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Intracardiac Ultrasound During Left Atrial Ablation for Atrial Fibrillation. Background: Esophageal injury during left atrial ablation is associated with a significant risk of mortality and morbidity. There are no validated approaches to reduce injury outside of avoidance, a strategy critically dependent on a precise understanding of the esophageal anatomy and location. Intracardiac ultrasound (ICE) can provide a real-time assessment of the esophagus during ablation. We hypothesized that ICE can accurately define esophageal anatomy and location to enhance avoidance strategies during ablation. Methods: Fifty patients underwent atrial fibrillation (AF) ablation. The left atrium and pulmonary vein anatomies were rendered by traditional electroanatomic mapping (CARTO). A Navistar catheter within the esophagus was used to create a traditional electroanatomic esophageal anatomy. ICE imaging was used to create a second geometry of the esophagus. The traditional and ICE anatomies of the esophagus were compared and the greatest border dimensions used to avoid injury. Results: The average age was 66 ± 10 years, 45% had persistent/longstanding persistent AF, and 18% had a prior AF ablation. The esophagus location was leftward in 17 (34%), midline in 22 (44%), and rightward in 11 (22%). Traditional esophagus and ICE imaging correlated within 1 cm in the greatest distance in 26 (52%) patients. Traditional imaging underestimated the esophageal location by >1–1.5 cm in 9 (18%) and >1.5 cm in 15 (30%). In those with poor correlation (>1.5 cm), the most common cause was the presence of a hiatal hernia. Ablation energy delivery was performed outside the greatest esophagus anatomy borders. Of those with 12-month follow-up, 75% were AF/atrial flutter free without antiarrhythmic drugs. No esophageal injuries were observed. One patient experienced a TIA greater than 6 months postablation. Conclusion: These data demonstrate that traditional means of mapping the esophagus using a catheter within the esophagus are insufficient and often grossly underestimate the actual anatomy. Imaging techniques that define the complete esophageal lumen should be considered to truly minimize esophageal injury risk. (J Cardiovasc Electrophysiol, Vol. 24, pp. 33-39, January 2013)

Background: Previous studies have observed that short-term exposure to elevated concentrations of particulate matter (PM) air pollution increases risk of acute ischemic heart disease events and heart failure hospitalization, alters cardiac autonomic function, and increases risk of arrhythmias. This study explored the potential associations between short-term elevations in PM exposure and atrial fibrillation (AF). Methods and Results: A case-crossover study design was used to explore associations between fine PM (PM2.5, particles with an aerodynamic diameter ≤2.5 μm) and 10,457 AF hospitalizations from 1993 to 2008 of patients who lived on Utah's Wasatch Front. Patients were hospitalized at Intermountain Healthcare facilities with a primary diagnosis of AF. Concurrent day exposure and cumulative lagged exposures for up to 21 days were explored and the data were stratified by sex, age, and previous or subsequent admission for myocardial infarction. Although the estimated associations between PM2.5 and AF hospitalizations for the various lag structures and strata were consistently positive suggestive of risk, they were not statistically significant and they were extremely small compared to previously observed associations with ischemic heart disease events and heart failure hospitalizations. Further, we observed no additive risk between PM2.5 and AF hospitalization in those with respiratory disease or sleep apnea. Conclusions: Unlike previously observed associations with ischemic heart disease events and heart failure hospitalizations using similar study design and approaches, this study found that hospitalization for AF was not significantly associated with elevations in short-term exposure to fine PM air pollution. (PACE 2011; 34:1475–1479)

A Strategy of Rapid Cardioversion. Background: The significance of early recurrent atrial tachyarrhythmias after atrial fibrillation (AF) ablation is unclear. Atrial remodeling driven by these tachyarrhythmias can result in electrical, contractile, and structural changes that may impair long-term therapy success. Aggressive attempts to restore sinus rhythm in the temporal period of healing after ablation might improve outcomes. Methods: A total of 1,759 AF ablations were performed at Intermountain Medical Center or LDS Hospital. A total of 455 of those were among patients requiring repeat ablations. Patients were instructed to take their pulse daily and, if greater than 100 bpm or irregular, present the following business day fasting to the clinic for evaluation and cardioversion if AF or atrial flutter (AFL) were present. Results: Of the ablations performed, a total of 515 (29%, age: 65.6 ± 11.2 years, male: 57.9%) developed AF/AFL that required cardioverison. The majority of these arrhythmias first occurred in the initial 90 days (63.7%) postablation. During this period, 62.8% were on an antiarrhythmic drug (AAD). Only 25.1% were using an AAD at 3 months. The majority of ablations (75.6%) who experienced AF/AFL within the first 90 days after ablation were in sinus rhythm with no AAD at 1 year. Further, 48% of those with the first recurrence from 90 to 180 days were in sinus rhythm with no AAD at 1 year. Conclusions: The time at which the first recurrence of AF/AFL occurs impacts long-term outcomes. An aggressive strategy of rapid cardioversion postablation reduces the significance of recurrent AF/AFL during the first 6 months. (J Cardiovasc Electrophysiol, Vol. 22, pp. 761-766, July 2011)

Aims The complete blood count (CBC) and basic metabolic profile are common, low-cost blood tests, which have previously been used to create and validate the Intermountain Risk Score (IMRS) for mortality prediction. Mortality is the most definitive clinical endpoint, but medical care is more easily applied to modify morbidity and thereby prevent death. This study tested whether IMRS is associated with clinical morbidity endpoints. Methods Patients seen for coronary angiography (n = 3927) were evaluated using a design similar to a genome-wide associand results ation study. The Bonferroni correction for 102 tests required a P-value of ≤ 4.9 x 10 -4 for significance. A second set of angiography patients (n = 10 413) was used to validate significant findings from the first patient sample. In the first patient sample, IMRS predicted heart failure (HF) (P trend = 1.6 x 10 -26 ), coronary disease (P trend = 2.6 x 10 -11 ), myocardial infarction (MI) (P trend = 3.1 x 10 -25 ) , atrial fibrillation (P trend = 2.5 × 10 -20 ), and chronic obstructive pulmonary disease (P trend = 4.7 × 10 -4 ). Even more, IMRS predicted HF readmission [hazard ratio (HR) = 2.29/category, P trend = 1.2 x 10 -6 ), incident HF (HR = 1.88/category, P trend = 0.02), and incident MI (HR = 1.56/category, P trend = 4.7 x 10 -4 ). These findings were verified in the second patient sample. Conclusion Intermountain Risk Score, a predictor of mortality, was associated with morbidity endpoints that often lead to mortality. Further research is required to fully characterize its clinical utility, but its low-cost CBC and basic metabolic profile composition may make it ideal for initial risk estimation and prevention of morbidity and mortality. An IMRS web calculator is freely available at http://intermountainhealthcare.org/IMRS. Trial Registration: Database registry ofthe Intermountain Heart Collaborative Study: NCT00406185 (ClinicalTrials.gov).

Radiofrequency ablation is an effective treatment for atrial fibrillation (AF). With improved safety, the therapy has been offered to increasingly older populations. Arrhythmia mechanisms, medical comorbidities, and safety may vary in the very elderly population.Patients presenting for AF ablation were divided into two groups [or =80 years (n = 35),80 years (n = 717)]. AF ablation consisted of pulmonary vein antral isolation with or without additional linear lesions. A successful outcome was defined as no further AF and off all antiarrhythmic medications3 months following 1 + ablation procedures.The type of AF was similar in both groups (paroxysmal: 46% in the older group vs 54% in the younger, P = 0.33). Older patients were more likely to have a higher CHADS2 score, coronary artery disease, and less likely to have had a prior ablation. The hospital stay on average was longer in the older cohort (2.9 +/- 7.7 vs 2.1 +/- 1.1 days, P = 0.001). There was no increased risk of peri-procedural complications. One-year survival free of AF or flutter was 78% in those80 and 75% in those younger (P = 0.78). There was no difference between groups if the AF was paroxysmal (P = 0.44) or persistent/chronic (P = 0.74). Over a 3-year follow-up period, five patients died and four strokes occurred all in the younger cohort.Octogenarian patients, despite more coexistent cardiovascular diseases, have favorable outcomes after AF ablation measured by successful rhythm management. On an average their hospital stay is longer, but no significant increase in short- or long-term complications was observed. These data support AF ablation in select octogenarians.

Background: Atrial fibrillation (AF) is associated with an increased risk of mortality and stroke. However, it is unclear if AF is independently associated with these poor outcomes or it is merely a risk marker of other processes that convey the risk. Methods: Consecutive patients who underwent angiography for suspicion of coronary artery disease, but without a history of AF, were studied. Traditional CHADS2 (congestive heart failure, hypertension, age >75 years, diabetes, stroke/transient ischemic attack) risk factors for each patient were recorded. Results: A total of 343 AF patients (age = 69 ± 10 years, 215 [63%] male) and 2,945 non-AF patients (age = 63 ± 12 years, 2,012 [67%] male) were studied. Among AF patients, 51 (15%) had a myocardial infarction (MI), 35 (10%) had a stroke, and 180 (52%) died. CHADS2 score incrementally increased risk of stroke (adjusted hazard ratio [HR] for 1:1.92, 2:2.30, 3:1.14, 4:3.83, 5:10.96; P-trend = 0.14), death (HR for 1:1.83, 2:2.34, 3:3.69, 4:2.27, 5:4.53; P-trend < 0.001), and major adverse cardiac event (MACE)(HR for 1:1.29, 2:1.54, 3:2.07, 4:2.41, 5:2.68; P-trend = 0.002). Among non-AF patients, CHADS2 score incrementally increased risk of stroke (HR for 1:1.18, 2:3.17, 3:5.08, 4:10.78, 5:7.50; P-trend < 0.001), MI (HR for 1:1.05, 2:1.46, 3:1.57, 4:0.53, 5:4.76; P-trend = 0.002), death (HR for 1:1.79, 2:3.22, 3:6.23, 4:9.09, 5:14.00; P-trend < 0.001), and MACE (HR for 1:1.47, 2:2.36, 3:4.16, 4:5.91, 5:7.56; P-trend < 0.001). Among all patients, both CHADS2 score (all P ≤ 0.001) and AF were independent risk factors for stroke (AF: P = 0.002), MI (AF: P = 0.035), death (AF: P < 0.001), and MACE (AF: P < 0.001). Conclusion: The CHADS2 score is a powerful predictor of stroke and death. AF increases the risk of these outcomes in an independent manner. These data support the concept that AF is a risk factor of future cardiovascular disease.

Background: Inflammation has been shown to have a direct role in the initiation, maintenance, and recurrence of atrial fibrillation (AF) although the underlying mechanisms are unknown. Similarly, it is unclear if inflammatory markers are elevated due to the AF alone or the coexisting cardiovascular diseases that increase the risk of AF. Methods: Consecutive patients who underwent angiography for suspicion of coronary artery disease, but without a myocardial infarction, were studied. Serum was analyzed to determine high-sensitivity C-reactive protein (hs-CRP) level. Patients’ AF status was determined through ICD-9 codes, review of hospital discharge summaries, clinical evaluations, and electrocardiograms. Results: A total of 2,340 patients were studied (64±12 years). Comorbid diseases included 1,438 (61%) coronary artery disease, 1,309 (56%) hypertension, 433 (19%) diabetes, 345 (15%) congestive heart failure, and 43 (2%) a prior stroke. The hs-CRP level was significantly higher in patients with AF (n = 238) compared to those without (14.0 mg/L vs 9.1 mg/L, P < 0.001). Greater CHADS2 score was also significantly associated with higher hs-CRP in a linear fashion (medians [mg/L], 0: 1.99, 1: 2.91, 2: 3.49, 3: 3.89, 4–5: 4.82, P

Esophogeal Perforation, Stenting, and AF Ablation. Background: Left atrial catheter ablation (LACA) has emerged as a successful method to eliminate atrial fibrillation (AF). Recent reports have described atrio-esophageal fistulas, often resulting in death, from this procedure. Temporary esophageal stenting is an established therapy for malignant esophageal disease. We describe the first case of successful temporary esophageal stenting for an esophageal perforation following LACA. Case: A 48-year-old man with symptomatic drug refractory lone AF underwent an uneventful LACA. Fifty-nine ablations with an 8-mm tip ablation catheter (30 seconds, 70 Watts, 55°C), as guided by 3-D NavX™ mapping, were performed in the left atrium to isolate the pulmonary veins as well as a left atrial flutter and roof ablation line. In addition, complex atrial electrograms in AF and sites of vagal innervation were ablated. Two weeks later, he presented with sub-sternal chest pain, fever, and dysphagia. A chest CT showed a 3-mm esophageal perforation at the level of the left atrium with mediastinal soiling and no pericardial effusion. An urgent upper endoscopy with placement of a PolyFlex removable esophageal stent to seal off the esophago-mediastinal fistula was performed. After 3 weeks of i.v. antibiotics, naso-jejunal tube feedings, and esophageal stenting, the perforation resolved and the stent was removed. Over 18 months of follow-up, there have been no other complications, and he has returned to a physically active life and remains free from AF on previously ineffective anti-arrhythmic drugs. Conclusion: Early diagnosis of esophageal perforations following LACA may allow temporary esophageal stenting with successful esophageal healing. Prompt chest CT scans with oral and i.v. contrast should be considered in any patient with sub-sternal chest pain or dysphagia following LACA.

1. When coherent light was passed through isolated isometric cardiac muscles during the diastolic or resting period, intensity fluctuations were observed in the scattered field. The frequency of these intensity fluctuations (f((1/2))) varied with many experimental interventions known to enhance Ca(2+) flux into the cell.2. In rat muscles stimulated at low frequencies (0.1 +/- 2.0 min(-1)) stepwise increases (0.4-10 mm) of [Ca(2+)] in the bathing fluid ([Ca(2+)](e)), or addition of ouabain (10(-6)-6 x 10(-4)m) to the perfusate caused stepwise increases in f((1/2)). These were paralleled by increments in resting force (RF) such that the changes in f((1/2)) and RF were highly correlated. Substitution of K(+) for Na(+) in the perfusate resulted in parallel transients in RF and f((1/2)).3. In contrast to the rat, most cat muscles stimulated at low frequencies in the steady state exhibited neither diastolic intensity fluctuations nor Ca(2+)-dependent changes in RF in [Ca(2+)](e) of 10 mm or less; when [Ca(2+)](e) was increased to 12-32 mm, however, steady-state Ca(2+)-dependent f((1/2)) and RF were observed. In a given [Ca(2+)](e) reduction of [Na(+)](e) increased f((1/2)). In the transient state following cessation of regular stimulation at more rapid rates (12-96 min(-1)) intensity fluctuations were present in all [Ca(2+)](e) and decayed with time (seconds to minutes); the f((1/2)) and time course of the decay of the fluctuations were determined by the rate of prior stimulation and [Ca(2+)](e).4. Maximum potentiation of twitch force in response to the above inotropic interventions was associated with an optimal level of f((1/2)) which was similar in both species; when higher levels of f((1/2)) were produced by more intense inotropic intervention, twitch force declined. Over the range of inotropic intervention up to and including that at which maximum twitch potentiation occurred, the increase in diastolic f((1/2)) predicted the extent of twitch potentiation with a high degree of accuracy (r0.97) both in the transient and steady states.5. In contrast to the other inotropic interventions studied, catecholamines were unique in that neither f((1/2)) nor RF increased over a full range of concentrations that resulted in maximum potentiation of the twitch.6. It is concluded from these observations that f((1/2)) reflects diastolic Ca(2+)-dependent myofilament interaction; the increase in the extent of this interaction by inotropic interventions that do not alter the affinity of the myofilaments for Ca(2+) probably reflects an increase in diastolic myoplasmic [Ca(2+)], an optimal level of which is associated with maximal potentiation of twitch force; the difference in f((1/2)) in rat and cat muscles under a given set of in vitro conditions may be related to the marked species difference in the effectiveness of excitation-contraction coupling.