Survival, therapeutics and clinical prognosis after bidirectional ventricular tachycardia

Abstract Background Survival and clinical prognosis after bidirectional ventricular tachycardia (BiVT), defined as a dual QRS morphologies alternating on a beat-to-beat basis in the inferior leads, is unknown. Purpose To describe events during follow-up and therapeutic approaches to BiVT. Methods We conducted an ambispective and multicentric registry on 13 hospitals, consisting on relevant clinical characteristics, diagnosis, therapeutics and follow-up. Results A total of 19 patients were evaluated, with their clinical characteristics and etiologies summarized in the Table. Among them, 42% received an implantable cardioverter-defibrillator (ICD) before discharge. The mean follow-up period was 39 (12;104) months. Beta-blockers were the most commonly prescribed and clinically effective medication at discharge (26.32%), followed by flecainide and amiodarone. The recurrence rate during follow-up was 36.84%. No in-hospital mortality was observed; however, two patients died within the first year after the event, due to heart failure and septic shock. Kaplan-Meier curves (Figure) illustrate the composite endpoint of death and/or recurrences (n=9). Distinct etiologies showed varying recurrence rates (n=7), with channelopathies (Andersen-Tawil and/or CPVT) accounting for the highest recurrence rate at 71% (5 cases). In contrast, all mortality events occurred in patients with structural heart disease. Conclusion Our study represents the largest population of BiVT described to date with structured follow-up. Both, recurrences and mortality are linked to the etiology rather than the descriptive bidirectionality on the ECG. Nearly half of the population suffered the composite end-point of recurrence and/or death, which might be due to the existence of a permanent trigger (i.e. channelopathy) and the absence of etiology-tailored treatments. Figure (Kaplan-Meier curve)