Bilateral Cardiac Sympathetic Denervation for Refractory Multifocal Premature Ventricular Contractions in Patients With Nonischemic Cardiomyopathy.

BACKGROUND: Bilateral cardiac sympathetic denervation (BCSD) for refractory life-threatening ventricular arrhythmias is a neuromodulatory intervention targeting sympathetically driven focal or re-entrant ventricular arrhythmias. OBJECTIVES: This study sought to provide a more complete and successful option for intervention in patients in whom premature ventricular contraction (PVC) ablation is not feasible or has been unsuccessful. METHODS: A total of 43 patients with >5% PVC burden and concomitant nonischemic cardiomyopathy (NICM) who previously failed medical and ablation therapies were referred for BCSD. All patients underwent bilateral video-assisted thoracoscopic surgical approach with T1-T4 sympathectomy. Primary effectiveness endpoints were postprocedural PVC burden resolution, improvement in left ventricular ejection fraction (LVEF), and cessation of antiarrhythmic drugs (AADs). Safety endpoints included peri- and postprocedural complications. Outcomes were assessed over a 1-year follow-up period. RESULTS: Among the 43 patients who underwent BCSD, the mean age was 52.3 ± 14.7 years, 69.8% of whom were male patients. Presenting mean LVEF was 38.7% ± 7.8%, and PVC burden was 23.7% ± 9.9%. There were significant reductions in PVC burden postprocedurally (1.3% ± 1.1% post-BCSD, compared with 23.7% ± 9.9% pre-BCSD, P < 0.001) and improvements in LVEF (46.3% ± 9.5% post-BCSD, compared with 38.7% ± 7.8% pre-BCSD, P < 0.001). The rate of ICD therapies decreased from 81.4% (n = 35) to 11.6% (n = 5) (P < 0.001), leading to a significant reduction in use of AADs (100.0% to 11.6%, P < 0.001) and improvement in mean NYHA functional class (2.5 ± 0.5 to 1.4 ± 0.2, P < 0.001). Major intraoperative complications were seen in 4.7% of patients (hemothorax and chylothorax). Of the patients, 81.4% (n = 35) experienced no mortality or major complications over a 1-year follow-up period, with the remaining still within their first year postprocedure. CONCLUSIONS: BCSD is effective for the management of refractory PVCs and ventricular tachycardia who have failed previous ablation therapy.

In-vivo evaluation of catheter integrity with the use of a novel catheter torque tool.

INTRODUCTION: Electrophysiology studies and ablation procedures require strength, steadiness, and dexterity to manipulate catheters. We have previously described a novel catheter torque tool (Peritorq) that improves torqueability and stability and decreases user muscle fatigue. The objective was to evaluate measures of catheter integrity with and without the torque tool in place using multiple diagnostic and ablation catheters in an adult porcine model. METHODS: Diagnostic and ablation catheters were inserted through the femoral or jugular vein into areas of the right atrium, coronary sinus (CS), and right ventricle. Electrical measurements including impedance, sensing, and capture thresholds were obtained with and without the torque tool. Ablation lesions (30 s) were given at different locations using both irrigated and nonirrigated catheters and measurements were recorded with and without the torque tool. RESULTS: Procedures were performed in eight adult pigs. Measurements with and without the torque tool in all locations did not differ significantly using any of the catheters. With the nonirrigated ablation catheter there was a significant difference in maximum (mean 1.7 W, p = .03) and average power (mean 9.1 W, p = .04) delivery at the PS tricuspid valve, but there were no other differences with the irrigated or nonirrigated catheters. Subjective assessment by the operator revealed a substantial improvement in maneuverability, ability to transfer torque, and stability within the cardiac space. CONCLUSION: In an in-vivo environment, a novel catheter torque tool subjectively improved catheter manipulation and did not have a significant impact on the integrity of electrophysiologic catheters. Further study including additional catheters and in-vivo human testing is indicated.

Evaluation of Multimodality LAA Leak Closure Methods Following Incomplete Occlusion: The LAA Leak Study.

BACKGROUND: Incomplete left atrial appendage (LAA) closure is an evolving topic of clinical significance and thromboembolic potential, with recent long-term studies suggesting lower cutoffs for relevant leak size. OBJECTIVES: The aim of this prospective observational study was to assess 3 different closure techniques for persistent peridevice leaks after incomplete LAA closure and compare their efficacy and safety outcomes. METHODS: We studied 160 patients (mean age 72 ± 9 years; 71% men) who underwent 1 of the 3 available modalities (detachable embolization coils, vascular plugs or septal occluders, and radiofrequency ablation) for residual central or eccentric leak closure. Both acute postprocedural success (closure or <1-mm leak at the end of the procedure) and closure at 1-year follow-up transesophageal echocardiography imaging were evaluated. RESULTS: Of 160 patients, 0.6%, 41.3%, and 58.1% had mild (1-2 mm), moderate (3-5 mm), and severe (≥5 mm) leaks, respectively. Baseline LAA closure type was 72.5% Watchman FLX, 16.3% Lariat, 5.6% surgical ligation, 1.9% AtriClip, and 1.9% Amulet. Successful closure (0- or <1-mm leak) was seen in 100% of patients in all cohorts following intervention, with overall complete closure (0-1 mm) or mild or minimal leaks (1-2 mm) on 1-year follow-up transesophageal echocardiography seen in 100% of the atrial septal occluder or vascular plug cohort, 85.9% of the coil cohort, and 83.3% of the radiofrequency ablation cohort (P < 0.001). Two patients (1.3%) experienced cardiac tamponade, and there were no deaths or other complications. CONCLUSIONS: Peridevice leaks can safely and effectively be closed using 3 different modalities depending on size and location.

Muscle usage and workload assessment of cardiac ablation procedure with the use of a novel catheter torque tool in a pediatric simulator.

BACKGROUND: Cardiac ablation catheters are small in diameter and pose ergonomic challenges that can affect catheter stability. Significant finger dexterity and strength are necessary to maneuver them safely. We evaluated a novel torque tool to reduce muscle activation when manipulating catheters and improve perceived workload of ablation tasks. The objective was to evaluate measurable success, user perception of workload, and muscle usage when completing a simulated ablation task with and without the use of a catheter torque tool. METHODS: Cardiology attendings and fellows were fitted with surface electromyographic (EMG) sensors on 6 key muscle groups in the left hand and forearm. A standard ablation catheter was inserted into a pediatric cardiac ablation simulator and subjects navigated the catheter tip to 6 specific electrophysiologic targets, including a 1-min simulated radiofrequency ablation lesion. Time to complete the task, number of attempts required to complete the lesion, and EMG activity normalized to percentage of maximum voluntary contraction were collected throughout the task. The task was completed 4 times, twice with and twice without the torque tool, in semi-randomized order. A NASA Task Load Index survey was completed by the participant at the conclusion of each task. RESULTS: Time to complete the task and number of attempts to create a lesion were not altered by the tool. Subjectively, participants reported a significant decrease in physical demand, effort, and frustration, and a significant increase in performance. Muscle activation was decreased in 4 of 6 muscle groups. CONCLUSION: The catheter torque tool may improve the perceived workload of cardiac ablation procedures and reduce muscle fatigue caused by manipulating catheters. This may result in improved catheter stability and increased procedural safety.

Emerging role of artificial intelligence in cardiac electrophysiology.

Artificial intelligence (AI) and machine learning (ML) have significantly impacted the field of cardiovascular medicine, especially cardiac electrophysiology (EP), on multiple fronts. The goal of this review is to familiarize readers with the field of AI and ML and their emerging role in EP. The current review is divided into 3 sections. In the first section, we discuss the definitions and basics of AI, ML, and big data. In the second section, we discuss their application to EP in the context of detection, prediction, and management of arrhythmias. Finally, we discuss the regulatory issues, challenges, and future directions of AI in EP.

Exclusion of electrical and mechanical function of the left atrial appendage in patients with persistent atrial fibrillation: differences in efficacy and safety between endocardial ablation vs epicardial LARIAT ligation (the EXCLUDE LAA study).

BACKGROUND: Electrical isolation of the left atrial appendage (LAA) may provide incremental benefits for arrhythmia management in patients undergoing radiofrequency ablation (RFA) for persistent atrial fibrillation (AF). OBJECTIVE: The aim of this study was to compare efficacy and safety of endocardial ablation and LAA exclusion with LARIAT device for electrical and mechanical exclusion of LAA. METHODS: We compared patients who underwent endocardial LAA isolation during index RFA for persistent AF and underwent a repeat RFA to patients who underwent LAA exclusion with LARIAT device followed by RFA for AF in this multicenter registry. Efficacy of electrical and mechanical isolation of LAA was assessed. RESULTS: We included 182 patients of which 91 patients underwent endocardial LAA isolation during RFA for AF, and 91 patients underwent LAA exclusion with LARIAT device followed by RFA for AF. Baseline characteristics were similar except for higher CHA2DS2-VASc score, coronary artery disease, and prior stroke rate in LARIAT arm. Persistence of electrical isolation (measured at beginning of second procedure) after LARIAT procedure was higher than one-time AF-RFA (96.7% vs 52.8%, p < 0.01). Acute pulmonary vein isolation rates were similar in both arms. AF recurrence rate after second isolation attempts at 1 year was similar in both arms. No difference in major complications was noted between both arms. CONCLUSIONS: LAA exclusion with LARIAT device appears to be more efficacious as compared to one-time endocardial ablation, but not compared to repeat isolation, in achieving complete electrical isolation of LAA for persistent AF.

Temporal relationships between esophageal injury type and progression in patients undergoing atrial fibrillation catheter ablation.

BACKGROUND: Currently, little is known about the onset, natural progression, and management of esophageal injuries after atrial fibrillation (AF) ablation. OBJECTIVES: We sought to provide a systematic review on esophageal injury after AF ablation and identify temporal relationships between various types of esophageal lesions, their progression, and clinical outcomes. METHODS: A comprehensive search of PubMed and Web of Science was conducted until September 21, 2017. All AF ablation patients who underwent upper gastrointestinal endoscopy within 1 week of the procedure were included. Patients with esophageal lesions were classified into 3 types by using our novel Kansas City classification: type 1: erythema; type 2a: superficial ulcers; type 2b: deep ulcers; type 3a: perforation without communication with the atria; and type 3b: perforation with atrioesophageal fistula. RESULTS: Thirty studies met our inclusion criteria. Of the 4473 patients, 3921 underwent upper gastrointestinal evaluation. The overall incidence of esophageal injuries was 15% (570). There were 206 type 1 lesions (36%), 222 type 2a lesions (39%), and 142 type 2b lesions (25%). Six of 142 type 2b lesions (4.2%) progressed further to type 3, of which, 5 were type 3a and 1 was type 3b. All type 1 and type 2a and most type 2b lesions resolved with conservative management. One type 3a and 1 type 3b lesions were fatal. CONCLUSION: Based on our classification, all type 1 and most type 2 lesions resolved with conservative management. A small percentage (4.2% [6 of 142]) of type 2b lesions progressed to perforation and/or fistula formation, and these patients need to be followed closely.

Colchicine for prevention of post-cardiac procedure atrial fibrillation: Meta-analysis of randomized controlled trials.

BACKGROUND: Development of atrial fibrillation after certain cardiac procedures is a common medical problem. The inflammatory process plays an important role in the pathogenesis of post-cardiac procedure atrial fibrillation (PCP-AF). Colchicine, a potent anti-inflammatory agent, has been used in several studies to reduce the risk of PCP-AF. This meta-analysis of randomized controlled trials (RCTs) was conducted to assess the efficacy of colchicine in prevention of PC-PAF. METHODS: We searched PubMed, EMBASE, Web of Science, Cochrane Library database and Google Scholar for RCTs, using terms "Atrial fibrillation, atrial, or fibrillation and colchicine". The primary end-point was the occurrence of AF post cardiac procedure, which includes cardiac surgery or pulmonary vein isolation. The safety end point was the occurrence of any side effects. Estimated odds ratios (OR) and 95% confidence intervals (CI) were evaluated. RESULTS: A total of six RCTs were included in this meta-analysis, enrolling a total of 1257 patients. Colchicine significantly reduced the odds of PCP-AF (OR 0.52; 95% CI, 0.40-0.68, P<0.001, I2=0%). However, occurrence of side effects was significantly higher with colchicine when compared to placebo (OR 2.10; 95% CI, 1.34-3.30, P<0.001, I2=0%). The number needed to treat is 7 and the number needed to harm is 11.2. The proportion of patients discontinuing treatment was 16%. CONCLUSION: This meta-analysis shows that colchicine is an effective drug for prevention of PCP-AF. Colchicine could be considered as a prophylaxis to reduce PCP-AF, with some risk of treatment discontinuation due to the poor gastrointestinal tolerance (diarrhea).

Differences in complication rates between large bore needle and a long micropuncture needle during epicardial access: time to change clinical practice?

BACKGROUND: A dry epicardial access (EA) is increasingly used for advanced cardiovascular procedures. Conventionally used large bore needles (Tuohy or Pajunk needle; LBN) have been associated with low but definite incidence of major complications with EA. Use of micropuncture needle (MPN) may decrease the risk of complications. We intended to compare the outcomes of LBN with MPN for EA. METHODS AND RESULTS: We report a multicenter observational study of consecutive patients who underwent EA for ventricular tachycardia ablation or Lariat procedure using the LBN or MPN. Oral anticoagulation was stopped before the procedure. Baseline characteristics and procedure-related complications were collected and compared. Of the 404 patients, LBN and MPN were used in 46% and 54% of patients, respectively. There was no significant difference in the incidence of inadvertent puncture of myocardium between LBN and MPN (7.6% versus 6.8%, P=0.76). However, there was a significantly higher rate of large pericardial effusions with LBN compared with MPN (8.1% versus 0.9%; P<0.001). The incidence of pleural effusions were not significantly different between both (1.6% versus 2.3%; P=0.64). LBN group had an increase in other complications compared with MPN (open heart surgery to repair cardiac laceration [6 versus 0], injury to liver [1 versus 0], coronaries [1 versus 0], and superior epigastric artery requiring surgical exploration [0 versus 1]). CONCLUSIONS: The use of MPN is associated with decreased incidence of major complications, and the need for surgical repair and routine use should be considered for EA.

Initial real world experience with a novel insertable (Reveal LinQ(@Medtronic)) compared to the conventional (Reveal XT(@Medtronic)) implantable loop recorder at a tertiary care center - Points to ponder!

INTRODUCTION: Limited data is available regarding the novel Reveal LinQ (LinQ) which is a new generation implantable loop recorders (ILRs). METHODS: We performed a prospective, observational study of all consecutive patients undergoing conventional (Reveal XT; XT) and LinQ devices at our institution between January 2012 and December 2014. RESULTS: A total of 217 patients underwent ILR implantation. XT was implanted in 105 and LinQ in 112 patients. There were no significant differences in baseline characteristics between the two groups. LinQ implantation using the manufacturer's technique termed, "manufacturer's method" group had significantly higher incidence of pocket infection compared to XT (6/50, 12% vs 3/105, 3%, p=0.032). With modifications to the LinQ implantation technique (using a conventional scalpel and placing a suture when needed to the incision) termed "modified method" group, the rate of infection has decreased significantly compared to "manufacturer's method group" (0/62, 0% vs 6/50, 12%, p=0.004) (Table 3). In multivariate regression analysis, the only independent predictors of infection were younger age (OR 0.95; p=0.04), insertion of LinQ device (OR 30.02; p=0.006) and procedure time (OR 1.07; p=0.03). CONCLUSION: In our single-center, prospective, observational study we found that with the current implantable techniques, the novel insertable LinQ device is associated with increased risk of complications.

Role of yoga as an adjunctive therapy in patients with neurocardiogenic syncope: a pilot study.

BACKGROUND: Neurocardiogenic syncope (NCS) is a common clinical condition characterized by abrupt cardiovascular autonomic changes resulting in syncope. This is a recurring condition with mixed results from current strategies of treatment. METHODS: Subjects with a diagnosis of NCS were screened and enrolled. All the participants were given a DVD containing yoga videos and were instructed to practice yoga therapy for 60 min, three times a week for 3 consecutive months. Syncope functional status questionnaire score (SFSQS) was administered at the beginning and the end of the study. The subjects were followed for 3 months and underwent repeat tilt table testing at the end of the study. RESULTS: Of the 60 patients screened, 44 subjects were enrolled, 21 in the intervention group and 23 in the control group. Most of the participants were females, and the mean age was 21 ± 3 years. In the intervention group, who finished the yoga regimen, there was a statistically significant improvement from control phase to the intervention phase, in number of episodes of syncope (4 ± 1 vs 1.3 ± 0.7, p < 0.001) and presyncope (4.7 ± 1.5 vs 1.5 ± 0.5, p < 0.001). The mean SFSQS also decreased from 67 ± 7.8 to 29.8 ± 4.6 (p < 0.001). All subjects had positive head up tilt table (HUTT) study at the time of enrollment compared to only six patients at the completion of intervention phase (10/100 vs 6/28 %, p < 0.0001). CONCLUSION: Yoga therapy can potentially improve the symptoms of presyncope and syncope in young female patients with NCS.

Impact of left atrial appendage exclusion using an epicardial ligation system (LARIAT) on atrial fibrillation burden in patients with cardiac implantable electronic devices.

BACKGROUND: The left atrial appendage (LAA) is a well-known source of atrial arrhythmia and atrial fibrillation (AF). OBJECTIVE: The purpose of this study was to determine whether LAA exclusion using the LARIAT device would decrease AF burden. METHODS: A total of 50 patients with AF and cardiac implantable electronic devices who underwent successful LAA exclusion were enrolled in this prospective observational study. AF burden before LAA exclusion (baseline) and 3 and 12 months after exclusion was assessed by device interrogation. RESULTS: AF burden at 3-month follow-up (42% ± 34%) was significantly lower compared to baseline (76% ± 33%, P < .0001). The reduction in AF burden was sustained at 12 months (59% ± 26%, P < .001). Subgroup analysis revealed that AF burden at 3-month follow-up was similarly reduced in both paroxysmal AF (n = 19) and nonparoxysmal AF (n = 31). However, there was no reduction in AF burden in patients with paroxysmal AF at 12 months. AF burden in patients with known AF triggers in the LAA (n = 9) was significantly reduced at 3 months (52% ± 35%) and 12 months (42% ± 19%) compared to respective baseline (84 ± 31%, P < .0001). CONCLUSION: LAA exclusion appears to reduce AF burden. The presence of AF triggers in the LAA appears to be the strongest predictor of AF reduction. The study underscores the role of the LAA in arrhythmogenesis for AF and highlights the complementary role of LAA exclusion in restoration of normal sinus rhythm.

Elevated brain natriuretic peptide level in patients undergoing atrial fibrillation ablation: is it a predictor of failed ablation or a mere function of atrial rhythm and rate at a point in time?

BACKGROUND: Pre- and postablation atrial fibrillation (AF) brain natriuretic peptide (BNP) levels were shown to predict increased recurrence of AF following ablation. OBJECTIVE: Our objective was to assess whether elevated BNP levels merely represent the presence of AF at the time of measurement or indeed the true recurrence of AF. METHODS AND RESULTS: In a prospective study of 88 patients undergoing AF ablation, BNP levels were measured immediately before, after, 24 h, and 4-6 months postablation. BNP levels were stratified by presenting rhythm and ventricular rate at the time of measurement. Median BNP level preablation was higher in patients presenting in AF compared to sinus rhythm (SR) (54(44-79) pg/ml vs. 30(18-47) pg/ml, p < 0.001). Postablation restoration of SR in patients presenting in AF reduced median BNP levels from 54(44-79) pg/ml to 40(37-51) pg/ml, (p < 0.001). However, no change was noted in patients who presented in and maintained SR throughout the procedure (30(18-47) pg/ml to 27(16-40) pg/ml, p = 0.270). At 4-6 months, BNP measured in patients in SR was not significantly different from postablation BNP (35(22-53) pg/ml vs. 38(20-52) pg/ml, p = 0.656), although 35% of them had AF recurrence in 1-year follow-up. Median BNP level measured in five patients while in atrial arrhythmia was elevated compared to postablation BNP (464(421-464) pg/ml to 37(36-37) pg/ml, p = 0.043). BNP levels and ventricular rates are positively correlated at all times pre- and postablation. CONCLUSIONS: BNP level rises acutely during AF and with rapid ventricular rates. BNP level seems to be a function of atrial rhythm and ventricular rate rather than short- or long-term predictor of AF ablation success.