High-power and short-duration ablation for pulmonary vein isolation: Safety, efficacy, and long-term durability.

INTRODUCTION: PV reconnection is often the result of catheter instability and tissue edema. High-power short-duration (HP-SD) ablation strategies have been shown to improve atrial linear continuity in acute pre-clinical models. This study compares the safety, efficacy, and long-term durability of HP-SD ablation with conventional ablation. METHODS AND RESULTS: In 6 swine, 2 ablation lines were performed anterior and posterior to the crista terminalis, in the smooth and trabeculated right atrium, respectively; and the right superior PV was isolated. In 3 swine, ablation was performed using conventional parameters (Thermocool-Smarttouch® SF; 30 W/30 seconds) and in 3 other swine using HP-SD parameters (QDOT-MICRO™, 90 W/4 seconds). After 30 days, linear integrity was examined by voltage mapping and pacing, and the heart and surrounding tissues were examined by histopathology. Acute line integrity was achieved with both ablation strategies; however, HP-SD ablation required 80% less RF time compared with conventional ablation (P ≤ 0.01 for all lines). Chronic line integrity was higher with HP-SD ablation: all 3 posterior lines were continuous and transmural compared to only 1 line created by conventional ablation. In the trabeculated tissue, HP-SD ablation lesions were wider and of similar depth with 1 of 3 lines being continuous compared to 0 of 3 using conventional ablation. Chronic PVI without stenosis was evident in both groups. There were no steam-pops. Pleural markings were present in both strategies, but parenchymal lung injury was only evident with conventional ablation. CONCLUSIONS: HP-SD ablation strategy results in improved linear continuity, shorter ablation time, and a safety profile comparable to conventional ablation.

Incidence and risk factors for symptomatic heart failure after catheter ablation of atrial fibrillation and atrial flutter.

AIMS: To determine the incidence and risk factors for development of symptomatic heart failure (HF) following catheter ablation for atrial fibrillation (AF) and atrial flutter. METHODS AND RESULTS: We prospectively enrolled consecutive patients undergoing pulmonary vein isolation (PVI) or cavotricuspid isthmus (CTI) ablation between November 2013 and June 2014. Post-discharge symptoms were assessed via telephone follow-up and clinic visits. The primary outcome was symptomatic HF requiring treatment with new/increased diuretic dosing. Secondary outcomes were prolonged index hospitalization and readmission for HF ≤30 days. Univariate and multivariable logistic regressions were used to assess the relationship between patient/procedural characteristic and post-ablation HF. Among 111 PVI patients [median age 62.0 years; left ventricular ejection fraction (LVEF) 55%], 29 patients (26.1%) developed symptomatic HF, 6 patients (5.4%) required prolonged index hospitalization, and 8 patients (7.2%) were readmitted for HF. In univariate analyses, persistent AF [odds ratio (OR) 2.97, P = 0.02], AF at start of the procedure (OR 2.99, P = 0.01), additional ablation lines (OR 11.07, P < 0.0001), and final left atrial pressure (OR 1.10 per 1 mmHg increase, P = 0.02) were associated with HF development. Peri-procedural diuresis, net fluid balance, and LVEF were not correlated. In multivariable analyses, only additional ablation lines (ORadj 9.17, P = 0.007) were independently associated with post-ablation HF. Six patients (16.7%) developed HF after CTI ablation. CONCLUSION: A 26.1% of patients undergoing PVI and 16.7% of patients undergoing CTI ablation developed symptomatic HF when prospectively and uniformly assessed. 12.6% of patients experienced prolonged index hospitalizations or readmission for management of HF within 1 week after PVI. Improved understanding of risk factors for post-ablation HF may be critical in developing strategies to address during AF ablation.

How we implemented a resident-led medical simulation curriculum in a large internal medicine residency program.

Mannequin-based simulation in graduate medical education has gained widespread acceptance. Its use in non-procedural training within internal medicine (IM) remains scant, possibly due to the logistical barriers to implementation of simulation curricula in large residency programs. We report the Massachusetts General Hospital Department of Medicine's scale-up of a voluntary pilot program to a mandatory longitudinal simulation curriculum in a large IM residency program (n = 54). We utilized an eight-case curriculum implemented over the first four months of the academic year. An intensive care unit curriculum was piloted in the spring. In order to administer a comprehensive curriculum in a large residency program where faculty resources are limited, thirty second-year and third-year residents served as session facilitators and two senior residents served as chairpersons of the program. Post-session anonymous survey revealed high learner satisfaction scores for the mandatory program, similar to those of the voluntary pilot program. Most interns believed the sessions should continue to be mandatory. Utilizing residents as volunteer facilitators and program leaders allowed the implementation of a well-received mandatory simulation program in a large IM residency program and facilitated program sustainability.

Multi-sensor esophageal temperature probe used during radiofrequency ablation for atrial fibrillation is associated with increased intraluminal temperature detection and increased risk of esophageal injury compared to single-sensor probe.

BACKGROUND: Radiofrequency (RF) ablation in the posterior left atrium has risk of thermal injury to the adjacent esophagus. Increased intraluminal esophageal temperature has been correlated with risk of esophageal injury. The objective of this study was to compare esophageal temperature monitoring (ETM) using a multi-sensor temperature probe with 12 sensors to a single-sensor probe during catheter ablation for atrial fibrillation (AF). METHODS AND RESULTS: We compared the detection of intraluminal esophageal temperature rises in 543 patients undergoing RF ablation for AF with ETM. Esophageal endoscopy (EGD) was performed on all patients with maximum esophageal temperature ≥ 39°C. Esophageal lesions were classified by severity as mild or severe ulcerations. Four hundred fifty-five patients underwent RF ablation with single-sensor ETM and 88 patients with multi-sensor ETM. Thirty-nine percent of patients with single-sensor versus 75% with multi-sensor ETM reached a maximum detected esophageal temperature ≥ 39°C (P < 0.0001). Esophageal injury was detected by EGD in 29% of patients with maximum temperature ≥ 39°C by single-sensor versus 46% of patients with multi-sensor ETM (P = 0.021). Thirty-nine percent of patients with lesions in the single-sensor probe group had severe ulcerations compared to 33% of patients in the multi-sensor probe group (P = 0.641). CONCLUSIONS: Intraluminal esophageal temperature ≥ 39°C is detected more frequently by the multi-sensor temperature probe versus the single-sensor probe, with more frequent esophageal injury and with comparable severity of injury. Despite detecting esophageal temperature rises in more patients, the multi-sensor probe may not have any measurable benefit compared to a single-sensor probe.

Prevalence of Undiagnosed Sleep Apnea in Patients With Atrial Fibrillation and its Impact on Therapy.

OBJECTIVES: This study sought to evaluate the proportion of patients with atrial fibrillation (AF) who also have undiagnosed sleep apnea and examine the impact of its diagnosis on adherence to sleep apnea therapies. BACKGROUND: Sleep apnea is a modifiable risk factor for AF. However, the proportion of patients with AF who also have undiagnosed sleep apnea and the impact of its diagnosis on therapy have not been well studied. METHODS: This prospective study included 188 consecutive patients with AF without a prior diagnosis of sleep apnea who were scheduled to undergo AF ablation. Participants underwent home sleep apnea testing, completed a sleep apnea screening questionnaire (STOP-BANG [Snoring; Tiredness, Fatigue, or Sleepiness During the Daytime; Observation of Apnea and/or Choking During Sleep; Hypertension; Body Mass Index >35 kg/m2; Age >50 Years; Neck Circumference >40 cm; and Male Sex]) and were followed for ≥2 years to evaluate the impact of diagnosis on therapy. RESULTS: Home sleep apnea testing was positive in 155 of 188 patients (82.4%); among those 155, 127 (82%) had a predominant obstructive component and 28 (18%) had mixed sleep apnea with a 15.2 ± 7.4% central component. Sleep apnea severity was mild in 43.8%, moderate in 32.9%, and severe in 23.2%. The sensitivity and specificity of a STOP-BANG questionnaire were 81.2% and 42.4%, respectively. In a multivariate analysis, STOP-BANG was not predictive for sleep apnea (odds ratio: 0.54; 95% confidence interval: 0.17 to 1.76; p = 0.31). Therapy with continuous positive airway pressure ventilators was initiated in 73 of 85 patients (85.9%) with moderate or severe sleep apnea, and 68 of the 73 patients (93.1%) remained complaint after a mean follow-up period of 21 ± 6.2 months. CONCLUSIONS: Sleep apnea is exceedingly prevalent in patients with AF who are referred for ablation, with a large proportion being undiagnosed due the limited predictive value of sleep apnea symptoms in this AF population. Screening for sleep apnea resulted in high rate of long-term continuous positive airway pressure adherence.

High-Power and Short-Duration Ablation for Pulmonary Vein Isolation: Biophysical Characterization.

OBJECTIVES: This study sought to examine the biophysical properties of high-power and short-duration (HP-SD) radiofrequency ablation for pulmonary vein isolation. BACKGROUND: Pulmonary vein isolation is the cornerstone of atrial fibrillation ablation. However, pulmonary vein reconnection is frequent and is often the result of catheter instability, tissue edema, and a reversible nontransmural injury. We postulated that HP-SD ablation increases lesion-to-lesion uniformity and transmurality. METHODS: This study included 20 swine and a novel open-irrigated ablation catheter with a thermocouple system able to record temperature at the catheter-tissue interface (QDOT Micro Catheter). Step 1 compared 3 HP-SD ablation settings: 90 W/4 s, 90 W/6 s, and 70 W/8 s in a thigh muscle preparation. Ablation at 90 W/4 s was identified as the best compromise between lesion size and safety parameters, with no steam-pop or char. In step 2, a total of 174 single ablation applications were performed in the beating heart and resulted in 3 (1.7%) steam-pops, all occurring at catheter-tissue interface temperature ≥85°C. Additional 233 applications at 90 W/4 s and temperature limit of 65°C were applied without steam-pop. Step 3 compared the presence of gaps and lesion transmurality in atrial lines and pulmonary vein isolation between HP-SD (90 W/4 s, T ≤65°C) and standard (25 W/20 s) ablation. RESULTS: HP-SD ablation resulted in 100% contiguous lines with all transmural lesions, whereas standard ablation had linear gaps in 25% and partial thickness lesions in 29%. Ablation with HP-SD produced wider lesions (6.02 ± 0.2 mm vs. 4.43 ± 1.0 mm; p = 0.003) at similar depth (3.58 ± 0.3 mm vs. 3.53 ± 0.6 mm; p = 0.81) and improved lesion-to-lesion uniformity with comparable safety end points. CONCLUSIONS: In a preclinical model, HP-SD ablation (90 W/4 s, T ≤65°C) produced an improved lesion-to-lesion uniformity, linear contiguity, and transmurality at a similar safety profile of conventional ablation.

Infarct-Related Ventricular Tachycardia: Redefining the Electrophysiological Substrate of the Isthmus During Sinus Rhythm.

OBJECTIVES: In this study, the scientific objective was to characterize the electrophysiological substrate of the ventricular tachycardia (VT) isthmus during sinus rhythm. BACKGROUND: The authors have recently described the electrophysiological characteristics of the VT isthmus using a novel in vivo high-resolution mapping technology. METHODS: Sixteen swine with healed infarction were studied using high-resolution mapping technology (Rhythmia, Boston Scientific, Cambridge, Massachusetts) in a closed-chest model. The left ventricle was mapped during sinus rhythm and analyzed for activation, conduction velocity, electrogram shape, and amplitude. Twenty-four VTs allowed detailed mapping of the common-channel "isthmus," including the "critical zone." This was defined as the zone of maximal conduction velocity slowing in the circuit, often occurring at entrance and exit from the isthmus caused by rapid angular change in activation vectors. RESULTS: The VT isthmus corresponded to sites displaying steep activation gradient (SAG) during sinus rhythm with conduction velocity slowing of 58.5 ± 22.4% (positive predictive value [PPV] 60%). The VT critical zone displayed SAG with greater conduction velocity slowing of 68.6 ± 18.2% (PPV 70%). Critical-zone sites were consistently localized in areas with bipolar voltage ≤0.55 mV, whereas isthmus sites were localized in areas with variable voltage amplitude (1.05 ± 0.80 mV [0.03 to 2.88 mV]). Importantly, critical zones served as common-site "anchors" for multiple VT configurations and cycle lengths. Isthmus and critical-zone sites occupied only 18.0 ± 7.0% of the low-voltage area (≤1.50 mV). Isolated late potentials were present in both isthmus and nonisthmus sites, including dead-end pathways (PPV 36%; 95% confidence interval: 34.2% to 39.6%). CONCLUSIONS: The VT critical zone corresponds to a location characterized by SAG and very low voltage amplitude during sinus rhythm. Thus, it allows identification of a re-entry anchor with high sensitivity and specificity. By contrast, voltage and electrogram characteristics during sinus rhythm have limited specificity for identifying the VT isthmus.

Activation Mapping With Integration of Vector and Velocity Information Improves the Ability to Identify the Mechanism and Location of Complex Scar-Related Atrial Tachycardias.

BACKGROUND: Activation mapping of scar-related atrial tachycardias (ATs) can be difficult to interpret because of inaccurate time annotation of complex electrograms and passive diastolic activity. We examined whether integration of a vector map can help to describe patterns of propagation to better explain the mechanism and location of ATs. METHODS: The investigational mapping algorithm calculates vectors and applies physiological constraints of electrical excitation in human atrial tissue to determine the arrhythmia source and circuit. Phase I consisted of retrospective evaluation in 35 patients with ATs. Phase II consisted of prospective validation in 20 patients with ATs. Macroreentry was defined as a continuous propagation in a circular path >30 mm; localized reentry was defined as a circular path ≤30 mm; a focal source had a centrifugal spread from a point source. RESULTS: In phase I, standard activation mapping identified 28 of 40 ATs (70%): 25 macroreentry and 3 focal tachycardias. In the remaining 12 ATs, the mechanism and location could not be identified by activation and required entrainment or empirical ablation for termination (radiofrequency time, 17.3±6.6 minutes). In comparison, the investigational algorithm identified 37 of 40 (92.5%) ATs, including 5 macroreentry, 3 localized reentry, and 1 focal AT not identified by standard mapping. It also predicted the successful termination site of all 37 of 40 ATs. In phase II, the investigational algorithm identified 12 macroreentry, 6 localized reentry, and 2 focal tachycardias that all terminated with limited ablation (3.2±1.7 minutes). It identified 3 macroreentry, 3 localized reentry, and 1 focal AT not well characterized by standard mapping. The diagnosis of localized reentry was supported by highly curved vectors, resetting with increasing curve and termination with limited ablation (22±6 s). CONCLUSIONS: Activation mapping integrating vectors can help determine the arrhythmia mechanism and identify its critical components. It has particular value for identifying complex macroreentrant circuits and for differentiating a focal source from a localized reentry.

Evaluation of ablation catheter technology: Comparison between thigh preparation model and an in vivo beating heart.

BACKGROUND: An in vivo animal thigh model is the standard technique for evaluation of ablation catheter technologies, including efficacy and safety of ablation. However, the biophysics of ablation in a thigh model may not be similar to a beating heart. OBJECTIVE: The purpose of this study was to compare efficacy and safety of ablation between a thigh preparation model and a beating heart. METHODS: In 7 swine, radiofrequency ablation using a 3.5-mm open irrigated catheter (ThermoCool Smart Touch) was performed sequentially in a thigh muscle and in vivo beating ventricles. Ablation was performed at low (30 W for 40 s) and high (40 W for 60 s) energy settings and at similar contact force. Ablation lesions were scanned in high resolution and measured using electronic calipers. RESULTS: A total of 152 radiofrequency ablation lesions were measured (86 thigh and 66 heart). At low energy, lesion width was greater in the thigh model (12.19 ± 1.8 mm vs 8.99 ± 2.1 mm; P <.001), whereas lesion depth was similar between the thigh and heart (5.71 ± 0.8 mm vs 5.95 ± 1.3 mm, respectively; P = .18). The planar cross-sectional lesion area was greater in the thigh model (thigh 54.8 ± 10.8 mm2 vs heart 43.1 ± 16.1 mm2; P <.001). At the high-energy setting, lesion depth, width, and area were all greater in the thigh model (thigh 91.5 ± 16.8 mm2 vs heart 56.0 ± 15.5 mm2; P <.001). The incidence of steam pop and char formation was similar between the models. CONCLUSION: The thigh preparation model is a reasonable technique for evaluation of ablation catheter technology; however it often results in overestimation of lesion size, especially at higher energy settings.

Atrial Substrate and Triggers of Paroxysmal Atrial Fibrillation in Patients With Obstructive Sleep Apnea.

BACKGROUND: Obstructive sleep apnea (OSA) is associated with atrial remodeling, atrial fibrillation (AF), and increased incidence of arrhythmia recurrence after pulmonary vein (PV) isolation. We aimed to characterize the atrial substrate, including AF triggers in patients with paroxysmal AF and OSA. METHODS AND RESULTS: In 86 patients with paroxysmal AF (43 with ≥moderate OSA [apnea-hypopnea index ≥15] and 43 without OSA [apnea-hypopnea index <5]), right atrial and left atrial voltage distribution, conduction velocities, and electrogram characteristics were analyzed during atrial pacing. AF triggers were examined before and after PV isolation and targeted for ablation. Patients with OSA had lower atrial voltage amplitude (right atrial, P=0.0005; left atrial, P=0.0001), slower conduction velocities (right atrial, P=0.02; left atrial, P=0.0002), and higher prevalence of electrogram fractionation (P=0.0001). The areas of atrial abnormality were consistent among patients, most commonly involving the left atrial septum (32/43; 74.4%). At baseline, the PVs were the most frequent triggers for AF in both groups; however, after PV isolation patients with OSA had increased incidence of additional extra-PV triggers (41.8% versus 11.6%; P=0.003). The 1-year arrhythmia-free survival was similar between patients with and without OSA (83.7% and 81.4%, respectively; P=0.59). In comparison, control patients with paroxysmal AF and OSA who underwent PV isolation alone without ablation on extra-PV triggers had increased risk of arrhythmia recurrence (83.7% versus 64.0%; P=0.003). CONCLUSIONS: OSA is associated with structural and functional atrial remodeling and increased incidence of extra-PV triggers. Elimination of these triggers resulted in improved arrhythmia-free survival.

Evaluation of a novel high-resolution mapping technology for ablation of recurrent scar-related atrial tachycardias.

BACKGROUND: Rhythmia is a new technology capable of rapid and high-resolution mapping. However, its potential advantage over existing technologies in mapping complex scar-related atrial tachycardias (ATs) has not yet been evaluated. OBJECTIVE: The purpose of this study was to examine the utility of Rhythmia for mapping scar-related ATs in patients who had failed previous ablation procedure(s). METHODS: This multicenter study included 20 patients with recurrent ATs within 2 years after a previous ablation procedure (1.8 ± 0.7 per patient). In all cases, the ATs could not be adequately mapped during the index procedure because of scar with fractionated electrograms, precluding accurate time annotation, frequent change in the tachycardia in response to pacing, and/or degeneration into atrial fibrillation. These patients underwent repeat mapping and ablation procedure with Rhythmia. RESULTS: From a total of 28 inducible ATs, 24 were successfully mapped. Eighteen ATs (75%) terminated during radiofrequency ablation and 4 (16.6%) with catheter pressure or entrainment from the site of origin or isthmus. Two ATs that were mapped to the interatrial septum slowed but did not terminate with ablation. In 21 of 24 ATs the mechanism was macroreentry, while in 3 of 24 the mechanism was focal. Interestingly, in 5 patients with previously failed ablation of an allegedly "focal" tachycardia, high-resolution mapping demonstrated macroreentrant arrhythmia. The mean mapping time was 28.6 ± 17 minutes, and the mean radiofrequency ablation time to arrhythmia termination was 3.2 ± 2.6 minutes. During a mean follow-up of 7.5 ± 3.1 months, 15 of 20 patients (75%) were free of AT recurrences. CONCLUSION: The Rhythmia mapping system may be advantageous for mapping complex scar-related ATs.

Pulmonary vein isolation using the Rhythmia mapping system: Verification of intracardiac signals using the Orion mini-basket catheter.

BACKGROUND: During pulmonary vein isolation (PVI), a circular lasso catheter is positioned at the junction between the left atrium (LA) and the pulmonary vein (PV) to confirm PVI. The Rhythmia mapping system uses the Orion mini-basket catheter with 64 electrodes instead of the lasso catheter. However, its feasibility to determine PVI has not been studied. OBJECTIVE: The purpose of this study was to compare signals between the mini-basket and lasso catheters at the LA-PV junction. METHODS: In 12 patients undergoing PVI using Rhythmia, the mini-basket and lasso catheters were placed simultaneously at the LA-PV junction for baseline and post-PVI signal assessment. Pacing from both catheters was performed to examine the presence of exit block. RESULTS: At baseline, recordings of LA and PV potentials were concordant in all PVs. However, after PVI, concordance between the catheters was only 68%. Discordance in all cases resulted from loss of PV potentials on the lasso catheter with persistence of PV potentials on the mini-basket catheter. In 9 of 13 PVs (69%), these potentials represented true PV potentials that were exclusively recorded with the smaller and closely spaced mini-basket electrodes. In the other 4 PVs (31%), these potentials originated from neighboring structures and resulted in underestimation of PVI. CONCLUSION: The use of the mini-basket catheter alone is sufficient to determine PVI. While it improves recording of PV potentials after incomplete ablation, it is also associated with frequent recording of "PV-like" potentials originating from neighboring structures. In these cases, pacing maneuvers are helpful to determine PVI and avoid excessive ablation.

Acute pulmonary vein reconnection is a predictor of atrial fibrillation recurrence following pulmonary vein isolation.

PURPOSE: Arrhythmia recurrence following pulmonary vein isolation (PVI) occurs predominantly due to the reconnection of previously isolated pulmonary veins (PVs). The prognostic implications of detection and treatment of acute PV reconnection are not well understood. We aim to examine the prognostic significance of acute PV reconnection on arrhythmia recurrence at 1 year following PVI. METHODS: This prospective study included 44 patients (22 men, 60 ± 7 years) who underwent index PVI procedure for treatment of atrial fibrillation (AF). Acute PV reconnection and/or dormant PV conduction were assessed sequentially in response to a 30-min waiting period, intravenous isoproterenol infusion and/or adenosine. All cases of acute PV reconnection and/or dormant conduction were successfully targeted with additional ablation. RESULTS: Freedom from AF at 1 year was 75 % (83.3 % in paroxysmal and 65 % in persistent AF, p = ns). Acute PV reconnection and/or dormant conduction were evident in 16 of 44 patients (36.3 %). AF recurrence was documented in eight of 16 patients with, but only in three of 28 patients without acute reconnection (p = 0.009). Three patients underwent a redo procedure, all from the group of patients with acute PV reconnection. In a multivariate model, acute PV reconnection was a strong independent predictor of arrhythmia recurrence (hazards ratio [HR], 6.36; 95 % confidence interval [CI], 1.12-31.6). CONCLUSION: Identification of acute PV reconnection, even when successfully targeted, is a strong predictor of arrhythmia recurrence following PVI.

Radiofrequency ablation annotation algorithm reduces the incidence of linear gaps and reconnection after pulmonary vein isolation.

BACKGROUND: A common mechanism of atrial fibrillation recurrence after catheter ablation is resumption of pulmonary vein (PV) conduction due to gaps in the ablation line. These gaps may go unrecognized owing to inadequate ablation lesion annotation. OBJECTIVE: To examine the utility of an automated radiofrequency (RF) ablation annotation algorithm for the detection and treatment of ablation gaps during pulmonary vein isolation (PVI). METHODS: Eighty-four patients with paroxysmal atrial fibrillation underwent PVI. In 42 patients (group A), RF ablation was guided by an automated algorithm with predefined criteria of catheter stability range of motion ≤2 mm and impedance decrease ≥5% for individual ablation applications. In 42 control patients (group B), ablation was guided by the operator. Successful PVI, conduction recovery, and dormant conduction with adenosine were compared between the groups. RESULTS: Ipsilateral PVI at the completion of the initial anatomical line was obtained in 90.5% of group A patients (76 of 84 ipsilateral pairs of PVs) but only in 66.7% of group B patients (56 of 84 ipsilateral pairs of PVs) (P = .0001). Ineffective energy delivery was detected in 23% (1005 of 4362) of group A applications but only in 9% (368 of 4071) of group B applications (P = .0001). The frequency of conduction recovery was lower in group A than in group B (5.9% vs 25%; P = .001). Arrhythmia-free survival at 6 months trended higher in group A (38 of 42 [90%]) than in group B (32 of 42 [76%]; P = .07). CONCLUSION: Automated ablation lesion annotation provides real-time feedback of RF ablation that may improve effective energy delivery.

Severity of esophageal injury predicts time to healing after radiofrequency catheter ablation for atrial fibrillation.

BACKGROUND: The delivery of radiofrequency (RF) energy to the posterior left atrium creates a risk of injury to the adjacent esophagus. Esophageal endoscopy (EGD) is used to screen patients at risk for esophageal thermal injury after RF ablation. OBJECTIVE: The purpose of this study was to analyze the macroscopic features of the severity of esophageal injuries induced by RF ablation to the left atrium as seen by EGD and evaluate the association of these descriptions with the time elapsed until complete healing. METHODS: This study analyzed 219 patients undergoing RF ablation for atrial fibrillation. Esophageal temperature probes were used during each ablation, and EGD was performed in cases with intraesophageal temperature ≥39°C. Repeat EGD was obtained at 10 days to evaluate for healing in all cases demonstrating esophageal injury. Serial endoscopies were repeated every 2 weeks until complete healing was documented. Lesions were classified according to severity as superficial or deep ulceration; size and shape were also noted. RESULTS: We found 37.4% of patients (82 of 219) with esophageal intraluminal temperatures ≥39°C. Of these, 22 patients (27%) were identified with esophageal injury, with 68% being superficial ulcerations and 32% deep. On repeat EGD at 10 days, only 29% of deep ulcerations were healed, as compared with 87% of the superficial injuries (P = .0136). No difference in healing was found when analyzed for size or shape. CONCLUSIONS: The macroscopic severity of esophageal lesions detected on endoscopy the day after RF ablation can predict the time to resolution, with severe, deep ulcerations requiring a longer time to heal.