Cardiac resynchronization therapy (CRT) is an important treatment for patients with heart failure.1,2 In clinical practice, it is difficult to advance a left ventricular (LV) lead through narrow or tortuous vessels in some cases. In this report, we present a case of successful advancement of an LV lead into tortuous vessels. This was achieved by deep engagement of the coronary sinus with a cannulation catheter by applying the anchor technique using the Medtronic Attain Stability Quad lead. This useful technique for LV lead delivery has not been previously reported in the literature.

Introduction: Gastric hypomotility (GH) is a major complication of atrial fibrillation (AF) ablation. We aimed to clarify whether additional cryoballoon ablation (CBA) of the left atrial (LA) roof is associated with GH. Methods and Results: This study included 54 patients with non-paroxysmal AF who underwent CBA for pulmonary vein isolation and of the LA roof line. GH was defined according to the results of esophagogastroscopy performed 2 days after ablation. GH was observed in 10 patients. There were significant differences in LA diameter (LAD), right inferior pulmonary vein (RIPV) diameter, and the height of the LA roof from the point where the LA posterior wall and esophagus make contact between patients with (GH+) and without GH (GH–) (LAD: 41.0 [36.3–41.8] mm vs. 46.5 [42.8–50.0] mm, p<0.01; RIPV diameter: 19.7 [19.0–20.5] mm vs. 23.2 [21.2–24.9] mm, p<0.01; height of LA roof: 5.7 [5.1–6.1] mm vs. 8.8 [7.1–11.2] mm for, p<0.01, respectively). Multivariate analysis revealed that LA roof height was a predictor of GH. Moreover, Patient Assessment of Upper Gastrointestinal Disorders-Symptom Severity Index (PAGI-SYM) scores increased significantly 1 week after ablation (from 1.0 [0.0–2.8] to 5.0 [3.0–11.0], p=0.03) in patients with GH. Conclusion: The height of the LA roof may be a predictor of GH after CBA of the LA roof line. Additionally, GH-related symptoms may still appear 1 week after ablation.

Background & Objectives The FlexAbilityTM SE catheter has a laser-cut 8Fr 4-mm flexible tip irrigated through laser-cut kerfs with a thermocouple 0.3mm from the distal end. The TactiCathTM SE catheter has an 8Fr 3.5-mm tip and 6-irrigation port with a thermocouple 2.67mm proximal to the tip. We investigated the impact of these differences on the efficacy and safety of RF-applications. Methods RF applications at a range of powers (20W, 30W, and 40W), contact forces (5g, 15g, and 25g), and durations (10-60s) using perpendicular/parallel catheter orientation, were performed in excised porcine hearts. Lesion characteristics and incidence of steam pops were compared. Results 540 lesions were examined. The FlexAbilityTM SE catheter produced smaller lesion depths (4.0mm vs. 4.4mm, p=0.014 at 20W; 4.6mm vs. 5.6mm, p=0.015 at 30W), surface areas (22.7mm2 vs. 29.2mm2 at 20W, p=0.005; 23.2mm2 vs. 28.7mm2, p=0.009 at 30W) and volumes (126.1mm3 vs. 175.1mm3, p=0.018 at 20W; 183.2mm3 vs. 304.3mm3, p=0.002 at 30W) with perpendicular catheter placement. However, no differences were observed with parallel catheter placement. Steam-pops were significantly less frequently observed with the FlexAbilityTM SE catheter (4% vs. 22%, p<0.001) irrespective of catheter direction to the tissue. Multivariate analysis showed that use of the TactiCathTM SE catheter, power ≥40W, contact force ≥25g, RF duration >30s, parallel angle and impedance drop ≥20Ω were significantly associated with occurrence of steam-pops. Conclusions The FlexAbilityTM SE catheter reduced the risk of steam-pops, but produced smaller lesions with perpendicular catheter placement compared to the TactiCathTM SE catheter.

Background: Pulmonary vein isolation (PVI) with a balloon-based visually guided laser ablation (VGLA) is regarded as a useful therapeutic tool for treating atrial fibrillation (AF). The clinical efficacy of a VGLA has never been fully investigated in patients with a left common pulmonary vein (LCPV). Objective: We investigated the procedural safety as well as clinical usefulness of VGLA in patients with an LCPV. Methods: This study consisted of 130 consecutive patients who underwent VGLA of de novo non-valvular paroxysmal AF. Results: Eleven patients (8.5%) had an LCPV (ostium maximal average diameter: 27.5 ± 4.9 mm, ostium minimal average diameter: 17.7 ± 3.5 mm). Nine out of 11 (81.8%) LCPVs were successfully occluded and isolated at the ostium with a VGLA guided PVI. The ablation procedure time was significantly shorter in the patients with than without an LCPV (61.5 ± 15.4 vs. 86.9 ± 32.9 min, p = 0.01). There was no difference regarding the atrial tachyarrhythmia recurrence between those with and without an LCPV (p = 0.18). A total of fifteen patients underwent a redo procedure, but reconnections were not observed in any of the LCPV patients. Conclusion: The VGLA guided PVI was a useful therapeutic tool even in patients with an LCPV. The presence of an LCPV was not associated with any atrial tachyarrhythmia recurrence.

Introduction: Limited data exist on pulmonary vein isolation (PVI) using cryoballoon (CB) or radiofrequency (RF) ablation and additional non-pulmonary vein triggers ablation for non-paroxysmal atrial fibrillation (non-PAF). The objective of this study was to assess the outcomes of first-stage catheter ablation for non-PAF patients. Methods and Results: Initial PVI was performed on 734 non-PAF patients (age: 64±10 years; male: 584) between September 2014 and June 2018 [315 (43%), CB ablation; 419 (57%), RF catheter]. A logistic regression model was used to match 257 pairs (514 patients) according to propensity scores (CB group or RF group). After PVI, additional non-PV triggers ablation was performed if induced by isoproterenol. We analyzed the clinical outcomes of both groups. The mean procedural time was significantly shorter in the CB group (125 [range, 89–165] min) than in the RF group (190 [160–224] min; P < 0.001). The 1-year Kaplan-Meier event rate revealed similar atrial fibrillation-free survival rate between the groups (CB: 77.9%, RF: 82.3%; log-rank P = 0.111). The additional ablation percentage for non-PV foci (CB: 39%, RF: 41%; P = 0.653) and the complications incidence (CB: 5%, RF: 4%; P = 0.670) were also similar. Conclusion: In non-PAF patients, PVI using CB or RF ablation and non-PV triggers ablation achieved comparable outcomes. The safety and efficacy of the combination strategy of PVI and non-PV triggers ablation was demonstrated.

Introduction: Detailed clinical outcomes of cryoballoon ablation of the left atrial (LA) posterior wall (LAPW) in patients with non-paroxysmal atrial fibrillation (AF) have not been fully examined. Methods: We analyzed the outcomes of 191 patients with non-paroxysmal AF, of whom 135 underwent cryoballoon ablation of the LAPW including the LA roof in addition to pulmonary vein isolation with a cryoballoon. Results: Complete conduction block at the LA roof was obtained in 97.0% (131/135) of patients and LAPW was isolated in 85.2% (115/135) of patients. Over 372 days (range, 182–450 days) of follow-up, atrial arrhythmia recurrence was observed in 55 (40.7%) patients, and atrial tachycardia (AT) recurrence accounted for 25.5% of cases. The prevalence of LA roof cryoballoon ablation tended to be higher in patients without recurrence than those with (74.3% vs. 61.8%, respectively; p=0.11), especially those with persistent AF recurrence (74.5% vs. 46.2%, p=0.01). Multivariate analysis revealed that cryoballoon ablation of the LA roof was a predictor of freedom from persistent AF recurrence and that it was not associated with AT recurrence. Durable LA roof lesions were confirmed in 18 (72.0%) of 25 patients who underwent redo ablation. Conclusion: Cryoballoon ablation of the LAPW leads to a sufficient acute success rate of complete conduction block and durable lesions of the LA roof without increasing the risk of AT recurrence. The prevalence of persistent AF recurrence decreases after additional cryoballoon ablation of the LAPW in patients with non-paroxysmal AF.

Background: Contrast computed tomography (CT) is a useful tool for the detection of intracardiac thrombi. We aimed to assess the accuracy of the late-phase prone-position contrast CT (late-pCT) for thrombus detection in patients with persistent or long-standing persistent atrial fibrillation (AF). Methods: Early and late-phase pCT were performed in 300 patients with persistent or long-standing AF. If late-pCT did not show an intracardiac contrast defect (CD), catheter ablation (CA) was performed. Immediately prior to CA, intracardiac echocardiography (ICE) from the left atrium was performed to confirm thrombus absence and the estimation of the blood velocity of the left atrial appendage (LAA). For patients with CDs on late-pCT, CA performance was delayed, and late-pCT was performed again after several months following oral anticoagulant alterations or dosage increases. Results: Of the 40 patients who exhibited CDs in the early phase of pCT, six showed persistent CDs on late-pCT. In the remaining 294 patients without CDs on late-pCT, the absence of a thrombus was confirmed by ICE during CA. In all six patients with CD-positivity on late-pCT, the CDs vanished under the same CT conditions after subsequent anticoagulation therapy, and CA was successfully performed. Furthermore, the presence of residual contrast medium in the LAA on late-pCT suggested a decreased blood velocity in the LAA (≤ 15 cm/s) (sensitivity = 0.900 and specificity = 0.621). Conclusions: Late-pCT is a valuable tool for the assessment of intracardiac thrombi and LAA dysfunction in patients with persistent or long-standing persistent AF before CA.

Background: Although ablation energy (AE) and force-time integral (FTI) are well-known active predictors of lesion characteristics, these parameters do not reflect passive tissue reactions during ablation, which may instead be represented by drops in local impedance (LI). This study aimed to investigate if additional LI-data improves predicting lesion characteristics and steam-pops. Methods: RF applications at a range of powers (30W, 40W, and 50W), contact forces (8g, 15g, 25g, and 35g), and durations (10-180s) using perpendicular/parallel catheter orientations, were performed in excised porcine hearts (N=30). The correlation between AE, FTI and lesion characteristics was examined and the impact of LI (%LI-drop [%LID] defined by the ΔLI/Initial LI) was additionally assessed. Results: 375 lesions without steam-pops were examined. Ablation energy (W*s) and FTI (g*s) showed a positive correlation with lesion depth (ρ=0.824:P<0.0001 and ρ=0.708:P<0.0001), surface area (ρ=0.507:P<0.0001 and ρ=0.562:P<0.0001) and volume (ρ=0.807:P<0.0001 and ρ=0.685:P<0.0001). %LID also showed positive correlation individually with lesion depth (ρ=0.643:P<0.0001), surface area (ρ=0.547:P<0.0001) and volume (ρ=0.733, P<0.0001). However, the combined indices of AE*%LID and FTI*%LID provided significantly stronger correlation with lesion depth (ρ=0.834:P<0.0001 and ρ=0.809P<0.0001), surface area (ρ=0.529:P<0.0001 and ρ=0.656:P<0.0001) and volume (ρ=0.864:P<0.0001 and ρ=0.838:P<0.0001). This tendency was observed regardless of the catheter placement (parallel/perpendicular). AE (P=0.02) and %LID (P=0.002) independently remained as significant predictors to predict steam-pops (N=27). However, the AE*%LID did not increase the predictive power of steam-pops compared to the AE alone. Conclusion: LI, when combined with conventional parameters (AE and FTI), may provide stronger correlation with lesion characteristics.

Introduction: Subselection inner catheters (Inner-Cath) are used adjunctively with outer guiding catheters (Outer-Cath) during cardiac resynchronization therapy (CRT) device implantation. This study aims to investigate the feasibility and efficacy of left ventricular lead placement (LV-LP) guided by Inner-Cath alone. Methods: A total of 74 patients undergoing de novo CRT implantation were investigated. LV-LP was initially guided by Inner-Cath in 42 patients (Inner-Cath group) and Outer-Cath in 32 patients (Outer-Cath group). In the Inner-Cath group, a 7Fr Inner-Cath was advanced to the coronary sinus through a 7 Fr sheath inserted in a subclavian vein. In the Outer-Cath group , 9Fr or 10Fr Outer-Caths were used. Success rate of LV-LP, additional use of inner or outer catheters and procedure-related complications were compared between groups. Results: LV-LP was successful in all patients in the Inner-Cath group while LV-LP had to be abandoned in 2 patients of the Outer-Cath group due to CS perforation caused by Outer-Cath manipulation. Procedure time was significantly shorter in the Inner-Cath group (148 vs 168 min; P=0.024). Deployment of both an inner and outer cath became necessary less frequently for the Inner-Cath group (4.8% vs 56.3%; P<0.001). Mechanical CS injuries due to guiding catheter manipulation were only observed in the Outer-Cath group (0% vs 15.6%, P=0.013). Conclusion: LV-LP guided by Inner-Cath alone was feasible in over 95% of the patients without severe complications. This methodology for LV-LP may be preferable in CRT candidates with severe LV dysfunction in terms of shorter procedure time, smaller guiding sheath and less complications.

Introduction Sedation during pulmonary vein isolation (PVI) of atrial fibrillation often provokes a decline in left atrial (LA) pressure (LAP) under atmospheric pressure and increases the risk of systemic air embolisms. This study aimed to investigate the efficacy of adaptive servo-ventilation (ASV) on the LAP in sedated patients. Methods and Results Fifty-one consecutive patients undergoing cryoballoon PVI were enrolled. All patients underwent sedation using propofol throughout the procedure. Sedation status was monitored by the bispectral index. After the transseptal puncture and inserting the long sheath into the LA, the LAP was measured via the sheath. Then, the ASV treatment was started, and the LAP was re-measured. The LAP before and after the ASV support was investigated. Before the ASV, the LAP during inspiratory phase was significantly smaller than that during expiratory phase (4.9±5.4 mmHg vs. 14.0±5.2 mmHg, p<0.01). The lowest LAP was -2.2±5.1 mmHg and was under 0 mmHg in 37 (73%) patients. After the ASV, the LAP during inspiratory phase significantly increased to 8.9±4.1 mmHg (p<0.01), and lowest LAP to 4.7±5.9 mmHg (p<0.01). The negative lowest LAP value became positive in 30/37(81%) patients. There were no statistical differences regarding obstructive sleep apnea (OSA), obesity, gender, or other comorbidities between patients with and without a negative lowest LAP after the ASV support. Conclusion ASV is effective for increasing the LAP above 0 mmHg and might prevent air embolisms during PVI. A negative LAP after the ASV was rare but occurred in patients even without comorbidities such as OSA and obesity

Introduction: Pulmonary vein (PV) isolation (PVI) with a balloon-based visually guided laser ablation (VGLA) is a useful tool for treating atrial fibrillation (AF), however, phrenic nerve injury (PNI) is an important complication. We investigated the predictors of developing PNI during VGLA. Methods and Results: This study included 130 consecutive patients who underwent an initial VGLA of non-valvular paroxysmal AF. During the ablation of the right-sided pulmonary veins, continuous and stable right phrenic nerve pacing was performed, and the compound motor action potentials (CMAPs) were recorded. Twenty patients developed PNI during the PVI. The patients who suffered from PNI had a significantly larger right superior PV (RSPV) ostium area (284.7 ± 47.0 mm2 vs. 233.1 ± 46.4 mm2, P < 0.01) than that of the other patients. Receiver operating characteristic analyses revealed that the area under the curve of the RSPV ostial area was 0.79 (95% confidence interval: 0.69-0.90) with an optimal cut-off point of 238.0 mm2 (sensitivity: 0.58, specificity: 0.95). In the multivariate analyses, large RSPV ostial area (HR 1.02, 95% confidence interval: 1.01-1.03, P < 0.01) and small balloon size (HR 0.72, 95% confidence interval: 0.53-0.98, P = 0.03) were independent risk factors for PNI. PNI remained in 13 patients after the procedure, but 12 of those patients recovered from PNI during the follow-up period. Conclusion: The incidence of PNI during the VGLA was relatively high, but the PNI improved in the majority of cases. During the VGLA, a large RSPV and small balloon size were predictors of PNI.