Preclinical evaluation of semi-automated laser ablation for pulmonary vein isolation: A comparative study.

INTRODUCTION: Visually-guided laser balloon ablation (VGLA) currently requires careful manual rotation of the laser to create overlapping lesions. A novel semi-automated VGLA may reduce ablation times and lesion gaps. We aimed to compare semi-automated (SA) VGLA to that of manual (MN) VGLA. METHODS: Acute: Nine swine underwent right superior pulmonary vein isolation (PVI) using either SA (n = 3, 13-18 W), MN (n = 3, 8.5-12 W), or radiofrequency (RF, n = 3, 25-40 W) and were killed acutely. Chronic: 16 swine, underwent PVI using either SA (n = 8, 15 W) or MN (n = 8, 10 W), and were survived for 1 month before being killed. All hearts were then submitted for pathological evaluation. RESULTS: Acute: PVI was successful in all 9/9 swine with lesion counts significantly lower in the SA arm (5.3 ± 5.9, 33.7 ± 10.0, and 28.0 ± 4.4 in SA, MN, and RF arms; p = .007 for SA and MN). At necropsy, circumferentiality and transmurality were 98% and 94% in SA, 98% and 80% in MN, and 100% and 100% in RF arms. A single steam pop was noted on sectioning in the SA arm swine and occurred in the high dose (18 W) strategy. Chronic: PVI was acutely successful in 16/16 swine with no difference in PVI durability rates (62.5% vs. 75.0%), lesion transmurality (95.8 ± 17.4% vs.91.9 ± 25.9%), and circumferentiality (95.8 ± 6.6% vs. 94.8 ± 6.3%) between SA and MN arms. Catheter use time and lesion counts were lower in the SA arm compared to the MN arm (11.5 ± 12.7 vs. 21.8 ± 3.8 min, p = .046 and 4.8 ± 3.83 vs. 35.4 ± 4.4, p < .001). CONCLUSION: Motor-assisted semi-automated laser balloon ablation can improve upon procedural efficiency by reducing ablation time.

SGLT2 inhibitors reduce sudden cardiac death risk in heart failure: Meta-analysis of randomized clinical trials.

INTRODUCTION: Multiple randomized controlled trials have demonstrated sodium-glucose cotransporter-2 inhibitors (SGLT2i) decrease the composite endpoint of cardiovascular death or heart failure hospitalizations in all heart failure patients. It is uncertain whether SGLT2i impacts the risk of sudden cardiac death in patients with heart failure. METHODS: A comprehensive search was performed to identify relevant data published before August 28, 2022. Trials were included if: (1) all patients had clinical heart failure (2) SGLT2i and placebo were compared (3) all patients received conventional medical therapy and (4) reported outcomes of interest (sudden cardiac death [SCD], ventricular arrhythmias, atrial arrhythmias). RESULTS: SCD was reported in seven of the eleven trials meeting selection criteria: 10 796 patients received SGLT2i and 10 796 received placebo. SGLT2i therapy was associated with a significant reduction in the risk of SCD (risk ratios [RR]: 0.68; 95% confidence intervals [CI]: 0.48-0.95; p = .03; I2 = 0%). Absent dedicated rhythm monitoring, there were no significant differences in the incidence of sustained ventricular arrhythmias not associated with SCD (RR: 1.03; 95% CI: 0.83-1.29; p = .77; I2 = 0%) or atrial arrhythmias (RR: 0.91; 95% CI: 0.77-1.09; p = .31; I2 = 29%) between patients receiving an SGLT2i versus placebo. CONCLUSION: SGLT2i therapy is associated with a reduced risk of SCD in patients with heart failure receiving contemporary medical therapy. Prospective trials are needed to determine the long-term impact of SGLT2i therapy on atrial and ventricular arrhythmias.

Preclinical assessment of the feasibility, safety and lesion durability of a novel 'single-shot' pulsed field ablation catheter for pulmonary vein isolation.

AIMS: Single-shot pulmonary vein isolation can improve procedural efficiency. To assess the capability of a novel, expandable lattice-shaped catheter to rapidly isolate thoracic veins using pulsed field ablation (PFA) in healthy swine. METHODS AND RESULTS: The study catheter (SpherePVI; Affera Inc) was used to isolate thoracic veins in two cohorts of swine survived for 1 and 5 weeks. In Experiment 1, an initial dose (PULSE2) was used to isolate the superior vena cava (SVC) and the right superior pulmonary vein (RSPV) in six swine and the SVC only in two swine. In Experiment 2, a final dose (PULSE3) was used for SVC, RSPV, and left superior pulmonary vein (LSPV) in five swine. Baseline and follow-up maps, ostial diameters, and phrenic nerve were assessed. Pulsed field ablation was delivered atop the oesophagus in three swine. All tissues were submitted for pathology. In Experiment 1, all 14/14 veins were isolated acutely with durable isolation demonstrated in 6/6 RSPVs and 6/8 SVC. Both reconnections occurred when only one application/vein was used. Fifty-two and 32 sections from the RSPVs and SVC revealed transmural lesions in 100% with a mean depth of 4.0 ± 2.0 mm. In Experiment 2, 15/15 veins were isolated acutely with 14/15 veins (5/5 SVC, 5/5 RSPV, and 4/5 LSPV) durably isolated. Right superior pulmonary vein (31) and SVC (34) sections had 100% transmural, circumferential ablation with minimal inflammation. Viable vessels and nerves were noted without evidence of venous stenosis, phrenic palsy, or oesophageal injury. CONCLUSION: This novel expandable lattice PFA catheter can achieve durable isolation with transmurality and safety.

Transcoronary mapping with an over-the-wire multielectrode catheter in scar-related ventricular tachycardia patients.

AIMS: The usefulness of coronary venous system mapping has been reported for assessing intramural and epicardial substrates in patients with scar-related ventricular tachycardia (VT). However, there has been little data on mapping from coronary arteries. We investigated the safety and utility of mapping from coronary arteries with a novel over-the-wire multielectrode catheter in scar-related VT patients. METHODS AND RESULTS: Ten consecutive scar-related VT patients with non-ischaemic cardiomyopathy who underwent mapping from a coronary artery were analysed. Six patients underwent simultaneous coronary venous mapping. High-density maps were created by combining the left ventricular endocardium and coronary vessels. Substrate maps were created during the baseline rhythm with 2438 points (IQR 2136-3490 points), including 329 (IQR 59-508 points) in coronary arteries. Abnormal bipolar electrograms were successfully recorded within coronary arteries close to the endocardial substrate in seven patients. During VT, isthmus components were recorded within the coronary vessels in three patients with no discernible isthmus components on endocardial mapping. The ablation terminated the VT from an endocardial site opposite the earliest site in the coronary arteries in five patients. CONCLUSION: The transcoronary mapping with an over-the-wire multielectrode catheter can safely record abnormal bipolar electrograms within coronary arteries. Additional mapping data from the coronary vessels have the potential to assess three-dimensional ventricular substrates and circuit structures in scar-related VT patients.

Superiority of the Combination of Input and Output Parameters to the Single Parameter for Lesion Size Estimation.

BACKGROUND: For lesion size prediction, each input parameter, including ablation energy (AE), and output parameter, such as impedance, is individually used. We hypothesize that using both parameters simultaneously may be more optimal.Methods and Results: Radiofrequency applications at a range of power (30-50 W), contact force (10 g and 20 g), duration (10-60 s), and catheter orientation with normal saline (NS)- or half-normal saline (HNS)-irrigation were performed in excised porcine hearts. The correlations, with lesion size of AE, absolute impedance drop (∆Imp-drop), relative impedance drop (%Imp-drop), and AE*%Imp-drop were examined. Lesion size was analyzed in 283 of 288 lesions (NS-irrigation, n=142; HNS-irrigation, n=141) without steam pops. AE*%Imp-drop consistently showed the strongest correlations with lesion maximum depth (NS-irrigation, ρ=0.91; HNS-irrigation, ρ=0.94), surface area (NS-irrigation, ρ=0.87; HNS-irrigation, ρ=0.86), and volume (NS-irrigation, ρ=0.94; HNS-irrigation, ρ=0.94) compared with the other parameters. Moreover, compared with AE alone, AE*%Imp-drop significantly improved the strength of correlation with lesion maximum depth (AE vs. AE*%Imp-drop, ρ=0.83 vs. 0.91, P<0.01), surface area (ρ=0.73 vs. 0.87, P<0.01), and volume (ρ=0.84 vs. 0.94, P<0.01) with NS-irrigation. This tendency was also observed with HNS-irrigation. Parallel catheter orientation showed a better correlation with lesion depth and volume using ∆Imp-drop, %Imp-drop, and AE*%Imp-drop than perpendicular orientation. CONCLUSIONS: The combination of input and output parameters is more optimal than each single parameter for lesion prediction.

A single-center experience with early adoption of physiologic pacing approaches.

BACKGROUND: Increasing interest in physiological pacing has been countered with challenges such as accurate lead deployment and increasing pacing thresholds with His-bundle pacing (HBP). More recently, left bundle branch area pacing (LBBAP) has emerged as an alternative approach to physiologic pacing. OBJECTIVE: To compare procedural outcomes and pacing parameters at follow-up during initial adoption of HBP and LBBAP at a single center. METHODS: Retrospective review, from September 2016 to January 2020, identified the first 50 patients each who underwent successful HBP or LBBAP. Pacing parameters were then assessed at first follow-up after implantation and after approximately 1 year, evaluating for acceptable pacing parameters defined as sensing R-wave amplitude >5 mV, threshold <2.5 V @ 0.5 ms, and impedance between 400 and 1200 Ω. RESULTS: The HBP group was younger with lower ejection fraction compared to LBBAP (73.2 ± 15.3 vs. 78.2 ± 9.2 years, p = .047; 51.0 ± 15.9% vs. 57.0 ± 13.1%, p = .044). Post-procedural QRS widths were similarly narrow (119.8 ± 21.2 vs. 116.7 ± 15.2 ms; p = .443) in both groups. Significantly fewer patients with HBP met the outcome for acceptable pacing parameters at initial follow-up (56.0% vs. 96.4%, p = .001) and most recent follow-up (60.7% vs. 94.9%, p ≤ .001; at 399 ± 259 vs. 228 ± 124 days, p ≤ .001). More HBP patients required lead revision due to early battery depletion or concern for pacing failure (0% vs. 13.3%, at a mean of 664 days). CONCLUSION: During initial adoption, HBP is associated with a significantly higher frequency of unacceptable pacing parameters, energy consumption, and lead revisions compared with LBBAP.

Catheter ablation for atrial fibrillation in elderly patients: Systematic review and a meta-analysis.

AIMS: Catheter ablation (CA) is established therapy for patients with atrial fibrillation (AF); however, there is a limited understanding of CA in elderly patients. We studied the long-term efficacy and periprocedural safety of radiofrequency and cryoballoon CA for elderly patients with AF. METHODS: PubMed and Embase were searched through April 2021 to investigate the comparative outcomes between elderly and non-elderly patients who underwent CA for AF. The primary efficacy and safety endpoints were AF recurrence and procedure-related complications, respectively. Subgroup analyses were performed by procedure type of CA. RESULTS: The search identified 20 observational studies with 110,606 patients, including 8009 elderly patients (7.2%). The risk of AF recurrence was not significantly different between elderly and non-elderly patients (hazard ratio, 1.37; 95% confidence interval [CI], 0.94-2.00; p = .10, I2  = 70%). However, relative to the non-elderly, elderly patients had significantly higher major complications (risk ratio [RR], 1.32; 95% CI, 1.14-1.54], p < .01, I2  = 0%) and overall complications (RR, 1.26; 95% CI, 1.00-1.57; p = .05, I2  = 56%) with higher cerebrovascular events (RR, 1.68; 95% CI, 1.25-2.25; p = < .01, I2  = 0%). Subgroup analysis with cryoballoon CA showed that procedure-related complications in elderly patients were similar to those in non-elderly patients but not with radiofrequency CA. CONCLUSIONS: CA for AF in elderly patients has comparable long-term efficacy compared to that in non-elderly patients; however, the incidence of procedure-related complications were higher in elderly patients. Cryoballoon CA did not confer a higher procedure-related risk in elderly patients.

How does the level of pulmonary venous isolation compare between pulsed field ablation and thermal energy ablation (radiofrequency, cryo, or laser)?

AIMS: We studied the extent/area of electrical pulmonary vein isolation (PVI) after either pulsed field ablation (PFA) using a pentaspline catheter or thermal ablation technologies. METHODS AND RESULTS: In a clinical trial (NCT03714178), paroxysmal atrial fibrillation (PAF) patients underwent PVI with a multi-electrode pentaspline PFA catheter using a biphasic waveform, and after 75 days, detailed voltage maps were created during protocol-specified remapping studies. Comparative voltage mapping data were retrospectively collected from consecutive PAF patients who (i) underwent PVI using thermal energy, (ii) underwent reablation for recurrence, and (iii) had durably isolated PVs. The left and right PV antral isolation areas and non-ablated posterior wall were quantified. There were 20 patients with durable PVI in the PFA cohort, and 39 in the thermal ablation cohort [29 radiofrequency ablation (RFA), 6 cryoballoon, and 4 visually guided laser balloon]. Pulsed field ablation patients were younger with shorter follow-up. Left atrial diameter and ventricular systolic function were preserved in both cohorts. There was no significant difference between the PFA and thermal ablation cohorts in either the left- and right-sided PV isolation areas, or the non-ablated posterior wall area. The right superior PV isolation area was smaller with PFA than RFA, but this disappeared after propensity score matching. Notch-like normal voltage areas were seen at the posterior aspect of the carina in the balloon sub-cohort, but not the PFA or RFA cohorts. CONCLUSION: Catheter-based PVI with the pentaspline PFA catheter creates chronic PV antral isolation areas as encompassing as thermal energy ablation.

Safety and effectiveness of intracardiac echocardiography in ventricular tachycardia ablation: a nationwide observational study.

Intracardiac echocardiography (ICE) utilized in conjunction with three-dimensional (3-D) mapping systems could enhance ventricular tachycardia (VT) ablation procedures. ICE has been increasingly used in VT ablation; however, the safety and effectiveness of VT ablation under the combined use of ICE remains unclear. The present study aimed to analyze the safety and short-term effects of VT ablation with or without ICE. We retrospectively enrolled patients who underwent initial VT ablation with a combination of ICE and a 3-D mapping system within 3 days of hospitalization and discharged from April 2011 to March 2017 using a nationwide Japanese inpatient database. Following enrollment, we conducted a propensity score-matching analysis to compare safety (in-hospital complications) and effectiveness (readmission within 30 days after discharge due to cardiovascular disease and readmissions within 30 days for repeat VT ablations) between patients who underwent VT ablation with (ICE group) and without ICE (non-ICE group). 3-D mapping systems were applied to both groups. We identified 5,804 eligible patients (1,272 and 4,532 patients in the ICE and non-ICE groups, respectively). One-to-one propensity score matching created a total of 1,147 pairs between the ICE and non-ICE groups. The ICE group showed a significantly lower prevalence of cardiac tamponade than the non-ICE group. There were no significant differences observed between the two groups regarding other outcomes concerning safety and effectiveness. Ventricular tachycardia ablation with ICE used in combination with a 3-D mapping system may reduce cardiac tamponade; however, no additional clinical advantages were noted in terms of safety and effectiveness.

Quality of life improvements by durable pulmonary vein isolation in patients with atrial fibrillation.

INTRODUCTION: Successful pulmonary vein isolation (PVI) can improve the quality of life (QOL) of patients with atrial fibrillation (AF). However, the role of durable PVI for such QOL improvement is not known. The aim of this study was to clarify the effectiveness of durable PVI in improving the QOL of patients with AF. METHODS AND RESULTS: We assessed 119 patients who underwent PVI (age 66.4 ± 9.6 years, 104 paroxysmal AF). A scheduled electrophysiological study was performed 6 months after the first PVI session-regardless of recurrence of AF-to assess the durability of PVI and to identify and re-isolate reconnected pulmonary veins. QOL scores were evaluated by an AF-specific QOL questionnaire and checked at baseline, 6 months, and 1 year after the first session. In patients without AF recurrence (nonrecurrence group, n = 93), the scores at 6 months improved compared with those at baseline; conversely, the scores did not improve in patients with AF recurrence (n = 26). Nevertheless, the scores at 1 year improved compared with those at 6 months in both groups. Within the nonrecurrence group, the score difference between 6 months and baseline was higher in the durable PVI group (n = 58) than that in the nondurable PVI group (n = 35). CONCLUSIONS: The QOL of AF patients improved by the resumption of sinus rhythm following PVI. Patients with durable PVI had increased QOL scores compared with those with nondurable PVI. The durability of PVI may achieve further improvements in the QOL of patients with AF.

Comparison of touch-up ablation rate and pulmonary vein isolation durability between hot balloon and cryoballoon.

INTRODUCTION: This study aimed to compare touch-up ablation (TUA) rates and pulmonary vein isolation (PVI) durability of hot balloon ablation (HBA) and cryoballoon ablation (CBA) in paroxysmal atrial fibrillation (PAF) patients. METHODS: In total, 137 PAF patients were enrolled in the study. Among them, 59 underwent two HBA procedures at 6-month intervals and 78 patients underwent two CBA sessions, both regardless of atrial fibrillation recurrence. Propensity score matching was performed to estimate similar patient characteristics between the HBA and CBA groups. RESULTS: Each group comprised of 46 matched patients for comparison. The TUA rate at the first session was higher for HBA (49 of 184 PVs) than for CBA (20 PVs) (P = .01), with the highest incidence at the left superior pulmonary vein (LSPV). The rates of PVI durability at the second session performed 7 months later were similar between HBA (168 of 184 PVs) and CBA (162 PVs) groups. The PVI durability rate at the TUA sites of the first session was higher for HBA than for CBA (41 of 49 PVs vs 10 PVs, respectively; P = .01). Fifty percent of the patients underwent HBA at 73°C for the LSPV. HBA performed at 73°C yielded a lower TUA rate than that at 70°C (16 of 23 PVs vs 7 of 23 PVs; P = .008). CONCLUSIONS: While PVI durability was similar between HBA and CBA, the TUA rate was higher for HBA than for CBA, especially on the LSPV. For LSPV, HBA at a balloon temperature of 73°C may reduce the TUA rate.

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.

Syncope and presyncope in patients with COVID-19.

INTRODUCTION: Recent studies have described several cardiovascular manifestations of COVID-19 including myocardial ischemia, myocarditis, thromboembolism, and malignant arrhythmias. However, to our knowledge, syncope in COVID-19 patients has not been systematically evaluated. We sought to characterize syncope and/or presyncope in COVID-19. METHODS: This is a retrospective analysis of consecutive patients hospitalized with laboratory-confirmed COVID-19 with either syncope or presyncope. This "study" group (n = 37) was compared with an age and gender-matched cohort of patients without syncope ("control") (n = 40). Syncope was attributed to various categories. We compared telemetry data, treatments received, and clinical outcomes between the two groups. RESULTS: Among 1000 COVID-19 patients admitted to the Mount Sinai Hospital, the incidence of syncope/presyncope was 3.7%. The median age of the entire cohort was 69 years (range 26-89+ years) and 55% were men. Major comorbidities included hypertension, diabetes, and coronary artery disease. Syncopal episodes were categorized as (a) unspecified in 59.4% patients, (b) neurocardiogenic in 15.6% patients, (c) hypotensive in 12.5% patients, and (d) cardiopulmonary in 3.1% patients with fall versus syncope and seizure versus syncope in 2 of 32 (6.3%) and 1 of 33 (3.1%) patients, respectively. Compared with the "control" group, there were no significant differences in both admission and peak blood levels of d-dimer, troponin-I, and CRP in the "study" group. Additionally, there were no differences in arrhythmias or death between both groups. CONCLUSIONS: Syncope/presyncope in patients hospitalized with COVID-19 is uncommon and is infrequently associated with a cardiac etiology or associated with adverse outcomes compared to those who do not present with these symptoms.

Macroreentrant atrial tachycardia detouring the epicardium at the anterior wall of the left atrium.

A 79-year-old woman with a history of pulmonary vein isolation for persistent atrial fibrillation was admitted for recurrence of atrial tachycardia, with a tachycardia cycle length of 236 milliseconds. The ultra-high-resolution mapping system revealed that tachycardia circuit detouring the epicardium at the anterior wall scar and breaking through to the endocardium below the left atrial appendage. Radiofrequency energy was applied to this site, which successfully terminated the tachycardia. This case suggests that epicardial conduction could occur even at the left atrial anterior wall and identifies a variation in epicardial conduction around the left atrium, which could be a tachycardia circuit.

Characteristics of ventricular intracardiac electrograms of ventricular tachycardias originating from the epicardia in patients with an implantable cardioverter defibrillator.

INTRODUCTION: While characteristic waveforms of 12-lead electrocardiograms have been reported to predict the epicardial origin of ventricular tachycardia (VT), it has not been fully examined whether ventricular intracardiac electrograms (VEGMs) recorded from the implantable cardioverter defibrillator (ICD) via telemetry can determine the origin of VT or not. The aim of this study was to investigate the VEGM characteristics of VT originating from the epicardia. METHOD AND RESULTS: Intracardiac VEGMs of the induced VTs, with detected sites of origin during the VT study, were recorded in 15 (23 VTs) of the 46 patients. The characteristics of the 23 VTs were evaluated using far-field and near-field VEGMs recorded via telemetry. Five of 23 VTs were found to be focused on the epicardial site (epi group) and 18 VTs were focused on the endocardium (endo group). VTs of the epi group had longer VEGM duration in far-field EGM than those of the endo group (epi group: 240 ± 49 ms vs endo group: 153 ± 45 ms; P = 0.002) and the duration from the onset to the peak of VEGM was also longer than that of the endo group (epi group: 153 ± 53 ms vs endo group: 63 ± 28 ms; P < 0.001). There was no difference in the V wave duration in tip-ring EGM between both groups (epi group: 122 ± 52 ms vs endo group: 98 ± 6 ms; P = 0.377). CONCLUSION: Evaluation of intracardiac VEGM before VT ablation may be helpful to predict the epicardial origin of VT in patients with an ICD.

Usefulness of epicardial impedance evaluation for epicardial mapping and determination of epicardial ablation site for ventricular tachycardia: A pilot study.

BACKGROUND: During epicardial mapping, determination of appropriate ablation sites in low voltage areas (LVA) is challenging because of large epicardial areas covered by adipose tissue. OBJECTIVE: To evaluate the impedance difference between epicardial fat and the epicardial LVA using multiple detector computed tomography (MDCT). METHODS: We enrolled patients who underwent ventricular tachycardia (VT) ablation via the epicardial approach after endocardial ablation failure. After the procedure, MDCT-derived images of epicardial fat were loaded to the mapping system. Then, all points acquired during sinus rhythm were retrospectively superimposed and analyzed. RESULTS: This study included data from 7 patients (62.5 ± 3.9 years old) who underwent eight epicardial VT ablation procedures. After the procedure, MDCT-derived images of epicardial fat were registered in eight procedures. Retrospective analysis of 1,595 mapping and 236 ablation points was performed. Of the 1,595 mapping points on the merged electroanatomical and epicardial fat maps, normal voltage area (NVA) and low voltage area (LVA) without fat had lower impedance than those with fat (NVA without fat 182 ± 46 Ω vs. NVA with fat 321 ± 164.0 Ω, P  =  0.001, LVA without fat 164 ± 69 Ω vs. LVA with fat 248 ± 89 Ω, P  =  0.002). Of the 236 ablation points, initial impedance before ablation was higher on epicardial fat than on epicardial LVA without fat (134 ± 16 Ω vs. 156 ± 28 Ω, P  =  0.01). CONCLUSIONS: Real time epicardial impedance evaluation may be useful to determine effective epicardial ablation sites and avoid adipose tissue. However, the number of patients in the present study is limited. Further investigation with a large number of patients is needed to confirm our result.

Sodium Bicarbonate-Ascorbic Acid Combination for Prevention of Contrast-Induced Nephropathy in Chronic Kidney Disease Patients Undergoing Catheterization.

BACKGROUND: Sodium bicarbonate and ascorbic acid have been proposed to prevent contrast-induced nephropathy (CIN). The present study evaluated the effect of their combined use on CIN incidence.Methods and Results:We prospectively enrolled 429 patients with chronic kidney disease (CKD: baseline estimated glomerular filtration rate <60 mL/min/1.73 m2) prior to elective coronary catheterization. CIN was defined as absolute (≥0.5 mg/dL) or relative (≥25%) increase in serum creatinine within 72 h. In the saline hydration (n=218) and combined sodium bicarbonate+ascorbic acid (n=211) groups, a total of 1,500-2,500 mL 0.9% saline was given before and after the procedure. In addition, the combination group received 20 mEq sodium bicarbonate and 3 g ascorbic acid i.v. before the procedure, followed by 2 g ascorbic acid after the procedure and a further 2 g after 12 h. There were no significant differences between the basic characteristics and contrast volume in the 2 groups. CIN occurred in 19 patients (8.7%) in the saline group, and in 6 patients (2.8%) in the combined treatment group (P=0.008). CONCLUSIONS: Combined sodium bicarbonate and ascorbic acid could prevent CIN following catheterization in CKD patients.

The significance of non-sustained ventricular tachycardia on life-threatening ventricular arrhythmia events in patients with non-ischemic cardiomyopathy in the contemporary era: A systematic review and meta-analysis.

BACKGROUND: Risk stratification for patients with non-ischemic cardiomyopathy (NICM) remains challenging as previous studies predicting life-threatening ventricular arrhythmia (LTVA) events were conducted before the establishment of the current standard treatment. We investigated the prognostic value of non-sustained ventricular tachycardia (NSVT) in NICM patients among recent studies. METHODS: MEDLINE, Embase were searched from January 2000 to October 2023. The risk of NSVT on LTVA and mortality was assessed using a random-effects model for patients with NICM. A meta-regression analysis was employed to identify sources of heterogeneity. The systematic review and meta-analysis were carried out according to the PRISMA guidelines. RESULTS: A total of 18 studies were identified, including 5238 pooled participants. Meta-analysis demonstrated that the presence of NSVT was considered a significant prognostic indicator for LTVA events [hazard ratio (HR): 2.90; 95 % CI; 2.31-3.64] with low heterogeneity (I2: 19 %) and for mortality (HR; 2.28; 95%CI; 1.26-4.13) with high heterogeneity (I2: 69 %). The prognostic value of NSVT for LTVA was not affected by either ejection fraction or medications at baseline. CONCLUSION: NSVT remained an important predictor of LTVA events even in patients receiving healthcare in contemporary eras. Detection of NSVT helps us to identify the high-risk patients with NICM.