Burn and plug: is it too much for the left atrial appendage?

Peri-procedural use of direct anticoagulation agents during cardiac device implantation: vitamin K antagonists vs direct oral anticoagulants Abstract Background Warfarin is deemed safe compared to bridging with heparin in the peri-procedure setting while implanting cardiac devices. The timing of discontinuation and re-initiation of direct anticoagulant agents (DOACs) such as dabigatran, apixaban, and rivaroxaban in the peri-procedural setting in comparison to warfarin is not well studied. Objective We wanted to compare three DOAC agents with warfarin during cardiac device implantation. Methods Consecutive patients on treatment with dabigatran, rivaroxaban, or apixaban (group A) undergoing a cardiac device generator change, upgrade, or new implantation procedure were compared to those on warfarin (group B). Incidence of hematoma, infection, effusion, stroke, and other complications were noted at 1 day, 1 week, and 3 months. Results A total of 311 patients in group A underwent the above procedures with 73 patients on dabigatran, 153 on rivaroxaban, and 85 on apixaban. There were 467 patients on warfarin in group B. Mean age of the total population was 68 ± 12 years with 67% males and > 80% Caucasians. The last dose of the DOAC was the night prior to the procedure and resumed the night of the procedure (single dose interruption for apixaban and dabigatran and no un-interruption for rivaroxaban). There was no difference noted in the incidence of minor or major hematoma (9% vs 8.5%, p = 0.7). No stroke occurred in either group. Conclusion Use of DOAC agents with transient interruption of one dose is as safe as warfarin in the peri-procedural setting during implantation of cardiac devices.

Estimation of the accessory pathway location of the manifest Wolf-Parkinson-White syndrome using synthesized right-sided chest leads Abstract Purpose The classification using QRS morphology of V1 lead is a useful simple predictor of accessory pathway location (type A, R or Rs pattern; type B, rS pattern; type C, QS or Qr pattern), but often leads to misdiagnosis of accessory pathway location, especially in types B and C. The synthesized 18-lead electrocardiography (ECG) derived from standard 12-lead ECG can provide virtual waveforms of right-sided chest leads. This study aimed to evaluate the usefulness of the right-sided chest lead ECG for prediction of accessory pathway location. Methods This retrospective study included 44 patients in whom successful ablation of manifest Wolff-Parkinson-White (WPW) syndrome was performed. Synthesized ECG waveforms were automatically generated, and ECG data obtained before the procedure. Results There were 26, 4, and 14 patients with left, right, and septal accessory pathways, respectively. All left accessory pathway cases have type A in V1 and syn-V4R leads. Of the 4 right accessory pathway cases, 2 have type B in V1 and syn-V4R leads. Other 2 of 4 cases have type C. In V1 lead, 5 of 14 septal accessory pathway cases have type C, 7 of 14 cases have type B, and 2 of 14cases have type A. In syn-V4R lead, all 14 septal accessory pathway cases have type C. The QRS morphology of V1 and syn-V4 leads could predict the site of accessory pathway with overall accuracy of 79% and 95%, respectively. Conclusions QRS morphology of syn-V4R lead may be useful for predicting accessory pathway location of manifest WPW syndrome.

Comparison of echocardiographic and fluoroscopic sizing of the left atrial appendage prior to percutaneous closure Abstract Purpose Sizing of the left atrial appendage (LAA) ostium prior to occlusion (LAAO) is routinely performed with transesophageal echocardiography (TEE). We sought to compare the utility of sizing via fluoroscopy to TEE for percutaneous LAAO. Methods We retrospectively evaluated all patients undergoing percutaneous LAAO at our institution from April 2015 through January 2018 (n = 195). We evaluated baseline characteristics, maximum measured ostium size (for both TEE and fluoroscopy), and differences in measured size to device size for both techniques. Results Of the total cohort, 185 (95%) had both intraoperative TEE and fluoroscopic images available for analysis and were included in the final analysis. The mean age was 74 years and 64% were male. Hypertension was present in 89%, diabetes in 30%, and stroke in 32% of patients. The mean ejection fraction was 51%. The most common LAA morphology was “wind sock” (52%). Measured ostial diameter on fluoroscopy was larger compared with TEE (2.04 ± 3.43 mm larger on fluoroscopy, p < 0.001). Ostium diameter on TEE was more closely correlated to the size of the device implanted compared with fluoroscopy (0.76 vs. 0.61, p = 0.001). Conclusions Fluoroscopy results in larger estimated LAA ostium diameter compared with TEE. Despite this, TEE was more strongly correlated to operator choice in device sizing, which may reflect practice patterns. Because compression of the ostium on the device is necessary for long-term procedural success, under-sizing may lead to a higher rate of leaks. Prospective evaluation of the utility of routine fluoroscopic sizing compared with TEE is warranted.

Is paroxysmal supraventricular tachycardia truly benign? Insightful association between PSVT and stroke from a National Inpatient Database Study Abstract Background Atrial fibrillation and flutter are well-known causes of stroke. Whether other atrial arrhythmias categorized as paroxysmal supraventricular tachycardia (PSVT) are associated with stroke is less clear. We aimed to evaluate the association of PSVT with ischemic and embolic stroke and its impact on short-term outcomes in hospitalized stroke patients. Methods National Inpatient Sample database of the USA was used to assess the association of PSVT with ischemic stroke. Atrial fibrillation and flutter were excluded to minimize the confounding effects. The association of PSVT with stroke was evaluated using univariate and multivariate analysis. Subgroup analyses by gender, age, and stroke type were also performed. Results PSVT was associated with increased odds of overall ischemic stroke in univariate [OR 1.18 (95% CI 1.09–1.27) p < 0.001] analysis. No such association was observed in multivariate analysis (OR 1.06 (95% CI 0.98–1.14) p = 0.1) or with subgroup analysis by gender and age. However, PSVT was associated with embolic stroke in both univariate (OR 2.01 (95%CI 1.67–2.43, p < 0.001) and multivariate analysis (OR 1.7 (95%CI 1.4–2.14) p < 0.001) as well as in subgroup analyses by gender and age. Furthermore, the presence of PSVT was associated with increased mortality in embolic stroke (OR 4.11, CI 2.29 to 7.39, p < 0.001) and increased total hospital cost and length of hospital stay in all stroke types. Conclusions PSVT is independently associated with higher prevalence of embolic stroke but not with overall ischemic stroke. Patients with embolic stroke in the presence of PSVT have worse in-hospital outcomes with increased mortality.

Nanostim leadless pacemaker retrieval and simultaneous micra leadless pacemaker replacement: a single-center experience Abstract Purpose The leadless pacemaker (LP) is a promising new technology in pacing therapy that avoids a generator pocket and transvenous lead-related complications. However, extraction experience with simultaneous re-implant of a leadless device remains limited. We sought to study the outcomes of Nanostim LP retrieval and simultaneous reimplantation of Micra LP. Methods Patients undergoing retrieval of the Nanostim LP and receiving a Micra LP implant between 2016 and 2018 at Mayo Clinic (Rochester, MN) were studied. The procedural and outcome data were collected from the electronic medical record. Results Nine patients underwent attempted Nanostim LP retrieval and 6 of these simultaneously received a Micra LP reimplant. All retrievals were considered chronic due to implant durations of > 1 year. Extraction procedures were completed with a success rate of 89% and simultaneous reimplantations were performed successfully in all cases with no major complications. Newly implanted Micra LP device function was normal at follow-up. Factors such as duration of device implant and device positioning appeared to impact ease of extraction. Conclusions Retrieval of the Nanostim LP system and simultaneous replacement with an alternate Micra leadless device appears to be a feasible approach.

Magnetic resonance imaging of patients with epicardial leads: in vitro evaluation of temperature changes at the lead tip Abstract Purpose The aim of this study was to systematically investigate the potential heating effects of magnetic resonance imaging (MRI) in the presence of epicardial leads, which are connected to a device or abandoned, using a series of in vitro measurements. Methods The heating effects of MRI in a 1.5-T scanner were measured at the lead tip in a gel-filled tank. First, a transvenous lead (5086—45 cm, Medtronic) was compared with an epicardial lead (4968—35 cm, Medtronic) with and without connection to an MR-conditional pacemaker. Then, experiments were conducted using various lengths of epicardial leads exposed to MRI. Results (1) A temperature rise of + 2.5 °C was observed for the transvenous lead attached to an MRI-conditional pacemaker. The epicardial lead attached to the same pacemaker showed four times higher heating. (2) The transvenous lead without pacemaker showed four times higher heating, and the epicardial lead without pacemaker showed 30 times higher heating. (3) The epicardial lead coiled to 20 cm length without pacemaker showed 9 times higher heating. (4) Experiments with various lengths of epicardial leads showed that the shorter the leads were, the smaller was the heating effect. Conclusion Standard clinical MRI investigations may result in pronounced heating at the tip of epicardial electrodes. Epicardial leads, which are not connected to a pacemaker and thus mimicking abandoned leads, may even result in a more pronounced rise in temperature at the lead tip. Therefore, current epicardial pacing systems may carry a substantial risk of inducing thermal damage of the neighboring tissue during MRI scanning.

Feasibility and safety of pulmonary vein isolation by high-power short-duration radiofrequency application: short-term results of the POWER-FAST PILOT study Abstract Purpose Pulmonary vein (PV) isolation (PVI) by point-by-point radiofrequency application (PPRF) results in longer procedures than that achieved by single-shot ablation techniques. In addition, it is associated with significant risk of oesophageal injury. The POWER-FAST pilot study evaluated the feasibility and safety of PVI by high-power short-duration (HPSD) PPRF. Methods HPSD PPRF around the PVs was done in 48 consecutive patients with atrial fibrillation. Fifty watts was delivered until a predefined lesion index value was reached (LSI ≥ 5 or Abl-I ≥ 350) and 60 W during 7–10 s in the first 18 and last 30 patients, respectively. A control group of 47 consecutive patients who had undergone PVI before the HPSD group with conventional PPRF (30 W for 30 s) was included for reference. Echocardiography and oesophageal endoscopy was performed shortly after ablation in all patients. Results PVI of all targeted veins was achieved in 98% and 100% of patients of the conventional and HPSD groups, respectively (p = 0.59). Total radiofrequency time was 34 ± 11, 24 ± 8, and 15 ± 5 min in groups 30 W, 50 W, and 60 W (p < 0.001). Audible steam pops occurred in 4 out of 48 (8%) patients in the HPSD group, accounting for 4 (0.08%) out of 5 269 HPSD radiofrequency applications. No patient in the HPSD group developed pericardial effusion. The incidence of oesophageal lesions was 28%, 22%, and 0% in groups 30 W, 50 W, and 60 W, respectively (p = 0.007) Conclusions PVI can be achieved with HPSD PPRF in most patients. This approach appears safe and associated with low risk of esophageal damage.

Electroanatomical mapping-guided ablation during atrial fibrillation: a novel usage of fractionation mapping in a case with sinus bradycardia and paroxysmal atrial fibrillation

Contact-force radiofrequency ablation of non-paroxysmal atrial fibrillation: improved outcomes with increased experience Abstract Introduction Clinical trials have failed to reliably show improved outcomes with utilization of contact-force sensing (CFS) radiofrequency (RF) ablation catheters. It is unknown whether the unfavorable outcomes observed in these trials are attributable to inexperience with CFS technology. Objectives To compare catheter ablation outcomes of stepwise linear ablation with versus without CFS technology and to assess the impact of operator experience with CFS technology on procedural outcomes. Methods Clinical outcomes were evaluated in 228 consecutive NPAF patients undergoing first-time left atrial ablation using a stepwise linear approach. Arrhythmia recurrence was assessed using 2-week event monitors at 3-month intervals following index ablation. Results A total of 228 patients were included in our study. There was no statistically significant difference in risk of recurrent atrial arrhythmias at 12 and 24 months between CFS and non-CFS patients (p = 0.5 and p = 0.169). The time to recurrence of atrial arrhythmias at 24 months in the second half of CFS patients was significantly lower when compared to both the first half of CFS patients (p = 0.002) and non-CFS patients (p = 0.005). Conclusion While there was no difference in overall outcomes between CFS and non-CFS ablation using a stepwise linear approach in patients with NPAF, procedural efficacy of the second half of CFS patients was significantly improved compared to both the first half of CFS patients and all non-CFS patients. Lack of benefit seen in clinical trials using CFS technology may be related to operator inexperience with CFS ablation catheters at the time of the trials.