A case of premature ventricular contractions, ventricular tachycardia, and arrhythmic storm induced by right ventricular pacing during cardiac resynchronization therapy: Electrophysiological mechanism and catheter ablation

Abstract

A 77-year-old man with ischemic cardiomyopathy and a cardiac resynchronization therapy-defibrillator (CRT-D) device came to our attention due to incessant ventricular tachycardia and multiple implantable cardioverter defibrillator (ICD) shocks. An electrocardiogram showed non-sustained monomorphic ventricular tachycardias (NSVTs) constantly occurring after each biventricular stimulation. During an electrophysiological study, NSVTs reproducibly recurred only after right ventricular (RV) pacing; LV pacing did not induce any NSVTs.The activation map was consistent with a localized reentry at the interventricular septum, and a double exit; at the LV exit site, a single radiofrequency energy application immediately interrupted the occurrence of the NSVTs.Current evidence supports LV pacing to be pro-arrhythmogenic in few CRT patients. This unusual case shows that RV pacing during CRT could produce frequent ventricular arrhythmias and arrhythmic storm. Catheter ablation can be considered an effective therapeutic option, especially when CRT maintenance is highly advisable.

Right ventricular lead induced ventricular arrhythmia—A rare complication of cardiac resynchronization therapy

“…Of note, our patient had large scar of LV (fixed perfusion defect >50% of LV), including interventricular septum close to the site of the RV lead, most likely representing scarring and fibrosis from prior MI (Michalski et al, ). Therefore, the additional mechanism of pExV, VT, and ventricular rhythm in this case, related to pacing within or very close to a region of slow conduction, should be taken into the account, as presented by Pedretti et al (). In their case report, they described a possible underlying electrophysiological mechanism of RV pacing‐induced VTs, which was originating from postmyocardial infarction scar region and based on the localized, RV pacing‐induced reentry, successfully treated with the use of radiofrequency energy ablation (Pedretti et al, ).…”

“…Therefore, the additional mechanism of pExV, VT, and ventricular rhythm in this case, related to pacing within or very close to a region of slow conduction, should be taken into the account, as presented by Pedretti et al (). In their case report, they described a possible underlying electrophysiological mechanism of RV pacing‐induced VTs, which was originating from postmyocardial infarction scar region and based on the localized, RV pacing‐induced reentry, successfully treated with the use of radiofrequency energy ablation (Pedretti et al, ). The relationship between the potentially proarrhythmic tissue and the pacing lead can evolve in time with heart remodeling or later scaring, and thus, one cannot exclude that this mechanism may be still responsible for ventricular arrhythmia developing late after new lead implantation, even if it would be hardly suspected clinically.…”

“…Similar case of monomorphic VT resulting from RV pacing in a patient with CRT device implanted has been described previously by Hayase et al and arrhythmias resolved by programming LV preceding RV pacing (Hayase et al, ). Other authors successfully treated the patient with CRT device and RV lead pacing triggered ventricular arrhythmia with the use of catheter ablation (Pedretti et al, ). Our therapeutic approach has combined noninvasive CRT‐D programming abolishing RV stimulation supported by echocardiographic optimization of hemodynamic performance.…”

“…This is consistent with results of ECHO‐CRT trial where CRT was first shown to increase mortality in narrow‐QRS heart failure population. Up to date, only single cases of late RV pacing‐induced arrhythmias have been reported and different individualized treatment strategies were applied (Hayase, Khakpour, Shivkumar, & Bradfield, ; Pedretti, Vargiu, Paolucci, & Lunati, ).…”

A kardiális reszinkronizációs terápia proaritmiás hatásai és azok kezelési lehetőségei

“…A különböző vezetőképességű területek gyorsabb és lassabb vezetése miatt unidirekcionális blokk alakulhat ki, amely reentry kör részeként vehet részt a ritmuszavarok kialakulásában (31). Több szerző adatai és véleménye alapján a fenti mechanizmussal kialakuló ritmuszavarok szimultán bal és jobb kamrai ingerlés mellett ritkábban jelentkeznek (32). Szerencsére manapság az epikardiális hegszövetek felderítésére is van mód, az egyre nagyobb teret hódító és egyre kifinomultabb minőségű kardiális MR-vizsgálatok által.…”