Optimal ablation settings of TactiFlex SE laser-cut irrigated-tip catheter: comparison with ThermoCool SmartTouch SurroundFlow porous irrigated-tip catheter.

BACKGROUND: The TactiFlex SE catheter (TFSE, Abbott) with a contact force (CF) sensor and a laser-cut irrigated-tip has recently become available but lacks a lesion quality marker. This study aimed to explore distinctions in lesion characteristics between the TFSE and the ThermoCool SmartTouch SurroundFlow catheter (STSF, Biosense Webster), which utilizes a porous irrigated tip, and to assess the most effective application settings for the TFSE. METHODS: Lesions were generated using varying settings of radiofrequency power (30-50 W), CF (10-20 g), application duration (10-40 s), and catheter orientation (perpendicular or parallel) in an ex vivo porcine model. Comparative analysis between the TFSE and STSF was conducted for lesion characteristics and incidence of steam pops using predictive models in regression analyses. RESULTS: Among 720 applications, the TFSE exhibited a significantly lower incidence of steam pops compared to the STSF (0.6% vs. 36.8%, P < 0.001). Moreover, coefficients of determination (R2) for the TFSE were higher than those for the STSF concerning lesion depth (0.710 vs. 0.541) and volume (0.723 vs. 0.618). The lesion size generated with the TFSE was notably smaller than that with the STSF under identical application settings. Additionally, to achieve a lesion depth ≥ 4.0 mm, the TFSE required an application duration 8-12 s longer than the STSF under similar settings. CONCLUSIONS: The TFSE demonstrated a lower incidence of steam pops and superior predictability in lesion size compared to the STSF. However, the TFSE necessitated a longer application duration than the STSF to achieve an adequate lesion size.

Septal coronary artery fistula after left bundle branch area pacing assessed by multi-imaging modalities and shunt volume quantification.

Septal coronary artery fistula is a rare but concerning complication of left bundle branch area pacing (LBBAP). We report the case of an 82-year-old man who was indicated for cardiac resynchronization therapy and underwent LBBAP. The patient had no chest symptoms during or after implantation. Postoperative echocardiography demonstrated a new abnormal tunnel inside the interventricular septum (IVS) and shunt flow from the IVS toward the right ventricle. Coronary angiography confirmed a septal coronary artery fistula, which might have been formed by failed deep screw attempts. Since the shunt volume assessed by the Qp /Qs was small, the patient was treated conservatively.

Efficacy of His Bundle Pacing on LV Relaxation and Clinical Improvement in HF and LBBB.

OBJECTIVES: This study aimed to compare acute hemodynamic improvements and responses to His bundle pacing (HBP) and conventional biventricular pacing (BVP). BACKGROUND: HBP can correct left bundle branch block (LBBB) and may be an alternative cardiac resynchronization therapy (CRT) to BVP. METHODS: Fourteen consecutive patients with heart failure (HF) and typical LBBB who required CRT were enrolled. The acute hemodynamic responses during HBP and BVP were compared using a micromanometer-tipped catheter inserted into the left ventricle (LV) before CRT. Each configuration was compared with AAI mode. A permanent HBP device was implanted when LBBB correction threshold was ≤1.5 V at 1.0 ms, and remaining patients were treated with BVP. Clinical and echocardiographic improvements were assessed during a 12-month follow-up period. RESULTS: The LV contractile index (positive maximal rate of LV pressure rise [dP/dtmax]) increased similarly during HBP and BVP (18.8% ± 6.4% vs 18.0% ± 10.2%; P = 0.810). LV relaxation indices (negative dP/dtmax and tau) were significantly improved during HBP compared with BVP (negative dP/dtmax: 14.3% ± 5.5% vs 3.1% ± 8.1%; P < 0.001; tau: 7.2% ± 4.3% vs -0.8% ± 8.1%; P = 0.001). Nine (64%) patients received permanent HBP devices, while 5 patients were treated with BVP. The New York Heart Association functional class, LV ejection fraction, LV end-systolic volume, and B-type natriuretic peptide level improved in patients treated with HBP and BVP (all P < 0.05 vs baseline). Patients treated with HBP exhibited earlier and greater improvements of the LV ejection fraction and LV end-systolic volume than did those with BVP. CONCLUSIONS: HBP improves systolic function and LV relaxation in patients with HF and LBBB. CRT via HBP produced earlier and greater clinical responses than BVP.