Loss of His-bundle and Right Ventricular Septal Capture Following Transcatheter Aortic Valve Replacement-A Case Report.

Conduction abnormalities following transcatheter aortic valve replacement (TAVR) are common. High-grade atrioventricular block (AVB) and new-onset left bundle branch block remain the most reported. These often require the placement of a permanent pacemaker (PPM). His-bundle (HB) pacing is increasingly being utilized as the preferred mode of ventricular pacing due to its more physiologic ventricular activation. In this case report, we present a case of a patient who developed loss of HB capture and experienced an increase in the local right ventricular (RV) capture threshold after TAVR that led to unrecognized intermittent loss of ventricular capture and symptoms. An 80-year-old man with severe aortic stenosis presented with symptomatic bradycardia due to typical atrial flutter (AFL) with a high-grade AVB and an underlying right bundle branch block. He underwent placement of a dual-chamber PPM (Medtronic, Inc., Minneapolis, MN, USA) with a HB pacing lead. HB mapping demonstrated a normal H-V interval, and the lead was fixated with non-selective HB capture. The R-waves measured 2.8 mV, the pacing impedance was 544 Ω, and the non-selective HB and local RV capture threshold was 0.5 V @ 1 ms. He underwent AFL ablation, and his atrial leads were normal. He subsequently underwent successful TAVR with a 29-mm Sapien 3 valve (Edwards Lifesciences, Irvine, CA, USA). Post-TAVR, PPM interrogation showed a loss of HB capture with a left bundle paced QRS morphology. Following discharge, he presented with stroke-like symptoms and was noted to have intermittent loss of RV capture with complete heart block (CHB) and a slow ventricular escape rhythm. PPM interrogation revealed an elevated pacing threshold, and his RV output was gradually increased to a maximum output of 7.5 V @ 1.5 ms. He also developed a fever and was found to have enterococcal bacteremia. Transesophageal echocardiography demonstrated vegetations on his prosthetic valve and pacemaker lead, without a perivalvular abscess. He underwent explantation of the pacemaker system and insertion of a temporary PPM. After intravenous antibiotic therapy with negative blood cultures, he underwent re-implantation of a new right-sided dual-chamber PPM, and an RV pacing lead was placed into the RV outflow tract. HB pacing is becoming the preferred mode of physiologic ventricular pacing. This case illustrates the potential risks of the TAVR procedure in patients with existing HB pacing leads. We observed a loss of HB capture and the development of CHB due to traumatic injury to the HB distal to the HB pacing lead after TAVR placement together with an increase in the local RV capture threshold. The depth of TAVR placement is an important aspect of the TAVR procedure that determines the risk of developing CHB and may also affect the HB and local RV pacing thresholds post-procedure.

Asreb A ，Ahn J 《-》

Predictors of right ventricular pacing and pacemaker dependence in transcatheter aortic valve replacement patients.

Sharma E ，Chu AF 《-》

Feasibility of His-bundle pacing in patients with conduction disorders following transcatheter aortic valve replacement.

Conduction disorders requiring permanent pacemaker implantation occur frequently after transcatheter aortic valve replacement (TAVR). This multicenter study explored the feasibility and safety of His bundle pacing (HBP) in TAVR patients with a pacemaker indication to correct a TAVR-induced left bundle branch block (LBBB). Patients qualifying for a permanent pacemaker implant after TAVR were planned for HBP implant. HBP was performed using the Select Secure (3830; Medtronic) pacing lead, delivered through a fixed curve or deflectable sheath (C315HIS or C304; Medtronic). Successful HBP was defined as selective or nonselective HBP, irrespective of LBB recruitment. Successful LBBB correction was defined as selective or nonselective HBP resulting in paced QRS morphology similar to pre-TAVR QRS and paced QRS duration (QRSd) less than 120 milliseconds with thresholds less than 3.0 V at 1.0-millisecond pulse width. The study enrolled 16 patients requiring a permanent pacemaker after TAVR (age 85 ± 4 years, 31% female, all LBBB; QRSd: 161 ± 14 milliseconds). Capture of the His bundle was achieved in 13 of 16 (81%) patients. HBP with LBBB correction was achieved in 11 of 16 (69%) and QRSd narrowed from 162 ± 14 to 99 ± 13 milliseconds and 134 ± 7 milliseconds during S-HBP and NS-HBP, respectively (P = .005). At implantation, mean threshold for LBBB correction was 1.9 ± 1.1 V at 1.0 millisecond. Thresholds remained stable at 11 ± 4 months follow-up (1.8 ± 0.9 V at 1.0 millisecond, P = .231 for comparison with implant thresholds). During HBP implant, one temporary complete atrioventricular block occurred. Permanent HBP is feasible in the majority of patients with TAVR requiring a permanent pacemaker with the potential to correct a TAVR-induced LBBB with acceptable pacing thresholds.

De Pooter J ，Gauthey A ，Calle S ，Noel A ，Kefer J ，Marchandise S ，Coeman M ，Philipsen T ，Kayaert P ，Gheeraert P ，Jordaens L ，Timmermans F ，Van Heuverswyn F ，Bordachar P ，le Polain de Waroux JB ... -  《-》

Aortic Valve Calcification as a Predictor of Post-Transcatheter Aortic Valve Replacement Pacemaker Dependence.

Atrioventricular block requiring permanent pacemaker (PPM) implantation is a common complication of transcatheter aortic valve replacement (TAVR). The mechanism of atrioventricular (AV) block during TAVR is not fully understood, but it may be due to the mechanical stress of TAVR deployment, resulting in possible injury to the nearby compact AV node. Aortic valve calcification (AVC) may worsen this condition and has been associated with an increased risk for post-TAVR PPM implantation. We performed a retrospective analysis to determine if AVC is predictive for long-term right ventricular (RV) pacing in post-TAVR pacemaker patients at 30 days. A total of 262 consecutive patients who underwent TAVR with a balloon-expandable valve were analyzed. AVC data were derived from contrast-enhanced computed tomography and characterized by leaflet sector and region. A total of 25 patients (11.1%) required post-TAVR PPM implantation. Seventeen patients did not require RV pacing at 30 days. Nine of these 17 patients had no RV pacing requirement within 10 days. The presence of intra-procedural heart block (P = 0.004) was the only significant difference between patients who did not require PPM and those who required PPM but they were not RV pacing-dependent at 30 days. Non-coronary cusp (NCC) calcium volume was significantly higher in patients who were pacemaker-dependent at 30 days (P = 0.01) and a calcium volume of > 239.2 mm3 in the NCC was strongly predictive of pacemaker dependence at 30 days (area under the curve (AUC) = 0.813). Pre-existing right bundle branch block (RBBB) (odds ratio (OR) 105.4, P = 0.004), bifascicular block (OR 12.5, P = 0.02), QRS duration (OR 70.43, P = 0.007) and intra-procedural complete heart block (OR 12.83, P = 0.03) were also predictive of pacemaker dependence at 30 days. In patients who required PPM after TAVR, quantification of AVC by non-coronary leaflet calcium volume was found to be a novel predictor for RV pacing dependence at 30 days. The association of NCC calcification and PPM dependence may be related to the proximity of the conduction bundle to the non-coronary leaflet. Further studies are necessary to improve risk prediction for long-term RV pacing requirements following TAVR.

Sharma E ，McCauley B ，Ghosalkar DS ，Atalay M ，Collins S ，Parulkar A ，Sheikh W ，Ahmed MB ，Chu A ... -  《-》

Transcatheter Heart Valve Selection and Permanent Pacemaker Implantation in Patients With Pre-Existent Right Bundle Branch Block.

Right bundle branch block is an established predictor for new conduction disturbances and need for a permanent pacemaker (PPM) after transcatheter aortic valve replacement. The aim of the study was to evaluate the absolute rates of transcatheter aortic valve replacement related PPM implantations in patients with pre-existent right bundle branch block and categorize for different transcatheter heart valves. We pooled data on 306 transcatheter aortic valve replacement patients from 4 high-volume centers in Europe and selected those with right bundle branch block at baseline without a previously implanted PPM. Logistic regression was used to evaluate whether PPM rate differed among transcatheter heart valves after adjustment for confounders. Mean age was 83±7 years and 63% were male. Median Society of Thoracic Surgeons score was 6.3 (interquartile range, 4.1-10.2). The following transcatheter valve designs were used: Medtronic CoreValve (n=130; Medtronic, Minneapolis, MN); Edwards Sapien XT (ES-XT; n=124) and Edwards Sapien 3 (ES-3; n=32; Edwards Lifesciences, Irvine, CA); and Boston Scientific Lotus (n=20; Boston Scientific Corporation, Marlborough, MA). Overall permanent pacemaker implantation rate post-transcatheter aortic valve replacement was 41%, and per valve design: 75% with Lotus, 46% with CoreValve, 32% with ES-XT, and 34% with ES-3. The indication for PPM implantation was total atrioventricular block in 98% of the cases. Lotus was associated with a higher PPM rate than all other valves. PPM rate did not differ between ES-XT and ES-3. Ventricular paced rhythm at 30-day and 1-year follow-up was present in 81% at 89%, respectively. Right bundle branch block at baseline is associated with a high incidence of PPM implantation for all transcatheter heart valves. PPM rate was highest for Lotus and lowest for ES-XT and ES-3. Pacemaker dependency remained high during follow-up.

van Gils L ，Tchetche D ，Lhermusier T ，Abawi M ，Dumonteil N ，Rodriguez Olivares R ，Molina-Martin de Nicolas J ，Stella PR ，Carrié D ，De Jaegere PP ，Van Mieghem NM ... -  《Journal of the American Heart Association》