Targeting non-pulmonary vein triggers in persistent atrial fibrillation: results from a prospective, multicentre, observational registry.

AIMS: We evaluated the efficacy of an ablation strategy empirically targeting pulmonary veins (PVs) and posterior wall (PW) and the prevalence and clinical impact of extrapulmonary trigger inducibility and ablation in a large cohort of patients with persistent atrial fibrillation (PerAF). METHODS AND RESULTS: A total of 1803 PerAF patients were prospectively enrolled. All patients underwent pulmonary vein antrum isolation (PVAI) extended to the entire PW. A standardized protocol was performed to confirm persistent PVAI and elicit any triggers originating from non-PV sites. All non-PV triggers initiating sustained atrial tachyarrhythmias were ablated. Ablation of non-PV sites triggering non-sustained runs (<30 s) of atrial tachyarrhythmias or promoting frequent premature atrial complexes (≥10/min) was left to operator's discretion. Overall, 1319 (73.2%) patients had documented triggers from non-PV areas. After 17.4 ± 8.5 months of follow-up, the cumulative freedom from atrial tachyarrhythmias among patients without inducible non-PV triggers (n = 484) was 70.2%. Patients with ablation of induced non-PV triggers had a significantly higher arrhythmia control than those whose triggers were not ablated (67.9% vs. 39.4%, respectively; P < 0.001). After adjusting for clinically relevant variables, patients in whom non-PV triggers were documented but not ablated had an increased risk of arrhythmia relapse (hazard ratio: 2.39; 95% confidence interval: 2.01-2.83; P < 0.001). CONCLUSION: Pulmonary vein antrum isolation extended to the entire PW might provide acceptable long-term arrhythmia-free survival in PerAF patients without inducible non-PV triggers. In our population of PerAF patients, non-PV triggers could be elicited in ∼70% of PerAF patients and their elimination significantly improved outcomes.

Effects of permanent cardiac pacing on ventricular repolarization when compared to cardioneuroablation.

INTRODUCTION: The impact of cardioneuroablation (CNA) on ventricular repolarization by using corrected QT interval (QTc) measurements has been recently demonstrated. The effects of cardiac pacing (CP) on ventricular repolarization have not been studied in patients with vasovagal syncope (VVS). We sought to compare ventricular repolarization effects of CNA (group 1) with CP (group 2) in patients with VVS. METHODS: We enrolled 69 patients with age 38 ± 13 years (53.6% male), n = 47 in group 1 and n = 22 in group 2. Clinical diagnosis of cardioinhibitory type was supported by cardiac monitoring or tilt testing. QTc was calculated at baseline (time-1), at 24 h after ablation (time-2), and at 9-12 months (time-3) in the follow-up. RESULTS: In the group 1, from time-1 to time-2, a significant shortening in QTcFredericia (from 403 ± 27 to 382 ± 27 ms, p < 0.0001), QTcFramingham (from 402 ± 27 to 384 ± 27 ms, p < 0.0001), and QTcHodges (from 405 ± 26 to 388 ± 24 ms, p < 0.0001) was observed which remained lower than baseline in time-3 (373 ± 29, 376 ± 27, and 378 ± 27 ms, respectively). Although the difference between measurements in time-1 and time-2 was not statistically significant for QTcBazett, a significant shortening was detected between time-1 and time-3 (from 408 ± 30 to 394 ± 33, p = 0.005). In the group 2, there was no time-based changes on QTc measurements. In the linear mixed model analysis, the longitudinal reduction tendency in the QTcFredericia and QTcFramingham was more pronounced in group 1. CONCLUSIONS: Our results demonstrate that CNA reduces QTc levels through neuromodulation effect whereas CP has no effect on ventricular repolarization in patients with VVS.

Safety and Efficacy of Apixaban versus warfarin in patients with atrial fibrillation or Venous Thromboembolism and End-Stage renal disease on hemodialysis: A systematic review and meta-analysis.

BACKGROUND: Warfarin is traditionally the drug of choice for stroke prophylaxis or treatment of venous thromboembolism in patients with end-stage renal disease (ESRD) on hemodialysis as data on apixaban use is scarce. We aimed to assess the safety and efficacy of Apixaban in patients with ESRD on hemodialysis when compared with warfarin. METHODS: A comprehensive literature search in PubMed, Google Scholar, and Cochrane databases from inception until Nov 25, 2019, was performed. Studies reporting clinical outcomes comparing Apixaban (2.5 mg BID or 5 mg BID) versus Warfarin in ESRD patients on hemodialysis were included. Mantel-Haenszel risk ratio (RR) random-effects model was used to summarize data. RESULTS: Four studies (three retrospective and one randomized) with a total of 9862 patients (apixaban = 2,547, warfarin = 7315) met inclusion criteria. The overall mean age was 66.6 ± 3.9 years and mean CHA2DS2-VASc score 4.56 ± 0.58. Apixaban was associated with lower rates of major bleeding (RR 0.53, 95% CI 0.45-0.64, p < 0.0001], gastrointestinal (GI) bleed (RR 0.65, 95% CI 0.55-0.76, p < 0.0001), intracranial bleed (RR 0.56, 95% CI 0.36-0.89, p = 0.01), and stroke/systemic embolism [RR 0.65, 95% CI 0.52-0.83, p = 0.0004] compared with warfarin in patients with ESRD on hemodialysis. There was no significant increased risk of all-cause mortality with the apixaban vs. warfarin (RR 0.90, 95% CI 0.41-1.96, p = 0.78). CONCLUSION: Apixaban had an overall favorable risk-benefit profile, with significant reductions in ischemic stroke, major bleeding, and intracranial bleeding compared to Warfarin in ESRD patients on hemodialysis with non-valvular AF and/or venous thromboembolism.

Warfarin vs non-vitamin K oral anticoagulants for left atrial appendage thrombus: A meta-analysis.

INTRODUCTION: Novel oral anticoagulants (NOACs) are commonly used for thromboembolic risk reduction and treatment of pulmonary embolism and deep venous thrombosis. However, data regarding their efficacy and safety in comparison to warfarin for left atrial appendage thrombus is limited. METHODS: A comprehensive literature search in PubMed, Google Scholar, and Cochrane Review from inception to 30 October 2019 was performed. Studies reporting clinical outcomes comparing warfarin vs NOACs were included. Two investigators independently extracted the data and individual quality assessment was performed. A meta-analysis was performed using random-effects model to calculate risk ratio (RR) and 95% confidence interval (CI). The analysis was performed using RevMan 5.3. RESULTS: Four studies met inclusion criteria and a total of 322 patients were included of whom 141 were in the NOAC arm and 181 were in the warfarin arm. There was no significant difference in thrombus resolution between the two groups (RR, 1.00; 95% CI [0.77-1.29; P = .98]). There was no significant difference in major bleeding (RR, 1.30; 95% CI [0.14-12.21; P = .82]) or stroke (RR, 0.42; 95% CI [0.09-2.06; P = .29]) between the two groups. CONCLUSION: The results of our meta-analysis show that NOACs are as efficacious and safe as warfarin in the treatment of left atrial appendage thrombus in patients with non-valvular atrial fibrillation.

Role of cardiac sympathetic denervation in ventricular tachycardia: A meta-analysis.

BACKGROUND: Cardiac sympathetic denervation (CSD) is being used in the management of refractory ventricular tachycardia (VT) and electrical storm. However, data on the role of CSD in the management of ventricular arrhythmia is limited. METHODS: We performed a meta-analysis of retrospective studies to calculate the pooled rate of freedom from VT and the standard mean difference of ICD shocks before and after CSD. RESULTS: 14 nonrandomized studies with a total of 311 patients with refractory VT or electrical storm were included. At a mean follow up of 15 ± 10.7 months, the pooled rate of freedom from VT (VT nonrecurrence rate) after CSD in all causes of arrhythmia was 60% (range 48.8% to 70%, I2   = 43%). When analysis was restricted to only arrhythmias caused by conditions other than catecholaminergic polymorphic ventricular tachycardia (CPVT) and long QT syndrome (LQTS), the pooled VT non-recurrence rate was 50% (range 41% to 58%, I2   = 5%). After CSD, mean total number of ICD shocks per person diminished by 3.01 (95% CI 1.09-4.94, P = .002, I2  = 96%) in overall analysis and by 0.97(95% CI 0.41-1.5, P = .001, I2  = 45%) when CPVT and LQTS were excluded. CONCLUSION: In patients with refractory VT or electrical storm, CSD is associated with pooled VT nonrecurrence rate of 60% at a mean follow-up of 15 ± 10.7 months. CSD was also associated with significantly lower mean number ICD shocks per person. Further studies are needed to validate this finding in a prospective setting.

Risks and Benefits of Removal of the Left Atrial Appendage.

PURPOSE OF REVIEW: In patients with atrial fibrillation who are unable to take novel oral anticoagulants for stroke prophylaxis due to bleeding risk or other contraindications, left atrial appendage (LAA) occlusion and exclusion devices have shown benefit. In this review, we highlight the risks and benefits associated with LAA removal. RECENT FINDINGS: LAA, once considered a vestigial organ, has been shown to have physiological, anatomical, and arrhythmogenic properties. Device-related complications such as pericardial effusion, device embolization, device-related thrombus, while uncommon, are still present. With increased operator experience related to appendage occlusion, overall procedural complications have declined. Further refinements in device technology will help decrease complications. While benefits of appendage removal are plenty, procedural complications need to be weighed into the equation when making decisions regarding LAA occlusion.

Meta-Analysis on the Impact of Ventricular Arrhythmias on Mortality in Patients With Continuous Flow Left Ventricular Assist Devices.

Patients with continuous flow left ventricular assist devices (CFLVADs) have an increased risk of ventricular arrhythmias (VA), but the impact of VA on survival is unclear. A systematic search of electronic databases was conducted to identify studies that reported the impact of VA on all-cause mortality and right ventricular failure (RVF) in patients with CFLVAD. The Mantel-Haenszel method was used to calculate the 95% confidence interval (CI) and pooled risk ratio (RR) with a random-effects model. A total of 19 observational studies with 4,544 patients and a median follow-up of 18.5 months (interquartile range 11.5 to 26.4) were included. There was statistically significantly higher mortality in patients with any VA than in those with no VA after CFLVAD implantation (RR 1.33, 95% CI 1.01 to 1.75, p = 0.04, I2 = 78%). On sensitivity analysis, after removing the largest study by Rehorn et al,10 the association between overall mortality and VA was lost, suggesting that these results should be interpreted with caution. Early VA developing within 30 days after implantation was associated with a higher risk of mortality (RR 1.37, 95% CI 1.15 to 1.63, p <0.01, I2 = 52%), whereas late VA developing after 30 days after CFLVAD implantation was not associated with any significant difference in mortality (RR: 1.00; 95% CI: 0.80 to 1.24; p = 0.98, I2 = 35%). In addition, there was a statistically significant higher risk of RVF in patients with VA than in those with no VA (RR 1.58, 95% CI 1.20 to 2.08, p <0.01, I2 = 0%). In conclusion, in patients with CFLVAD, the development of any VA was associated with a 33% higher risk of all-cause mortality. Early VA developing within 30 days after implantation was significantly associated with a higher risk of mortality, whereas late VA was not associated with mortality. VA after left ventricular assist device was significantly associated with a higher risk of developing RVF.

Permanent pacing versus cardioneuroablation for cardioinhibitory vasovagal syncope.

BACKGROUND: We compared the efficacy and safety of cardioneuroablation (CNA) vs. permanent pacing (PM) for recurrent cardioinhibitory vasovagal syncope (CI-VVS). METHODS: One hundred sixty-two patients (CNA = 61, PM = 101), age 36 + 11 years) with syncope frequency of 6.7 ± 3.9/year were included in this multicenter study. All patients with CNA were provided by a single center, while patients with PM were provided by 4 other centers. In the CNA arm, an electroanatomic mapping guided approach was used to detect and ablate ganglionated plexus sites. Dual chamber rate drop response (RDR) or close loop stimulation (CLS) transvenous and leadless pacemakers were implanted using standard technique. The primary endpoint was freedom from syncope. RESULTS: Of 101 patients in the PM group, 39 received dual-chamber pacemaker implants with the CLS algorithm, 38 received dual-chamber pacemakers with the RDR algorithm, and 24 received a leadless pacemaker. At 1-year follow-up, 97% and 89% in the CNA and PM group met the primary endpoint (adjusted HR = 0.27, 95% CI 0.06-1.24, p = 0.09). No significant differences in adverse events were noted between groups. There was no significant association between age (HR:1.01, 95% CI 0.96-1.06, p = 0.655), sex (HR:1.15, 95% CI 0.38-3.51, p = 0.809), and syncope frequency in the past year (HR:1.10, 95% CI 0.97-1.25, p = 0.122) and the primary outcome in univariable analyses. CONCLUSIONS: After adjustment for patient characteristics, the medium-term syncope recurrence risk of CI-VVS patients who underwent CNA was similar to that of a population of patients undergoing pacemaker implantation with a similar safety profile.

Pacing therapies for sleep apnea and cardiovascular outcomes: A systematic review.

PURPOSE: Phrenic and hypoglossal nerve pacing therapies have shown benefit in sleep apnea. We sought to analyze the role of pacing therapies in sleep apnea and their impact on heart failure. METHODS: A comprehensive literature search in PubMed and Google Scholar from inception to August 5, 2019, was performed. A meta-analysis was performed using fixed effects model to calculate mean difference (MD) with 95% confidence interval (CI). RESULTS: Six studies were eligible and included 626 patients, of whom 334 were in the control arm and 393 were in the experimental arm. Phrenic nerve pacing (MD - 23.20 events/h, 95% CI - 27.96 to - 18.44, p < 0.00001) and hypoglossal nerve pacing (MD - 20.24 events/h, 95% CI - 23.22 to - 17.27, p < 0.00001) were associated with improvements in apnea-hypopnea index (AHI). Phrenic nerve pacing was associated with a trend towards improvements in left ventricular ejection fraction (MD 3.95%, 95% CI - 0.04 to 7.94, p = 0.05). Hypoglossal and phrenic nerve pacing were associated with improvements in the quality of life as assessed by improvements in Epworth sleepiness scale (MD 3.71 points, 95% CI 2.89 to 4.54, p < 0.00001). CONCLUSIONS: Our analysis suggests that phrenic and hypoglossal nerve pacing improves AHI and quality of life with a trend towards improvement in left ventricular ejection fraction, especially in central sleep apnea. Complications were high but future refinement in technology will likely improve clinical outcomes and minimize complications.

Evaluating the role of transesophageal echocardiography (TEE) or intracardiac echocardiography (ICE) in left atrial appendage occlusion: a meta-analysis.

PURPOSE: Intracardiac echocardiography (ICE) is increasingly common among periprocedural imaging modalities used during complex cardiac procedures. We sought to perform a meta-analysis comparing transesophageal echocardiography (TEE) and ICE in endocardial left atrial appendage occlusion (LAAO). METHODS: We searched PubMed and Google Scholar regarding abstracts and manuscripts using keywords: atrial fibrillation, left atrial appendage occlusion, Watchman, Amplatzer Cardiac Plug, Amulet, intracardiac echocardiography, and transesophageal echocardiography from their inception to July 12, 2019. Data extraction was performed using standard form for the following: title, year of publication, sample size, comorbid conditions, LAAO device, type of pre-procedural imaging, intraprocedural imaging, and clinical outcomes including the following: acute procedural success, fluoroscopy, and total procedure time and complications. RESULTS: A total of 42 relevant studies were screened resulting in inclusion of 8 observational studies comparing TEE and ICE in endocardial LAAO. Outcomes assessed including procedural success (RR 1.00, 95% CI (0.97-1.03, p = 0.98)), complications (RR 0.77, 95% CI (0.52 to 1.15, p = 0.20)), fluoroscopy time (mean difference - 0.40, 95% CI (-3.12-2.32, p = 0.77)), and procedural time (mean difference - 8.02, 95% CI (-22.81 to 6.76, p = 0.29)) were found to be similar between both groups. CONCLUSIONS: While TEE is the gold standard for perioperative imaging with LAAO, ICE is a feasible and safe alternative that reduces exposure to general anesthesia and associated potential risks.

Left Atrial Appendage Occlusion Device Embolization (The LAAODE Study): Understanding the Timing and Clinical Consequences from a Worldwide Experience.

BACKGROUND: Left atrial appendage occlusion device embolization (LAAODE) is rare but can have substantial implications on patient morbidity and mortality. Hence, we sought to perform an analysis to understand the timing and clinical consequences of LAAODE. METHODS: A comprehensive search of PubMed and Web of Science databases for LAAODE cases was performed from October 2nd, 2014 to November 1st, 2017. Prior to that, we included published LAAODE cases until October 1st, 2014 reported in the systematic review by Aminian et al. RESULTS: 103 LAAODE cases including Amplatzer cardiac plug (N=59), Watchman (N=31), Amulet (N=11), LAmbre (N=1) and Watchman FLX (N=1) were included. The estimated incidence of device embolization was 2% (103/5,000). LAAODE occurred more commonly in the postoperative period compared with intraoperative (61% vs. 39%). The most common location for embolization was the descending aorta 30% (31/103) and left atrium 24% (25/103) followed by left ventricle 20% (21/103). Majority of cases 75% (77/103) were retrieved percutaneously. Surgical retrieval occurred most commonly for devices embolized to the left ventricle, mitral apparatus and descending aorta. Major complications were significantly higher with postoperative LAAODE compared with intraoperative (44.4% vs. 22.5%, p=0.03). CONCLUSIONS: LAAODE is common with a reported incidence of 2% in our study. Post-operative device embolization occurred more frequently and was associated with a higher rate of complications than intraoperative device embolizations. Understanding the timings and clinical sequelae of DE can aid physicians with post procedural follow-up and also in the selection of patients for these procedures.

Diagnostic Utility of Smartwatch Technology for Atrial Fibrillation Detection - A Systematic Analysis.

BACKGROUND: Smartphone technologies have been recently developed to assess heart rate and rhythm, but their role in accurately detecting atrial fibrillation (AF) remains unknown. OBJECTIVE: We sought to perform a meta-analysis using prospective studies comparing Smartwatch technology with current monitoring standards for AF detection (ECG, Holter, Patch Monitor, ILR). METHODS: We performed a comprehensive literature search for prospective studies comparing Smartwatch technology simultaneously with current monitoring standards (ECG, Holter, and Patch monitor) for AF detection since inception to November 25th, 2019. The outcome studied was the accuracy of AF detection. Accuracy was determined with concomitant usage of ECG monitoring, Holter monitoring, loop recorder, or patch monitoring. RESULTS: A total of 9 observational studies were included comparing smartwatch technology, 3 using single-lead ECG monitoring, and six studies using photoplethysmography with routine AF monitoring strategies. A total of 1559 patients were enrolled (mean age 63.5 years, 39.5% had an AF history). The mean monitoring time was 75.6 days. Smartwatch was non-inferior to composite ECG monitoring strategies (OR 1.06, 95% CI 0.93 - 1.21, p=0.37), composite 12 lead ECG/Holter monitoring (OR 0.90, 95% CI 0.62 - 1.30, p=0.57) and patch monitoring (OR 1.28, 95% CI 0.84 - 1.94, p=0.24) for AF detection. The sensitivity and specificity for AF detection using a smartwatch was 95% and 94%, respectively. CONCLUSIONS: Smartwatch based single-lead ECG and photoplethysmography appear to be reasonable alternatives for AF monitoring.

Radiofrequency Energy Applications Targeting Significant Residual Leaks After Watchman Implantation: A Prospective, Multicenter Experience.

OBJECTIVES: The aim of this study was to evaluate the efficacy of radiofrequency (RF) energy applications targeting the atrial side of a significant residual leak in patients with acute and chronic evidence of incomplete percutaneous left atrial appendage (LAA) occlusion. BACKGROUND: RF applications have been proved to prevent recanalization of intracranial aneurysms after coil embolization, thereby favoring complete sealing. From a mechanistic standpoint, in vitro and in vivo experiments have demonstrated that RF promotes collagen deposition and tissue retraction. METHODS: Forty-three patients (mean age 75 ± 7 years mean CHA2DS2-VASc score 4.6 ± 1.4, mean HAS-BLED score 4.0 ± 1.1) with residual leaks ≥4 mm after Watchman implantation were enrolled. Procedural success was defined as complete LAA occlusion or presence of a mild or minimal (1- to 2-mm) peridevice leak on follow-up transesophageal echocardiography (TEE), which was performed approximately 45 days after the procedure. RESULTS: RF-based leak closure was performed acutely after Watchman implantation in 19 patients (44.2%) or scheduled after evidence of significant leaks on follow-up TEE in 24 others (55.8%). The median leak size was 5 mm (range: 4-7 mm). On average, 18 ± 7 RF applications per patient (mean maximum contact force 16 ± 3 g, mean power 44 ± 2 W, mean RF time 5.1 ± 2.5 minutes) were performed targeting the atrial edge of the leak. Post-RF median leak size was 0 mm (range: 0-1 mm). A very low rate (2.3% [n = 1]) of major periprocedural complications was observed. Follow-up TEE revealed complete LAA sealing in 23 patients (53.5%) and negligible residual leaks in 15 (34.9%). CONCLUSIONS: RF applications targeting the atrial edge of a significant peri-Watchman leak may promote LAA sealing via tissue remodeling, without increasing complications. (RF Applications for Residual LAA Leaks [REACT]; NCT04726943).

Pacing Therapies for Vasovagal Syncope.

Vasovagal Syncope (VVS) is mediated by a cardiac autonomic reflex with resultant bradycardia and hypotension, precipitating syncope. While benign and mostly well controlled, recurrent VVS can be debilitating and warrants intervention. Non-pharmacological management of VVS have had variable success. In patients with recurrent cardioinhibitory VVS, permanent pacing can be effective. The utility of pacing to preempt the syncopal depends on the prominent temporal role of bradycardia during the vasovagal reflex. Current guidelines recommend pacing as a therapy to consider in older patients with recurrent VVS. Although younger patients can benefit, one should be cautious given the long-term risk of complications. Available data appears to favor a dual chamber pacemaker with closed loop stimulation algorithm to prevent recurrent cardioinhibitory VVS. Several aspects, including mechanistic understanding of VVS and appropriate patient selection, remain unclear, and require further study.

Cutaneous Conundrums in Cardiac Sarcoidosis: A Series on Skin Disease in Immunosuppression.

Sarcoidosis is a complex systemic condition resulting in formation of non-caseating granulomas. Infiltrative disease in cardiac sarcoidosis can have significant ramifications on mortality and is one of the few indications for systemic immunosuppressive therapy. In the patient on immunosuppressive medication, resultant sequelae such as skin and soft tissue infections are common and must be differentiated from cutaneous forms of sarcoidosis and other skin pathologies. Patients with humoral or cellular immunodeficiencies may have cutaneous lesions secondary to endemic fungi, mycobacterium, viral diseases, parasites, or encapsulated organisms. We report a rare case of cardiac sarcoidosis on immunosuppressive therapy, with a series of cutaneous sequelae due to opportunistic infection.

Cerebral Salt Wasting in Traumatic Brain Injury Is Associated with Increased Morbidity and Mortality.

INTRODUCTION: In the setting of cerebral injury, cerebral salt wasting (CSW) is a potential cause of hyponatremia, which contributes to adverse effects and mortality. OBJECTIVE: The primary objective of this study was to evaluate the clinical outcomes of severe traumatic brain injury (TBI) patients complicated by CSW. METHODS: A retrospective data analysis was performed on data collected from patients with TBI with an abbreviated injury scale (AIS) greater than 3. Data was divided into 2 groups of patients with CSW and those without. The primary endpoint was incidence of adverse effects of CSW in regard to injury severity score (ISS), hospital length of stay (HLOS), ventilator days, ICU length of stay (ICU LOS) and survival to discharge. Data was analyzed using a one-way analysis of variance (ANOVA). RESULTS: A total of 310 consecutive patients with severe head injury (anatomic injury score 3 or greater) were evaluated over a 3-year period. A total of 125 of the 310 patients (40%) were diagnosed with cerebral salt wasting as defined by hyponatremia with appropriate urinary output and salt replacement. Patients with CSW had poorer outcomes in regard to ISS (21.8 vs 14.2, p<0.0001), HLOS (14.1 vs 3.5, p<0.0001), ventilator days (5.0 vs 0.45, p<0.0001), ICU LOS (8.5 vs 1.6, p<0.0001), and survival to discharge (88% vs 99%, p<0.0001). DISCUSSION: Common adverse effects of CSW were noted in this study. Patients with TBI have a predilection towards development of CSW and consequently have poorer outcomes including increased morbidity and mortality. Data is sparse on the duration of CSW and degree of hyponatremia over time. Larger, comparative studies need to be performed to investigate the hyponatremic patient population and the clinical outcomes of those who present with CSW.

Implantable loop recorders for cardiac dysrhythmia monitoring.

Incorporation of technological advances in healthcare delivery has played a foundational role in development of modern healthcare. With the use of wireless transmission in conjunction with digitization of electrocardiography, continuous monitoring strategies have redefined our approach to dysrhythmia. These devices show promising results in evolving implantable loop recorder technology. In this review, we summarize the history of remote monitoring, indications for loop recorders, devices available, evidence for specific devices and anticipated studies.

Comparison of the safety and efficacy of Nanostim and Micra transcatheter leadless pacemaker (LP) extractions: a multicenter experience.

PURPOSE: Leadless pacemaker (LP) extraction is a relatively new field with limited operator experience. We sought to report a comparison of retrieval process for Nanostim vs Micra transcatheter LPs. METHODS: The list of retrievals for the Micra transcatheter pacemaker system (TPS) was obtained from Medtronic whereas Nanostim data was obtained from centers that participated in the Leadless II study. Details of retrieval such as indication, days post implantation, complications, and post procedure device management were obtained from the manufacturer database for each site, and any missing details were obtained from individual operators. Extractions performed on the same day were labeled as "Early" and thereafter were labeled as "Late." RESULTS: A total of 113 retrievals were attempted (73 in Nanostim and 40 in Micra TPS). The most common reasons for retrieval were battery advisory and inadequate pacing threshold (n = 16) for Nanostim and Micra, respectively. Success rate in Nanostim group was around 90% (66/73) compared with 100% in Micra group (p = 0.049). Late retrieval occurred in 50% of Micra TPS cases (20/40) compared with 100% of Nanostim LP cases. Median time to extraction was 46 days for Micra TPS and 256 days for Nanostim LP (p < 0.001). Rate of serious adverse events with Nanostim extraction was 3% (n = 2/73). CONCLUSION: Overall, LP extraction is feasible and safe to perform irrespective of the duration and type of the device.

Role of the Left Atrial Appendage in Systemic Homeostasis, Arrhythmogenesis, and Beyond.

The left atrial appendage (LAA) affects body homeostasis via atrial natriuretic peptide and the renin-angiotensin-aldosterone system and plays an important role in atrial compliance. Approximately 90% of clots in nonvalvular atrial fibrillation (AF) are formed in the LAA. AF is the most common sustained cardiac arrhythmia and is frequently associated with stroke. Because anticoagulation for stroke prophylaxis carries a higher bleeding risk, LAA closure via epicardial and endocardial approaches has gained popularity and is being increasingly pursued for arrhythmogenic, homeostatic, and stroke-reduction benefits. This review discusses the homeostatic role of the LAA and its involvement in arrhythmogenesis and thrombus formation.

Epicardial versus Endocardial Closure: Is One Better than the Other?

Left atrial appendage occlusion is an evolving technology with demonstrable benefits of stroke prophylaxis in patients with atrial fibrillation unsuitable for anticoagulation. This has resulted in the development of a plethora of transcatheter devices to achieve epicardial exclusion and endocardial occlusion. In this review, the authors summarize the differences in technique, target patient population, outcomes, and complication profiles of endocardial and epicardial techniques.