Association left ventricular lead and ventricular arrhythmias after upgrade to cardiac resynchronization therapy in patients with implantable cardioverter defibrillators

Abstract

Background There are some controversial reports related to the pro‐arrhythmic or anti‐arrhythmic potential of cardiac resynchronization therapy (CRT) and little is known about the relationship between ventricular arrhythmia (VA) and left ventricular (LV)‐lead threshold. Hypothesis Upgrade CRT is anti‐arrhythmic effect of VA with implantable cardioverter‐defibrillator (ICD) patients and has a relationship with the incident of VA and LV‐lead threshold. Methods Among 384 patients with the implantation of CRT‐defibrillator (CRT‐D), 102 patients underwent an upgrade from ICD to CRT‐D. We divided patients into three groups; anti‐arrhythmic effect after upgrade (n = 22), pro‐arrhythmic effect (n = 14), and unchanging‐VA events (n = 66). The VA event was determined by device reports. We described the electrocardiography parameters, LV‐lead characteristics, and clinical outcomes. Results Before upgrade, the numbers of VA were 305 episodes and the numbers of ICD therapy were 157 episodes. While after upgrade, the numbers of VA were 193 episodes and the number of ICD therapy were 74 episodes. Ventricular tachycardia cycle length (VT‐CL) after upgrade was significantly slower as compared to those with before upgrade. Pro‐arrhythmic group was significantly higher with delta LV‐lead threshold (after 1 month—baseline) as compared to those with anti‐arrhythmic group (0.74 vs −0.21 V). Furthermore, pro‐arrhythmic group was significantly bigger with delta VT‐CL (after 3 months—before 3 months) as compared to those with anti‐arrhythmic group ( P = .03). Conclusions We described upgrade‐CRT was associated with reduction of VA, ICD therapies and VT‐CL. While 14 patients had a pro‐arrhythmic effect and LV lead threshold might be associated with VA‐incidents.

Proarrhythmic effect of bipolar epicardial left ventricular stimulation in CRT resolved maintaining biventricular pacing with unipolar‐cathodical configuration: A peculiar case report

“…The proarrhythmic effect of CRT was previously established, but few cases were reported 6–10 . The most speculated explanation of the proarrhythmic effect of the epicardial LVp is the reversal of the physiological transmural activation sequence, thus delaying endocardial depolarization and subsequent repolarization.…”

“…Several studies reported a decreased risk of VA after CRT implantation, 5 but not all the literature confirmed this beneficial effect. 6 Some studies reported a potential proarrhythmic effect of epicardial LVp, 7 , 8 , 9 , 10 mainly due to enhanced transmural dispersion of repolarization and especially in nonresponder patients. 11 …”

Proarrhythmic effect of bipolar epicardial left ventricular stimulation in CRT, resolved maintaing biventricular pacing with unipolar-cathodical configuration: a peculiar case report

“…The proarrhythmic effect of CRT was previously established, but few cases were reported [5][6][7][8][9]. Most speculated explanation of the proarrhythmic effect of the epicardial LVp is the reversal of the physiological transmural activation sequence, thus delaying endocardial depolarization and subsequent repolarization.…”

“…Several studies reported a decreased risk of VA after CRT implantation, [4] but not all the literature confirmed this beneficial effect. [5] Some studies reported a potential proarrhythmic effect of epicardial LVp, [6][7][8][9] mainly due to enhanced transmural dispersion of repolarization and especially in non-responder patients. [10] We report a peculiar case of electrical storm (ES) triggered by conventional BiV and potentially due to anodal myocardium capture by epicardial LVp.…”

Use of Stereotactic Radioablation Therapy as a Bailout Therapy for Refractory Ventricular Tachycardia in a Patient with a No-entry Left Ventricle

“…We also transiently switched off the CRT device to exclude the possible lead-related VT, as there are some controversial data concerning the proarrhythmic or antiarrhythmic potential of CRT therapy. 10 As all available cardiologic therapeutic strategies failed to free the patient from VT recurrence, we decided to implement SBRT as a therapy of last resort after discussions in our group and with the patient and his relatives. In the next step, positron-emission tomography-computed tomography (PET-CT) showed hypometabolic scar areas in the inferolateral walls corresponding with previous electroanatomic maps ( Figure 2C ) .…”