Temporal and spatial pacemap parameters for identification of cardiac surfaces with critical sites for ventricular tachycardia.

INTRODUCTION: Multisurface pacemapping may help identify the surface of interest in scar-related ventricular tachycardia (VT). This study aimed to investigate the performance of pacemap parameters for detecting critical sites through multisurface mapping. METHODS AND RESULTS: In 26 patients who underwent scar-related VT ablation, pacemap parameters including a matching score, the difference between the longest and shortest stimulus-QRS intervals (Δs-QRS), and the distance between the good pacemap sites were measured. The parameters were compared between surfaces with and without critical sites and ablation outcomes. A total of 941 pacemap at 56 surfaces targeting 35 VTs were analyzed. A greater Δs-QRS (40 vs. 8 ms, p < .001) and longer distance between two good pacemap sites (24 vs. 13 mm, p < .001) were observed on the surfaces with critical sites. A similar trend was seen in multisurface pacemapping for the same VTs (52 vs. 18 ms in Δs-QRS, p = .021; 37 vs. 12 mm in distance, p = .019), although the best pacemap scores were comparable (94 vs. 87, p = .295). The Δs-QRS > 20 ms and the distance >19 mm showed high positive likelihood ratios (19.8 and 6.1, respectively) for discriminating the surface harboring the critical site. Ablation of VTs fulfilling these parameters was successful on the surfaces, but without the required multisurface ablation. CONCLUSION: Temporal (Δs-QRS) and spatial (distance) parameters for good pacemap match sites were excellent markers for detecting the surface harboring critical sites in scar-related VT. A multisurface pacemapping can successfully identify the surface of interest.

Fluoroscopic predictors of acceptable capture threshold during the implantation of the micra transcatheter pacing system.

INTRODUCTION: Few predictors of low capture threshold before the deployment of the Micra transcatheter pacing system (Micra TPS) have been determined. We aimed to identify fluoroscopic predictors of an acceptable capture threshold before Micra TPS deployment. METHODS: Sixty patients were successfully implanted with Micra TPS. Before deployment, gooseneck appearance of the catheter shaft was quantified using the angle between the tangent line of the shaft and the cup during diastole in the right anterior oblique (RAO) view. The direction of the device cup toward the ventricular septum was evaluated using the angle between the cup and the horizontal plane in the left anterior oblique (LAO) view. RESULTS: Of the 95 deployments we evaluated, 56 achieved an acceptable capture threshold of ≤2.0 V at 0.24 ms. In this acceptable threshold group, the deflection angle of the gooseneck shaft was significantly larger and the device cup was placed more horizontally with a lower elevation angle compared with those in the high threshold group. A deflection angle of ≥6° and an elevation angle of ≤30° were identified as the predictors of an acceptable capture threshold after deployment. An acceptable capture threshold was achieved in 24/31 (77.4%) patients in whom either angle criterion was satisfied at the first deployment. CONCLUSIONS: Diastolic gooseneck appearance of the delivery catheter in the RAO view or near-horizontal direction in the LAO view predicts an acceptable capture threshold after deployment. The shape of the delivery catheter before deployment should be evaluated using multiple fluoroscopic views to ensure successful implantation of Micra TPS.

Ambulatory electrocardiographic markers predict serious cardiac events in patients with chronic kidney disease: The Japanese Noninvasive Electrocardiographic Risk Stratification of Sudden Cardiac Death in Chronic Kidney Disease (JANIES-CKD) study.

BACKGROUND: Noninvasive electrocardiographic markers (NIEMs) are promising arrhythmic risk stratification tools for assessing the risk of sudden cardiac death. However, little is known about their utility in patients with chronic kidney disease (CKD) and organic heart disease. This study aimed to determine whether NIEMs can predict cardiac events in patients with CKD and structural heart disease (CKD-SHD). METHODS: We prospectively analyzed 183 CKD-SHD patients (median age, 69 years [interquartile range, 61-77 years]) who underwent 24-h ambulatory electrocardiographic monitoring and assessed the worst values for ambulatory-based late potentials (w-LPs), heart rate turbulence, and nonsustained ventricular tachycardia (NSVT). The primary endpoint was the occurrence of documented lethal ventricular tachyarrhythmias (ventricular fibrillation or sustained ventricular tachycardia) or cardiac death. The secondary endpoint was admission for cardiovascular causes. RESULTS: Thirteen patients reached the primary endpoint during a follow-up period of 24 ± 11 months. Cox univariate regression analysis showed that existence of w-LPs (hazard ratio [HR] = 6.04, 95% confidence interval [CI]: 1.4-22.3, p = .007) and NSVT [HR = 8.72, 95% CI: 2.8-26.5: p < .001] was significantly associated with the primary endpoint. Kaplan-Meier analysis demonstrated that the combination of w-LPs and NSVT resulted in a lower event-free survival rate than did other NIEMs (p < .0001). No NIEM was useful in predicting the secondary endpoint, although the left ventricular mass index was correlated with the secondary endpoint. CONCLUSION: The combination of w-LPs and NSVT was a significant risk factor for lethal ventricular tachyarrhythmias and cardiac death in CKD-SHD patients.

Accuracy of wristwatch-type photoplethysmography in detecting atrial fibrillation in daily life.

Aims: Detection of asymptomatic paroxysmal atrial fibrillation is challenging. Smartphone- or smartwatch-based photoplethysmography is efficient at detecting irregular rhythms using pulse waves but is too complex for older patients. We aimed to evaluate the detection accuracy of atrial fibrillation by a wristwatch-type continuous pulse wave monitor (PWM) in daily life. Methods and results: Patients at high risk of atrial fibrillation but with no history of atrial fibrillation (n = 163; mean CHADS2 score, 1.9) and patients with known atrial fibrillation (n = 123, including 34 with persistent atrial fibrillation) underwent PWM and telemetry electrocardiogram recording for 3 days. Risk of atrial fibrillation was judged using the 'Kyorin Atrial Fibrillation Risk Score', a scoring system based on previously reported atrial fibrillation risk scoring systems. The PWM assessed the presence of atrial fibrillation at 30 min intervals, and the results were compared with the telemetry electrocardiogram findings. The PWMs accurately diagnosed two patients with paroxysmal atrial fibrillation in the high-risk group. The PWMs accurately diagnosed 48 of the 55 patients with atrial fibrillation in the known-atrial fibrillation group. The PWM accuracy in detecting patients with atrial fibrillation was as follows: sensitivity, 98.0%; specificity, 90.6%; positive predictive value, 69.4%; negative predictive value, 99.5%. The respective values for intervals with atrial fibrillation were 86.9%, 98.8%, 89.6%, and 98.5%. Conclusion: The wristwatch-type PWM has shown feasibility in detecting atrial fibrillation in daily life and showed the possibility of being used as a screening tool.

Left Atrial Reverse Remodeling Following the Modified Box Isolation with Centerline in Patients with Persistent Atrial Fibrillation.

Esophageal injury is a rare but serious complication of atrial fibrillation (AF) ablation. To minimize esophageal injury, our persistent AF (PerAF) protocol involves complete left atrial posterior wall (LAPW) and pulmonary vein (PV) isolation (box isolation), with a centerline away from the esophagus. However, there has been a concern that extensive LA isolation might deteriorate LA function. There has been a paucity of data on LA remodeling after box isolation. Therefore, we compared LA size pre- and post-box isolation with an LAPW centerline in patients with PerAF.Patients who underwent catheter ablation (CA) for PerAF between November 2016 and December 2018 were retrospectively evaluated.The LAPW, including all PVs, was completely isolated in 105 consecutive patients (75 men; mean age: 68 ± 10 years) with PerAF, including 58 patients with long-standing PerAF. During a follow-up of 660 ± 332 days, 76 patients (72%) were arrhythmia-free. The LA dimension (38 ± 6 mm versus 42 ± 7 mm; P < 0.0001) and volume index (38 ± 13 mL/m2 versus 47 ± 14 mL/m2; P < 0.0001) at 6 months post-ablation were significantly decreased in patients who maintained sinus rhythm compared to pre-ablation. In patients with recurrent AF/atrial tachycardia (AT), these parameters were also significantly decreased (P < 0.001, respectively).Box isolation with a posterior centerline has no esophageal complications and a high clinical success rate in patients with PerAF. Reverse remodeling could be achieved even when using extensive isolation of the PV and LAPW in patients with PerAF.

Stellate Ganglion Phototherapy Using Low-Level Laser: A Novel Rescue Therapy for Patients With Refractory Ventricular Arrhythmias.

OBJECTIVES: This study investigates the effect of stellate ganglion (SG) phototherapy in healthy participants and assesses its efficacy in suppressing electrical storm (ES) refractory to antiarrhythmic drugs and catheter ablation. BACKGROUND: Modulation of the autonomic nervous system has been shown to be an effective adjunctive therapy for ES. METHODS: Ten-minute SG phototherapy was performed twice weekly for 4 weeks in 20 healthy volunteers. To evaluate the acute and chronic effects of SG phototherapy, heart rate variability and serum concentrations of adrenaline, noradrenaline, and dopamine were obtained before phototherapy, immediately after the first phototherapy session, after 8 sessions of phototherapy, and 3 months after the first phototherapy session. In addition, the efficacy of SG phototherapy was evaluated in 11 patients with ES refractory to medication, sedation, and catheter ablation. RESULTS: In healthy participants, serum adrenaline concentration significantly decreased after phototherapy, whereas low-frequency power/high-frequency power significantly decreased during phototherapy. Moreover, the effect on heart rate variability did not last beyond 3 months. In the clinical pilot study, 7 patients had a suppression of ES after SG phototherapy; however, without maintenance therapy, 2 patients had a recurrence of ventricular arrhythmias. Furthermore, it did not control ES in 4 patients. CONCLUSIONS: SG phototherapy reduced sympathetic activity and may be a safe and effective adjunctive therapy to control ES in some patients, but its long-term efficacy remains unknown. Chronic phototherapy might help reduce ES recurrence.

Safety of Distal His Bundle Pacing Via the Right Ventricle Backed Up by Adjacent Ventricular Capture.

OBJECTIVES: This study investigated the differences between distal His bundle pacing (HBP) via the right ventricle and proximal HBP via the right atrium with regard to pacing and sensing parameters. BACKGROUND: HBP preserves physiological ventricular activation. The capture threshold of the adjacent ventricle accompanying HBP has not been evaluated after implantation. METHODS: Fifty patients with bradycardia (58% with atrioventricular block) underwent successful HBP and were followed for 1 year. Precise locations of the lead tips were confirmed using follow-up echocardiography. RESULTS: HBP leads were fixed via the right atrium or right ventricle (25 patients each). Overall, the local ventricle and HBP thresholds were elevated during follow-up. The distal HBP thresholds did not significantly differ from the proximal HBP thresholds, although local ventricular thresholds of distal HBP were markedly lower than those of proximal HBP. At 6 months, the accepted ventricular threshold (≤2.5 V) was maintained in 39 patients (78%). An amplitude of ventricular electrogram post-fixation of ≥2.0 mV and a capture threshold of ≤1.1 V at implantation were determined to be optimal values for predicting the accepted threshold at 6 months, with areas under the curve of 0.86 and 0.84, respectively. Atrial oversensing was often detected in proximal HBP but not distal HBP. CONCLUSIONS: Distal HBP via the right ventricle captured the His bundle, similar to proximal HBP via the right atrium, with a superior local ventricular threshold during follow-up. Anatomy and electrophysiological ventricular properties at implantation may be critical for maintaining adjacent ventricle capture to prevent lead revision (Evaluation of Electrophysiological Parameters related to His Bundle Pacing in Patients With Bradyarrhythmias; UMIN000031364).

Transcatheter cryo-ablation of septal accessory pathways, multicenter observational study in Japan.

BACKGROUND: Ablation using radiofrequency energy has to be carefully performed when the arrhythmia substrate is located in close proximity to the atrioventricular (AV) node due to the risk of inadvertent permanent AV block. The aim of this study was to evaluate the efficacy and safety of catheter-based cryo-therapy for septal accessory pathways (APs). METHODS: A total of eleven patients (median = 56.3 years, range 13-74 years) with septal APs underwent cryoablation. Ice-mapping was performed during sinus rhythm and an AV reciprocating tachycardia utilizing the APs as a requisite limb with cooling of the catheter tip temperature to a maximum of -30℃ for less than 45 s. Cryo-ablation was performed for 4 min at a temperature of -80℃ only if ice-mapping abolished the pre-excitation or retrograde conduction over the AP without injury to the AV nodal conduction. RESULTS: Cryo-ablation was acutely successful in all eleven patients. No permanent cryo-related complications or adverse outcomes were reported. During the follow-up (range 14-26 months), no patients experienced any arrhythmia recurrences. CONCLUSION: Ice-mapping was a feasible and reliable method to determine the exact location of the APs owing to the possibility of validating the ablation site. Cryo-ablation of APs located near the AV junction is a safe and efficacious technique with a high success rate over the long term. IRB INFORMATION: Ethical Committee of Japan Red Cross Yokohama City Bay Hospital #2018-19.

High-density mapping in patients undergoing ablation of atrial fibrillation with the fourth-generation cryoballoon and the new spiral mapping catheter.

AIMS: To assess the value of high-density mapping (HDM) in revealing undetected incomplete pulmonary vein isolation (PVI) after the fourth-generation cryoballoon (CB4G) ablation compared to the previous cryoballoon's versions. METHODS AND RESULTS: Consecutive patients with paroxysmal or early-persistent atrial fibrillation (AF) undergoing CB ablation as the index procedure, assisted by HDM, were retrospectively included in this study. A total of 68 patients (52 males; mean age: 60 ± 12 years, 58 paroxysmal AF) were included, and a total of 272 veins were mapped. Fourth-generation cryoballoon with the new spiral mapping catheter (SMC) was used in 35 patients (51%). Time to PVI was determined in 102/132 (77%) and in 112/140 (80%) veins during second-generation cryoballoon/third-generation cryoballoon (CB2G/CB3G) and CB4G ablation, respectively (P = 0.66). There was a statistically significant difference in terms of discrepancy rate between the SMC and the mini-basket catheter in PV detection after CB4G and CB2G/CB3G ablation(1.4% vs. 7.6%; P = 0.01). A total of 57 patients (84%) remained free of symptomatic AF during a mean follow-up of 9.8 ± 4.6 months. CONCLUSION: High-density mapping after cryoballoon ablation using CB4G and the new SMC identifies incomplete PVI, not detected by the new SMC, in a significantly lower proportion of veins compared to HDM performed after the other generation CB ablation.

Conduction slowing area during sinus rhythm harbors ventricular tachycardia isthmus.

INTRODUCTION: The voltage map during sinus rhythm (SR) is a cornerstone of substrate mapping (SM) in scar-related ventricular tachycardia (VT) and frequently used with pace mapping (PM). Where to conduct PM is unclear in cases of an extensive or unidentified substrate. Conduction properties are another aspect incorporated by SM, and conduction slowing has gained interest as being related to successful ablation, although its mechanism has not been elucidated. We aimed to investigate the relationship between SR conduction properties and VT isthmuses. METHODS: Nineteen patients (mean age, 62 years) who underwent VT ablation with voltage mapping and PM were reviewed. Isochronal late activation maps (ILAMs) with eight zones were reconstructed and sequentially named from one to eight according to the SR propagation. Good PM sites were superimposed on ILAMs, and the isthmus was defined using different pacing latencies. ILAM properties harboring isthmuses were investigated. RESULTS: Twenty-eight ILAMs (13 epicardium, 1 right ventricular [RV], and 14 left ventricular [LV] endocardium) were reviewed. Eighteen isthmuses of 24 target VTs were identified, in which the proximal ends were in a later zone than the distal ends (zone 6 vs 4; P < .001), suggesting a reverse isthmus vector to the SR. The conduction velocity of the zone involving the distal isthmus was significantly lower than that of the SR preceding zone (0.40 vs 1.30 m/s; P < .001). SR conduction velocity decelerated by 69.5% (range 59.7%-74.5%) before propagating into the isthmus area. CONCLUSION: Conduction slowing area during SR were related with the exit portion of the VT isthmuses.

Assessing the perforation site of cardiac tamponade during radiofrequency catheter ablation using gas analysis of pericardial effusion.

BACKGROUND: The incidence of pericardial effusion (PE) during radiofrequency catheter ablation (CA) for atrial fibrillation is approximately 1%. PE is a major complication during CA, but there has been limited literature about the perforation site responsible. OBJECTIVE: This study aimed to retrospectively investigate the characteristics of the procedure and the patients in whom PE developed during CA. METHODS: Of 1363 consecutive patients who underwent catheter ablation from January 2015 to June 2019 in Kyorin University Hospital, we reviewed patients who developed PE during CA. RESULTS: PE during CA occurred in 18 (1.32%) patients (median age, 71 [interquartile range (IQR) 65-77] years, 7 women). The median body mass index was 24 (IQR 20-27). Target arrhythmias for CA of patients with PE include atrial fibrillation (AF) (n = 13, 72%), premature ventricular contraction (n = 2, 11%), ventricular tachycardia (n = 1, 6%), atrial flutter (n = 1, 6%), and orthodromic reciprocating tachycardia (n = 1, 6%). Seventeen patients required pericardiocentesis, resulting in 300 (IQR 192.5-475) mL of drainage. Two patients required emergency surgical repair, and 1 died from aortic dissection. Based on the gas analysis, the drained blood was of venous origin in 47% of the total events and 54% of AF ablation. CONCLUSION: PE caused by a diagnostic catheter in the right heart is not uncommon, even in AF ablation.

Risk stratification for cardiac mortality using electrocardiographic markers based on 24-hour Holter recordings: the JANIES-SHD study.

BACKGROUND: Recent guidelines have stated that left ventricular ejection fraction (LVEF) is the gold standard marker for identifying patients at risk for cardiac mortality. However, little information is present regarding electrocardiographic (ECG) markers. This study aimed to assess ECG markers for predicting mortality or serious arrhythmia in patients with structural heart disease (SHD). METHODS: In total, 1829 patients were enrolled into the Japanese Multicenter Observational Prospective Study (JANIES study). In this study, we analyzed data of 719 patients (569 men, age 64 ± 13 years) with SHD including mainly ischemic heart disease (65.8%). As ECG markers based on 24-hour Holter recordings, nonsustained ventricular tachycardia (NSVT), ventricular late potentials, and heart rate turbulence (HRT) were assessed. The primary endpoint was all-cause mortality, and the secondary endpoint was fatal arrhythmic events. RESULTS: During a mean follow-up of 21 ± 11 months, all-cause mortality was eventually observed in 39 patients (5.4%). Among those patients, 32 patients (82%) suffered from cardiac causes such as heart failure and arrhythmia. Multivariate Cox regression analysis showed that after adjustment for age and LVEF, documented NSVT [hazard ratio = 2.46, 95% confidence interval (CI): 1.16-5.18, p = 0.02] and abnormal HRT (hazard ratio = 2.40, 95% CI: 1.16-4.93, p = 0.02) were significantly associated with the primary endpoint. These two ECG markers also had significant predictive values with the secondary endpoint. The combined assessment of two ECG markers improved predictive accuracy. CONCLUSION: This study demonstrated that combined assessment of documented NSVT and abnormal HRT based on 24-hour Holter ECG recordings are recommended for predicting future serious events in this population.

Reducing radiation exposure during atrial fibrillation ablation using lectures to promote awareness.

Objective: Recently, concern has increased regarding the hazards of radiation exposure in patients and laboratory staff. Since the numbers of complex catheter ablations (CA) performed, duration of procedure times, and need for multiple sessions have increased, radiation exposure during each session needs to be minimised. Our study aimed to assess the impact of awareness on radiation exposure during CA for atrial fibrillation (AF). Methods: Mini-course lectures was delivered to the physicians and staff in the electrophysiology division. Its effect on the fluoroscopic time and radiation dose during AF ablation before (Group I, n=70), shortly after (Group II: n=70) and remotely after the mini-lecture (Group III, n=70) were evaluated. Patient demographics, preoperative testing and procedural parameters were collected. Results: The fluoroscopic time significantly reduced after the lecture (Group I and II: 25.1±10.0 and 15.1±7.3 min, respectively (p<0.0001)), and remained so in Group III (13.0±5.4 min), despite the increase in the number of persistent AFs. The radiation dose also significantly reduced (Groups I, II, III: 295.0±263.0, 109.6±103.5 and 110.1±89.6 mGy, respectively (p<0.0001)). Conclusion: Awareness on radiation exposure led to a significant reduction in fluoroscopic time and radiation dose during CA for AF, the effect of which persisted even to remote periods following the procedure.

Deep Negative Deflection in Unipolar His-Bundle Electrogram as a Predictor of Excellent His-Bundle Pacing Threshold Postimplant.

Background His-bundle pacing (HBP) is a physiological form of pacing. Although high capture thresholds are common, few predictors of low HBP threshold have been determined. We aimed to identify electrophysiological predictors. Methods Fifty-one patients (53% with atrioventricular block) underwent HBP for bradycardia with an intrinsic QRS duration of <120 ms. Attempts to anchor the HBP lead were guided by unipolar His-bundle electrograms (HB EGMs) recorded with an electrophysiology recording system. Patients were followed-up for >6 months. Results In total, 153 attempts at anchoring the HBP lead were made, of which, 45 achieved acceptable HBP thresholds (≤2.5 V at 1 ms). The amplitude of negative deflection in HB EGM and the selective HBP form at fixation were independently associated with achieving an acceptable threshold. A negative amplitude of ≥0.060 mV in HB EGM was determined as the optimal value for identifying the acceptable threshold. This deep negative HB EGM was recorded with an HBP threshold of 1.4±1.3 V (in 34 attempts), significantly lower than that of positive HB EGM without deep negative deflection (2.8±1.3 V, in 31 trials; or >5 V, in 38 trials). The permanent HBP lead remained with deep negative (≥0.060 mV) or positive HB EGMs in 28 and 14 patients, respectively, and with positive or negative HB injury current in 19 and 23 patients, respectively. During follow-up, increased HBP threshold of >1 V was significantly more prevalent in the positive HB EGM group. The HBP thresholds of deep negative HB EGM and HB injury current, but not of the selective HBP group, were significantly lower than the other subgroups during follow-up. Conclusions Deep negative HB EGM at fixation was associated with an excellent short-term HBP threshold, similar to HB injury current. Analysis of unipolar HB EGM postfixation may enable prediction of permanent HBP threshold.

Pulmonary vein-gap re-entrant atrial tachycardia following atrial fibrillation ablation: an electrophysiological insight with high-resolution mapping.

AIMS: The circuit of pulmonary vein-gap re-entrant atrial tachycardia (PV-gap RAT) after atrial fibrillation ablation is sometimes difficult to identify by conventional mapping. We analysed the detailed circuit and electrophysiological features of PV-gap RATs using a novel high-resolution mapping system. METHODS AND RESULTS: This multicentre study investigated 27 (7%) PV-gap RATs in 26 patients among 378 atrial tachycardias (ATs) mapped with Rhythmia™ system in 281 patients. The tachycardia cycle length (TCL) was 258 ± 52 ms with P-wave duration of 116 ± 28 ms. Three types of PV-gap RAT circuits were identified: (A) two gaps in one pulmonary vein (PV) (unilateral circuit) (n = 17); (B) two gaps in the ipsilateral superior and inferior PVs (unilateral circuit) (n = 6); and (C) two gaps in one PV with a large circuit around contralateral PVs (bilateral circuit) (n = 4). Rhythmia™ mapping demonstrated two distinctive entrance and exit gaps of 7.6 ± 2.5 and 7.9 ± 4.1 mm in width, respectively, the local signals of which showed slow conduction (0.14 ± 0.18 and 0.11 ± 0.10m/s) with fragmentation (duration 86 ± 27 and 78 ± 23 ms) and low-voltage (0.17 ± 0.13 and 0.17 ± 0.21 mV). Twenty-two ATs were terminated (mechanical bump in one) and five were changed by the first radiofrequency application at the entrance or exit gap. Moreover, the conduction time inside the PVs (entrance-to-exit) was 138 ± 60 ms (54 ± 22% of TCL); in all cases, this resulted in demonstrating P-wave with an isoelectric line in all leads. CONCLUSION: This is the first report to demonstrate the detailed mechanisms of PV-gap re-entry that showed evident entrance and exit gaps using a high-resolution mapping system. The circuits were variable and Rhythmia™-guided ablation targeting the PV-gap can be curative.

Idiopathic Ventricular Arrhythmia Ablation Using Non-Fluoroscopic Catheter Visualization System.

A novel, sensor-based, electromagnetic, non-fluoroscopic catheter visualization (NFCV) system shows tracked catheters directly on pre-acquired fluoroscopy or cine loops. We aimed to evaluate the effectiveness of this system in the setting of catheter ablation for idiopathic premature ventricular contractions/ventricular tachycardia (i-PVC/VT).A total of 30 i-PVC/VT ablation procedures were performed using the NFCV system in conjunction with three-dimensional electroanatomic mapping system (3D-EMS) between January 2013 and April 2017. At the beginning of the procedure, cine loops of right and left anterior oblique views were obtained and replayed for subsequent mapping and ablation. Right ventriculography, aortography, or coronary angiography was performed, depending on the chamber of interest. We reviewed procedural parameters, comparing with the i-PVC/VT ablation procedure using conventional fluoroscopy (CvF) system (pre-, and post-NFCV implementation; 20 and 11 cases, respectively).I-PVC/VTs were successfully eliminated in 26 patients (87%) in the NFCV group and in 26 (84%) in the CvF group (P = 1.000). The procedure time in the NFCV group was comparable to that in the CvF group (119.8 versus 125.0 minutes, respectively, P = 0.868); the total fluoroscopy time was significantly shorter in the NFCV group (3.3 versus 16.6 minutes, P < 0.001). One patient in the CvF group experienced cardiac tamponade, requiring pericardial drainage. No major complications were encountered in the NFCV group.NFCV system, in conjunction with 3D-EMS, was safe and feasible for i-PVC/VT mapping and ablation. The system contributed to dramatically reduced fluoroscopy time, compared with CvF.

Value of high-resolution mapping in optimizing cryoballoon ablation of atrial fibrillation.

BACKGROUND: Unrecognized incomplete pulmonary vein isolation (PVI), as opposed to post-PVI pulmonary vein reconnection, may be responsible for clinical recurrences of atrial fibrillation (AF). To date, no data are available on the use of high-resolution mapping (HRM) during cryoballoon (CB) ablation for AF as the index procedure. The aims of this study were: - to assess the value of using a HRM system during CB ablation procedures in terms of ability in acutely detecting incomplete CB lesions; - to compare the 8-pole circular mapping catheter (CMC, Achieve) and the 64-pole mini-basket catheter (Orion) with respect to pulmonary vein (PV) signals detection at baseline and after CB ablation; - to characterize the extension of the lesion produced by CB ablation by means of high-density voltage mapping. METHODS: Consecutive patients with drug-resistant paroxysmal or early-persistent AF undergoing CB ablation as the index procedure, assisted by a HRM system, were retrospectively included in this study. RESULTS: A total of 33 patients (25 males; mean age: 59 ±â€¯18 years, 28 paroxysmal AF) were included. At baseline, CMC catheter revealed PV activity in 102 PVs (77%), while the Orion documented PV signals in all veins (100%). Failure of complete CB-PVI was more frequently revealed by atrial re-mapping with the Orion as compared to the Achieve catheter (24% vs 0%, p < 0.05). A repeat ablation was performed in 8 patients (24%). In 9% of cases, the Orion catheter detected far-field signals originating from the right atrium. Quantitative assessment of the created lesion revealed a significant reduction of the left atrial area having voltage >0.5 mV. A total of 29 patients (88%) remained free of symptomatic AF during a mean follow-up of 13.2 ±â€¯3.7 months. CONCLUSION: Atrial re-mapping after CB ablation by means of a HRM system improves the detection of areas of incomplete ablation, characterizes the extension of the cryo-ablated tissue and can identify abolishment of potential non-PVI related sources of AF.