Rates of pulmonary vein reconnection at repeat ablation for recurrent atrial fibrillation and its impact on outcomes among females and males.

BACKGROUND: Several studies have demonstrated that females have a higher risk of arrhythmia recurrence after pulmonary vein (PV) isolation for atrial fibrillation (AF). There are limited data on sex-based differences in PV reconnection rates at repeat ablation. We aimed to investigate sex-based differences in electrophysiological findings and atrial arrhythmia recurrence after repeat AF ablation METHODS: We conducted a retrospective study of 161 consecutive patients (32% female, age 65 ± 10 years) who underwent repeat AF ablation after index PV isolation between 2010 and 2022. Demographics, procedural characteristics and follow-up data were collected. Recurrent atrial tachycardia (AT)/AF was defined as any atrial arrhythmia ≥30 s in duration. RESULTS: Compared to males, females tended to be older and had a significantly higher prevalence of prior valve surgery (10 vs. 2%; P = .03). At repeat ablation, PV reconnection was found in 119 (74%) patients. Males were more likely to have PV reconnection at repeat ablation compared to females (81 vs. 59%; P = .004). Excluding repeat PV isolation, there were no significant differences in adjunctive ablation strategies performed at repeat ablation between females and males. During follow-up, there were no significant differences in freedom from AT/AF recurrence between females and males after repeat ablation (63 vs. 59% at 2 years, respectively; P = .48). CONCLUSIONS: After initial PV isolation, significantly fewer females have evidence of PV reconnection at the time of repeat ablation for recurrent AF. Despite this difference, long-term freedom from AT/AF was similar between females and males after repeat ablation.

Initial experience with stylet-driven versus lumenless lead delivery systems for left bundle branch area pacing.

INTRODUCTION: Left bundle branch area pacing (LBBP) has emerged as an alternative method for conduction system pacing. While initial experience with delivery systems for stylet-driven and lumenless lead implantation for LBBP has been described, data comparing outcomes of stylet-driven versus lumenless lead implantation for LBBP are limited. In this study, we compare success rates and outcomes of LBBP with stylet-driven versus lumenless lead delivery systems. METHODS: Eighty-three consecutive patients (mean age 74.1 ± 11.2 years; 56 [68%] male) undergoing attempted LBBP at a single institution were identified. Cases were grouped by lead delivery systems used: stylet-driven (n = 53) or lumenless (n = 30). Baseline characteristics and procedural findings were recorded and compared between the cohorts. Intermediate term follow-up data on ventricular lead parameters were also compared. RESULTS: Baseline characteristics were similar between groups. Successful LBBP was achieved in 77% of patients, with similar success rates between groups (76% in stylet-driven, 80% in lumenless, p = 0.79), and rates of adjudicated LBB capture and other paced QRS parameters were also similar. Compared with the lumenless group, the stylet-driven group had significantly shorter procedure times (90 ± 4 vs. 112 ± 31 min, p = 0.004) and fluoroscopy times (10 ± 5 vs. 15 ± 6 min, p = 0.003). Ventricular lead parameters at follow-up were similar, and rates of procedural complications and need for lead revision were low in both groups. CONCLUSION: Delivery systems for stylet-driven and for lumenless leads for LBBP have comparable acute success rates. Long-term follow-up of lead performance following use of the various delivery systems is warranted.

Lead management in patients undergoing percutaneous tricuspid valve replacement or repair: a 'heart team' approach.

Clinically significant tricuspid regurgitation (TR) has historically been managed with either medical therapy or surgical interventions. More recently, percutaneous trans-catheter tricuspid valve (TV) replacement and tricuspid trans-catheter edge-to-edge repair have emerged as alternative treatment modalities. Patients with cardiac implantable electronic devices (CIEDs) have an increased incidence of TR. Severe TR in this population can occur for multiple reasons but most often results from the interactions between the CIED lead and the TV apparatus. Management decisions in patients with CIED leads and clinically significant TR, who are undergoing evaluation for a percutaneous TV intervention, need careful consideration as a trans-venous lead extraction (TLE) may both worsen and improve TR severity. Furthermore, given the potential risks of 'jailing' a CIED lead at the time of a percutaneous TV intervention (lead fracture and risk of subsequent infections), consideration should be given to performing a TLE prior to a percutaneous TV intervention. The purpose of this 'state-of-the-art' review is to provide an overview of the causes of TR in patients with CIEDs, discuss the available therapeutic options for patients with TR and CIED leads, and advocate for including a lead management specialist as a member of the 'heart team' when making treatment decisions in patients TR and CIED leads.

Concomitant leadless pacemaker implantation and lead extraction during an active infection.

INTRODUCTION: The need for transvenous lead extractions due to cardiac implantable electronic device (CIED)-related infections continues to rise. Current guidelines recommend complete device removal in the setting of an active infection, which can be challenging in pacemaker-dependent patients. METHODS: We retrospectively reviewed all leadless pacemaker implants between January 2018 and November 2019 and identified a subset of patients who had undergone a concomitant CIED extraction in the setting of an active infection. Baseline characteristics, procedural details, and clinical follow-ups were recorded. RESULTS: Seventeen patients received a leadless pacemaker during the same procedure as the CIED extraction. There were no procedural complications. All patients were being treated for an active CIED infection at the time of the procedure. Fourteen patients (82.4%) were completely pacemaker-dependent and four patients (23.5%) had positive blood cultures at the time of the leadless pacemaker implantation. During a median follow-up of 143 days (interquartile range: 57, 181 days), there were no recurrent infections. CONCLUSION: Simultaneous leadless pacemaker implantation and CIED extraction are safe and feasible in the setting of an active infection. This strategy may be particularly useful in patients that are pacemaker-dependent.

Implantation of leadless pacemakers via inferior vena cava filters is feasible and safe: Insights from a multicenter experience.

BACKGROUND: The leadless Micra transcatheter-pacing system (Micra-TPS) is implanted via a femoral approach using a 27-French introducer sheath. The Micra Transcutaneous Pacing Study excluded patients with inferior vena cava (IVC) filters. OBJECTIVE: To examine the feasibility and safety of Micra-TPS implantation through an IVC filter. METHODS: This multicenter retrospective study included patients with an IVC filter who underwent a Micra-TPS implantation. Data for clinical and IVC filter characteristics, preprocedure imaging, and procedural interventions were collected. The primary outcome was a successful leadless pacemaker (LP) implantation via a femoral approach in the presence of an IVC filter. Periprocedural and delayed clinical complications were also evaluated. RESULTS: Of the 1528 Micra-TPS implants attempted, 23 patients (1.5%) had IVC filters. The majority (69.6%) of IVC filters were permanent. Six (26.1%) patients underwent preprocedural imaging to assess for filter patency. One patient's filter was retrieved before LP implantation. The primary outcome was achieved in 21 of 22 patients (95.5%) with an existing IVC filter. An occluded IVC precluded LP implantation in one patient. Difficulty advancing the stiff guidewire or the 27-Fr sheath was encountered in five patients. These cases required repositioning of the wire (n = 2), gradual sheath upsizing (n = 2), or balloon dilation of the filter (n = 1). Postprocedure fluoroscopy revealed intact filters in all cases. During a median 6-month follow-up, there were no clinical complications related to the filter or the Micra-TPS. CONCLUSION: This multicenter experience demonstrates the feasibility and safety of Micra-TPS implantation via an IVC filter without acute procedural or delayed clinical complications.

Electrocardiographic localization of ventricular arrhythmias successfully ablated from the distal great cardiac vein.

BACKGROUND: Idiopathic ventricular arrhythmias (IVAs) from the left ventricular (LV) summit may be successfully ablated from the distal great cardiac vein (dGCV). Using a 12-lead electrocardiogram (ECG) to localize IVAs that can be ablated from the dGCV is valuable for ablation planning. OBJECTIVE: To determine if a "w" wave, a notch in the Q wave in lead I, and other ECG features can identify IVAs that can be successfully ablated from the dGCV. METHODS: We reviewed outflow tract premature ventricular contraction (PVC) ablations performed at two centers between September 2010 and June 2018. Successful PVC ablations, in which the PVCs were mapped from the right ventricular outflow tract, coronary cusps, commissures, endocardial LV, and the coronary venous system including the dGCV were included. ECG characteristics were compared between patients with successful ablations in the dGCV and non-dGCV sites. RESULTS: Of the 120 patients (age 56.8 ± 13.8 years, 45% female) that met the inclusion criteria, the dGCV was the successful ablation site in 18 patients (15%). Multivariate analysis with binary logistic regression showed that a "w" in lead I in combination with an early precordial pattern break and a maximum deflection index (MDI) ≥ 0.5 had sensitivity and specificity for a successful ablation in the dGCV of 94.4% and 96.1%, respectively. CONCLUSION: Combining a "w" wave in lead I with an early precordial pattern break and an MDI ≥ 0.5 is highly sensitive and specific for identifying the dGCV as a successful ablation site for PVCs.

Escape mapping to achieve bidirectional block: A case series.

Escape mapping is a novel technique that can be used to locate sites of persistent conduction and achieve exit block during an atrial fibrillation ablation. This method allows for mapping solely with the ablation catheter in the left atrium by annotating to a catheter in the coronary sinus. We illustrate the utility escape mapping during an atrial fibrillation ablation where entrance block is achieved without exit block. We further expand upon this technique by describing the first reported case of escape mapping being used to achieve bidirectional block during an atrial flutter ablation.

Recovery of atrioventricular conduction in patients with heart block after transcatheter aortic valve replacement.

INTRODUCTION: Recovery of conduction has been demonstrated in >50% of patients who receive pacemakers (PPMs) for high-degree atrioventricular block (HD-AVB) after transcatheter aortic valve replacement (TAVR). Little information is available about the time course of conduction recovery in these patients and if any features predict early recovery of conduction. METHODS: A retrospective review was performed of patients who underwent TAVR with balloon and self-expanding valves who required PPMs for HD-AVB. Serial PPM interrogations were analyzed to detect recovery of AV conduction. Analysis was performed to identify predictors and timing of conduction recovery. RESULTS: Of a total population of 578 patients, 54 (9%) received PPMs for HD-AVB. In multivariate analysis, predictors of HD-AVB requiring a PPM included age (P = 0.014), right bundle branch block (OR 7.33 [3.64-14.8], P < 0.0001), atrial fibrillation (OR 2.16 [1.16-4.05], P = 0.016), and self-expanding valves (OR 4.19 [2.20-7.97], P < 0.0001). Of the 54 patients who received PPMs, 38 had follow-up sufficient to evaluate AV conduction recovery. Of these, 23 (61%) showed recovery of AV nodal conduction; 20 had already recovered by their first interrogation, a median of 22 days (IQR 14-31) post-PPM placement. There were no statistically significant predictors of AV nodal conduction recovery, including type of valve implanted. CONCLUSIONS: A majority of patients who receive PPMs for HD-AVB after TAVR recover AV conduction during follow-up, and in most patients conduction recovery occurs within weeks. These findings imply that programming to minimize ventricular pacing may be beneficial in a majority of these patients.

Clinical Significance of Nonsustained Ventricular Tachycardia on Stored Electrograms in Permanent Pacemaker Patients.

BACKGROUND: Permanent pacemaker electrograms record a variety of arrhythmias, including nonsustained ventricular tachycardia (NSVT). Little has been reported regarding incidence and clinical significance of NSVT in pacemaker patients after long-term monitoring. METHODS: Records from all patients implanted with Medtronic pacemakers (Medtronic, Minneapolis, MN, USA) at a single institution from January 1, 2009 to February 27, 2012 were reviewed. Demographic characteristics, imaging studies, pacemaker interrogations, and the Social Security Death Index were examined in patients older than 18 years of age who had ≥ 2 follow-up device interrogations. RESULTS: A total of 262 patients with an ejection fraction (EF) >40% were included in the final analysis with a mean follow-up of 29.2 months. Of these patients, 83.2% (n = 218) had hypertension (HTN) and 45.4% (n = 119) had NSVT. Among patients with an EF ≥ 55%, hypertensive patients had a NSVT burden 2.46 times greater than normotensive patients (incidence rate ratio: 2.46, 95% confidence interval: 1.10-5.50; P < 0.028). NSVT was not associated with increased mortality (P < 0.1229). CONCLUSION: In this cohort of patients, there was a high prevalence of HTN and while hypertensive subjects had a significantly higher NSVT burden, NSVT was not associated with an increased mortality.

Site-specific effects of dobutamine on cardiac conduction and refractoriness.

BACKGROUND: Isoproterenol, a non-specific beta agonist, is commonly used during electrophysiology studies (EPS). However, with the significant increase in the price of isoproterenol in 2015 and the increasing number of catheter ablations performed, the cost implications cannot be ignored. Dobutamine is a less expensive synthetic compound developed from isoproterenol with a similar mechanism to enhance cardiac conduction and shorten refractoriness, thus making it a feasible substitute with a lower cost. However, the use of dobutamine for EPS has not been well-reported in the literature. OBJECTIVE: To determine the site-specific effects of various doses of dobutamine on cardiac conduction and refractoriness and assess its safety during EPS. METHODS: From February 2020 to October 2020, 40 non-consecutive patients scheduled for elective EPS, supraventricular tachycardia, atrial fibrillation, and premature ventricular contraction ablations at a single center were consented and prospectively enrolled to assess the effect of dobutamine on the cardiac conduction system. At the end of each ablation procedure, measures of cardiac conduction and refractoriness were recorded at baseline and with incremental doses of dobutamine at 5, 10, 15, and 20 mcg/kg/min. For the primary analysis, the change per dose of dobutamine from baseline to each dosing level of dobutamine received by the patients, comparing atrioventricular node block cycle length (AVNBCL), ventricular atrial block cycle length (VABCL) and sinus cycle length (SCL), was tested using mixed-effect regression. For the secondary analysis, dobutamine dose level was tested for association with relative changes from baseline of each electrophysiologic parameter (SCL, AVNBCL, VABCL, atrioventricular node effective refractory period (AVNERP), AH, QRS, QT, QTc, atrial effective refractory period (AERP), ventricular effective refractory period (VERP), using mixed-effect regression. Changes in systolic and diastolic blood pressures were also assessed. The Holm-Bonferroni method was used to adjust for multiple testing. RESULTS: For the primary analysis there was no statistically significant change of AVNBCL and VABCL relative to SCL from baseline to each dose level of dobutamine. The SCL, AVNBCL, VABCL, AVNERP, AERP, VERP and the AH, and QT intervals all demonstrated a statistically significant decrease from baseline to at least one dose level with incremental dobutamine dosing. Two patients (5%) developed hypotension during the study and one patient (2.5%) received a vasopressor. Two patients (5%) had induced arrhythmias but otherwise no major adverse events were noted. CONCLUSION: In this study, there was no statistically significant change of AVNBCL and VABCL relative to SCL from baseline to any dose level of dobutamine. As expected, the AH and QT intervals, and the VABCL, VERP, AERP and AVNERP all significantly decreased from baseline to at least one dose level with an escalation in dobutamine dose. Dobutamine was well-tolerated and safe to use during EPS.

Defibrillation waveform duration adjustment increases the proportion of acceptable defibrillation thresholds in patients implanted with single-coil defibrillation leads.

The aim of this study was to determine whether defibrillation waveform duration adjustment with single-coil defibrillation leads can be used to increase the proportion of patients with satisfactory defibrillation thresholds (DFTs). A retrospective analysis of the DFT levels for 105 patients with implantable cardioverter-defibrillator devices and a single-coil defibrillation lead was performed. Two groups of patients were compared: 34 patients who had undergone waveform tuning (group A) and 71 patients with a fixed-tilt waveform (group B). Additional data including demographics, etiology, New York Heart Association functional class, left ventricular ejection fraction, high-voltage lead impedance and medications were gathered to determine what effect these variables had on the DFT levels. Of the 34 patients who had undergone waveform adjustment (group A), 27 (79%) were found to have satisfactory DFTs, while 41 (58%) of the 71 patients with fixed-tilt devices (group B) had satisfactory DFTs. Waveform duration adjustment was found to significantly increase the proportion of patients with satisfactory DFTs (p = 0.03).

Concomitant leadless pacing in pacemaker-dependent patients undergoing transvenous lead extraction for active infection: Mid-term follow-up.

BACKGROUND: The rate of transvenous lead extraction (TLE) due to cardiac implantable electronic device (CIED) infection continues to rise. CIED infections are associated with significant morbidity and mortality. Temporary pacing in patients with active CIED infections after TLE can be challenging. Leadless pacing has emerged as an alternative approach in this patient population. OBJECTIVE: The purpose of this study was to describe the outcomes of a strategy using concomitant leadless pacemaker implantation and TLE in patients with active infections and ongoing pacing requirements. METHODS: This study involved all leadless pacemaker implantation procedures performed during TLE between June 2018 and September 2022 in the setting of active infection. Demographic characteristics, procedural details, and clinical outcomes were analyzed. RESULTS: The study included 86 patients with indications for ongoing pacing, 60 (70%) men with mean age 77.4 ± 10.5 years, who underwent TLE and concomitant leadless pacemaker implantation in the setting of active infection. There were no procedure-related complications. Sixty-five patients (76%) had evidence of bacteremia, 80% of whom were discharged to complete their antimicrobial treatment. During a median follow-up of 163 days (interquartile range 57-403 days), there were no recurrent infections. Of the 25 deaths (29%) during the study period, 22 (88%) were unrelated to the initial infection. Nine deceased patients (36%) had methicillin-resistant Staphylococcus aureus or Candida infections, 3 of whom had persistent infection despite TLE. CONCLUSION: Leadless pacing is a safe and efficacious approach for the management of patients with pacing requirements that undergo CIED extraction in the setting of active infection.

Safety and Efficacy of a Novel Approach to Pulmonary Vein Isolation Using Prolonged Apneic Oxygenation.

BACKGROUND: Improved ablation catheter-tissue contact results in more effective ablation lesions. Respiratory motion causes catheter instability, which impacts durable pulmonary vein isolation (PVI). OBJECTIVES: This study sought to evaluate the safety and efficacy of a novel ablation strategy involving prolonged periods of apneic oxygenation during PVI. METHODS: We conducted a multicenter, prospective controlled study of 128 patients (mean age 63 ± 11 years; 37% women) with paroxysmal atrial fibrillation undergoing PVI. Patients underwent PVI under general anesthesia using serial 4-minute runs of apneic oxygenation (apnea group; n = 64) or using standard ventilation settings (control group; n = 64). Procedural data, arterial blood gas samples, catheter position coordinates, and ablation lesion characteristics were collected. RESULTS: Baseline characteristics between the 2 groups were similar. Catheter stability was significantly improved in the apnea group, as reflected by a decreased mean catheter displacement (1.55 ± 0.97 mm vs 2.25 ± 1.13 mm; P < 0.001) and contact force SD (4.9 ± 1.1 g vs 5.2 ± 1.5 g; P = 0.046). The percentage of lesions with a mean catheter displacement >2 mm was significantly lower in the apnea group (22% vs 44%; P < 0.001). Compared with the control group, the total ablation time to achieve PVI was reduced in the apnea group (18.8 ± 6.9 minutes vs 23.4 ± 7.8 minutes; P = 0.001). There were similar rates of first-pass PVI, acute PV reconnections and dormant PV reconnections between the two groups. CONCLUSIONS: A novel strategy of performing complete PVI during apneic oxygenation results in improved catheter stability and decreased ablation times without adverse events. (Radiofrequency Ablation of Atrial Fibrillation Under Apnea; NCT04170894).

Pacemaker interactions induce reentrant wave dynamics in engineered cardiac culture.

Pacemaker interactions can lead to complex wave dynamics seen in certain types of cardiac arrhythmias. We use experimental and mathematical models of pacemakers in heterogeneous excitable media to investigate how pacemaker interactions can be a mechanism for wave break and reentrant wave dynamics. Embryonic chick ventricular cells are cultured in vitro so as to create a dominant central pacemaker site that entrains other pacemakers in the medium. Exposure of those cultures to a potassium channel blocker, E-4031, leads to emergence of peripheral pacemakers that compete with each other and with the central pacemaker. Waves emitted by faster pacemakers break up over the slower pacemaker to form reentrant waves. Similar dynamics are observed in a modified FitzHugh-Nagumo model of heterogeneous excitable media with two distinct sites of pacemaking. These findings elucidate a mechanism of pacemaker-induced reentry in excitable media.

Temporal Changes and Clinical Implications of Delayed Peridevice Leak Following Left Atrial Appendage Closure.

OBJECTIVES: The aim of this study was to assess temporal changes and clinical implications of peridevice leak (PDL) after left atrial appendage closure. BACKGROUND: Endocardial left atrial appendage closure devices are alternatives to long-term oral anticoagulation (OAC) for patients with atrial fibrillation. PDL >5 mm may prohibit discontinuation of OAC. METHODS: Patients included in the study had: 1) successful Watchman device implantation without immediate PDL; 2) new PDL identified at 45 to 90 days using transesophageal echocardiography; 3) eligibility for OAC; and 4) 1 follow-up transesophageal echocardiographic study for PDL surveillance. Relevant clinical and imaging data were collected by chart review. The combined primary outcome included failure to stop OAC after 45 to 90 days, transient ischemic attack or stroke, device-related thrombi, and need for PDL closure. RESULTS: Relevant data were reviewed for 1,039 successful Watchman device implantations. One hundred eight patients (10.5%) met the inclusion criteria. The average PDL at 45 to 90 days was 3.2 ± 1.6 mm. On the basis of a median PDL of 3 mm, patients were separated into ≤3 mm (n = 73) and >3 mm (n = 35) groups. In the ≤3 mm group, PDL regressed significantly (2.2 ± 0.8 mm vs 1.6 ± 1.4 mm; P = 0.002) after 275 ± 125 days. In the >3 mm group, there was no significant change in PDL (4.9 ± 1.4 mm vs 4.0 ± 3.0 mm; P = 0.12) after 208 ± 137 days. The primary outcome occurred more frequently (69% vs 34%; P = 0.002) in the >3 mm group. The incidence of transient ischemic attack or stroke in patients with PDL was significantly higher compared with patients without PDL, irrespective of PDL size. CONCLUSIONS: New PDL detected by transesophageal echocardiography at 45 to 90 days occurred in a significant percentage of patients and was associated with worse clinical outcomes. PDL ≤3 mm tended to regress over time.

Atrial fibrillation is an independent predictor for in-hospital mortality in patients admitted with SARS-CoV-2 infection.

BACKGROUND: Atrial fibrillation (AF) is the most encountered arrhythmia and has been associated with worse in-hospital outcomes. OBJECTIVE: This study was to determine the incidence of AF in patients hospitalized with coronavirus disease 2019 (COVID-19) as well as its impact on in-hospital mortality. METHODS: Patients hospitalized with a positive COVID-19 polymerase chain reaction test between March 1 and April 27, 2020, were identified from the common medical record system of 13 Northwell Health hospitals. Natural language processing search algorithms were used to identify and classify AF. Patients were classified as having AF or not. AF was further classified as new-onset AF vs history of AF. RESULTS: AF occurred in 1687 of 9564 patients (17.6%). Of those, 1109 patients (65.7%) had new-onset AF. Propensity score matching of 1238 pairs of patients with AF and without AF showed higher in-hospital mortality in the AF group (54.3% vs 37.2%; P < .0001). Within the AF group, propensity score matching of 500 pairs showed higher in-hospital mortality in patients with new-onset AF as compared with those with a history of AF (55.2% vs 46.8%; P = .009). The risk ratio of in-hospital mortality for new-onset AF in patients with sinus rhythm was 1.56 (95% confidence interval 1.42-1.71; P < .0001). The presence of cardiac disease was not associated with a higher risk of in-hospital mortality in patients with AF (P = .1). CONCLUSION: In patients hospitalized with COVID-19, 17.6% experienced AF. AF, particularly new-onset, was an independent predictor of in-hospital mortality.

Tips and Tricks for Safe Retrieval of Tine-based Leadless Pacemakers.

As leadless pacing (LP) use is expected to increase, it becomes increasingly essential that operators become familiar with the tools and techniques needed to retrieve an LP successfully. The purpose of this review is to describe a stepwise approach for the successful retrieval of tine-based LP devices, including ways to minimize complications.