Successful Catheter Ablation of Two Types of Ventricular Tachycardias Triggered by Cardiac Resynchronization Therapy: A Case Report

Abstract

We report a case of a patient with nonischemic dilated cardiomyopathy and implantable cardioverter-defibrillator, in whom an upgrade to biventricular pacing triggered multiple episodes of ventricular tachycardias (VTs) of two morphologies. First VT presented as repetitive nonsustained arrhythmia of the same morphology as isolated ectopic beats, suggesting its focal origin. Second VT was reentrant and was triggered by the former ectopy, leading to a therapy from the device. Electroanatomical mapping of the left ventricle revealed relatively small low voltage area in the left ventricular outflow tract and identified both an arrhythmogenic focus as well as critical isthmus for reentrant VT. Radiofrequency catheter ablation successfully abolished both VTs. After the procedure, biventricular pacing was continued without any recurrences during a period of 24 months. The report emphasizes the role of catheter ablation in management of VTs triggered by cardiac resynchronization therapy.

Cardiac Resynchronization Therapy and Proarrhythmia: Weathering the Storm

“…However, there are some interesting similarities among the patients who have suffered this complication in published reports that are worth noting. First, the majority of patients who develop VT storm after CRT in this 11 and prior reports 4,6,7,9,10 had previously experienced an episode of spontaneous sustained VT. This is somewhat reassuring since most of these patients would already be treated with an ICD for secondary prevention, and the majority of these cases did occur at the time of upgrade from an ICD to CRT‐D.…”

“…If the patient can be managed without CRT or the indication is marginal, then leaving LV pacing off may be a reasonable management strategy. Alternatively, data from this 11 and other reports 6,10 suggest that radiofrequency ablation may eliminate VT and allow CRT to be resumed for some patients presenting with monomorphic VT. However, radiofrequency ablation has not been curative in all reports, 7 and in certain cases the only intervention that is effective is inactivation of LV pacing.…”

“…Despite clear benefits of cardiac resynchronization therapy (CRT) on mortality and morbidity in randomized controlled trials among select patients with systolic dysfunction and severe congestive heart failure (CHF), 1,2 there have been numerous case reports over the past 5 years describing significant ventricular proarrhythmia, which manifests primarily as ventricular tachycardia (VT) storm, encountered usually within hours to days after initiation of biventricular pacing 3–10 . At first, the association appeared to be most significant for polymorphic VT, 3,5 but, subsequently, a predominance of monomorphic VT among patients with ischemic cardiomyopathy has been reported 4,6,7,9 .…”

Sustained Right Ventricular Tachycardia Originating Close to Defibrillator Lead Tip in Hypertrophic Cardiomyopathy

“…Despite the evidence of a fibrotic reaction development around pacing leads, scar‐related proarrhythmic event appears to be very rare. In literature, anecdotal reports have suggested proarrhytmic effect of epicardial LV leads, leading to recurrent VTs 9 ; in these cases, the mechanism proposed is a triggered activity promoted by the different activation pattern in areas with anisotropic conduction.…”

Left ventricular sensing in cardiac resynchronization devices—opportunities and pitfalls for device programming

“…Note that the LVPP can be as short as 300 ms, which is below the values in Biotronik's devices but desynchronization events are not ruled out as well. In contrast, the LVRP should be sufficiently long to include the T‐wave to avoid T‐wave oversensing by the LV lead. Deactivation of the LVPP is only possible if LV sensing and pacing are deactivated, which is not desired simply to avoid desynchronization events. Very rarely, CRT‐induced arrhythmias may require complete deactivation of the LV lead During LV threshold tests, Boston Scientific suggests considering temporary shortening/deactivation of the LVPP to ensure continuous LV pacing.…”