Linda Koutbi

Novel Electromyographic Monitoring Technique for Prevention of Right Phrenic Nerve Palsy During Cryoballoon Ablation

Background—Right phrenic nerve palsy (PNP) is the most frequent complication of cryoballoon ablation. Diaphragmatic electromyography can predict PNP with a comfortable safety margin. Our goal was to evaluate the feasibility, efficacy, and safety of electromyography-guided PN monitoring using a novel hepatic vein approach for prevention of PNP. Methods and Results—This study includes 57 patients (47 males) indicated for cryoballoon ablation for treatment of atrial fibrillation. During right superior pulmonary vein ablation, the PN was paced at 60 beats per minute and diaphragmatic compound motor action potential (CMAP) amplitude was recorded via a quadripolar catheter positioned in a subdiaphragmatic hepatic vein. If a 30% drop in CMAP amplitude was observed, ablation was discontinued with forced deflation. Reliable recording of CMAP before ablation was feasible in 50 of 57 patients (88%). In 7 patients (12%), stable PN pacing could not be achieved. In 44 of 50 patients, CMAP amplitude remained constant during cryoapplication. The mean value of CMAP amplitude was 639.7±240.5 µV; mean variation was 13±4.3%. In 6 of 50 patients (12%) including 5 treated with a 23-mm cryoballoon and 1 with a 28-mm cryoballoon, the 30% reduction cutoff was reached and cryoablation was discontinued. Recovery of CMAP amplitude after discontinuing cryoablation took <60 seconds in all cases. No PNP or complication related to PN monitoring occurred. Conclusions—Recording of diaphragmatic CMAP using a catheter positioned in a subdiaphragmatic hepatic vein seems feasible during cryoballoon ablation. Electromyography-guided PN monitoring seems safe and potentially helpful for prevention of PNP.

Extraction of transvenous leads in the operating room versus electrophysiology laboratory: A comparative study

BACKGROUND Although risks and life-threatening complications associated with lead extraction are well characterized, practice patterns vary regarding whether procedures are performed in an operating room (OR) or electrophysiology (EP) laboratory with cardiothoracic surgical backup. OBJECTIVE Our objective was to compare procedural outcomes and complications associated with lead extraction in the OR vs. EP laboratory. METHODS Prospectively acquired data were pooled from 2 referral centers. Lead extraction procedures were performed between 2000 and 2010, encompassing a transition phase from the OR to EP laboratory. Analyses were conducted using generalized estimating equations. RESULTS A total of 1,364 leads (533 OR; 831 EP laboratory) were targeted in 684 consecutive procedures, 41.2% of which were in the OR. Laser sheaths and snares were used for 699 (51.2%) and 101 (7.4%) leads, respectively. Overall, 775 (93.1%) vs. 487 (91.4%) leads were completely extracted in the EP laboratory vs. OR [odds ratio 1.3, 95% confidence interval 0.9 to 2.1]. Complications occurred in 2.24% vs. 2.84%, respectively (P = .431). Two patients died because of superior vena caval lacerations (0.29%), 1 in each group. Rapid surgical intervention was helpful in 6 (0.9%) patients [4 OR (2 subclavian vein lacerations, 1 tricuspid valve laceration, 1 tamponade); 2 EP laboratory (tamponades)], with subsequently favorable outcomes. The only independent predictor of complications was older lead age [odds ratio 1.11 per year, 95% confidence interval 1.02 to 1.20]. CONCLUSION Lead extraction in the EP laboratory with surgical backup is associated with a similarly low rate of complications and mortality as procedures performed in the OR.

Electromyographic monitoring for prevention of phrenic nerve palsy in second-generation cryoballoon procedures.

Background—Electromyography-guided phrenic nerve (PN) monitoring using a catheter positioned in a hepatic vein can aid in preventing phrenic nerve palsy (PNP) during cryoballoon ablation for atrial fibrillation. We wanted to evaluate the feasibility and efficacy of PN monitoring during procedures using second-generation cryoballoons. Methods and Results—This study included 140 patients (43 women) in whom pulmonary vein isolation was performed using a second-generation cryoballoon. Electromyography-guided PN monitoring was performed by pacing the right PN at 60 per minute and recording diaphragmatic compound motor action potential (CMAP) via a quadripolar catheter positioned in a hepatic vein. If a 30% decrease in CMAP amplitude was observed, cryoapplication was discontinued with forced deflation to avoid a PNP. Monitoring was unfeasible in 8 of 140 patients (5.7%), PNP occurred in 1. Stable CMAP amplitudes were achieved before ablation in 132 of 140 patients (94.3%). In 18 of 132 patients (13.6%), a 30% decrease in CMAP amplitude occurred and cryoablation was discontinued. Each time, recovery of CMAP amplitude took <60 s. In 9 of 18 cases, a second cryoapplication in the same pulmonary vein was safely performed. We observed no PNP or complication related to electromyography-guided PN monitoring. Conclusions—Electromyography-guided PN monitoring using a catheter positioned in a hepatic vein seems feasible and effective to prevent PNP during cryoballoon ablation using second-generation cryoballoon.

Vagal Reactions during Cryoballoon-Based Pulmonary Vein Isolation: A Clue for Autonomic Nervous System Modulation?

Although paroxysmal atrial fibrillation (AF) is known to be initiated by rapid firing of pulmonary veins (PV) and non-PV triggers, the crucial role of cardiac autonomic nervous system (ANS) in the initiation and maintenance of AF has long been appreciated in both experimental and clinical studies. The cardiac intrinsic ANS is composed of ganglionated plexi (GPs), located close to the left atrium-pulmonary vein junctions and a vast network of interconnecting neurons. Ablation strategies aiming for complete PV isolation (PVI) remain the cornerstone of AF ablation procedures. However, several observational studies and few randomized studies have suggested that GP ablation, as an adjunctive strategy, might achieve better clinical outcomes in patients undergoing radiofrequency-based PVI for both paroxysmal and nonparoxysmal AF. In these patients, vagal reactions (VR) such as vagally mediated bradycardia or asystole are thought to reflect intrinsic cardiac ANS modulation and/or denervation. Vagal reactions occurring during cryoballoon- (CB-) based PVI have been previously reported; however, little is known on resulting ANS modulation and/or prevalence and significance of vagal reactions during PVI with the CB technique. We conducted a review of prevalence, putative mechanisms, and significance of VR during CB-based PVI.

Hyperpnea test triggering malignant ventricular arrhythmia in a child with early repolarization

Introduction Syncope is common in children and adolescents. Most cases involve reflex syncope, but a few may have potentially life-threatening causes. In this regard, recent studes linked early repolarization (ER) in the inferior leads f standard electrocardiogram to an increased risk of rrhythmic sudden cardiac death in middle-aged subects. 4 This report describes syncope associated with R in a child in whom malignant ventricular arrhythmia as elicited by the hyperpnea test during electroencephlography (EEG).

Ventricular Arrhythmia Occurrence and Compliance in Patients Treated With the Wearable Cardioverter Defibrillator Following Percutaneous Coronary Intervention

BACKGROUND The wearable cardioverter defibrillator (WCD) is a life-saving therapy in patients with high risk of arrhythmic death. We aimed to evaluate ventricular arrhythmia (VA) occurrence rate and compliance with the WCD during the first 90 days following myocardial revascularisation with percutaneous coronary intervention (PCI) in patients with left ventricular ejection fraction (LVEF) <30%. METHODS From September 2015 to November 2016, clinical characteristics, WCD recordings and compliance data of the aforementioned subset of patients were prospectively collected. RESULTS Twenty-four patients (men=20, 80%) were included in this analysis. Mean age was 56±10 years and mean LVEF at enrolment was 26.6±4.3%. During a mean wearing period of 3.0±1.3 months, two episodes of VA occurred in two patients (8.3%): one successfully treated with WCD shock and one with spontaneous termination. The mean and median daily use of the WCD was 21.5hours and 23.5hours a day, respectively. Eighteen patients (75%) wore the WCD more than 22hours a day. CONCLUSIONS The rate of VA, during the WCD period use after myocardial revascularisation with PCI, was high in our study. Otherwise it underlined that patient compliance is critical during the WCD period use. Remote monitoring and patient education are keys to achieve good compliance.

Theophylline as an adjunct to control malignant ventricular arrhythmia associated with early repolarization

Early repolarization (ER) has been associated with an increased risk of sudden cardiac arrest. Interestingly, ventricular arrhythmias seem to be triggered by parasympathetic stimulation. In the present case report, we describe complete control of highly frequent malignant ventricular arrhythmias after adding theophylline to ineffective oral hydroquinidine and high‐rate pacing in a patient suffering from malignant ER. We hypothesize that the theophylline‐mediated enhanced beta‐adrenergic stimulation could reduce the transmural myocardial voltage discrepancy by increasing the inward ICa,L current.

High-density mapping for catheter ablation of premature ventricular complexes originating from left ventricular papillary muscles: A case series

Ablation of premature ventricular complexes (PVCs) originating from left‐sided papillary muscles is challenging. We tested a new approach by performing high‐density mapping of PVC.

Comparison of epicardial vs. endocardial reimplantation in pacemaker-dependent patients with device infection

Aims Reimplantation of cardiac implantable electronic devices (CIEDs) after extraction due to device infection is a major issue in pacemaker-dependent patients. We compared in-hospital and long-term outcomes with two techniques: epicardial reimplantation (EPI) before CIED extraction and temporary pacing (TP) with a view to delayed endocardial reimplantation. Methods and results Two cohorts of consecutive pacemaker-dependent patients who underwent transvenous lead extraction at our tertiary centre were included in this retrospective cohort study. According to successive policies, either the EPI or the TP approach was used. In-hospital complications occurred at similar rates in the EPI (n = 59) and TP (n = 52) cohorts (37.3% vs. 32.7%, respectively; P = 0.61). Thirteen (25.0%) patients in the TP cohort eventually were reimplanted epicardially, mainly because of infection of the temporary lead. Finally, 65 patients were discharged with an epicardial device and 37 with an endocardial device. Median follow-up was 41.7 (interquartile range 34.1-51.5) months. No difference was observed in long-term mortality according to the reimplantation strategy, but use of TP was associated with a reduced risk of late endocarditis and device reintervention (hazard ratio (HR) 0.25, 95% confidence interval (CI) 0.09-0.069, P = 0.01), whereas epicardial device reimplantation was associated with an increased risk (HR 3.62, 95% CI 1.07-12.21, P = 0.04). Conclusion We observed similar in-hospital outcomes in our EPI and TP cohorts. Twenty-five percent of the patients initially paced by a TP strategy finally needed an epicardial device, mainly because of infection of their TP lead. Use of TP resulted in lower rates of late endocarditis and device reintervention.

Ablation of idiopathic ventricular tachycardia arising from posterior mitral annulus in an 11-month-old infant by transapical left ventricular access via median sternotomy

Case report An 11-month-old boy with an unremarkable medical record was referred to our institution for treatment of sustained VT leading to dilated cardiomyopathy (left ventricular ejection fraction [LVEF] 33%). On admission, 12-lead electrocardiogram (ECG) revealed broad tachycardia (QRS duration 130 ms, cycle length 300 ms), AV dissociation, and positive concordance pattern from lead V1 to V6 (Figure 1). Initial medical treatment using a combination of antiarrhythmic drugs including amiodarone failed to resolve the VT. On day 15 of treatment, cardiac function deteriorated suddenly, with 3 reversible cardiac arrests. Cardiogenic shock developed and required emergency mechanical circulatory assistance using venoarterial extracorporeal membrane oxygenation (ECMO) by peripheral cervical cannulation through the right internal jugular and common carotid artery. Cardiac monitoring during ECMO demonstrated incessant VT despite general anesthesia condition. Major left ventricular dysfunction developed with LVEF 25%. Cessation of VT was observed only during hypothermia or for a few seconds after administration of