Subcutaneous implantable cardioverter defibrillators (S-ICDs) are designed to avoid complications from transvenous leads, but patient selection requires careful screening, especially in conditions like hypertrophic cardiomyopathy (HCM) with frequent conduction abnormalities. A 27-year-old male with HCM underwent S-ICD implantation in 2015 after successful screening. In 2020, inappropriate shocks due to T-wave oversensing led to vector adjustments. By 2022, further shocks and failed re-screening revealed ineligibility for S-ICD due to low R/T ratios in multiple vectors. Imaging and ECG comparisons from 2015 to 2022 showed disease progression, with increased fibrosis and conduction abnormalities. As a result, a transvenous ICD was implanted. This case underscores how HCM progression, associated with fibrosis and ECG changes, can render S-ICD unsuitable over time. It highlights the importance of periodic reassessment in high-risk patients, as disease progression can compromise S-ICD eligibility, necessitating alternative solutions for inappropriate shocks.

Introduction: Antitachycardia pacing (ATP) is one of the therapies provided by an implantable cardioverter defibrillator (ICD) for the treatment of ventricular arrhythmias (VA). Successful ATP leads to avoidance of shock, that is related to an increase in mortality and morbidity. Methods and Results: A total of 63 documents have been obtained by using the key term “Antitachycardia pacing” in PubMed, focusing on optimal ATP and ICD programing to reduce inappropriate or avoidable therapies, predictive factors of ATP efficacy and latest technologies and devices still in experimentation. Conclusions: Antitachycardia pacing confirms to be a good therapeutic tool to interrupt ventricular arrhythmias. An optimal ICD programming could lead to the reduction of inappropriate or avoidable ATP therapies. Furthermore, a better knowledge in predictive factors of ATP efficacy not only could better orient physicians on the device to implant, but also could allow for a better arrhythmic risk stratification.

BACKGROUND Temporary transvenous cardiac pacing (TTCP) is a standard procedure in current practice, despite limited coverage in consensus guidelines. However, many authors reported several complications associated with TTCP, especially development of infections of cardiac implantable electronic devices (CIED). The aim of this survey was to provide a country-wide picture of current practice regarding TTCP. METHODS Data were collected using an online survey that was administered to members of the Italian Association of Arrhythmology and Cardiac Pacing. RESULTS We collected data from 102 physicians, working in 81 Italian hospitals from 17/21 regions. Our data evidenced that different strategies are adopted in case of acute bradycardia with a tendency to limit TTCP mainly to advanced atrioventricular block. However, some centers reported a greater use in elective procedures. TTCP is usually performed by electrophysiologists or interventional cardiologists and, differently from previous reports, mainly by a femoral approach and with nonfloating catheters. We found high inhomogeneity regarding prevention of infections and thromboembolic complications and in post-TTCP management, associated with different TTCP volumes and a strategy for management of acute bradyarrhythmias. CONCLUSION This survey evidenced a high inhomogeneity in the approaches adopted by Italian cardiologists for TTCP. Further studies are needed to explore if these divergences are associated with different long-term outcomes, especially incidence of CIED-related infections.

BACKGROUND:Ablation index (AI) is a new lesion quality marker that has been demonstrated to allow a high single-procedure arrhythmia-free survival in single-center studies. This prospective, multi-center study was designed to evaluate the reproducibility of pulmonary vein (PV) isolation guided by the AI. METHODS:A total of 490 consecutive patients with paroxysmal (80.4%) and persistent AF underwent first time PV isolation and were divided in four study groups according to operator's preference in choosing the ablation catheter (a contact force (ST) or contact force surround flow (STSF) catheter) and the AI setting (330-450 or 380-500 at anterior wall or posterior wall, respectively). RESULTS:At 12 months a high rate of freedom from AF recurrences was observed in patients with both paroxysmal and persistent AF (91% vs 83.3%; P = .039). There was no difference in the rate of AF recurrence among the four study groups (4.5% in group ST330-450, 12.2% in group ST 380-500, 14.9% in group STSF330-450, 9.4% in group STSF380-500; P = .083). Recurrence was also similar between patients treated with a ST (8%) or STSF catheter (12.1%; P = .2), and within patients targeting an AI settings of 330 to 450 (10.9%) or 380 to 500 (10.3%; P = .64). In patients with paroxysmal AF, there was no difference (P = .12) in the 1-year freedom from AF recurrence among 14 operators that performed ≥10 ablation procedure. CONCLUSIONS:An ablation protocol respecting strict criteria for contiguity and quality lesion resulted in high rate of 1-year freedom from AF recurrence, irrespective of the ablation catheters, AI settings, and operator.

Durable pulmonary vein isolation (PVI) is the goal of atrial fibrillation (AF) ablation. The endoscopic ablation system (EAS) is associated with a high rate of persistent PVI. The aim of this study was to analyze the incidence and pattern of conduction gaps in patients with arrhythmia recurrence after an EAS-guided PVI. Repeat ablations after an EAS-guided PVI were analyzed. After PV angiograms, PV reconnection was assessed. Radiofrequency ablation was delivered at the earliest pulmonary vein (PV) activation site (gap) with the goal of PV re-isolation. First, the incidence of reconnected PVs per patient was assessed. Second, the gap pattern according to the individual PV quadrant was analyzed. Fifty-nine out of 373 (16%) patients underwent a second procedure after index EAS. PV reconnection was observed in 71/230 (31%) PVs without statistically significant differences between individual PVs. A higher incidence of gaps was found for right PVs (49 vs. 27; p 0.0006). The carina between the superior and inferior PV presented a low incidence of gaps (18 vs. 56, p < 0.0001). Gaps were also predominant at the AS segment of the RSPV (11 gaps). No predictors of reconnection were found, except the higher total amount of application in the reconnected right inferior PV (26.03 ± 1.30 vs. 32.04 ± 2.89; p 0.0396). EAS-guided PVI results in a 72% durable PVI rate in patients with AF recurrences without difference between individual PVs. More of the gap was found in the right PVs especially in the anterosuperior segment of the RSPV.

Forty patients (56%) were treated with the Mitraclip System (MitraClip group) and 31 patients (44%) only with medical therapy (no-MitraClip group). MitraClip group presented higher surgical risk than no-MitraClip group, as older age, chronic kidney disease, higher NYHA functional class and lower left ventricular ejection fraction. At 24-month no differences in all-cause mortality were detected between the two groups (Kaplan-Meier curves log-rank p = 0.947), although the MitraClip group presented lower rate of HF hospitalizations than the no-MitraClip group (log-rank p = 0.048). After adjustment for confounding factors, time to HF hospitalization or death was significantly delayed in MitraClip group (hazard ratio: 0.38; p-value 0.018).

OBJECTIVES:The aim of this study was to identify predictors of cardiac tamponade (CT) during atrial fibrillation (AF) ablation using different technologies and strategies.BACKGROUND:The major cause of death during catheter ablation of AF is related to CT. The risk for CT may be linked to different procedural steps (transseptal puncture, catheter manipulation during left atrial and pulmonary vein mapping and ablation).METHODS:All AF ablation procedures undertaken from May 2010 to July 2015 at a single center were included. Two ablation groups were defined: group A, radiofrequency current, and group B, balloon. Group A was divided into groups A1 (pulmonary vein isolation [PVI] only) and A2 (PVI plus additional ablation). In group A, 2 transseptal punctures were performed, followed by wide-area circumferential point-by-point PVI (group A1) within a 3-dimensional left atrial map and complex fractionated atrial electrograms and/or linear lesions (group A2). In group B, 1 transseptal puncture by balloon-based PVI (cryoballoon, laser balloon). All episodes of CT were analyzed.RESULTS:In total, 3,000 AF ablation procedures were performed, 2,125 in group A (group A1, n = 1,559; group A2, n = 566) and 875 in group B (cryoballoon, n = 589; laser balloon, n = 286). The rate of CT was 1.1% (32 of 3,000) and was significantly lower in group B than in group A: 0.1% (1 of 875) versus 1.5% (31 of 2,125) (p = 0.001). The reduced CT risk remained if PVI only (group B vs. group A1) was compared: 0.8% (13 of 1,559) versus 0.1% (1 of 875) (p = 0.024). The greatest CT risk was seen in group A2: 3.2% (18 of 566). Radiofrequency current ablation beyond PVI was a predictor of CT.CONCLUSIONS:The risk for CT in patients undergoing AF ablation at a single high-volume center was decreased with the use of balloon catheters. Extensive radiofrequency current ablation beyond PVI leads to an increased perforation risk.

Introduction: The ablation strategy for atrial fibrillation (AF) despite pulmonary vein isolation (PVI) is controversial. Left atrial appendage isolation (LAAI) may contribute to improve outcome. We describe an ablation approach ("Maze-like"-LAAI) that (1) modifies the underlying LA substrate by linear ablation (2) eliminates the LAA as a putative AF trigger site and (3) incorporates an unambiguous procedural endpoint. The role of LAA closure (LAAC) after LAAI was investigated. Methods: Patients with atrial tachyarrhythmias nonresponsive to PVI underwent a LAAI ablation procedure. LAAI was achieved by combining (a) an anterior line, (b) a LA roof line and (c) a mitral isthmus line. Patients continued oral anticoagulation (OAC) therapy or underwent LAAC >= 6 weeks after LAAI. Results: Maze-like LAAI was attempted in our center in 107 of 3,611 AF ablation procedures (2.9%) and achieved in 88 of 107 patients (82%). In 8 of 107 (7%) patients cardiac tamponade occurred, all managed conservatively. During follow-up sinus rhythm was established in 65% at 1 year. After LAAI, 45 patients remained on OAC and 40 underwent LAAC. In both groups 1 patient experienced a bleeding complication. Thromboembolism exclusively occurred in the OAC group in 3 (7%) patients. Conclusion: LAA isolation by Maze-like substrate modification may be considered a viable option for PVI non-responders. It offers a reproducible approach with an unambiguous procedural endpoint and leads to a favorable clinical outcome. However, extensive LA ablation increased the risk of tamponade. Consecutive LAA occlusion may offer a nonpharmacologic strategy to overcome the high thromboembolic risk associated with absent mechanical LAA contraction.

BACKGROUND:Clinical outcome after pulmonary vein isolation (PVI) may be linked to both durability of PVI and the antral lesion size. Data on balloon-guided technologies are scarce. We investigated the size of the isolated surface area (ISA) acutely after PVI achieved by cryoballoon (CB) or laser balloon (LB), both using voltage mapping. METHODS AND RESULTS:In 40 patients (73% male, mean age 66±9 years), a bipolar voltage map before and after PVI in sinus rhythm was acquired to delineate the isolated antral surface area (IASA, contiguous area of low voltage <0.5 mV) and the ISA (relative size of the low-voltage area in relation to the whole antral surface area including the posterior wall). IASA (CB: 57±14 cm2vs. LB: 42±15 cm2; P=0.002) as well as ISA (65±8% vs. 54±10%; P=0.001) were significantly larger in the CB than in the LB group. No periprocedural complications occurred. During a mean follow-up of 326±142 days, 4/20 and 5/20 patients experienced an AF/AT recurrence in the CB and LB groups, respectively. No differences in clinical outcome were observed between patients with a large (≥55%) or small (<55%) ISA. CONCLUSIONS:Balloon-guided PVI is associated with antral lesion formation. CB-guided PVI is associated with the largest ISA as compared with LB procedures. ISA size did not correlate with clinical outcome after a single procedure in the present study population.

Background The ideal energy dosing remains unclear in second-generation cryoballoon (CB) pulmonary vein isolation (PVI). We aimed to investigate the effect of an individualized dosing strategy based on time to PVI (TTI). Objective The purpose of this study was to prospectively investigate the safety and efficacy of individualized PVI using the second-generation CB guided by real-time pulmonary vein recordings. Methods Two groups were prospectively randomized: ICE-T group: if TTI <75 seconds, then no bonus freeze; and control group: acute PVI followed by 1 empiric bonus freeze. Freeze duration was set to 240 seconds. The primary end point was single procedure sinus rhythm after 12 months (blanking period 3 months). Secondary end points included procedural data, complications, and biomarker release. Results In total, 100 patients with paroxysmal atrial fibrillation were randomized. The primary end point was not different (88% vs 82%). Procedure and fluoroscopy times were significantly shorter in the ICE-T group (70 ± 20 minutes vs 89 ± 21 minutes; P < .001 and 10.6 ± 3.9 minutes vs 12.7 ± 5.5 minutes; P = .03). More complications occurred in the control group (n = 9 vs n=3) (persistent phrenic nerve injury: n=1 vs n=0; transient phrenic nerve injury: n=5 vs n=2; esophageal lesions: n=3 vs n=1). Postablation troponin T levels were not different (ICE-T group vs control group: 1035 ± 402 ng/L vs 1219 ± 509 ng/L; P = .099), whereas a significantly lower lactic acid dehydrogenase release was observed in the ICE-T group (259 ± 47 U/L vs 282 ± 57 U/L; P = .038). Multivariate analysis identified a mean TTI of >43 seconds as the only independent predictor of recurrent atrial tachyarrhythmia. Conclusion The individualized CB PVI strategy allows faster atrial fibrillation ablation without affecting the favorable clinical outcome. A short TTI appears to predict freedom from recurrent atrial tachyarrhythmia.

AIM:A novel third-generation cryoballoon (CB3) to perform pulmonary vein isolation (PVI) has recently been released, featuring a shortened distal balloon tip when compared with the second-generation (CB2), possibly allowing for enhanced intra-ablation pulmonary vein (PV) signal mapping. We aimed to investigate procedural efficacy and safety of the CB3 as compared to the CB2.METHODS AND RESULTS:We studied 472 consecutive patients who underwent CB-PVI for paroxysmal or persistent atrial fibrillation (CB3: 49 patients; CB2: 423 patients). Detailed procedural data and in-hospital complications were registered in a prospective database. Complete PVI using the CB only was achieved in 98% of patients in each group. Single-freeze PVI was observed in 84/88% (CB2/CB3, P = n.s.) of the PVs. Time-to-PVI (TPVI) was 49 ± 32 (CB2) and 45 ± 27 s (CB3) (P = n.s.). Time-to-PVI determination rate was higher in the CB3 group (89.5 vs. 82.6%, P = 0.016). Signal noise due to ice formation on mapping electrodes occurred after 70 ± 46 s using CB3 and did not interfere with TPVI determination. Exchange of the spiral mapping catheter with a guide wire was more frequently required in the CB3 group (8.2 vs. 0.7% patients, P < 0.001). Balloon dislodgement during hockey stick manoeuvres occurred in 6.1% patients of the CB3 group only (P = 0.001). Complication rates were not different between the groups.CONCLUSION:The CB3 offers a higher TPVI determination rate, facilitating dosing schemes based on TPVI, with equally high single-freeze efficacy compared with the CB2. The shortened distal tip of the CB3 requires adaptation of standard catheter manoeuvers to avoid balloon dislodgement.

Introduction: Second generation cryoballoon (CB2) for pulmonary vein isolation (PVI) was introduced in 2012. Several reports showed promising acute and mid-term follow-up (FU) outcome. However, long-term FU data are sparse. We therefore investigated the 2-years procedural success associated with the use of CB2. Methods: All patients (Pts) treated with the single big cryoballoon (CB) technique using the Arctic Front Advance (CB2, 28 mm) in conjunction with the intraluminal spiral catheter (Achieve, 20mm) reaching the 2-years FU were included. There was no patient selection based on pre-procedural PV anatomy screening. A 90 days blanking period was applied. During FU visits (3-6-12, 18, 24 months) a 72 hours ECG holter was scheduled. In case of symptoms suggestive of atrial tachyarrhythmia (ATa) repetitive ECG and Holter ECG were performed. ATa recurrence was defined as any documented episode lasting > 30s. Results: Since CB2-release (May 2012), 423 pts underwent CB-PVI in our center. 99 pts reached the 2-years FU (54 males, 66 ± 11 years old, 83 paroxysmal atrial fibrillation, PAF). All PVs (387/387, 100%) were isolated using only the CB2, no touch up ablations were required. No periprocedural death, stroke or tamponade occurred. Persistent phrenic nerve palsy was observed in 4 pts; further complications included TIA (n = 1) and major vascular access complications (n = 3). Single procedure success after 2 years FU was documented in 67/99 (68%) pts. Specifically, in pts classified as PAF and persistent AF (PersAF) success was, respectively, 59/83 (71%) and 8/16 (50%). The type of ATa recurrence was PAF in 21/32 pts (PAF pts = 18/24, PersAF pts = 3/8) and Persistent AF in 7/32 (PAF = 3/24, PersAF = 4/8); LAT (4/32) and typical AFL (4/32) were also reported. A repeat procedure was performed in 26/32 pts with recurrence: persistent PVI was observed in 73/102 veins (72%). After a single CB procedure, at a 2-year FU 68% of pts was free of AF recurrence; after a mean of 1.1 ± 0.3 procedure, 22/26 were thereafter in sinus rhythm, increasing 2-years success rate to 90%. Conclusion: Single big cryoballoon PVI is associated with a 68% single procedure and 90% repeat procedure AF ablation success rate after 2 years. This data indicates a favorable long-term outcome using CB-2 ablation.