Treatment of arrhythmic storm in implantable defibrillator patients.

BACKGROUND

A common ICD therapy-related complication is arrhythmic storm (AS). The objective of our study was to define the impact of AS on patients' prognoses in order to compare the total mortality of AS patients with the rest of the group.

MATERIAL/METHODS: We studied 138 patients who received ICDs between 1994 and 2001. Patients who experienced one or more arrhythmic storms were statistically compared with patients who had no accumulation of malignant arrhythmia or no episodes.

RESULTS

One thousand four hundred ninety episodes of arrhythmia were analyzed. Arrhythmia recurrence was present in 71% of the patients. The majority of episodes (78%) were ventricular tachycardias and only 3% of episodes were ventricular fibrillation. Seventy percent of all arrhythmic episodes were asymptomatic. The ICD therapy sensitivity was 99.7%. Thirty-eight arrhythmic storms in 19 patients (14%) were observed during follow-up. The occurrence of AS was twice as high among patients with LVEF <35% than the rest of the group (18% vs. 8%). The total survival of patients with AS was significantly lower than that of the ICD patients who did not experience an AS (36.8% vs. 16.8%, p=0.042). All episodes of arrhythmic clusters during the AS were ventricular tachycardias.

CONCLUSIONS

Arrhythmic storm is a serious risk marker for cardiac death. Ventricular tachycardia is a basic rhythm disorder of AS episodes and occurs significantly more often than ventricular fibrillation. Arrhythmic storm is responsible for a 4.6 times more frequent re-admission to hospital.