Introduction: Patients with hypertrophic cardiomyopathy (HCM) and atrial fibrillation (AF) require chronic anticoagulation due to a high thromboembolic risk. Evidence supporting use of non-vitamin K oral anticoagulants (NOACs) in patients with HCM remains sparse, and there are no data regarding the use of NOACs in HCM patients undergoing catheter ablation of AF. Methods: Observational non-randomised study in 4 European Centres. We aimed to investigate the safety and efficacy of NOACs compared with vitamin-K antagonists (VKAs) in patients with HCM undergoing catheter ablation for AF. Results: One hundred thirty-seven HCM patients (mean age 55.0±13.4, 29.1% female) underwent 230 catheter ablations for AF (1.7±1.0 per patient). A total of 55 patients (39.4%) underwent 70 procedures (30.4%) on NOAC, while the remaining were on VKA. Warfarin (97.6%) and rivaroxaban (56.4%) were the most frequently used agents in the respective groups. No procedure-related deaths were reported. We observed no significant difference in the rate of thromboembolism (VKA 0.6%; NOAC 0%; p=1.0) or minor bleeding (VKA 0.6%; NOAC 1.4%; p=0.54). There was a non-significant trend towards a lower incidence of major bleeding (VKA 6.8%; NOAC 1.4%; p=0.09). Conclusion: These preliminary data suggest that NOACs are at least as safe and effective as VKAs in patients with HCM undergoing catheter ablation for AF.
Cardiac pacing is the only effective therapy for patients with symptomatic brady-arrhythmia. Traditional right ventricular apical pacing causes electrical and mechanical dyssynchrony resulting in left ventricular dysfunction, recurrent heart failure and atrial arrhythmias. Physiological pacing activates the normal cardiac conduction thereby providing synchronized contraction of ventricles. Though His bundle pacing (HBP) acts as an ideal physiological pacing modality, it is technically challenging and associated with troubleshooting issues during follow up. Left bundle branch pacing (LBBP) has been suggested as an effective alternative to overcome the limitations of HBP as it provides low and stable pacing threshold, lead stability and correction of distal conduction system disease. This paper will focus on the implantation technique, troubleshooting, clinical implications and a review of published literature of LBBP
Irregular narrow QRS complex tachycardia with intermittent atrioventricular dissociation: What is the mechanism?Atsushi Doi, MD, PhD; Naoko Miyazaki, MD; Tomohiko Goda, MD; Haruya Yamane, MD; Kei Tanaka, MD; Ryo Araki, MD,PhD; Fumi Sato, MD, PhD; Takayuki Yamada, MD.Department of Cardiovascular Medicine, Otemae Hospital, 1-5-34 Otemae, Chuo-ku, Osaka, 540-0008, Japan.Correspondence to Atsushi Doi, MD, PhD. Department of Cardiovascular Medicine, Otemae Hospital, 1-5-34 Otemae, Chuo-ku, Osaka, 540-0008, Japan.Tel: 81-6-6941-0484, Fax: 81-6-6942-2848E-mail; [email protected]
Background Data on the optimal location of the ECG leads for the diagnosis of drug-induced long QT syndrome (diLQTS) with Torsades de Pointes (TdP) are lacking. Methods We systematically reviewed the literature for ECGs of patients with diLQTS and subsequent TdP. We assessed T-wave morphology in each lead and measured the longest QT interval in the limb and chest leads in a standardized fashion. Results Of 84 patients, 61.9% were female and mean age was 58.8 years. QTc was significantly longer in chest versus limb leads (mean (standard deviation) 671 (102) vs 655 (97) ms, p=0.02). Using only limb leads for QT interpretation, 18 (21.4%) ECGs were non-interpretable: 10 (11.9%) due to too flat T-waves, 7 (8.3%) due to frequent, early PVCs and 1 (1.2%) due to too low ECG recording quality. In the chest leads, ECGs were non-interpretable in 9 (10.7%) patients: 6 (7.1%) due to frequent, early PVCs, 1 (1.2%) due to insufficient ECG quality, 2 (2.4%) due to missing chest leads but none due to too flat T-waves. The most common T-wave morphologies in the limb leads were flat (51.0%), broad (14.3%) and late peaking (12.6%) T-waves. Corresponding chest lead morphologies were inverted (35.5%), flat (19.6%) and biphasic (15.2%) T-waves. Conclusions Our results indicate that QT evaluation by limb leads only underestimates the incidence of diLQTS experiencing TdP and favors the screening using both limb and chest lead ECG.
Background Atrial tachyarrhythmias (ATAs) are common within the three-month blanking period following catheter ablation of atrial fibrillation (AF). However, little evidence is available regarding the current guidelines on the blanking period after surgical AF ablation. We investigate the incidence and significance of early recurrence of atrial tachyarrhythmia (ERAT) and evaluate the optimal blanking period after surgical AF ablation. Methods Data from 259 patients who underwent surgical AF ablation from 2009 to 2016 were collected. ERAT was defined as documented ATA episodes lasting for 30 seconds. A multivariate Cox proportional hazard model was constructed to evaluate the role of ERAT as a predictor of late recurrences (LR) for AF. Results In total, 127 patients (49.0%) experienced their last episodes of ERAT during the first (n=65), second (n=14), or third (n=48) month of the three-month blanking period (p<0.001). One-year freedom from ATAs was 97.8% in patients without ERAT compared with 95.4%, 64.3%, and 8.3% in patients with ERAT in the first, second, and third month after the index procedure, respectively (p<0.001). Hazard ratios of LR according to the timing of the last episode of ERAT first, second, and third month after the procedure were 2.84, 16.70, and 119.75, respectively. Conclusions The ERAT occurred in 49.0% of patients within the first three months after surgical ablation. The occurrence of ERAT within three months after surgical AF ablation was a significant independent predictor of LR. Hence, the currently accepted three-month blanking period needs to be redefined in patients with AF surgical ablation.
To the Editor,We have read with great interest the article entitled ‘Management of Patients with Interrupted Inferior Vena Cava Requiring Electrophysiology Procedures’ by Hanley et al1 in the latest issue of the journal. We would like to thank the authors for their difficult case series with interrupted vena cava inferior and for successfully performed electrophysiologic studies. Electrophysiologic procedures including mapping and percutaneous catheter ablation of left-sided accessory pathways via the retrograde transaortic approach have been successfully applied techniques in patients with supraventricular tachycardia with and without Wolff-Parkinson-White electrocardiographic pattern for a long time.2 If no anatomic obstacles are found, a deflectable mapping catheter can easily be advanced from the femoral artery and positioned in the mitral annulus to localize the accessory pathway, even in patients with congenital anomalies.3 One should keep in mind that the retrograde transaortic approach has the potential adverse events related to percutaneous arterial access and tight contact with valvular leaflets although it seems as a simpler and less time consuming approach requiring less specialized equipment compared to the transseptal way.Mapping and percutaneous catheter ablation of the atrioventricular node or the His bundle can also be performed from the left side via the retrograde transaortic approach. Some electrophysiologists prefer the retrograde transaortic route as a first-line approach although most operators perform catheter ablation from the venous side.The electrophysiologists’ preferences are generally based on experience, familiarity with the equipment and the procedure, and personal thoughts about the patient.Keywords: ablation; left-sided; retrograde transaortic approach
Introduction: Early recurrence (ER) of atrial fibrillation (AF) is defined as the recurrence of atrial tachyarrhythmias within 3 months after AF ablation, however, this definition is based on data from the era of radiofrequency catheter ablation (RFCA), without contact force (CF) technology. We investigated the significance of ER as a risk factor for late recurrence (LR) in paroxysmal AF (PAF) patients treated with CF and non-CF-guided ablation. Methods and Results: We studied 395 patients with PAF who underwent RFCA. Of these, 97 patients underwent RFCA without CF technology (Non-CF group) and 298 underwent with CF technology (CF group). Over a 2-year post-ablation follow-up period, LR occurred in 54 of 97 (55.7%) patients in the Non-CF group, and in 105 of 298 (35.2%) patients in the CF group. ER had a more significant relationship with LR in the CF than in the Non-CF group, and all patients in the CF group with ER in the 3rd month developed LR. Conclusion: ER in PAF patients who have undergone CF-guided ablation have a greater risk of LR than those who have undergone non-CF-guided ablation. ER in the 3rd month after CF-guided ablation may indicate an absolute risk of LR. Blanking period could be defined as 2 months in the CF era.
In 1999, Paul Myles et al. published an important paper outlining the details of a novel assessment tool to measure patients’ quality of recovery (QoR) post-anesthesia and surgery. The following year, Paul Myles et al. published another article outlining the QoR-40. This study, as well as multiple other studies, further studied QoR-40’s validity, reliability, internal consistency, test-retest reliability, inter-rater reliability, and split-half coefficient.[1–3] It can be completed in a relatively short period (around five minutes).[3,4] However, its administration by the investigators provides more complete and timely data as compared to self-administration. It has been translated into multiple languages and validated by these languages as well. However, even though the QoR-40’s score has a maximum score of 200 with a range of 160, the minimal clinically important difference is only 4.8 units to translate into clinically relevant change. The difference between the mean QoR-40 scores post-cardiac surgery (with and without complications) was only four units while maintaining a wide standard deviation within groups.[5,6] QoR’s utility lies in its correlation with patient satisfaction as well as with another measure of patient well-being, the quality of life (QoL) score. Furthermore, the QoR-40’s score three days post-cardiac surgery correlated well with the SF-36’s measure of QoL 3 months after the operation. Hence QoR-40 is helpful in assess patient’s short-term prognosis. These findings hold even three years after the operation; however, the correlation level does decrease. In this issue of the journal of cardiovascular electrophysiology, Wasserlauf et al. utilized the QoR-40 to measure the impact of the anesthesia used during cryoballoon ablation of paroxysmal atrial fibrillation. Catheter ablation has become a common procedure for the management of paroxysmal atrial fibrillation with minor procedural complication. [10,11] Patients undergoing cryoballoon ablation for atrial fibrillation experience less pain than radiofrequency ablation. Multiple sedative modalities can be utilized for cardiac catheter ablation. One modality is the use of a light anesthetic: It alerts the physician of patient discomfort, it comforts the physician and nursing staff and carries a lower risk of drug overdose. However, it does increase the patients’ intraoperative motion. Other modalities include general anesthesia and deep sedation. However, it should be noted that conscious sedation does carry a risk of hypoventilation and aspiration.  In a previous study, no significant difference in complication rate was present following ventricular tachycardia ablation during minimal as compared to deep sedation.  Also, in another study, patients undergoing percutaneous epicardial access (for ventricular tachycardia or premature ventricular complex) had similar complication rates regardless of whether they did the procedure under general anesthesia or moderate/deep sedation.  Furthermore, in a study by Tang et al., patients who underwent non-conscious sedation during catheter ablation for atrial fibrillation had more transient anesthetic complications as compared to conscious sedation. However, these two groups did not reveal a difference in the procedure-related complication/success rates.  Finally, Wasserlauf et al. found moderate sedation to carry a lower procedure time without jeopardizing the complication and recurrence rate up to a median follow-up duration of 0.9 years. This paper studied patients undergoing cryoballoon ablation for paroxysmal atrial fibrillation. Given the previously reported evidence supporting the use of conscious anesthesia during atrial fibrillation catheter ablation, Wasserlauf et al. set on a task to expand our knowledge of patients’ tolerance of moderate sedation during cryoballoon ablation.  Consequently, they studied patients undergoing cryoballoon ablation for paroxysmal atrial fibrillation under general anesthesia or moderate sedation. Within 24 hours after the procedure, patients would provide the QoR-40 and their likelihood to recommend the procedure and sedation method. The mean QoR-40 was greater than 180 in the two groups with a difference of less than 5 unites. Furthermore, the difference in the QoR-40 scores was not statistically significant.  These scores were better than scores observed by Myles in minor surgeries (178 ± 17) and cardiac surgeries without complications (176 ± 16).  Moreover, patients reported a high satisfaction rate with a high likelihood to recommend the procedures (83% and 89%) and a high likelihood to recommend the sedation method (94% and 85%) depending on the sedation method (general anesthesia and moderate sedation respectively). However, the difference was not statistically significant. This result is similar to a previous study that found that 96% of patients would recommend radiofrequency ablation for atrial fibrillation. What these results mean is that they support the use of moderate sedation as compared to general anesthesia, given the similar patient experience, but different procedure time, expense, and possible complications from general anesthesia. This study, however, does have limitations. It was a single-center non-randomized study. The QoR-40 has sections that are heavily dependent on the medical center and staff; hence this is an important issue to consider. Furthermore, the assignment to anesthesia groups was not standardized, and the decision was dependent on physician and patient preference. Though understandable, the physician preference can be made to be dictated by a predefined set of criteria to minimize nonrandom assignment. Finally, we note that the QoR-40 scores presented by Wasserlauf et al. were the means and standard deviations.  When calculating the 95% confidence intervals of the difference of the mean QoR-40 scores of the two groups, we find that there is no statistically significant difference between the two groups.In conclusion, Wasserlauf et al. have added to our knowledge of cryoballoon ablation under moderate sedation which might become the more frequently adopted anesthesia strategy during AFib cryoablation.References:1. Myles PS, Hunt JO, Nightingale CE, et al. Development and psychometric testing of a quality of recovery score after general anesthesia and surgery in adults. Anesth Analg. 1999;88(1):83-90. doi:10.1097/00000539-199901000-000162. Myles PS, Weitkamp B, Jones K, Melick J, Hensen S. Validity and reliability of a postoperative quality of recovery score: The QoR-40. Br J Anaesth. 2000;84(1):11-15. doi:10.1093/oxfordjournals.bja.a0133663. Gornall BF, Myles PS, Smith CL, et al. Measurement of quality of recovery using the QoR-40: A quantitative systematic review. Br J Anaesth. 2013;111(2):161-169. doi:10.1093/bja/aet0144. Gower ST, Quigg CA, Hunt JO, Wallace SK, Myles PS. A comparison of patient self-administered and investigator-administered measurement of quality of recovery using the QoR-40. Anaesth Intensive Care. 2006;34(5):634-638. doi:10.1177/0310057x06034005145. Myles PS. Measuring quality of recovery in perioperative clinical trials. Curr Opin Anaesthesiol. 2018;31(4):396-401. doi:10.1097/ACO.00000000000006126. Myles PS. Clinically Important Difference in Quality of Recovery Scores. Anesth Analg. 2016;122(1):13-14. doi:10.1213/ANE.00000000000010607. Myles PS, Hunt JO, Fletcher H, Solly R, Woodward D, Kelly S. Relation between quality of recovery in hospital and quality of life at 3 months after cardiac surgery. Anesthesiology. 2001;95(4):862-867. doi:10.1097/00000542-200110000-000138. Myles PS, Viira D, Hunt JO. Quality of life at three years after cardiac surgery: Relationship with preoperative status and quality of recovery. Anaesth Intensive Care. 2006;34(2):176-183. doi:10.1177/0310057x06034002209. Wasserlauf, Jeremiah; Kaplan, Rachel; Walega, David; Arora, Rishi; Chicos, Alexandr; Kim, Susan; Lin, Albert; Verma, Nishant; Patil, Kaustubha; Knight, Bradley; Passman R. Patient-Reported Outcomes After Cryoballoon Ablation Are Equivalent Between Moderate Sedation And General Anesthesia. J Cardiovasc Electrophysiol. 2020.10. Chung MK, Refaat M, Shen WK, Kutyifa V, Cha YM, Di Biase L, Baranchuk A, Lampert R, Natale A, Fisher J, Lakkireddy DR. Atrial Fibrillation: JACC Council Perspectives. J Am Coll Cardiol. Apr 2020; 75 (14): 1689-1713.11. D’Avila A, Ptaszek LM, Yu PB, Walker JD, Wright C, Noseworthy PA, Myers A, Refaat M, Ruskin JN: Left Atrial-Esophageal Fistula After Pulmonary Vein Isolation. Circulation May 2007; 115(17): e432-3.12. Attanasio P, Huemer M, Shokor Parwani A, et al. Pain Reactions during Pulmonary Vein Isolation under Deep Sedation: Cryothermal versus Radiofrequency Ablation. PACE - Pacing Clin Electrophysiol. 2016;39(5):452-457. doi:10.1111/pace.1284013. Defaye P, Kane A, Jacon P, Mondesert B. Cryoballoon for pulmonary vein isolation: Is it better tolerated than radiofrequency? Retrospective study comparing the use of analgesia and sedation in both ablation techniques. Arch Cardiovasc Dis. 2010;103(6-7):388-393. doi:10.1016/j.acvd.2010.06.00414. Calkins H, Kuck KH, Cappato R, et al. 2012 HRS/EHRA/ECAS Expert Consensus Statement on Catheter and Surgical Ablation of Atrial Fibrillation: Recommendations for Patient Selection, Procedural Techniques, Patient Management and Follow-up, Definitions, Endpoints, and Research Trial Design. Heart Rhythm. 2012;9(4):632-696.e21. doi:10.1016/j.hrthm.2011.12.01615. Wutzler A, Mueller A, Loehr L, et al. Minimal and deep sedation during ablation of ventricular tachycardia. Int J Cardiol. 2014;172(1):161-164. doi:10.1016/j.ijcard.2013.12.17516. Killu AM, Sugrue A, Munger TM, et al. Impact of sedation vs. general anaesthesia on percutaneous epicardial access safety and procedural outcomes. Europace. 2018;20(2):329-336. doi:10.1093/europace/euw31317. Tang RB, Dong JZ, Zhao W Du, et al. Unconscious sedation/analgesia with propofol versus conscious sedation with fentanyl/midazolam for catheter ablation of atrial fibrillation: A prospective, randomized study. Chin Med J (Engl). 2007;120(22):2036-2038. doi:10.1097/00029330-200711020-0001818. Wasserlauf J, Knight BP, Li Z, et al. Moderate Sedation Reduces Lab Time Compared to General Anesthesia during Cryoballoon Ablation for AF Without Compromising Safety or Long-Term Efficacy. PACE - Pacing Clin Electrophysiol. 2016;39(12):1359-1365. doi:10.1111/pace.1296119. Ezzat VA, Chew A, McCready JW, et al. Catheter ablation of atrial fibrillation - Patient satisfaction from a single-center UK experience. J Interv Card Electrophysiol. 2013;37(3):291-303. doi:10.1007/s10840-012-9763-5
Catheter ablation is the current standard of care for the management of symptomatic atrial fibrillation (AFib) refractory to pharmacological therapy. One of the complications of this procedure is thermal injury to the esophagus due to its anatomical proximity to the posterior wall of the left atrium (1). Rarely (<1%), an atrioesophageal fistula can form connecting the lumen of damaged esophagus to the atrial chamber (2). This complication is almost always fatal and can result in exsanguination, air embolism, and sepsis (3, 4). With a growing number of catheter ablations being performed each year, the rate of atrioesophageal fistulas is only expected to rise (5). Other more frequent complications include esophageal wall erosions and ulcers (47%), and thermal injury to the vagus nerve plexus leading to esophageal dysmotility and gastroparesis (17%) (6, 7). Therefore, protecting the esophagus from thermal injuries is paramount in ablative procedures and several strategies have been devised to help mitigate this risk. Many physicians monitor the luminal esophageal temperature (LET) [ as a surrogate for intramural esophageal tissue temperature] with a single sensor or multisensor temperature probe and interrupt energy delivery when LET reaches 38°C or 39°C during radiofrequency ablation. However, this technique significantly impacts the procedural workflow due to the waiting periods for LET to return to baseline. Alternative strategies involve cooling of the esophagus with ice water or reducing the ablation lesion power, contact force and/or duration but this strategy may increase the chances for pulmonary vein reconnection (8). To that end, there has been a growing interest in mechanical devices capable of deflecting the esophagus away from the atrium protecting it from thermal injury.In the current issue of the Journal of Cardiovascular Electrophysiology, Houmsse et al. introduce a novel device capable of mobilizing the esophagus laterally to protect it from injury when performing catheter ablation for AFib. Although other devices have been developed and/or used for this purpose (such as the transesophageal echocardiography probe, endotracheal stylet, Esosure stylet and DV8 shaped balloon retractor), this is the only one to operate using vacuum suction allowing it to latch onto the esophageal wall. The device consists of four main components: outer extrusion, inner stacking plates, deflecting arm and control handle. The outer extrusion is inserted via a trochanter or a bougie into the esophagus and is the only portion of the retractor that comes in contact with the surrounding tissues. Small perforations at the distal end allow for vacuum suction to adhere to the esophagus and for a radiocontrast agent to be delivered to delineate the esophageal contour. The inner stacking plates are then introduced through the outer extrusion and are designed to allow movement of the deflecting arm in the medio-lateral plane only. The deflecting arm is connected to the distal end of the stacking plates through a pivot point and can be steered using the control handle. The authors have evaluated the effectiveness and safety of the device on canine and swine animal models by measuring the distance and direction of displacement of the esophagus, examining the cellular architecture after prolonged suction, measuring the LET, and assessing compatibility of device with electroanatomical mapping systems. A total of 68 deviations were performed on four canine models. The average rightward deflection was equal to 26.6 ± 2.5mm compared to 18.7 ± 2.3mm for the direct leftward deflection (p<0.001), and 96% of deviations did not have an esophageal trailing edge. With the exception of one study, the average distance displaced using the suction retractor was superior to other devices (9-13). The substantial distance of deflection and the minimal esophageal trailing edge significantly decreased the rise in LET from baseline (mean increase of 0.2°C vs 2.5°C without deflection). Examination of the esophageal tissue integrity following one hour of continuous suctioning revealed no change in the esophageal cellular architecture, and only minimal circular areas of hyperemia in mucosa due to the suction ports without injury to the muscularis layer. Finally, the retractor did not interfere with the electroanatomical mapping systems used (CARTO and EnSite).Despite its interesting findings, this study has several limitations that should be acknowledged. First, the study was performed on swine and canine animal models, which are known to have an anatomy close to humans; however, the safety profile of the device and its effectiveness in displacing the esophagus may not translate in humans. Second, subjects may exhibit symptoms secondary to extreme deviation of the esophagus in the absence of distortion of the cellular architecture. Clinical studies are needed to assess the safety profile and side effects of this esophageal retractor. Third, it is unclear whether these results would be reproducible under monitored anesthesia care. Finally, the fluoroscopic equipment tools lacked electronic caliper capabilities, and the measurements were performed using radiopaque rulers.Overall, the authors should be commended on their efforts to introduce and evaluate an inexpensive and innovative tool for esophageal protection during AFib ablation. This retractor addresses the limitations of other products that serve a similar purpose. In fact, the suctioning power of the product minimizes the trailing edge of the esophagus that could not be managed with other devices which left esophageal tissue in the ablation field (10, 13). In addition, the control handle offers significant flexibility in device manipulation allowing physicians to choose the site of angulation and the angle of deflection depending on the patient’s anatomy. Future studies should focus on evaluating the safety and effectiveness of this device in humans. Given the growing number of esophageal retracting devices, studies should also aim to determine the device that produces the best esophageal protection and most desirable outcomes of ablation.REFERENCES1. Chung MK, Refaat M, Shen WK, Kutyifa V, Cha YM, Di Biase L, Baranchuk A, Lampert R, Natale A, Fisher J, Lakkireddy DR. Atrial Fibrillation: JACC Council Perspectives. J Am Coll Cardiol. Apr 2020; 75 (14): 1689-1713.2. D’Avila A, Ptaszek LM, Yu PB, Walker JD, Wright C, Noseworthy PA, Myers A, Refaat M, Ruskin JN. Left Atrial-Esophageal Fistula After Pulmonary Vein Isolation. Circulation May 2007; 115(17): e432-3.3. Aryana A, Arthur A, O’ Neill PG, D’Avila A. Catastrophic manifestations of air embolism in a patient with atrioesophageal fistula following minimally invasive surgical ablation of atrial fibrillation. Journal of cardiovascular electrophysiology. 2013;24(8):933-4.4. Stöckigt F, Schrickel JW, Andrié R, Lickfett L. Atrioesophageal fistula after cryoballoon pulmonary vein isolation. Journal of cardiovascular electrophysiology. 2012;23(11):1254-7.5. Oral H, Siontis KC. Prevention of Atrioesophageal Fistula After Catheter Ablation: If the Esophagus Cannot Stand the Heat (Cold), Can It Be Moved to the Sidelines? : JACC: Clinical Electrophysiology; 2017.6. Shah D, Dumonceau J-M, Burri H, Sunthorn H, Schroft A, Gentil-Baron P, et al. Acute pyloric spasm and gastric hypomotility: an extracardiac adverse effect of percutaneous radiofrequency ablation for atrial fibrillation. Journal of the American College of Cardiology. 2005;46(2):327-30.7. Schmidt M, Nölker G, Marschang H, Gutleben K-J, Schibgilla V, Rittger H, et al. Incidence of oesophageal wall injury post-pulmonary vein antrum isolation for treatment of patients with atrial fibrillation. Europace. 2008;10(2):205-9.8. Tran VN, Kusa S, Smietana J, Tsai W-C, Bhasin K, Teh A, et al. The relationship between oesophageal heating during left atrial posterior wall ablation and the durability of pulmonary vein isolation. Ep Europace. 2017;19(10):1664-9.9. Mateos JCP, Mateos EIP, Peña TGS, Lobo TJ, Mateos JCP, Vargas RNA, et al. Simplified method for esophagus protection during radiofrequency catheter ablation of atrial fibrillation-prospective study of 704 cases. Brazilian Journal of Cardiovascular Surgery. 2015;30(2):139-47.10. Bhardwaj R, Naniwadekar A, Whang W, Mittnacht AJ, Palaniswamy C, Koruth JS, et al. Esophageal Deviation During Atrial Fibrillation Ablation: Clinical Experience With a Dedicated Esophageal Balloon Retractor. JACC Clin Electrophysiol. 2018;4(8):1020-30.11. Herweg B, Johnson N, Postler G, Curtis AB, Barold SS, Ilercil A. Mechanical esophageal deflection during ablation of atrial fibrillation. Pacing and clinical electrophysiology. 2006;29(9):957-61.12. Palaniswamy C, Koruth JS, Mittnacht AJ, Miller MA, Choudry S, Bhardwaj R, et al. The extent of mechanical esophageal deviation to avoid esophageal heating during catheter ablation of atrial fibrillation. JACC: Clinical Electrophysiology. 2017;3(10):1146-54.13. Parikh V, Swarup V, Hantla J, Vuddanda V, Dar T, Yarlagadda B, et al. Feasibility, safety, and efficacy of a novel preshaped nitinol esophageal deviator to successfully deflect the esophagus and ablate left atrium without esophageal temperature rise during atrial fibrillation ablation: The DEFLECT GUT study. Heart Rhythm. 2018;15(9):1321-7.
To the Editor,We have read with great interest the article entitled ‘Electrogram-only guided approach to His bundle pacing with minimal fluoroscopy: A single-center experience’ by Zanon et al1 in the latest issue of the journal. We would like to thank the authors for their study regarding the use of electrograms during implantation of the His lead with minimal or no fluoroscopy. Related radiation dose parameters such as fluoroscopy time and dose area product (DAP) were also presented. Radiation dose related to the fluoroscopy system is generally dependent on various autoregulated variables including the tube voltage, the tube current and the pulse duration. In addition, various programmable settings including the frame rate, collimation, and magnification are used to regulate the amount of radiation although the number of variables which can be programmed in the manufacturer specific system varies. Fluoroscopy time should not be an estimation factor for radiation dose because its correlation with other standard radiation measures is weak. Manufacturer specific calculations, either total time while pressing on the fluoroscopy pedal or only a sum of fluoroscopic pulses, make the radiation dose difficult to estimate. The air kerma area product, or DAP (Gy.cm2) is accepted as the most accurate measurement of radiation energy given for fluoroscopic purposes. Roughly, the effective dose (ED) (mSv) of fluoroscopic source of radiation can be calculated using a conversion factor of 0.20 from the DAP measurement. For instance, routine single/dual-chamber pacemaker/defibrillator implantation has an average ED of 4 mSv, compared to an average ED of nearly 20 mSv for a cardiac resynchronization therapy device implantation.2 The frame rate, collimation and magnification should be properly set to reduce the DAP/ED values.The frame rate seems as the most important programmable factor related to the radiation dose. Continuous fluoroscopy has generally the frame rate of ≥30 frames per second (fps), which is associated with increased radiation exposure. Therefore, the frame rate should be set as low as achievable. Decreasing the frame rate from 30 fps to 7.5 fps reduces the ED by 75%. Compensatory tube current increase generally occurs during pulsed fluoroscopy, which is associated with the same number of x-rays produced during continuous fluoroscopy. However, significantly decreased number of pulses cause significant reduction of radiation exposure in a linear way. The frame rates as low as ≤3 fps should be used during diagnostic and ablation procedures and device implantations in the electrophysiology laboratory although reduced temporal resolution.2,3 Furthermore, configuring the frame rate ≤1 fps using the ECG triggering or pacing artifact can be the best approach. Configuration of the pulsed fluoroscopy at the lowest frame rate needed has the greatest potential for ensuring radiation dose at the lowest level.Properly configured and applied collimation, reduction of radiation to an anatomical area that requires imaging, has an important role in reducing both the direct and the scattered radiation. Collimation, especially the asymmetric one, reduces visualization area and decreases the DAP/ED in a linear way. During the procedure, the use of collimation restricts the view on the cardiac contour. After viewing the whole anatomy, re-collimation should be performed.Another option for reducing the radiation dose is to set the largest field of view, or the smallest magnification, possible. In the smallest field of view mode, or the largest magnification mode, a smaller radiation area is projected in the image intensifier and, a larger image is produced on the screen. This process is related to a lower radiation output and a dimmer image. The fluoroscopy unit has an automatic system for controlling the brightness sensed. Therefore, the automatic system compensates for the lower brightness by increasing radiation exposure from the tube. With the use of magnification, the radiation dose increase in flat-panel detectors is lower compared to the image-intensifiers, however it is still remarkable.4In the light of all above-mentioned settings, the fluoroscopy time should not be used as an important variable measuring the radiation dose. Instead, the DAP/ED values should be reported.Keywords: dose area product/effective dose; fluoroscopy; programmable; radiation dose
Background: Transvenous permanent pacemaker related infection is a severe condition associated with significant morbidity and mortality. Leadless pacemakers may be more resistant to bacterial seeding during bloodstream infection because of its small surface area and encapsulation in the right ventricle. This study reports the incidence and outcomes of bacteraemia in patients implanted with a Micra leadless pacemaker. We present 18F-FDG PET/CT findings obtained in a sub-group of patients. Methods: We report a retrospective cohort study of 155 patients who underwent a Micra TPS implant procedure at the University Hospitals of Leuven between July 2015 and July 2019. We identified the patients who developed an episode of bacteraemia, proved by ≥2 positive blood cultures. Results: Of the 155 patients, 15 patients presented an episode of bacteraemia at a median of 226 days (range: 3-1129) days after the implant procedure. Gram positive species accounted for 73.3% (n=11) of the bacteraemia including Staphylococcus (n=5), Enterococcus (n=3) and Streptococcus (n=3). The source of infection was identified in 9 patients (60%) including endocarditis in 4 patients, urinary tract in 3 patients, and skin in 2 patients. 18F-FDG PET/CT imaging performed in 6 patients did not show sign of infection around the leadless pacemaker. Bacteraemia was resolved in all patients after adequate antibiotherapy. Four patients died early during follow up. For all other patients, there were no recurrence of bacteraemia during a median follow up of 263 days (range 15-1134). Conclusion: In our small cohort, no leadless pacemaker endocarditis was observed among patients with bacteraemia.
Introduction：LAmbre occluder (Lifetech Scientific, Shenzhen, China), a new device for left atrial appendage (LAA) occlusion, is increasingly used, but the procedure for retrieval after dislodgement has rarely reported in human. Methods and Results：An 80-year-old male patient with permanent atrial fibrillation underwent the implantation of LAA occlusion device. The occluder dislodged to left atrium (LA) at the end of procedure. We failed to retrieve device in LA with a LASSO catheter and forceps with the 8.5F sheath. After it suddenly flowing into aortic arch, we successfully retrieved with a 14F flexible sheath and forceps. We also discussed reasons for the device dislodgment and reported experiences for device retrieval. Conclusion: Combination of the 14F flexible sheath and forceps could be used to retrieve the dislocation of LAA occlusion device.
Near-field Signals Detected by a Standard Bipolar Electrode without Detection of Corresponding Signals by Microelectrode: What is the Mechanism?Short title ; Near-filed Microelectrode signalTakashi Nakashima, MD*, Cyril Goujeau, MD, Yosuke Nakatani, MD,Ghassen Cheniti, MD, Pierre Jaïs, MD, Frédéric Sacher, MDAll authors have no conflicts of interest to disclose.Department of Cardiac Electrophysiology, Service de Rhythmologie, Hôpital Cardiologique du Haut-Lévêque (Centre Hospitalier Universtaire de Bordeaux)Avenue de Magellan, 33604, Bordeaux-Pessac, FranceCorrespondence to Takashi Nakashima, MDDepartment of Cardiac Electrophysiology, Service de Rhythmologie, Hôpital Cardiologique du Haut-Lévêque (Centre Hospitalier Universtaire de Bordeaux)Avenue de Magellan, 33604, Bordeaux-Pessac, FranceTel: +33 5 57 65 68 63 19, Fax: +33 5 57 65 68 96 20, Email; [email protected], ORCID: 0000-0002-8538-9259Key words: Ablation; Electrogram analysis; Microelectrode; Ventricular tachycardia