Troubleshooting Programming of Conduction System Pacing

Conduction system pacing (CSP) comprises His bundle pacing and left bundle branch area pacing and is rapidly gaining widespread adoption. Effective CSP not only depends on successful system implantation but also on proper device programming. Current implantable impulse generators are not specifically designed for CSP. Either single chamber, dual chamber or CRT devices can be used for CSP depending on the underlying heart rhythm (sinus rhythm or permanent atrial arrhythmia) and the aim of pacing. Different programming issues may arise depending on the device configuration. This article aims to provide an update on practical considerations for His bundle and left bundle branch area pacing programming and follow-up

Programmierung und Nachverfolgung bei Patienten mit His-Bündel-Stimulation

His bundle pacing (HBP) is being increasingly adopted worldwide, with the aim of providing more physiological stimulation of the heart as opposed to right ventricular pacing or as an alternative to cardiac resynchronization therapy (CRT). Current devices are not specifically designed for HBP, which gives rise to programming challenges. This article aims to provide practical recommendations for HBP programming and follow-up

HOT-CRT ECG imaging study

AbstractTo compare electrical synchrony of His bundle pacing with His-Optimized CRT and Biventricular pacing using ECG imaging. Study funded by the SNF

Cryoablation vs. radiofrequency ablation of the atrioventricular node in patients with His-bundle pacing

Aims: Radiofrequency ablation (RFA) of the atrioventricular node (AVN) with His-bundle pacing (HBP) can cause rise in capture thresholds. Cryoablation (CRYO) may offer reversibility in case of threshold rise but has never been tested for AVN ablation in this setting. Our aim was to compare procedural characteristics and outcome of CRYO compared with RFA for AVN ablation in patients with HBP. Methods and results: Forty-four patients with HBP underwent AVN ablation for an 'ablate and pace' indication. Cryoablation was performed in the first 22 patients and RFA in the following 22 patients. Procedural characteristics, success rates, and change in His capture thresholds were compared between groups. Distance from the ablation site to the His lead was measured using biplane fluoroscopy. Acute success was 100% with both strategies. Median procedural duration was significantly longer for CRYO {50 [interquartile range (IQR) 38-63] min} compared with RFA [36 (IQR, 30-41) min; P = 0.027]. An acute threshold rise of ≥1 V was observed in four CRYO (one complete loss of capture) and three RFA patients (P = 0.38), with all of the applications being within 6 mm of the His lead tip. During follow-up, nine patients had AVN re-conduction (six CRYO vs. three RFA; P = 0.58), but only four patients required a redo procedure (all CRYO; P = 0.09). Conclusion: Cryoablation does not offer any advantage over RFA for AVN ablation in patients with HBP and tended to require more redo procedures. If possible, a distance of ≥6 mm should be maintained from the His lead tip to avoid a rise in capture thresholds.</p

His bundle pacing to avoid electrical dyssynchrony with traditional right ventricular pacing: Importance of heart size

Background: His Bundle Pacing (HBP) is attracting interest as an alternative to traditional right ventricular pacing (RVP) because it avoids electrical dyssynchrony induced by RVP. This study aims to evaluate the effect of heart size on benefit from HBP compared to RVP in terms of achieving electrical synchrony. Methods: Fifty-nine patients with HBP and a RVP back-up lead underwent pre-implantation echocardiography to measure left ventricular end-diastolic volume (LVEDV). Electrical benefit from HBP was calculated as the difference in QRS duration (QRSd) between RVP and HPB. Results: LVEDV was significantly correlated with RVP QRSd (R = 0.53; p &lt; 0.001). In contrast, LVEDV was unrelated to HBP QRSd (R = 0.16; p = 0.24). Electrical benefit of HBP over RVP was directly related with LVEDV (R = 0.43; p = 0.001). In addition, electrical benefit of HBP was larger for patients with LVEDV above median (99 mL) than below (49 ± 27 ms vs. 34 ± 19 ms, p = 0.014). Conclusions: This study is the first to demonstrate that patients with larger LV size may benefit most from HBP as a replacement of traditional RVP to avoid electrical dyssynchrony. Our results indicate that LV size impacts QRSd during RVP with slow cell-to-cell conduction, whereas it does not affect electrical synchrony during HBP with fast His-Purkinje conduction.</p

His-optimized cardiac resynchronization therapy with ventricular fusion pacing for electrical resynchronization in heart failure

This study sought to evaluate the effectiveness of His-optimized cardiac resynchronization therapy (HOT-CRT) for reducing left ventricular activation time (LVAT) compared to His bundle pacing (HBP) and biventricular(BiV) pacing (including multipoint pacing [MPP]), using electrocardiographic (ECG) imaging. HBP may correct bundle branch block (BBB) and has shown encouraging results for providing CRT. However, HBP does not correct BBB in all patients and may be combined with univentricular or BiV fusion pacing to deliver HOT-CRT to maximize resynchronization. Nineteen patients with a standard indication for CRT, implanted with HBP without correction of BBB and BiV (n=14) or right ventricular (n=5) leads, were prospectively enrolled. Patients underwent ECG imaging while pacing in different configurations using different LV electrodes and at different HBP ventricular pacing (VP) delays. The primary endpoint was reduction in LVAT with HOT-CRT, and the secondary endpoints included various other dys-synchrony measurements including right ventricular activation time (RVAT). Compared to HBP, HOT-CRT reduced LVAT by 21% (−17 ms [95% confidence interval [CI]: −25 to −9 ms]; p HOT-CRT acutely improves ventricular electrical synchrony beyond BiV and MPP. The impact of this finding needs to be evaluated further in studies with clinical follow-up. (Electrical Resynchronization and Acute Hemodynamic Effects of Direct His Bundle Pacing Compared to Biventricular Pacing; NCT03452462).</p

Clinical outcomes of heart-team-guided treatment decisions in high-risk patients with aortic valve stenosis in a health-economic context with limited resources for transcatheter valve therapies.

AIMS: Transcatheter aortic valve implantation (TAVI) is the preferred treatment modality for patients with severe aortic stenosis at high or prohibitive risk for surgical aortic valve replacement (SAVR). We aimed to evaluate real-world outcomes after treatment according to the decisions of the multidisciplinary heart team in a Belgian health-economic context. METHODS AND RESULTS: Four hundred and five high-risk patients referred to a tertiary centre between 1 March 2008 and 31 December 2015 were screened and planned to undergo SAVR, TAVI or medical treatment (MT). Patients undergoing SAVR had lower Society of Thoracic Surgeons scores and Euroscore-II when compared to TAVI or MT (median [IQR]: 6[4-8]; 7[5-10]; 8[6-13]; p < .001 and 6[4-10]; 8[5-15]; 8[4-16]; p = .006). At 1 year all-cause mortality was 14, 17 and 51% with SAVR, TAVI and MT, respectively (p < .001). Cardiovascular death and disabling stroke occurred in 9, 7 and 35% (p < .001) and 2, 2.7 and 1.7% (p = .91). According to Valve-Academic-Research-Consortium-II criteria, device success was 95 and 92% for TAVI and SAVR. The combined safety endpoint at 30 days favoured TAVI (22% vs. 47%) (p < .001). The combined efficacy endpoint at 1 year was comparable between groups (38 and 40%; p = .703). Finally, hospital stay was shorter with TAVI vs. SAVR (9[6-14] and 16[12-22] days; p < .001). CONCLUSIONS: Limited resources for transcatheter valve therapies in Belgium push a significant number of patients to SAVR, while TAVI in even higher risk patients translates into similar outcomes and shorter hospital stay. These findings underscore the need for broadening indications for TAVI, as well as readjustment of the budgetary allocations for hospitals in Belgium.epub ahead of printstatus: Published onlin