Kato and colleagues from Hiroshima City Asa Hospital retrospectively analyzed the efficacy of intracoronary verapamil to treat these arrhythmias.
Of 390 patients with acute MI who received early mechanical revascularization therapy, 109 experienced reperfusion-induced tachyarrhythmias and 31 (28%) were treated with 0.25 to 1.0 milligrams intracoronary verapamil.
Six of the patients had premature ventricular contractions (PVC), 19 had accelerated idioventricular rhythms, 3 had VT, 2 had VF, and 1 had torsades de pointes.
Intracoronary verapamil led to the rapid resolution of all of these arrhythmias except VF. “We used a low dose of intracoronary verapamil and clinical side effects were rare,” Dr. Kato told Reuters Health. Two patients developed temporary hypotension and one had bradycardia. All three recovered spontaneously.
He emphasized, however, that the incidence of reperfusion-induced VT in this study (28%) “is not high enough for us to use intracoronary verapamil in all patients treated with coronary reperfusion therapy because of their unfavorable side effects.”
