Atrial Tachycardias Utilizing the Ligament of Marshall Region Following Single Ring Pulmonary Vein Isolation for Atrial Fibrillation WILLIAM W.B. CHIK, M.B.B.S.,*,† JACKY KIT CHAN, M.B.B.S.,*,‡ DAVID L. ROSS, PH.D.,*,† JACKIE WAGSTAFF, R.N.,* EDDY KIZANA, PH.D.,*,† ARAVINDA THIAGALINGAM, PH.D.,*,† PRAMESH KOVOOR, PH.D.,*,† and STUART P. THOMAS, PH.D.*,† From the *Cardiology Department, Westmead Public and Private Hospitals, Sydney, Australia; †Sydney Medical School, University of Sydney, Sydney, Australia; and ‡Ruttonjee and Tang Shiu Kin Hospitals, Wan Chai, Hong Kong, SAR
Background: Organized atrial tachycardias (OATs) after pulmonary vein isolation (PVI) procedure are common. Arrhythmia mechanisms include mitral annular, ring gap, or roof-dependent gap-related flutters. In this series, we describe a mechanism of arrhythmia utilizing the ridge between left pulmonary vein (PV) and left atrial appendage (LAA) in the Ligament of Marshall (LOM) region. Methods and Results: Five tachycardias involving the LOM region were identified from a group of 240 patients who underwent a single ring PVI procedure for symptomatic atrial fibrillation. The common characteristics of these tachycardias were the endocardial breakout over a broad area adjacent to the LOM region, presence of presystolic or mid-diastolic potentials, and abolition by ablation of the presystolic or mid-diastolic potentials remote from the endocardial breakout site. In all five cases, tachycardias were present after isolation of the veins and posterior left atria. All demonstrated characteristic areas of very slow conduction in the LOM region highlighted by presence of either low voltage, long duration fractionated potentials, or mid-diastolic potentials with a fixed temporal relationship to the subsequent endocardial activation. The pattern of activation and termination of tachycardia during ablation was consistent with an arrhythmia utilizing an electrically insulated tract within LOM and the PV-LAA ridge region. Conclusions: We identified a pattern of arrhythmias involving a concealed presystolic component and a broad endocardial breakout site related to the LOM region. Successful ablation site involved careful identification of small diastolic potentials in the LAA/ridge region or adjacent to the coronary sinus. (PACE 2014; 37:1149–1158) catheter ablation, atrial tachycardia, ablation, arrhythmia, electrophysiology, ligament of Marshall, atrial fibrillation
Introduction Pulmonary vein (PV) isolation (PVI) is the common element of most techniques used to treat atrial fibrillation (AF).1 Organized atrial tachycardias (OAT) developing during or following PVI procedures are common, particularly when wider electrical isolation techniques are employed.2–4 Understanding the underlying mechanisms of arrhythmia recurrence is important for treatment and development of preventative strategies. The No financial disclosures. Address for reprints: Stuart Thomas, Ph.D., Cardiology Department, Westmead Public and Private Hospitals, Corner Darcy and Hawkesbury Roads, Westmead, NSW 2145, Australia. Fax: 61-2-9845 8323; e-mail: [email protected] Received July 21, 2013; revised March 2, 2014; accepted April 1, 2014. doi: 10.1111/pace.12423
mechanisms of arrhythmia recurrence depend on the initial PVI technique.5,6 We previously reported outcomes after an ablation strategy utilizing a single ring to isolate all four PVs and the posterior left atrial wall.7,8 Macroreentrant arrhythmias were common, occurring in 34% of patients after this procedure.9 The most frequent mechanisms were mitral annular flutter and gap-related macro-reentrant flutter.6,9,10 The Ligament of Marshall (LOM) has previously been implicated as a source of focal activity initiating either atrial tachycardia or fibrillation.11–14 In this case series, we describe a novel mechanism of arrhythmia occurring either spontaneously or inducible during PVI procedures. These arrhythmias utilized the LOM region in the ridge between the left PVs and left atrial appendage (PV-LAA Ridge) as a critical component of the reentrant circuit. In all five
©2014 Wiley Periodicals, Inc. PACE, Vol. 37
September 2014
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CHIK, ET AL.
cases, the tachycardia did not involve the adjacent PVs and posterior left atrium. Methods Single Ring PVI Technique All seven patients underwent PVI using the single ring ablation approach as previously described.7,8 The procedures were performed under general anesthesia or during intravenous sedation with midazolam and fentanyl. A transesophageal echocardiogram was performed before all procedures to exclude left atrial thrombus. Three right femoral vein punctures were performed. A Daig SL3 (St. Jude Medical, Inc., St. Paul, MN, USA) sheath was used to selectively engage the coronary sinus (CS). A 6F decapolar ablation catheter was inserted into the CS. A single transseptal puncture was performed, SL0 (St. Jude Medical, Inc.) and deflectable 9F Agilis sheaths (Ultimum Agilis, St. Jude Medical, Inc.) advanced to the left atrium. Mapping was performed using a ten-pole circular mapping catheter (Navistar Lasso catheter, Biosense Webster, Diamond Bar, CA, USA, or Reflexion SpiralTM , St. Jude Medical, Inc.) via the DaigTM SL0 long sheath (St. Jude Medical, Inc.). Radiofrequency (RF) ablation was delivered using an open irrigated 7F, 3.5-mm-tip, deR flectable ablation catheter (Thermocool Navistar , Biosense Webster; or Coolpath Duo Catheter, St. Jude Medical, Inc.). Generator power was limited to 40 W during ablation on the septum, left free wall, and roof of the left atrium. A maximum power of 30 W was used for posterior left atrial wall ablations. This was further reduced to 25– 30 W when ablation was required on the venous side of the ridge separating the left-sided veins and the LAA. A maximum of 25 W was used for ablations within the CS. Temperature was limited to 50°C. RF ablation was continued at each site until local electrograms were abolished or for 30 seconds. RF ablations were applied at 2- to 5-mm intervals to create a contiguous ablation line. The CoolFlow pump was programmed to deliver saline irrigation at 24 mL/min when power was 30 W and 17 mL/min when power R
Background: Organized atrial tachycardias (OATs) after pulmonary vein isolation (PVI) procedure are common. Arrhythmia mechanisms include mitral annular, ring gap, or roof-dependent gap-related flutters. In this series, we describe a mechanism of arrhythmia utilizing the ridge between left pulmonary vein (PV) and left atrial appendage (LAA) in the Ligament of Marshall (LOM) region. Methods and Results: Five tachycardias involving the LOM region were identified from a group of 240 patients who underwent a single ring PVI procedure for symptomatic atrial fibrillation. The common characteristics of these tachycardias were the endocardial breakout over a broad area adjacent to the LOM region, presence of presystolic or mid-diastolic potentials, and abolition by ablation of the presystolic or mid-diastolic potentials remote from the endocardial breakout site. In all five cases, tachycardias were present after isolation of the veins and posterior left atria. All demonstrated characteristic areas of very slow conduction in the LOM region highlighted by presence of either low voltage, long duration fractionated potentials, or mid-diastolic potentials with a fixed temporal relationship to the subsequent endocardial activation. The pattern of activation and termination of tachycardia during ablation was consistent with an arrhythmia utilizing an electrically insulated tract within LOM and the PV-LAA ridge region. Conclusions: We identified a pattern of arrhythmias involving a concealed presystolic component and a broad endocardial breakout site related to the LOM region. Successful ablation site involved careful identification of small diastolic potentials in the LAA/ridge region or adjacent to the coronary sinus. (PACE 2014; 37:1149–1158) catheter ablation, atrial tachycardia, ablation, arrhythmia, electrophysiology, ligament of Marshall, atrial fibrillation
Introduction Pulmonary vein (PV) isolation (PVI) is the common element of most techniques used to treat atrial fibrillation (AF).1 Organized atrial tachycardias (OAT) developing during or following PVI procedures are common, particularly when wider electrical isolation techniques are employed.2–4 Understanding the underlying mechanisms of arrhythmia recurrence is important for treatment and development of preventative strategies. The No financial disclosures. Address for reprints: Stuart Thomas, Ph.D., Cardiology Department, Westmead Public and Private Hospitals, Corner Darcy and Hawkesbury Roads, Westmead, NSW 2145, Australia. Fax: 61-2-9845 8323; e-mail: [email protected] Received July 21, 2013; revised March 2, 2014; accepted April 1, 2014. doi: 10.1111/pace.12423
mechanisms of arrhythmia recurrence depend on the initial PVI technique.5,6 We previously reported outcomes after an ablation strategy utilizing a single ring to isolate all four PVs and the posterior left atrial wall.7,8 Macroreentrant arrhythmias were common, occurring in 34% of patients after this procedure.9 The most frequent mechanisms were mitral annular flutter and gap-related macro-reentrant flutter.6,9,10 The Ligament of Marshall (LOM) has previously been implicated as a source of focal activity initiating either atrial tachycardia or fibrillation.11–14 In this case series, we describe a novel mechanism of arrhythmia occurring either spontaneously or inducible during PVI procedures. These arrhythmias utilized the LOM region in the ridge between the left PVs and left atrial appendage (PV-LAA Ridge) as a critical component of the reentrant circuit. In all five
©2014 Wiley Periodicals, Inc. PACE, Vol. 37
September 2014
1149
CHIK, ET AL.
cases, the tachycardia did not involve the adjacent PVs and posterior left atrium. Methods Single Ring PVI Technique All seven patients underwent PVI using the single ring ablation approach as previously described.7,8 The procedures were performed under general anesthesia or during intravenous sedation with midazolam and fentanyl. A transesophageal echocardiogram was performed before all procedures to exclude left atrial thrombus. Three right femoral vein punctures were performed. A Daig SL3 (St. Jude Medical, Inc., St. Paul, MN, USA) sheath was used to selectively engage the coronary sinus (CS). A 6F decapolar ablation catheter was inserted into the CS. A single transseptal puncture was performed, SL0 (St. Jude Medical, Inc.) and deflectable 9F Agilis sheaths (Ultimum Agilis, St. Jude Medical, Inc.) advanced to the left atrium. Mapping was performed using a ten-pole circular mapping catheter (Navistar Lasso catheter, Biosense Webster, Diamond Bar, CA, USA, or Reflexion SpiralTM , St. Jude Medical, Inc.) via the DaigTM SL0 long sheath (St. Jude Medical, Inc.). Radiofrequency (RF) ablation was delivered using an open irrigated 7F, 3.5-mm-tip, deR flectable ablation catheter (Thermocool Navistar , Biosense Webster; or Coolpath Duo Catheter, St. Jude Medical, Inc.). Generator power was limited to 40 W during ablation on the septum, left free wall, and roof of the left atrium. A maximum power of 30 W was used for posterior left atrial wall ablations. This was further reduced to 25– 30 W when ablation was required on the venous side of the ridge separating the left-sided veins and the LAA. A maximum of 25 W was used for ablations within the CS. Temperature was limited to 50°C. RF ablation was continued at each site until local electrograms were abolished or for 30 seconds. RF ablations were applied at 2- to 5-mm intervals to create a contiguous ablation line. The CoolFlow pump was programmed to deliver saline irrigation at 24 mL/min when power was 30 W and 17 mL/min when power R
