Feasibility of energy-guided short duration protocol of laser balloon based pulmonary vein isolation for atrial fibrillation (EG-Laser Study).

BACKGROUND: Laser balloon-based pulmonary vein isolation (LB-PVI) is available for atrial fibrillation (AF) ablation. The lesion size depends on laser energy; however, the default protocol is not an energy-based setting. We hypothesized that an energy-guided (EG) short-duration protocol may be an alternative to shorten the procedure time without affecting efficacy and safety. METHODS: We evaluated the efficacy and safety of the EG short-duration protocol (EG group) (target energy 120 J/site [12W/10s; 10W/12s; 8.5W/14s; 5.5W/22s]) compared with the default protocol (control group) (12W/20s; 10W/20s; 8.5W/20s; 5.5W/30s). RESULTS: A total of 52 consecutive patients (EG: n = 27 [103veins] and control: n = 25 [91veins]) undergoing LB-PVI (64 ± 10 years, 81% male, 77% paroxysmal) were enrolled. The EG group had a shorter total time in the pulmonary vein (PV) (43.0 ± 13.9 min vs. 61.1 ± 16.0 min, p < .0001), a shorter total laser application time (1348 ± 254 sec vs. 2032 ± 424 sec, p < .0001), and lower total laser energy (12455 ± 2284J vs. 18084 ± 3746J, p < .0001). There was no difference in the total number of laser applications (p = 0269) or first-pass isolation (p = .725). Acute reconduction was identified only in one vein in the EG. No significant differences were observed in the incidence of pinhole rupture (7.4% vs. 4%, p = 1.000) or phrenic nerve palsy (3.7% vs. 12%, p = .341). During a mean follow-up of 13.5 ± 6.1 months, Kaplan-Meier analysis revealed no significant difference in atrial tachyarrhythmia recurrence (p = .227). CONCLUSION: LB-PVI with the EG short-duration protocol may be achieved in a shorter procedure time to avoid deterioration of efficacy and safety. The EG protocol is feasible as a novel point-by-point manual laser-application approach.

Prevalence and Characteristics of Inspiration-Induced Negative Left Atrial Pressure during Pulmonary Vein Isolation.

BACKGROUND: Atrial fibrillation (AF) ablation is performed under deep sedation, which may cause inspiration-induced negative left atrial pressure (INLAP) associated with deep inspiration. INLAP could be the cause of periprocedural complications. METHODS: We retrospectively enrolled 381 patients with AF (mean age, 63.9 ± 10.8 years; 76 women; 216 cases of paroxysmal AF) who underwent CA under deep sedation using an adaptive servo ventilator (ASV). Patients whose LAP was not obtained were excluded. INLAP was defined as <0 mmHg of mean LAP during inspiration immediately after the transseptal puncture. The primary and secondary endpoints were the presence of INLAP and the incidence of periprocedural complications. RESULTS: Among 381 patients, INLAP was observed in 133 (34.9%). Patients with INLAP had higher CHA2DS2-Vasc scores (2.3 ± 1.5 vs. 2.1 ± 1.6) and 3% oxygen desaturation indexes (median 18.6 (interquartile range 11.2-31.1) vs. 15.7 (8.1-25.3)), and higher prevalence of diabetes mellitus (23.3 vs. 13.3%) than patients without INLAP. Air embolism occurred in four patients with INLAP (3.0 vs. 0.0%). CONCLUSION: INLAP is not rare in patients undergoing CA for AF under deep sedation with ASV. Much attention should be paid to the possibility of air embolism in patients with INLAP.

Individualised left anterior oblique projection for lead implantation into interventricular septum.

OBJECTIVE: We sought to investigate whether it is possible to obtain individualised left anterior oblique (LAO) by preprocedural electrocardiographic parameters and, if so, whether these parameters can help to improve the success rate of right ventricular (RV) lead implantation into the interventricular septum. METHODS: In this observational study, we assessed the relationship between preoperative electrocardiographic parameters and the angle of the interventricular septum obtained using thoracic CT. The participants were divided into two groups: a retrospective derivation cohort to derive the optimal formula for the individual septum axis, and a prospective internal validation cohort to which we applied the optimal formula and implanted using the new method. RESULTS: In the retrospective derivation cohort (n=39), the mean angle of individualised LAO assessed by thoracic CT was 53.1°±8.9°, and the preoperative ECG QRS axis was strongly correlated with the interventricular septum axis (R2=0.490). LAO projection derived from the preoperative ECG QRS axis confirmed that the RV lead was placed in the interventricular septum during the pacemaker procedure in the prospective internal validation group (n=30). The success rate for placing the RV lead into the interventricular septum was significantly improved in the internal validation cohort (93% vs 64%, p<0.05). In addition, the N-terminal pro-brain natriuretic peptide level decreased significantly after surgery in the interventricular septal indwelling group. CONCLUSIONS: Individualised LAO angle derived from the preoperative ECG QRS axis is a new useful and simple method for RV lead implantation into the interventricular septum. TRIAL REGISTRATION NUMBER: UMIN000045741.

Safety of a Cardiac Resynchronization Therapy Device Implantation in a Patient with Unstable Heart Failure Who Require Impella-Device Assistance.

Implantation of a cardiac resynchronization therapy (CRT) device is usually scheduled in the compensated phase of heart failure; however, procedural safety may be sometimes disturbed in the decompensated phase. We report a case of a successful semi-urgent implantation of a CRT device temporary assisted with Impella in a patient with the decompensated phase of severe heart failure dependent on inotropic agents and who cannot maintain the supine position. Impella assistance with left ventricular (LV) unloading and maintenance of end-organ perfusion contributed to early recovery from acute heart failure. Furthermore, an acute effect of mechanical resynchronization by biventricular pacing plays an important role in weaning from the mechanical support or inotropic dependence. These mutual effects of mechanical support and CRT might contribute to a decrease in LV end-diastolic pressure and to a remarkable early recovery from a severely decompensated condition.

Pre-procedural predictors of left atrial low-voltage zones in patients undergoing catheter ablation of atrial fibrillation.

Pulmonary vein isolation has become a cornerstone treatment for catheter ablation of atrial fibrillation (AF). Recent reports show that additional ablation targeting low-voltage zones reduces AF recurrence. However, the pre-procedural predictors of low-voltage zones remain elusive. We retrospectively enrolled 359 patients (mean age 63.7 ± 10.8 years; 73 females; and 149 had persistent atrial fibrillation) who underwent catheter ablation for AF and left atrial (LA) voltage mapping during sinus rhythm or atrial pacing. Low-voltage zones were defined as area of > 5 cm2 with a bipolar electrogram amplitude of < 0.50 mV. Overall, 51 (14.2%) patients had low-voltage zones. Patients with low-voltage zones were older (67.9 ± 9.9 vs. 63.0 ± 10.8 years; P = 0.003), predominantly female (33.3% vs. 18.2%; P = 0.013), had higher prevalence of dilated cardiomyopathy (DCM) (11.8% vs. 1.6%; P = 0.002) and hypertrophic cardiomyopathy (HCM) (9.8% vs. 2.6%; P = 0.025), and had larger LA volumes (153.6 ± 46.4 vs. 117.7 ± 67.8 mL; P < 0.001) than those without low-voltage zones. Multivariate logistic regression analysis revealed that age (OR 1.060; 95% CI 1.022-1.101, P = 0.002), female sex (OR 2.978; 95% CI 1.340-6.615, P = 0.007), DCM (OR 8.341; 95% CI 1.381-50.372, P = 0.021), HCM (OR 5.044; 95% CI 1.314-19.363, P = 0.018), persistent AF (OR 4.188; 95% CI 1.928-9.100, P < 0.001), and larger LA volume (OR 3.215; 95% CI 1.378-7.502, P = 0.007) were independently associated with the presence of low-voltage zones. Patient age, female sex, DCM, HCM, persistent AF and larger LA volume may predict the presence of low-voltage zones and could be useful in selecting the appropriate ablation strategy for AF.

Intra-Left Ventricular Hemodynamics Assessed with 4D Flow Magnetic Resonance Imaging in Patients with Left Ventricular Thrombus.

Left ventricular thrombus (LVT) has been identified to be crucial in patients with reduced ejection fraction (EF). Three-dimensional cine phase-contrast magnetic resonance imaging (4D flow MRI) can visualize the intra-LV vortex during diastole and quantify the maximum flow velocity (Vmax) at the apex. In this study, we investigated whether the change in the intra-LV vortex was associated with the presence of LVT in patients with cardiac disease.In total, 36 patients (63.5 ± 11.9 years, 28 men, 12/24 with/without LVT) with diffuse LV dysfunction underwent 4D flow MRI. The relative vortex area using streamline images and Vmax of blood flow toward the apex at the apical left ventricle were evaluated. The correlation between the relative vortex area and Vmax was assessed using Pearson's correlation coefficient. The ability to detect LVT was evaluated using the area under the curve (AUC) of the receiver operating characteristic.The relative vortex area was found to be smaller (27 ± 10% versus 45 ± 11%, P = 0.000026), whereas Vmax at the apical left ventricle was lower (19.1 ± 4.4 cm/second versus 27.4 ± 8.9 cm/second, P = 0.0006) in patients with LVT. Vmax at the apical left ventricle demonstrated significant correlations with the relative vortex area (r = 0.43, P = 0.01) and relative transverse length of the vortex (r = 0.45, P = 0.007). The AUC was 0.91 for the relative vortex area, whereas it was 0.80 for Vmax in the apical left ventricle.A smaller LV vortex and lower flow velocity at the LV apex were associated with LVT in patients with reduced EF.

Tortuous inferior vena cava with severe scoliosis: An impediment to successful leadless pacemaker implantation.

Both a multicenter cohort and a post-approval registry of the Micra™ transcatheter pacemaker (Medtronic, Minneapolis, MN, USA) reported high successful implantation rates (>99%) with long-term stability of electrical performance and long-term safety. Therefore, there has been little discussion on the causes of cases of failure in terms of anatomical findings. We report a case of failure of implantation of the Micra because of a tortuous inferior vena cava (IVC) secondary to severe scoliosis. A retrospective assessment of 3D reconstructed computed tomography imaging could visualize the configuration of the IVC-right atrium junction. A preprocedural anatomical assessment may help to predict the implantability of the transcatheter leadless pacemaker or to image the manipulation of the delivery catheter. 99%). There has been little discussion on the causes of cases of failure in terms of anatomical findings. We report a case of failure of implantation of the Micra device because of a tortuous inferior vena cava secondary to severe scoliosis. A preprocedural 3D reconstructed computed tomography may help to predict the procedural difficulty of the Micra implantation or to image a manipulation of the delivery catheter.>.

Pseudothrombotic appearance on pulmonary valve by intracardiac echocardiography during atrial fibrillation ablation.

We report a case with a thrombus-like image on pulmonary valve detected by intracardiac echocardiography before transseptal puncture for atrial fibrillation (AF) ablation. The multimodality assessment provided diagnosis of the imaging artifact and exclusion from the harmful mass. This finding could be useful for a safety management of AF ablation and avoidance of an unnecessary interruption of the procedure.

Clinical feasibility of pulmonary vein orifice pacing for the prediction of phrenic nerve injury during cryoballoon ablation of atrial fibrillation.

INTRODUCTION: Phrenic nerve (PN) injury is a well-known complication of cryoballoon ablation (CBA) for pulmonary vein (PV) isolation in patients with atrial fibrillation. However, it is still insufficient to practically predict phrenic nerve injury (PNI) before freezing. We hypothesized that phrenic nerve capture (PNC) with phrenic nerve orifice pacing (PVOP) might be a surrogate sign of the close proximity of the PN, and that might predict PNI and changes in the compound motor action potential (CMAP) amplitude. METHODS: Seventy patients (60 ± 12 years, male 80%, paroxysmal 56%) underwent PVOP with a 20-electrode ring catheter before the CBA. The clinical outcome was the occurrence of transient and persistent PNI. In addition, the PV position and pacing threshold during PNC with PVOP, and changes in the CMAP amplitude were recorded. We compared these measurements between patients with and without PNC (PNC/non-PNC group) with PVOP. RESULTS: PNC with PVOP occurred in 39 (56%) patients and was localized only to the right superior PV. Transient PNI occurred in seven (10%) patients and permanent in none. The CMAP amplitude decreased significantly more in the PNC group (PNC 33% vs non-PNC 16%, P = .027). PNC group had a higher risk of the composite outcome of transient PNI or ≥30% decrease in the CMAP amplitude (PNC 54% vs non-PNC 13%; P < .001). CONCLUSIONS: This PVOP technique could be feasible and contribute to predicting transient PNI and CMAP amplitude reductions before cryoapplications. Further studies are necessary to elucidate the additional efficacy of PVOP over CMAP monitoring alone.

Accidental Entrapment of Electrical Mapping Catheter by Chiari's Network in Right Atrium during Catheter Ablation Procedure.

A 78-year-old male was admitted to our hospital due to frequent palpitation. His electrocardiogram (ECG) presented regular narrow QRS tachycardia with 170 bpm, and catheter ablation was planned. During electroanatomical mapping of the right atrium (RA) with a multiloop mapping catheter, the catheter head was entrapped nearby the ostium of inferior vena cava. Rotation and traction of the catheter failed to detach the catheter head from the RA wall. Exfoliation of connective tissue twined around catheter tip by forceps, which were designed for endomyocardial biopsy, succeeded to retract and remove the catheter. Postprocedural echocardiography and pathologic examination proved the existence of Chiari's network. The handling of complex catheters in the RA has a potential risk of entrapment with Chiari's network.