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Despite advancements, the goal of durable pulmonary vein isolation (PVI) in all patients undergoing ablation for atrial fibrillation (AF) remains elusive. New high-density mapping (HDM) allows detection of concealed low-voltage signals (CLVSs) that persist after PVI and may represent vulnerabilities in the lesion set.The purpose of this study was to determine the incidence of CLVSs after PVI and the effect of CLVS ablation on outcomes.We conducted a case control study comparing 150 patients undergoing HDM-guided PVI and subsequent CLVS mapping and ablation (39 redo, 111 de novo) against 452 historical controls undergoing traditional PVI alone. PVI was similarly performed and confirmed in both groups.Baseline characteristics were similar, except left atrial size was larger in the HDM-guided group. Acute PVI was achieved in nearly all patients in both groups. In the HDM group, 31 of 150 patients exhibited CLVS after luminal PVI, and all were subsequently eliminated. During mean follow-up of 320 days, after controlling for baseline characteristics, the HDM-guided group exhibited a hazard ratio of 0.19 in freedom from AF (P.001). De novo patients exhibited a hazard ratio of 0.44 relative to redo patients in the HDM-guided group. Both subgroups exhibited significantly lower event rates compared to controls in log-rank analysis (P.001).CLVSs are commonly identified with HDM after PVI, likely representing vulnerabilities in antral lesion sets. Ablation of these targets seems to significantly improve freedom from AF compared to PVI alone.

Complete occlusion of the pulmonary veins (PV) is crucial for successful PV isolation. While two different sizes of cryoballoons (23 and 28 mm) are available, complete occlusion is not always achieved in any given PV. We investigated the role of PV ostial anatomy during cryoballoon PV occlusion grading and atrial fibrillation (AF) recurrence rate.PV ostial diameter was analyzed in 168 consecutive patients (111 men, 61 ± 10 years, 124 paroxysmal (px) and 44 persistent AF) using cardiac computed tomography (CT) prior to procedure. The ovality index at the PV ostial level was calculated in any given PV. During follow-up, 7-day holter monitors were performed at 1, 3, 6, 9, 12, 18 and 24 months post-ablation.The success rate at 12 ± 6 months follow-up was 69% including a 3-month blanking period (px AF: 66%; persistent AF 77%). The ovality index of the left-sided PVs was significantly larger ("more oval") than that of the right-sided PVs (p0.001). An optimized PV occlusion in all individual PVs (complete occlusion, grading 4/4) was achieved during ablation in 49% of patients with AF recurrence and in 73% of patients without AF recurrence (p=0.004). Patients with AF recurrence had "more oval" left-sided PVs compared to patients free from AF recurrence (LSPV 0.40 ± 0.2 vs. 0.33 ± 0.2; p=0.04 and LIPV 0.41 ± 0.3 vs. 0.32 ± 0.2; p=0.03), whereas no significant association was found for right sided PVs.The ostial PV anatomy seems to have an important impact on clinical outcome and should be considered when planning and performing cryoballoon AF ablation procedures.

Background: In the current age of ever-increasing healthcare costs, it is of utmost importance to adopt strategies that reduce hospital stay and cost, while still maintaining patient safety. In this study we review our approach of same-day discharge following implantable cardioverter defibrillator (ICD) placement for primary prevention of sudden cardiac death (SCD). Methods: We conducted a retrospective chart review of 415 consecutive patients who underwent ICD implantation for prevention of SCD between 2007 and 2010. Patients were divided into an outpatient group (Group A) and an inpatient group (Group B). We evaluated the patients’ demographics, comorbidities, and the rate of short-term surgical complications on or before the 2-week follow-up appointment. Results: Of 252 patients included in Group A, 198 (78.6%) were successfully discharged on the same day (Group A1). At the 2-week wound check appointment, four patients (2%) had minor surgical site bleeding, one patient had a hematoma, and one patient developed fever and swelling around the implantation site. Of the Group A patients, 54 (21.4%) were not discharged on the same day (Group A2). A total of 53 patients were included in Group B, four (7.5%) developed a hematoma at the 2-week follow-up wound check visit. Conclusions: Procedure-related complications after ICD placement are rare. Same-day discharge is safe and feasible following ICD placement for primary prevention of SCD and hence a reduction in healthcare costs can be achieved by decreasing the length of hospital stay. (PACE 2013; 00:1‐7)

Implantable cardioverter defibrillators (ICDs) have become an important part of the management of patients with congestive heart failure. At the time of ICD implantation, ventricular fibrillation (VF) is induced to assess adequate energy required for defibrillation. There are multiple parameters which influence the defibrillation safety margin (DSM); however, these factors are not well-established when ICDs are implanted for the primary prevention of sudden cardiac death (SCD) in patients with severe systolic dysfunction. We evaluated multiple clinical and echocardiographic parameters as predictors of adequate DSM in patients referred for ICD implantation for the primary prevention of SCD.We prospectively enrolled 41 patients for ICD implantation with clinical indications for the primary prevention of SCD. Two blinded independent readers evaluated the prespecified echocardiographic parameters. These included left ventricular (LV) mass, indices of right ventricular and LV systolic and diastolic functions, and LV geometric dimensions. Basic clinical demographics, including age, gender, comorbidities, and etiology of cardiomyopathy, were also evaluated. DSM was established using our standard protocol for defibrillation testing which includes VF with successful first shock terminating VF at a value at least 10 J below the maximum output of the implanted device. High defibrillation thresholds (DFT) were defined as21 J.The mean age is 61.8 ± 14.7 years, with men comprising the majority of the patients (73 %). The only clinical variables which predicted the high DFT were age (in years) (54.5 ± 17.5 vs. 65.7 ± 11.3, p = 0.044), QRS duration (in milliseconds) (116.0 ± 29.5 vs. 110.5 ± 21.8, p = 0.03), LV mass (in grams) (241.0 ± 77.9 vs. 181.9 ± 52.3, p = 0.006), and LV mass index (in grams per square meter) (111.1 ± 38.2 vs. 86.4 ± 21.1, p = 0.02). On multivariate logistic regression analysis, LV mass was the only independent predictor of low DFT (≤22 J) in patients with ICD implanted for the primary prevention of SCD.LV mass may help predict an adequate DSM in patients who are referred for ICD implantation for the primary prevention of SCD. These results may help distinguish the patients who may require high-energy devices prior to the implantation procedure. These results may help distinguish patients requiring high-energy devices, coils, or advanced programming prior to implantation and appropriate referral to electrophysiologists.

Background: Nonaccidental falls are often the result of a combination of factors including cardiovascular disorders such as orthostatic hypotension and unspecified cardiac arrhythmias. The objective of this study was to determine if there is an association between atrial fibrillation (AF) and nonaccidental falls. Methods: We reviewed the records of 442 consecutive patients >65 years old who presented to the Emergency Department at the University of Utah Medical Center with a complaint of fall. Results: Two-hundred eleven patients presented with nonaccidental fall, 231 patients with accidental fall. Patients with nonaccidental fall were more likely to be older, have a history of hypertension and neurological disorders, and taking five or more medications when compared to patients with accidental fall. Despite a similar prevalence of sinus rhythm at presentation, the prevalence of a history of AF was significantly higher in patients with nonaccidental fall compared to patients with accidental fall (26% vs 15%; P = 0.003). After adjusting for clinically and statistically significant predictors with a multivariate logistic regression analysis, AF, neurological disorders, and age ≤81 years were independent predictors of nonaccidental fall. In patients ≤81 years old (median age), the risk of nonaccidental falls was 2.5 times greater in patients with a history of AF when compared to those without a history of AF (odds ratio = 2.53 [confidence interval 95% 1.3-5], P = 0.007). Conclusion: AF is an independent risk factor for nonaccidental falls. Our results emphasize the need to screen for AF in patients presenting with nonaccidental fall. (PACE 2012;XX:1-7). Language: en

Introduction Chest pain after atrial fibrillation (AF) ablations is a common complaint with a wide differential diagnosis including coronary events. Elevation of troponins (Trop I) has been shown with radio-frequency (RF) ablation for atrial fibrillation. New devices including cryoballoon and multipolar ablation catheters have been introduced as alternative methods. We aim to compare cardiac injury following AF ablations according to different ablation technologies. Methods In consecutive patients undergoing AF ablations with RF ablation, cryoballoon or multipolar ablation catheter (PVAC), Trop I, creatine kinase (CK) and CRP were analyzed immediately prior to and 24h following completion of ablation. Coronary events and symptoms and serial ECGs post procedure were evaluated. Results A total of 243 patients were included, 18.5% of them females. The mean age was 63±11years old. Baseline Trop I, CK and CRP levels were within normal range in all patients. After RF ablation Trop I, CK and CRP levels were elevated in 100%, 20% and 91% of patients respectively (Trop I 3.55pg/ml [range: 0.60–24.01pg/ml], CK 147U/l [range: 56–380U/l] and CRP 2.15mg/dl [range: 0.28–20.98mg/dl]). All post-procedure Trop I levels were above the range of myocardial infarction (>0.15ng/ml). After cryoballoon ablation, Trop I and CK levels were significantly higher than after RF or PVAC ablation (p Conclusions Trop I elevations are not specific for ischemia in the setting of chest pain after AF ablation. Cryoballoon ablation resulted in a higher amount of cardiac injury.

The aim of this study was to assess acute ablation injuries seen on late gadolinium enhancement (LGE) magnetic resonance imaging (MRI) immediately post-ablation (IPA) and the association with permanent scar 3 months post-ablation (3moPA).Success rates for atrial fibrillation catheter ablation vary significantly, in part because of limited information about the location, extent, and permanence of ablation injury at the time of procedure. Although the amount of scar on LGE MRI months after ablation correlates with procedure outcomes, early imaging predictors of scar remain elusive.Thirty-seven patients presenting for atrial fibrillation ablation underwent high-resolution MRI with a 3-dimensional LGE sequence before ablation, IPA, and 3moPA using a 3-T scanner. The acute left atrial wall injuries on IPA scans were categorized as hyperenhancing (HE) or nonenhancing (NE) and compared with scar 3moPA.Heterogeneous injuries with HE and NE regions were identified in all patients. Dark NE regions in the left atrial wall on LGE MRI demonstrate findings similar to the "no-reflow" phenomenon. Although the left atrial wall showed similar amounts of HE, NE, and normal tissue IPA (37.7 ± 13%, 34.3 ± 14%, and 28.0 ± 11%, respectively; p = NS), registration of IPA injuries with 3moPA scarring demonstrated that 59.0 ± 19% of scar resulted from NE tissue, 30.6 ± 15% from HE tissue, and 10.4 ± 5% from tissue identified as normal. Paired t-test comparisons were all statistically significant among NE, HE, and normal tissue types (p0.001). Arrhythmia recurrence at 1-year follow-up correlated with the degree of wall enhancement 3moPA (p = 0.02).Radiofrequency ablation results in heterogeneous injury on LGE MRI with both HE and NE wall lesions. The NE lesions demonstrate no-reflow characteristics and reveal a better predictor of final scar at 3 months. Scar correlates with procedure outcomes, further highlighting the importance of early scar prediction.

BACKGROUND: Implantable heart rhythm devices are susceptible to interference in hospitals where electromagnetic interference (EMI) sources are ubiquitous. CASE DESCRIPTION: We report three cases in which EMI from the external defibrillator caused the inability to interrogate Boston Scientific cardiac resynchronization therapy-pacemaker (CRT-P) devices. We have documented interference with the Boston Scientific CRT-P Contact Renewal device model numbers H120/H125 (Natick, MA, USA) and two brands of external defibrillators: the Philips Heartstart XL model number M4735A (Andover, MA, USA) and the Hewlett-Packard Codemaster model number M1722B (Palo Alto, CA, USA). For device implants, we routinely place external pacing pads with the external defibrillator in the "standby" mode for transcutaneous pacing so that only the pacer "start/stop" button needs to be pressed when necessary. We have not been able to interrogate three consecutive Boston Scientific CRT-P devices prior to closure while the external defibrillator had the back-up pacing mode on "standby." In our initial case, a second device was opened because this interaction was not recognized. We documented EMI with the standby pacing mode ON and discovered that by disabling only the "standby" pacing mode on the external defibrillator, the device could be interrogated without difficulty. CONCLUSIONS: This is a case series reporting EMI with a Boston Scientific CRT-P Contact Renewal device H120/H125 telemetry from an external defibrillator with pacing mode on "standby." Failure to recognize this important interaction may lead to inappropriate device and resource utilization.

Cardiac rhythm devices are increasingly being utilized as the population ages and the incidence of chronic heart failure, bradyarrhythmias and the indications for pacing and prevention of sudden cardiac arrest expand. The number of patients receiving oral anticoagulants and dual antiplatelet therapy is similarly increasing. Implantation of cardiac rhythm devices during concomitant use of oral anticoagulants or antiplatelet regimens poses an increased risk of perioperative bleeding complications. Traditionally, heparin-based bridging protocols have been recommended for such patients to mitigate the bleeding risk while reducing the risk of thrombotic complications. Although the literature is limited, an appraisal of the literature reveals that bridging may not be the best strategy. We review the literature and propose strategies to promote successful perioperative outcomes, while reducing the risk of bleeding or thrombosis during the time of implantation for patients on chronic anticoagulation and antiplatelet therapies.

Despite identifying several risk factors for sudden cardiac death, our ability to predict arrhythmic events in patients with an implantable cardioverter defibrillator (ICD) remains poor. The purpose of this study was to determine if patients who received appropriate ICD shocks had a higher degree of right ventricular (RV) dysfunction at baseline when compared to patients who did not receive ICD shocks.We conducted a 1:2 case-control, retrospective study comparing RV end-diastolic and end-systolic areas (RV ED and RV ES areas, respectively), fractional RV area change, and RV wall thickness in 19 consecutive patients who received appropriate ICD shocks (shock group) with another group of 38 patients who did not receive ICD shocks (no-shock group).There was no significant difference in the RV end-diastolic areas between the groups. However, patients who experienced ICD shocks had a higher RV end-systolic area and a lower RV fractional area change when compared to patients without ICD shocks, 16.3 ± 4.9 cm(2) and 27.7 ± 9.0% in the shock group versus 14.2 ± 4.4 cm(2) and 35.8 ± 10.3% in the no-shock group; (p = 0.08 and 0.004, respectively). Furthermore, the RV wall thickness was greater in patients with ICD shocks when compared to patients without ICD shocks, 0.49 ± 0.05 cm and 0.44 ± 0.04 cm, respectively (p = 0.001). Utilizing a logistic regression analysis and after controlling for variables with univariate significance (p0.1), RV wall thickness independently predicted ICD shocks (OR 13.9 mm(-1) change of RV thickness, p = 0.004).Our findings suggest that some measurements of RV function might prove to be useful in predicting future arrhythmic events. Additional prospective studies are needed to test this hypothesis.

Background Magnetic resonance imaging (MRI) allows visualization of location and extent of radiofrequency (RF) ablation lesion, myocardial scar formation, and real-time (RT) assessment of lesion formation. In this study, we report a novel 3-Tesla RT -RI based porcine RF ablation model and visualization of lesion formation in the atrium during RF energy delivery. Objective The purpose of this study was to develop a 3-Tesla RT MRI-based catheter ablation and lesion visualization system. Methods RF energy was delivered to six pigs under RT MRI guidance. A novel MRI-compatible mapping and ablation catheter was used. Under RT MRI, this catheter was safely guided and positioned within either the left or right atrium. Unipolar and bipolar electrograms were recorded. The catheter tip–tissue interface was visualized with a T1-weighted gradient echo sequence. RF energy was then delivered in a power-controlled fashion. Myocardial changes and lesion formation were visualized with a T2-weighted (T2W) half Fourier acquisition with single-shot turbo spin echo (HASTE) sequence during ablation. Results RT visualization of lesion formation was achieved in 30% of the ablations performed. In the other cases, either the lesion was formed outside the imaged region (25%) or the lesion was not created (45%) presumably due to poor tissue–catheter tip contact. The presence of lesions was confirmed by late gadolinium enhancement MRI and macroscopic tissue examination. Conclusion MRI-compatible catheters can be navigated and RF energy safely delivered under 3-Tesla RT MRI guidance. Recording electrograms during RT imaging also is feasible. RT visualization of lesion as it forms during RF energy delivery is possible and was demonstrated using T2W HASTE imaging.

Background:Fainting is a major healthcare problem with significant morbidity, mortality, and healthcare cost. We sought to assess the appropriateness of current clinical practice when compared to a guideline-based algorithm. Methods:The records of 100 consecutive patients who presented with faint and were referred to the University of Utah for further evaluation by specialists were reviewed. We analyzed the clinical characteristics, tests performed, diagnosis made, and number of admissions. In addition, we applied a guideline-based algorithm to assess the appropriateness of these evaluations. Results:The mean age was 49 ± 21 years with 57% being female. One-third presented with their first event. Structural heart disease was present in 22% of the cases. Twelve (36%) of 32 admissions were inappropriate. There was an underutilization of orthostatic testing, carotid sinus massage, and implantable loop recorder and overutilization of imaging studies and neurologic consultation. Specifically, active standing and tilt-table testing were performed in only 24% and 7% of the cases, respectively, none of the patients had carotid sinus massage despite 26% of them being ≥65 years old, and only 3% of the patients received an implantable loop recorder. With the current practice, a final diagnosis was made in 45 cases with 17 (38%) of the 45 final diagnoses not being sufficiently supported by the completeness of the evaluation. Conclusion:With the current practice at a major university hospital, the cause of faint was unexplained in a high number of cases. Our findings highlight the need for a standardized approach to patients presenting with faint. (PACE 2011; 34:284–290)

Background: Ectopy-induced cardiomyopathy is an increasingly recognized cause of reversible left ventricular (LV) dysfunction. The underlying mechanisms remain unknown. Our goal was to create an animal model for ectopy-induced cardiomyopathy. Methods: Eleven mongrel dogs underwent the implantation of a dual-chamber pacemaker. Four dogs served as the control group and seven as the paced group. In the paced group, the pacemaker was connected to two endocardial right ventricular leads, one inserted into the atrial port and the other one into the ventricular port with an atrioventricular delay adjusted to ensure the presence of coupled pacing simulating ventricular bigeminy. Echocardiographic measurements of LV size (LV end-diastolic diameter [LV-EDD], LV end-systolic diameter [LV-ESD]), LV ejection fraction (LVEF), and mitral regurgitation (MR) were obtained at baseline and after 4 weeks of monitoring or pacing in all dogs except one who had lead dislodgement. Results: In the control group (n = 4), no significant changes in LV dimensions or function were noted. In the paced group (n = 6), LV-EDD and LV-ESD increased from 3.58 ± 0.65 cm and 2.47 ± 0.55 cm to 4.15 ± 0.59 cm and 3.21 ± 0.47 cm, respectively (P < 0.01). In addition, LVEF decreased from 60 ± 7% to 46 ± 9% (P < 0.05). No changes in MR were noted. Conclusion: We have shown that coupled pacing simulating ventricular bigeminy was feasible and resulted in increased LV dimensions and decreased LV function. By controlling the percentage of pacing, the coupling interval and the location of the pacing lead, this new model will allow the assessment of the relative roles of these variables in the development of ectopy-induced cardiomyopathy. (PACE 2011; 34:291–295)

Background: Understanding the frequency and economic impact of faint and fall is a prerequisite for the creation of cost-effective diagnostic approaches. Methods: We evaluated the total number of patients presenting with faint or fall to the University of Utah Health Care System between November 1, 2008, and October 31, 2009. Using these data, we estimated the prevalence and total cost of the faint and fall problem in the state of Utah. Results: A total of 1,936 and 6,043 patients presented with faint and fall resulting in a total number of visits equal to 2,701 and 8,163, respectively. The yearly prevalence of faints was 9.5 patients (13.2 visits) per 1,000 inhabitants and the yearly prevalence of falls was 29.8 patients (40.2 visits) per 1,000 inhabitants. The prevalence of faints and falls progressively increased with age, reaching the values of 40 and 115 per 1,000 inhabitants in subjects aged >80 years. In both patient populations, two-thirds of visits were outpatient evaluations. While the cardiovascular service was involved in the outpatient evaluation of faint visits in 24% of the cases, Language: en

BACKGROUND Lone atrial fibrillation (AF) is thought to be a benign type or an early stage of the disease. OBJECTIVE This study sought to compare the left atrium (LA) substrate using delayed-enhanced magnetic resonance imaging (DE-MRI) in patients with lone AF versus those with comorbidities. METHODS Forty of 333 included patients met criteria for lone AF. All patients underwent DE-MRI to quantify atrial fibrosis as a marker for structural remodeling (SRM) and underwent catheter ablation. Based on the degree of SRM, patients were staged into 4 groups: Utah I (5% LA wall enhancement), Utah II (5% to 20%), Utah III (20% to 35%), or Utah IV (35%). RESULTS Distribution in Utah I to IV was comparable in patients with lone AF and non‐lone AF. In both groups, a number of patients showed extensive SRM. Mean enhancement (14.08 8.94 vs. 16.94 11.37) was not significantly different between the 2 groups (P .0721). In the lone AF group, catheter ablation was successful in suppressing AF in all of Utah I, 81.82% of Utah II, 62.5% of Utah III, and none of Utah IV patients. Similar results were achieved in the non‐lone AF group. Outcome after ablation was significantly dependent on the SRM of the LA (P .001). CONCLUSION The degree of LA structural remodeling as detected using DE-MRI is independent of AF type and associated comorbidities. Selecting appropriate treatment candidates based on the quality and quantity of atrial fibrosis using DE-MRI would improve procedural outcome and avoid unnecessary intervention.

Ventricular tachycardia (VT) in patients without structural heart disease can be observed in 10% of patients presenting with ventricular arrhythmias. These VTs are characterized by QRS morphology, ventricular origin and their response to pharmacologic agents. It is essential to rule out structural heart disease in this population as this can significantly alter the management and the long-term prognosis. These VTs generally have a benign course and therapeutic options are aimed at relieving symptoms related to the arrhythmia. Medical therapy is effective in many patients and radiofrequency offers a cure to those who are refractory to medical therapy. Careful attention to the electrocardiogram can help localize the origin of the VTs, which is crucial when planning an ablation strategy.

Background: Many patients who need cardiac resynchronization therapy (CRT) require chronic anticoagulation. Current guidelines recommend discontinuation of warfarin and the initiation of anticoagulant “bridging” therapy during these procedures. We evaluated the safety of CRT-device (CRT-D) implantation without interruption of warfarin therapy. Methods: A total of 123 consecutive patients requiring CRT-D therapy were enrolled, 49 identified as high risk for thromboembolic events who received either intravenous heparin, low molecular weight heparin, or warfarin therapy. The control group comprised 74 patients with low risk of thromboembolic events who required only cessation of warfarin perioperatively. Patients were evaluated at discharge and 15 and 30 days postoperatively for pocket hematomas, thromboembolic events, and bleeding. Patients’ length of stay was also catalogued. Results: Patients in the bridging arm had a significant increase in the rate of pocket hematomas (4.1%[control] vs 5.0%[warfarin] vs 20.7%[bridging], P = 0.03) and subsequent longer length of stay (1.6 ± 1.6 [control] vs 2.9 ± 2.7 [warfarin] vs 3.7 ± 3.2 [bridging], P < 0.001). Hematoma formation postoperatively was not different among patients undergoing an upgrade procedure versus those without preexisting cardiac rhythm devices (12% vs 6.2%, P = NS). Patients with a prosthetic mechanical mitral valve had a higher incidence of pocket hematoma formation (1.8% vs 20%, P = 0.03). Conclusions: Our findings suggest that implantation of CRT-Ds without interruption of warfarin therapy in patients at high risk of thromboembolic events is a safe alternative to routine bridging therapy. This strategy is associated with reduced risk of pocket hematomas and shorter length of hospital stay. (PACE 2010; 400–406)

Radiofrequency catheter ablation (RFCA) has been established as a curative alternative to antiarrhythmic drug (AAD) therapy in patients with supraventricular arrhythmias other than atrial fibrillation (AF). Many currently used AAD have limited efficacy and cause cardiac and extracardiac adverse effects. There is a need for new AADs with high efficacy and a favorable safety profile in AF patients. Dronedarone and vernakalant are promising new agents with a low risk profile up to date. Effectively restoring sinus rhythm is a crucial aspect in heart failure (HF) patients with AF. RFCA, including pulmonary vein isolation and other left and right atrial ablation targets, offers the possibility of long-term suppressive or curative therapy of AF. New antiarrhythmic drug and interventional concepts in AF and HF patients are discussed.

Background. Because of small size and anatomic variation, implantation of intracardiac leads for permanent pacing in pediatric and congenital heart disease (CHD) patients can be challenging. A novel 4.1F bipolar catheter-delivered lead offers potential advantages for this population. Objective. The purpose of this study was to retrospectively evaluate this lead performance in this specific population. Methods. We performed a retrospective descriptive analysis of all pediatric and adult CHD patients at a single center implanted with a 4.1F bipolar catheter-delivered active fixation pacemaker lead (Medtronic model 3830, Medtronic, Inc, Minneapolis, MN, USA). Results. Over 10 months, 42 leads were implanted in 27 patients. Twenty-six atrial and 16 ventricular leads were placed. Patient ages were 1–28 years (mean 15 ± 7), and weights were 7.8–104 kg (mean 51.5 ± 26.6). Ventricular septal defect and D-transposition of great arteries were the most prevalent CHD diagnoses. Implant capture thresholds were 1.2 ± 0.8 V at 0.5 ms in the atrium and 0.8 ± 0.5 V at 0.5 ms in the ventricle. Implant sensing thresholds were 4.1 ± 2.7 mV in the atrium and 12.1 ± 4.9 mV in the ventricle. Phrenic nerve stimulation was avoided in all, and selective site pacing was achieved in most cases. Pacing and sensing thresholds remained stable during 90 ± 52 days follow-up. No lead related complications, failures, or extractions were observed. Conclusions. In our single-center experience with pediatric and CHD patients, a novel small, catheter-delivered bipolar lead has proven safe and effective for atrial and ventricular pacing in acute and subacute time periods. Longer performance trends will be required to determine chronic efficacy.

Cardiac imaging, both noninvasive and invasive, has become a crucial part of evaluating patients during the electrophysiology procedure experience. These anatomical data allow electrophysiologists to not only assess who is an appropriate candidate for each procedure, but also to determine the rate of success from these procedures. This article incorporates a review of the various cardiac imaging techniques available today, with a focus on atrial arrhythmias, ventricular arrhythmias and device therapy.

Background:The incidence of conduction disease requiring permanent pacemaker (PPM) implantation following aortic valve replacement (AVR) ranges from 3% to 6%. Data concerning the potential risks for PPM requirement associated with certain valve types have been conflicting and controversial. We sought to evaluate the prevalence, predictors for PPM implantation, and PPM dependency during follow-up in patients undergoing AVR. Methods:A total of 214 consecutive patients undergoing AVR were studied retrospectively. A total of 207 patients were included in the statistical analysis. Clinical variables including valve size and types were catalogued and the incidence of PPM evaluated. Cardiac rhythm device clinic records were examined and PPM dependency status was catalogued. Multivariate analyses were performed to determine predictors of PPM implantation and PPM dependency during follow-up. Results:Fifteen patients (7.2%) required PPM postoperatively. After controlling for clinical and surgical characteristics, predictors for PPM included preoperative first-degree atrioventricular block with and without left anterior fascicular block or intraventricular conduction delay [odd ratios (OR) = 12.5, P = 0.001], cardiac arrest postoperatively (OR = 9.4, P = 0.012), and combined aortic and mitral valve surgery (OR = 11.5, P = 0.027). Aortic valve types did not predict complete heart block (CHB) and PPM implantation. Of those patients who underwent PPM implantation, 70% were classified as PPM dependent during long-term follow-up. Conclusion:CHB and PPM implantation continue to be common complications of AVR. Preexisting atrioventricular with intrafascicular or intraventricular conduction disease along with cardiac arrest and dual valve surgery are the most important significant predictors of PPM implantation and PPM dependency during follow-up. The selection of valve types did not predict conduction disease requiring PPM implantation.

Aims: Pulmonary vein antrum isolation (PVAI) plays a pivotal role in the comprehensive treatment of atrial fibrillation (AF). The need for effective anticoagulation bridging following PVAI is associated with significant vascular complication rates and increased costs. We investigated the safety of PVAI in patients with therapeutic international normalized ratios (INR) the day of the procedure. Methods: A case-control analysis was performed on patients who underwent PVAI with therapeutic INR (>2). Patients with normal preprocedure INR served as controls. The incidence of major and minor hematomas, fistulas, vascular injury, and cardiac perforation or tamponade were catalogued. PVAI was performed under fluoroscopic, electro-anatomical, and intracardiac echocardiographic guidance, with an open irrigation ablation technique. Results: A total of 194 patients (mean age 64 ± 12) were included; 87 patients underwent PVAI with therapeutic INR (cases) and 107 with normal INR (controls). Persistent AF was more prevalent than paroxysmal AF in the therapeutic INR group. The mean INR for cases was 2.8 ± 0.7 compared to 1.4 ± 0.3 in the control group (P < 0.01). All procedures were completed without acute complications. Two major adverse events were observed, one in each arm. No significant difference in terms of minor (6.5% vs. 5.7%, P = 0.23) or major (0.93% vs. 1.15%, P = 0.49) vascular events or bleeding was detected between the therapeutic INR and the control group. The combined endpoint of major and minor complications did not differ among groups (9.35% vs. 8.05%, P = 0.19). Conclusion: Atrial fibrillation ablation in patients with therapeutic INR on the day of a procedure appears to be safe and feasible. Expensive outpatient anti-coagulation bridging may be safely avoided in this type of population.

Background— Atrial fibrillation (AF) is associated with diffuse left atrial fibrosis and a reduction in endocardial voltage. These changes are indicators of AF severity and appear to be predictors of treatment outcome. In this study, we report the utility of delayed-enhancement magnetic resonance imaging (DE-MRI) in detecting abnormal atrial tissue before radiofrequency ablation and in predicting procedural outcome. Methods and Results— Eighty-one patients presenting for pulmonary vein antrum isolation for treatment of AF underwent 3-dimensional DE-MRI of the left atrium before the ablation. Six healthy volunteers also were scanned. DE-MRI images were manually segmented to isolate the left atrium, and custom software was implemented to quantify the spatial extent of delayed enhancement, which was then compared with the regions of low voltage from electroanatomic maps from the pulmonary vein antrum isolation procedure. Patients were assessed for AF recurrence at least 6 months after pulmonary vein antrum isolation, with an average follow-up of 9.6±3.7 months (range, 6 to 19 months). On the basis of the extent of preablation enhancement, 43 patients were classified as having minimal enhancement (average enhancement, 8.0±4.2%), 30 as having moderate enhancement (21.3±5.8%), and 8 as having extensive enhancement (50.1±15.4%). The rate of AF recurrence was 6 patients (14.0%) with minimal enhancement, 13 (43.3%) with moderate enhancement, and 6 (75%) with extensive enhancement ( P Conclusions— DE-MRI provides a noninvasive means of assessing left atrial myocardial tissue in patients suffering from AF and might provide insight into the progress of the disease. Preablation DE-MRI holds promise for predicting responders to AF ablation and may provide a metric of overall disease progression.

Objectives We describe a noninvasive method of detecting and quantifying left atrial (LA) wall injury after pulmonary vein antrum isolation (PVAI) in patients with atrial fibrillation (AF). Using a 3-dimensional (3D) delayed-enhancement magnetic resonance imaging (MRI) sequence and novel processing methods, LA wall scarring is visualized at high resolution after radiofrequency ablation (RFA). Background Radiofrequency ablation to achieve PVAI is a promising approach to curing AF. Controlled lesion delivery and scar formation within the LA are indicators of procedural success, but the assessment of these factors is limited to invasive methods. Noninvasive evaluation of LA wall injury to assess permanent tissue injury may be an important step in improving procedural success. Methods Imaging of the LA wall with a 3D delayed-enhanced cardiac MRI sequence was performed before and 3 months after ablation in 46 patients undergoing PVAI for AF. Our 3D respiratory-navigated MRI sequence using parallel imaging resulted in 1.25 × 1.25 × 2.5 mm (reconstructed to 0.6 × 0.6 × 1.25 mm) spatial resolution with imaging times ranging 8 to 12 min. Results Radiofrequency ablation resulted in hyperenhancement of the LA wall in all patients post-PVAI and may represent tissue scarring. New methods of reconstructing the LA in 3D allowed quantification of LA scarring using automated methods. Arrhythmia recurrence at 3 months correlated with the degree of wall enhancement with >13% injury predicting freedom from AF (odds ratio: 18.5, 95% confidence interval: 1.27 to 268, p = 0.032). Conclusions We define noninvasive MRI methods that allow for the detection and quantification of LA wall scarring after RF ablation in patients with AF. Moreover, there seems to be a correlation between the extent of LA wall injury and short-term procedural outcome.

Introduction: Several noninvasive measures of cardiac risk such as heart rate variability (HRV) cannot be used in patients with atrial fibrillation (AF). One promising exception is the measure of ventricular cycle length entropy (VCLE) where initial data suggest that a reduction in VCLE portends an increased risk of cardiac death in patients with chronic AF. In this study, we hypothesized that measures of short-term HRV during sinus rhythm would correlate with measures of cycle length entropy during paroxysms of AF. Methods: We tested 25 Holter recordings of paroxysmal AF from the Physionet AF Prediction Database. We calculated HRV parameters including standard deviation of all NN intervals (SDNN), the root mean square root of the differences between adjacent NN intervals (RMSSD), standard deviation of 5-minute averages of NN intervals (SDANN), percentage of adjacent NN interval differences >50 ms (pNN50), and interbeat correlation coefficient (ICC) from 30 minutes of normal sinus rhythm, and entropy measures (the Shannon Informational Entropy [ShEn] and Average of Approximate Entropy [ApEn]) from 5 minutes of AF that occurred during the same 24-hour monitor. Pairwise correlations were used to assess associations, as regression residuals were normally distributed. Results: The mean entropy measures during AF were: ShEn: 4.78 ± 0.82, ApEn: 0.198 ± 0.21. When assessed during the 30 minutes immediately preceding AF onset, ICC showed a significant negative correlation with both ShEn (r =–0.65, P < 0.001) and ApEn (r =–0.60, P < 0.01). RMSSD also correlated with both ShEn (r = 0.41, P = 0.04) and ApEn (r = 0.39, P = 0.05), but other HRV measures showed no correlation with VCLE during AF. Conclusion: Reductions in RMSSD or increases in ICC, two short-term HRV measures that are known to reflect parasympathetic function in sinus rhythm, are correlated with reductions in the entropy of ventricular response intervals during AF. Our findings suggest that entropy during AF may be modulated, in part, by vagal innervation.

Although modest elevations in pacing rate improve cardiac output and induce reflex sympathoinhibition, the threshold rate above which hemodynamic perturbations induce reflex sympathoexcitation remains unknown. Systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressures (MAP) and sympathetic nerve activity (SNA) were measured during normal sinus rhythm (NSR) and atrioventricular (AV) sequential pacing in 25 patients. Pacing was performed at 100, 120, and 140 beats/min with an AV interval of 100 ms. Patients were divided into two groups based on normal or abnormal left ventricular ejection fraction (LVEF): group 1 ( n = 11; mean LVEF, 55%) and group 2 ( n = 14; mean LVEF, 31%). In group 1, relative to NSR, SBP decreased an average of 2%, 3%, and 8% at 100, 120, and 140 beats/min ( P < 0.001), respectively. DBP and MAP increased 9%, 15%, and 15% ( P = 0.001) and 3%, 6%, and 5% [ P = not significant (NS)], respectively. In group 2, SBP reductions were even greater, with an average decrease of 4%, 8%, and 16% ( P < 0.001). Whereas DBP increased 9%, 9%, and 8% at 100, 120, and 140 beats/min ( P = NS), MAP increased 3% and 2% at 100 and 120 beats/min but decreased 3% at 140 beats/min ( P = 0.001). SNA recordings were obtained in 11 patients (6 in group 1 and 5 in group 2). In group 1, SNA decreased during all rates, with a mean 21% reduction. In group 2, however, SNA decreased at 100 and 120 beats/min (49% and 38%) but increased 24% at 140 beats/min. Patients with depressed LVEF exhibited altered hemodynamic and sympathetic responses to rapid sequential pacing. The implications of these findings in device programming and arrhythmia rate control await future studies.

The catheter-based ablation of atrial fibrillation has been transformed greatly by the introduction of new technologies and techniques. This article describes the major advancements in real-time navigation systems, including both 3D mapping systems and 2D echocardiography. The relative strengths and weakness of these systems and their accuracy on clinical outcome is also discussed. Finally, we explore current and emerging MRI technologies that will allow the assessment of disease progression and enable procedural planning.

Aims The purpose of this study was to compare, in a prospective and operator-blinded fashion, the mapping accuracy of the three-dimensional (3D) electro-anatomical image integration and phased array intracardiac echocardiography (ICE) as a real-time imaging modality. Methods and results Prospectively, 18 patients undergoing pulmonary vein antrum isolation (PVAI) were included. Patients underwent a cardiac computerized tomography scan to define PV and left atrial (LA) anatomy. Image segmentation and integration was performed by CARTOMERGE, followed by 3D volume rendering and image integration. Error profiles between ICE-guided to CARTO and CARTO-guided to ICE were performed in an operator-blinded fashion over PV predetermined points. All patients underwent successful PVAI. The mean age was 55 +/- 10 years, with a mean LA size of 4.5 +/- 0.3 cm. CARTOMERGE-guided catheter positioning was subject to spatial errors on the order of 0.5-1.0 cm relative to ICE imaging, with greatest magnitude near the LA appendage (LAA) and least near the RIPV. The magnitude of spatial error between these two methods is demonstrable regardless of the choice of reference. Conclusion During electro-anatomical mapping of the LA, CARTO-guided navigation is associated with considerable spatial error relative to anatomic features as identified by ICE. Adjunctive real-time imaging is needed to ensure accurate delivery of radiofrequency lesions.

INTRODUCTION We performed a prospective study to compare efficacy and safety of both open irrigation tip (OIT) technology with intracardiac echo (ICE)-guided energy delivery in patients presenting for PVAI. METHODS AND RESULTS Fifty-three patients presenting for PVAI were randomized to ablation using an OIT catheter (Group 1, 26 patients; temperature and power were set at 50 degrees and 50 W, respectively, with a saline pump flow rate of 30 mL/min) or radiofrequency (RF) energy delivery under ICE guidance (Group 2, 27 patients; energy was titrated based on microbubbles formation). The mean procedure time and fluoroscopy exposure were lower in Group 1 (164 +/- 42 min and 7,560 +/- 2,298 microGray m2 vs 204 +/- 47 min and 12,240 +/- 4,356 microGray m2; P = 0.005 and 0.008, respectively). Moreover, the durations of RF lesions applied per PV antrum was lower in Group 1 compared with Group 2 (5.1 +/- 2.2 min vs 9.2 +/- 3.2 min, P = 0.03, respectively). Within 24 hours after PVAI in 35.7% (all erythema) of Group 1 and 57.1% (21.4% erythema and 35.7% necrosis) of Group 2, patients' esophageal wall changes were documented. After 14 +/- 2 months of follow up, recurrences were documented in 19.2% of Group 1 and 22.2% of Group 2 patients. CONCLUSION Although both OIT and ICE-guided energy delivery possess a similar effect in treating AF, OIT seems to be superior in terms of achieving isolation and shortening fluoroscopy exposure. Moreover, a lower incidence of esophageal wall injury was observed utilizing OIT for PVAI.

Papillary fibroelastoma (PFE) is an uncommon primary neoplasm of cardiac origin. They are solitary neoplasms that historically were an incidental finding at the time of autopsy. With the advent of two-dimensional echocardiography, symptomatic cases have been reported in current literature, thus causing a paradigm shift in the management of these tumors. Although the majority of PFE are benign, because of their potential risk for complication related to embolic and obstructive phenomena, they are now considered hazardous and require tumor excision even in asymptomatic patients. We report a case of an asymptomatic incidental large papillary fibroelastoma within the right ventricular outflow tract.

Prevalence of persistent atrial fibrillation in patients undergoing cardiac resynchronization therapy remains high. Several factors, including suboptimal biventricular capture rates, compound the significant mortality and response rates in patients with atrial fibrillation and severe heart failure. Atrioventricular nodal ablation provides the best mean of rate control in this population. In this article, the authors evaluate a recently published trial addressing this issue in a prospective fashion and discuss the results and clinical applications.

Dactylolysis spontanea is an idiopathic condition affecting the fifth toe, and sometimes other toes, that is frequently bilateral, with lesions in different stages. Between 1977 and 1999, a total 6000 radiographic studies of the feet were reviewed in a mainly African American population in Chicago, Illinois. After an initial screening based on the Cole criteria, 581 patients were selected and re-examined, and amplification techniques were performed. After reviewing the complementary exams, 102 patients were diagnosed with dactylolysis spontanea or ainhum. Soft-tissue constriction was the most frequently presented radiological sign on the initial screening. Kurtosis at the digit plantar fold and marked rotation of the fifth toe were normal findings in asymptomatic patients. Demographics, comorbidities, and radiological findings were analyzed in the selected population. Associated diseases occurring in these patients appeared to have no specific etiologic correlation with ainhum. African Americans and the dark-skinned population are affected exclusively by this condition, presumably due to the fibrogenic tendency of these individuals. Early diagnosis and accurate staging of ainhum are facilitated by radiological examination of the feet. The findings suggest that this condition is underdiagnosed and overlooked because its low prevalence and variable clinical presentations that might mimic more common etiologies, including localized trauma.

Cardiac resynchronization therapy (CRT) is indicated in patients with advanced heart failure secondary to severe systolic impairment and refractory symptoms despite optimized medical treatment and evidence of electro- mechanical dyssynchrony with a QRS complex greater than 120 milliseconds (msec). Approximately 20%-30% of patients who receive CRT fail to respond with little improvement in subjective symptoms, functional capacity, and left ventricular indices. To date, there fails to be a serologic marker to adequately assess the degree of ventricular dyssynchrony and electro-mechanical dissociation. Increased levels of erythropoietin (EPO), a hematopoietic cytokine, has been demonstrated in patients with more advanced stages of heart failure and is associated with an increase in mortality and hospital re-admission. A recent study demonstrated a significant response to CRT in patients with higher baseline EPO levels (> 25mU/mL) with improvements in cardiac function and reduced heart failure symptoms. The presence of elevated EPO levels in addition to traditional determinants of cardiac dyssynchrony may effectively predict those that will benefit from CRT. LETTER TO THE EDITOR Cardiac resynchronization therapy (CRT) is indicated in patients with advanced heart failure secondary to severe systolic impairment and refractory symptoms despite optimized medical treatment and evidence of electro- mechanical dyssynchrony with an ECG QRS complex greater than 120 msec. Simultaneous pacing of both the right and left ventricle (BiV pacing) has been shown to restore electro-mechanical synchrony, improve overall cardiac function, reduce hospitalizations, and confer a mortality benefit (1). Despite the cardiovascular benefits of BiV pacing demonstrated in recent trials, approximately 20%- 30% of patients who receive CRT fail to respond with little improvement in subjective symptoms, functional capacity, and left ventricular functional indices (2). Absence of electro-mechanical dyssynchrony despite prolonged QRS duration (>120ms), pre-existing right bundle branch block (RBBB), inappropriate lead placement and continued disease progression have been shown as causes for non-response to CRT. To date, there fails to be a serologic marker to adequately assess the degree of ventricular dyssynchrony and electro-mechanical dissociation. Erythropoietin (EPO), a hematopoietic cytokine, has traditionally been associated with erythropoiesis in response to anemic stress. Several studies have indicated the positive effects of EPO treatment in heart failure patients with concomitant anemia resulting in reductions in hospital re- admission, improved cardiac and renal function, as well as

Background: The incidence of adult patients with falls seeking medical assistance in the Salt Lake City area, Utah, is 28,000 per million adult inhabitants. Objective: We sought to evaluate the prevalence of cardiovascular risk assessment and cardiovascular abnormalities in patients presenting with nonaccidental falls at the University of Utah hospital and its affiliated clinics. Methods: We conducted a search of all patients in the University of Utah patient database as well as 9 affiliated primary care and family practice clinics in Utah who were evaluated for a “fall” during October 2009. We analyzed the records of 338 patients who had a fall within the previous 3 months. Nonaccidental falls were defined as falls unrelated to a contact incident or “slip or trip.” Results: Nonaccidental falls occurred in 81 (24%) patients, 39 of these being ≥65 years old. Cardiovascular risk assessment and specifically orthostatic testing were evaluated in 40% and 3% of the patients, respectively. In patients ≥65 years old, the prevalence of cardiovascular risk assessment, orthostatic testing, and carotid sinus massage were equally low at 56%, 5%, and 0%, respectively. Cardiovascular abnormalities were present in 17 (21%) patients, with 9 of them being referred for cardiac evaluation. Conclusion: Our results highlight the inconsistent assessment of potential cardiovascular risk factors in patients with nonaccidental falls, supporting the adoption of a standardized approach in these patients.

In the current age of ever-increasing healthcare costs, it is of utmost importance to adopt strategies that reduce hospital stay and cost, while still maintaining patient safety. In this study we review our approach of same-day discharge following implantable cardioverter defibrillator (ICD) placement for primary prevention of sudden cardiac death (SCD).We conducted a retrospective chart review of 415 consecutive patients who underwent ICD implantation for prevention of SCD between 2007 and 2010. Patients were divided into an outpatient group (Group A) and an inpatient group (Group B). We evaluated the patients' demographics, comorbidities, and the rate of short-term surgical complications on or before the 2-week follow-up appointment.Of 252 patients included in Group A, 198 (78.6%) were successfully discharged on the same day (Group A1). At the 2-week wound check appointment, four patients (2%) had minor surgical site bleeding, one patient had a hematoma, and one patient developed fever and swelling around the implantation site. Of the Group A patients, 54 (21.4%) were not discharged on the same day (Group A2). A total of 53 patients were included in Group B, four (7.5%) developed a hematoma at the 2-week follow-up wound check visit.Procedure-related complications after ICD placement are rare. Same-day discharge is safe and feasible following ICD placement for primary prevention of SCD and hence a reduction in healthcare costs can be achieved by decreasing the length of hospital stay.

Nonaccidental falls are often the result of a combination of factors including cardiovascular disorders such as orthostatic hypotension and unspecified cardiac arrhythmias. The objective of this study was to determine if there is an association between atrial fibrillation (AF) and nonaccidental falls.We reviewed the records of 442 consecutive patients65 years old who presented to the Emergency Department at the University of Utah Medical Center with a complaint of fall.Two-hundred eleven patients presented with nonaccidental fall, 231 patients with accidental fall. Patients with nonaccidental fall were more likely to be older, have a history of hypertension and neurological disorders, and taking five or more medications when compared to patients with accidental fall. Despite a similar prevalence of sinus rhythm at presentation, the prevalence of a history of AF was significantly higher in patients with nonaccidental fall compared to patients with accidental fall (26% vs 15%; P = 0.003). After adjusting for clinically and statistically significant predictors with a multivariate logistic regression analysis, AF, neurological disorders, and age ≤81 years were independent predictors of nonaccidental fall. In patients ≤81 years old (median age), the risk of nonaccidental falls was 2.5 times greater in patients with a history of AF when compared to those without a history of AF (odds ratio = 2.53 [confidence interval 95% 1.3-5], P = 0.007).AF is an independent risk factor for nonaccidental falls. Our results emphasize the need to screen for AF in patients presenting with nonaccidental fall.

Cryoballoon technology is a promising technique in paroxysmal atrial fibrillation (AF) ablation. However, success rates in patients with persistent AF have not been convincing. There is a trend toward performing more extensive procedures that are referred to as ‘pulmonary vein isolation plus.’ To combine pulmonary vein isolation (PVI) and antral substrate modification, we used both the 23-mm and 28-mm cryoballoon in a single approach in patients with persistent AF. 33 consecutive patients (26 men, age 60 ± 10 years, LA size 44 ± 5 mm) with persistent AF were prospectively included. All patients underwent the “double balloon strategy:” at least two applications at each pulmonary vein (PV) using the smaller 23-mm balloon to isolate the PV at the ostial level plus at least one additional freeze by the 28-mm balloon at the wide PV antral level. 7-day Holter monitors were performed during follow-up at 1, 3, 6, 9, 12, 18 and 24 months post-ablation. 131 of 133 PVs were targeted and isolated (98.4 %). A mean of 14 ± 2 cryoballoon applications per patient or 3.5 ± 1.5 applications per vein were performed. After a single procedure and mean follow-up of 15 ± 3 months, 69.7 % of patients remained in sinus rhythm (3-month blanking period). There were no major complications. In persistent AF, the “double balloon strategy;” combining the small and large cryoballoon allowed ostial PV isolation followed by antral cryoablation is feasible, safe and associated with a favorable outcome.

Aims Syncope is a major health care problem that accounts for many emergency department (ED) and hospital admissions. This study was conducted to investigate the short-term risk of serious events in patients presenting to the ED with syncope and to compare guideline-based admission criteria with those adopted in clinical practice. Methods and results A single-centre retrospective analysis was performed on ED visits between January and June 2009. We used the ICD-9 code 780.2 for syncope as the primary diagnosis. The prevalence of serious events within 7 days of the index presentation was evaluated. In addition, admissions and discharges were classified as being appropriate or inappropriate based on standardized guideline-based criteria integrated in a new Faint-Algorithm developed at the University of Utah. Two hundred and fifty-four ED visits met the inclusion criteria. One hundred and thirty-six patients were discharged home and the remaining 118 were admitted. The prevalence of serious events in the discharged and admission groups were 5 and 10, respectively, ( P = NS). According to the Faint-Algorithm, the number of inappropriate discharges and admissions were 8 out of 136 and 69 out of 118, respectively. Using the Faint-Algorithm, only 57 patients instead of 118 patients should have been admitted resulting in a 52% reduction in admission rate. Furthermore, in the remaining 197 patients who should have been discharged, the prevalence of serious events was not significantly different than that observed in the 136 patients who were actually discharged (3% vs. 4%). Conclusion There are significant numbers of inappropriate discharges and admissions in patients presenting with syncope. The standardized guideline-based criteria integrated in the new Faint-Algorithm provide promise but require further prospective evaluation.

Implantable heart rhythm devices are susceptible to interference in hospitals where electromagnetic interference (EMI) sources are ubiquitous.We report three cases in which EMI from the external defibrillator caused the inability to interrogate Boston Scientific cardiac resynchronization therapy-pacemaker (CRT-P) devices. We have documented interference with the Boston Scientific CRT-P Contact Renewal device model numbers H120/H125 (Natick, MA, USA) and two brands of external defibrillators: the Philips Heartstart XL model number M4735A (Andover, MA, USA) and the Hewlett-Packard Codemaster model number M1722B (Palo Alto, CA, USA). For device implants, we routinely place external pacing pads with the external defibrillator in the "standby" mode for transcutaneous pacing so that only the pacer "start/stop" button needs to be pressed when necessary. We have not been able to interrogate three consecutive Boston Scientific CRT-P devices prior to closure while the external defibrillator had the back-up pacing mode on "standby." In our initial case, a second device was opened because this interaction was not recognized. We documented EMI with the standby pacing mode ON and discovered that by disabling only the "standby" pacing mode on the external defibrillator, the device could be interrogated without difficulty.This is a case series reporting EMI with a Boston Scientific CRT-P Contact Renewal device H120/H125 telemetry from an external defibrillator with pacing mode on "standby." Failure to recognize this important interaction may lead to inappropriate device and resource utilization.

Radiofrequency atrial fibrillation ablation (AFA) is commonly performed in patients with atrial fibrillation. It is imperative to develop a strategy for the early detection of esophageal lesions secondary to AFA. The current protocol is to obtain cross-sectional imaging before and immediately after the procedure. If patients have evidence of esophageal inflammation, they undergo esophagogastroduodenoscopy (EGD). We hypothesized that esophageal abnormalities seen on imaging immediately post-ablation are a poor predictor of the damage seen during EGD.Patients referred for EGD following AFA from 1/2009 to 11/2010 were included. Two endoscopists reviewed and scored the EGD images. Two radiologists reviewed the post-AFA imaging studies. For computed tomography (CT) scans, esophageal inflammation was scored from 0 to 2. For T2 and delayed magnetic resonance imaging (MRI) pictures, esophageal enhancement was scored from 0 to 2, with the circumference involved as 0,50%, or50%, and the length of esophageal enhancement in mm.In total, 76 patients were included; 22 patients had only endoscopic images and 54 had both endoscopic and radiologic images for review. Of the post-AFA imaging studies, 16 were CTs and 60 were MRIs. The kappa score for the inter-rater agreement of esophageal inflammation on EGD was 0.4584 (moderate). For MRIs, the kappa scores for T2 images were 0.1980 and 0.2857 for edema and circumference, respectively. For delayed images, the kappa scores were 0.2687 and 0.3101 for edema and circumference, respectively. The kappa scores were negative between EGD score by T2 edema (-0.2104) and circumference (-0.2212), and between EGD score and delayed edema (-0.0588) and circumference (-0.0446). When measures were treated as dichotomous, the overall agreement between CT measures and EGD scores was kappa = 0, for T2 measures and EGD kappa = -0.2963, 95% confidence interval (CI) (-0.5643, -0.0282), and between delayed measures kappa = -0.0244, 95% CI (-0.1420, -0.0932).There was no agreement between immediate imaging and the endoscopic findings of esophageal inflammation after AFA. A longer period of time between AFA and obtaining an imaging study may be useful in detecting patients with significant esophageal injury who should undergo EGD to assess for complications of AFA. Further studies are needed in order to determine the best modalities and optimal timing to detect post-AFA esophageal damage in an attempt to prevent the formation of atrial-esophageal fistulas.

No previous study has assessed the role of renal impairment in predicting the long-term risk of atrial fibrillation recurrence after cardioversion.One hundred and fifty-nine consecutive patients with persistent atrial fibrillation undergoing successful cardioversion were enrolled. Renal function was assessed based on the estimated glomerular filtration rate (eGFR) at baseline and during follow-up. Patients were prospectively followed up for eGFR and recurrence of atrial fibrillation up to 1 year.Patients were divided into 4 groups based upon their eGFR (group 190 mL/min: 33 patients, group 2: 60-90 mL/min: 55 patients, group 3: 30-59 mL/min: 53 patients, group 4:30 mL/min: 18 patients). Overall, 101 out of 159 (64%) patients experienced atrial fibrillation recurrence within 1 year follow-up. Atrial fibrillation recurrence was independently associated with the level of reduction of eGFR at baseline (eGFR30 mL/min: hazard ratio [HR] 6.82, P0.001; eGFR 30-59 mL/min: HR 3.31, P = 0.01; eGFR 60-90 mL/min: HR 2.10, P = 0.13; eGFR90 mL/min reference group). In patients with maintained sinus rhythm after 12-month follow-up eGFR was increased (8.46 ± 9.49 mL/min [range -7 to 43]), whereas patients with atrial fibrillation recurrence showed a decrease in eGFR over time (-5.75 ± 9.4 [range -32 to 25], P0.001).Among a group of patients with persistent atrial fibrillation undergoing successful cardioversion, impaired renal function (based on estimated GFR) was associated with an increased risk of atrial fibrillation recurrence. Maintenance of sinus rhythm was associated with improvement in eGFR in patients with mild or moderate renal insufficiency.

ObjectivesThis study tried to determine the association between left atrial (LA) fibrosis, detected using delayed-enhanced magnetic resonance imaging (DE-MRI), and the CHADS2 score (point system based on individual clinical risk factors including congestive heart failure, hypertension, age, diabetes, and prior stroke) variables, specifically stroke.BackgroundIn patients with atrial fibrillation (AF), conventional markers for the risk of stroke base their higher predictive effect on clinical features, particularly previous stroke history, and not individual LA pathophysiological properties. We aimed to determine the association between LA fibrosis, detected using DE-MRI, and the CHADS2 score variables, specifically stroke.MethodsPatients with AF who presented to the AF clinic and received a DE-MRI of the LA were evaluated. Their risk factor profiles, including a CHADS2 score, were catalogued. The degree of LA fibrosis was determined as a percentage of the LA area. Any history of previous strokes, warfarin use, or cerebrovascular disease was recorded.ResultsA total of 387 patients, having a mean age of 65 ± 12 years, 36.8% female, were included in this study. A history of previous stroke was present in 36 (9.3%) patients. Those patients with previous strokes had a significantly higher percentage of LA fibrosis (24.4 ± 12.4% vs. 16.2 ± 9.9%, p < 0.01). A larger amount of LA fibrosis was also seen in those patients with a higher CHADS2 score (≥2: 18.7 ± 11.4 vs.

Atrial fibrillation is a significant public health burden, with clinically, epidemiologically and economically significant repercussions. In the last decade, catheter ablation has provided an improvement in morbidity and quality of life, significantly reducing long-term healthcare costs and avoiding recurrences compared with drug therapy. Despite recent progress in techniques, current catheter ablation success rates fall short of expectations. Late gadolinium-enhancement cardiovascular MRI is a well-established tool to image the myocardium and, most specifically, the left atrium. Unique imaging protocols allow for left atrial structural remodeling and fibrosis assessment, which has been demonstrated to correlate with clinical outcomes after catheter ablation, assessment of the individual's risks of thromboembolic events, and effective imaging of patients with left atrial appendage thrombus. Late gadolinium-enhancement MRI aids in the individualized treatment of atrial fibrillation, stratifying recurrence risk and guiding specific ablation strategies. Real-time MRI offers significant safety and effectiveness profiles that would optimize the invasive treatment of atrial fibrillation.

Fainting is a major healthcare problem with significant morbidity, mortality, and healthcare cost. We sought to assess the appropriateness of current clinical practice when compared to a guideline-based algorithm.The records of 100 consecutive patients who presented with faint and were referred to the University of Utah for further evaluation by specialists were reviewed. We analyzed the clinical characteristics, tests performed, diagnosis made, and number of admissions. In addition, we applied a guideline-based algorithm to assess the appropriateness of these evaluations.The mean age was 49 ± 21 years with 57% being female. One-third presented with their first event. Structural heart disease was present in 22% of the cases. Twelve (36%) of 32 admissions were inappropriate. There was an underutilization of orthostatic testing, carotid sinus massage, and implantable loop recorder and overutilization of imaging studies and neurologic consultation. Specifically, active standing and tilt-table testing were performed in only 24% and 7% of the cases, respectively, none of the patients had carotid sinus massage despite 26% of them being ≥65 years old, and only 3% of the patients received an implantable loop recorder. With the current practice, a final diagnosis was made in 45 cases with 17 (38%) of the 45 final diagnoses not being sufficiently supported by the completeness of the evaluation.With the current practice at a major university hospital, the cause of faint was unexplained in a high number of cases. Our findings highlight the need for a standardized approach to patients presenting with faint.

Ectopy-induced cardiomyopathy is an increasingly recognized cause of reversible left ventricular (LV) dysfunction. The underlying mechanisms remain unknown. Our goal was to create an animal model for ectopy-induced cardiomyopathy.Eleven mongrel dogs underwent the implantation of a dual-chamber pacemaker. Four dogs served as the control group and seven as the paced group. In the paced group, the pacemaker was connected to two endocardial right ventricular leads, one inserted into the atrial port and the other one into the ventricular port with an atrioventricular delay adjusted to ensure the presence of coupled pacing simulating ventricular bigeminy. Echocardiographic measurements of LV size (LV end-diastolic diameter [LV-EDD], LV end-systolic diameter [LV-ESD]), LV ejection fraction (LVEF), and mitral regurgitation (MR) were obtained at baseline and after 4 weeks of monitoring or pacing in all dogs except one who had lead dislodgement.In the control group (n = 4), no significant changes in LV dimensions or function were noted. In the paced group (n = 6), LV-EDD and LV-ESD increased from 3.58 ± 0.65 cm and 2.47 ± 0.55 cm to 4.15 ± 0.59 cm and 3.21 ± 0.47 cm, respectively (P0.01). In addition, LVEF decreased from 60 ± 7% to 46 ± 9% (P0.05). No changes in MR were noted.We have shown that coupled pacing simulating ventricular bigeminy was feasible and resulted in increased LV dimensions and decreased LV function. By controlling the percentage of pacing, the coupling interval and the location of the pacing lead, this new model will allow the assessment of the relative roles of these variables in the development of ectopy-induced cardiomyopathy.

MRI for AF Patient Selection and Ablation Approach. Introduction: Left atrial (LA) fibrosis and ablation related scarring are major predictors of success in rhythm control of atrial fibrillation (AF). We used delayed enhancement MRI (DE-MRI) to stratify AF patients based on pre-ablation fibrosis and also to evaluate ablation-induced scarring in order to identify predictors of a successful ablation. Methods and Results: One hundred and forty-four patients were staged by percent of fibrosis quantified with DE-MRI, relative to the LA wall volume: minimal or Utah stage 1; 35%. All patients underwent pulmonary vein (PV) isolation and posterior wall and septal debulking. Overall, LA scarring was quantified and PV antra were evaluated for circumferential scarring 3 months post ablation. LA scarring post ablation was comparable across the 4 stages. Most patients had either no (36.8%) or 1 PV (32.6%) antrum circumferentially scarred. Forty-two patients (29%) had recurrent AF over 283 ± 167 days. No recurrences were noted in Utah stage 1. Recurrence was 28% in Utah stage 2, 35% in Utah stage 3, and 56% in Utah stage 4. Recurrence was predicted by circumferential PV scarring in Utah stage 2 and by overall LA wall scarring in Utah stage 3. No recurrence predictors were identified in Utah stage 4. Conclusions: Circumferential PV antral scarring predicts ablation success in mild LA fibrosis, while posterior wall and septal scarring isneeded for moderatefibrosis. This may help select theproper candidate and strategy in catheter ablation of AF. (J Cardiovasc Electrophysiol, Vol. 22, pp. 16-22, January 2011) atrial fibrillation, atrial remodeling, catheter ablation, magnetic resonance imaging