Brett D Atwater

Duke University, Durham, North Carolina, United States

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Publications (26)63.79 Total impact

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    ABSTRACT: In contrast to LBBB patients less is known about patients with RBBB+LAFB regarding LV contractile abnormalities and the potential role of CRT. This study investigated whether patients with RBBB+LAFB morphology have echocardiographic mechanical strain abnormalities between the inferior and anterior LV walls, similar to abnormalities between septal and lateral walls in LBBB.
    No preview · Article · Feb 2016
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    ABSTRACT: Background: The Selvester QRS score consists of a set of electrocardiographic criteria designed to identify, quantify and localize scar in the left ventricle using the morphology of the QRS complex. These criteria were updated in 2009 to expand their use to patients with underlying conduction abnormalities, but these versions have thus far only been validated in small and carefully selected populations. Aim: To determine the specificity for each of the criteria of the left bundle branch block (LBBB) modified Selvester QRS Score (LB-SS) in a population with strict LBBB and no myocardial scar as verified by cardiovascular magnetic resonance imaging with late gadolinium enhancement (CMR-LGE). Methods: We identified ninety-nine patients with LBBB without scar on CMR-LGE, who underwent a clinically indicated CMR scan at three different centers. The ECG recording date was any time prior to or <30days after the CMR scan. The LB-SS was applied and specificity for detection of scar in each of the 46 separate criteria was determined. Results: The specificity ranged between 41% and 100% for the 46 criteria of LB-SS and 27/46 (59%) met ≥95% specificity. The mean±SD specificity was 90%±14%. Conclusion: Several of the criteria in the LB-SS lack adequate specificity. Elimination or modification of these nonspecific QRS morphology criteria may improve the specificity of the overall LB-SS.
    No preview · Article · Sep 2015 · Journal of electrocardiology

  • No preview · Article · Jul 2015 · Journal of electrocardiology
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    ABSTRACT: The Selvester QRS score is an electrocardiographic tool designed to quantify myocardial scar. It was updated in 2009 to expand its usefulness in patients with conduction abnormalities such as bundle-branch and fascicular blocks. There is need to further validate the updated score in a broader group of patients with cardiovascular disease and conduction abnormalities. We primarily hypothesized that the updated score could distinguish between presence and absence of scar by cardiac magnetic resonance imaging (CMR) with late gadolinium enhancement in 4 groups of patients with distinct conduction abnormalitites. A total of 193 patients were retrospectively identified that had received an electrocardiogram (ECG) and a CMR scan at Duke University Medical Center between January 2011 and August 2013: 62 with left bundle-branch block, 51 with right bundle-branch block (RBBB), 43 with left anterior fascicular block (LAFB), and 37 with RBBB + LAFB. Scar sizes estimated by ECG and by CMR were compared using scatterplots, modified Bland-Altman plots, and receiver operating characteristics curves. Of 193 patients, 96 (50%) had no scar by CMR. The QRS score generally overestimated CMR scar. The area under the curve ranged between 0.62 and 0.65 for the different conduction types, and 95% confidence intervals included 0.5 for all conduction types. Performance was slightly improved in LAFB and RBBB + LAFB by excluding all points derived from leads V4-V6. The Selvester QRS score for use in conduction abnormalities needs to be improved, primarily its specificity, to enable effective clinical use in a population with a wide range of left ventricular ejection fraction and low pretest probability of myocardial scar. Copyright © 2015 Elsevier Inc. All rights reserved.
    No preview · Article · May 2015 · American Heart Journal
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    ABSTRACT: Electrocardiographic (ECG) LV scar quantification may improve prediction of CRT response. Data were abstracted in 76 patients who underwent a first CRT implantation at 2 US centers. Selvester QRS scar quantification was performed using the LBBB modified QRS scoring method. Seven clinical variables previously associated with reverse LV remodeling (RLVR) and QRS score were included in logistic regression analysis. Survival was compared across QRS score quartiles using Kaplan-Meier curves. RLVR occurred more frequently in patients with QRS score≤5 (63%) than QRS score>5 (22%), (OR=5.83, 95% CI=2.11-16.07). After adjustment for clinical variables using logistic regression, QRS score>5 predicted RLVR (Chi-square=20.3, P=0.005, AUC=0.782). Patients in the lowest quartile of QRS score (<4) had improved survival compared to patients in the other QRS score quartiles (P=0.037). ECG quantified LV scar predicts RLVR and long-term survival in patients with LBBB undergoing CRT implantation. Copyright © 2015. Published by Elsevier Inc.
    No preview · Article · May 2015 · Journal of electrocardiology
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    ABSTRACT: While the accuracy of roentography for evaluation of lead tip position compared with three-dimensional imaging techniques has been well described, there remains considerable variability in the interpretation of the reproducibility of standard x-ray for right ventricular (RV) and left ventricular (LV) lead position. The aim of this study was to evaluate the accuracy and reliability of right ventricular (RV) and left ventricular (LV) lead tip position as determined by board-certified cardiac electrophysiologists (EP) using standard x-ray views. EP interpretations of RV and LV lead tip position using standard x-ray views (posterior-anterior, lateral, and left anterior oblique) were compared to thoracic computed tomography (CT). The accuracy of x-ray interpretation was compared to the reference CT location, and the reproducibility of x-ray interpretation was tested using the free-marginal Kappa statistic. A total of 58 EPs were invited to participate in the survey with a response rate of 43 % (25/58). The agreement between x-ray and CT lead tip position (accuracy) was 37 % for RV lead, 33 % for longitudinal LV lead, and 41 % for short axis LV lead. Reproducibility was 64 % for RV lead tip (k = 0.46), 58 % for longitudinal LV lead tip (k = 0.37), and 39 % for short axis LV lead tip (k = 0.24). Conventional roentography is limited in its ability to accurately and reliably determine pacing lead tip position.
    No preview · Article · Feb 2015 · Journal of Interventional Cardiac Electrophysiology
  • Björn Wieslander · Brett D. Atwater

    No preview · Article · Nov 2014 · Journal of Electrocardiology
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    ABSTRACT: Dr. Pokorney reports modest research grant support from AstraZeneca; and modest consultant/advisory board support from Janssen Pharmaceuticals. Dr. Atwater reports significant grants for clinical research from the American Heart Association and Medtronic; and modest consultant/advisory board support from Medtronic. Dr. Daubert reports significant research grant support from Biosense Webster, Medtronic, Boston Scientific, and Gilead; significant honoraria for lectures from Medtronic, Boston Scientific, Sorin, Biotronik, and St. Jude; modest consultant/advisory board support from Cardiofocus, Premier Healthcare Alliance, Gilead, Biosense Webster, Boston Scientific, Sanofi-Aventis, Northwestern University, VytronUS, and Medtronic; and significant fellowship support to Duke University from Biotronik, Biosense Webster, Medtronic, and Boston Scientific. Dr. Piccini reports significant research grant support from Johnson & Johnson/Janssen Pharmaceuticals; significant other research support from Bayer HealthCare Pharmaceuticals Inc (formerly Berlex Labs), Boston Scientific Corporation, and Johnson & Johnson Pharmaceutical Research & Development; modest consultant/advisory board support from Forest Laboratories Inc and Medtronic Inc; and significant consultant/advisory board support from Johnson & Johnson/Janssen Pharmaceuticals.
    No preview · Article · Jul 2014 · Heart rhythm: the official journal of the Heart Rhythm Society
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    ABSTRACT: Background Battery failure is an uncommon complication of implantable cardioverter-defibrillators (ICD), but unanticipated battery depletion can have life threatening consequences. Objective Describe the prevalence of a novel mechanism of battery failure in St. Jude Medical Fortify and Unify ICDs. Methods Cases of premature Fortify battery failure from a single center are reported. A search (1/1/2010 through 11/30/2013) for Fortify and Unify premature batter failure was conducted of the Food and Drug Administration’s Manufacturer and User Facility Device Experience Database (MAUDE), and these findings were supplemented with information provided by St. Jude Medical. Results Premature battery failure for two Fortify ICDs in our practice were attributed to the presence of Lithium clusters near the cathode, causing short circuiting and high current drain. The prevalence of this mechanism of premature battery failure was 0.6% in our practice. A MAUDE search identified 39 cases of Fortify (30) and Unify (9) premature battery depletion confirmed by the manufacturer, representing a 0.03% prevalence. Four additional Fortify and 2 Unify cases were identified in MAUDE as suspected premature battery depletion, but in these cases the pulse generator was not returned to the manufacturer for evaluation. St. Jude Medical identified 10 cases of premature battery failure due to Lithium clusters in Fortify devices (9) and Unify devices (1), representing a 0.004% prevalence. Conclusions The deposition of Lithium clusters near the cathode is a novel mechanism of premature battery failure. The prevalence of this problem is unknown. Providers should be aware of this mechanism for patient management.
    No preview · Article · Jan 2014
  • Christopher Swan · Albert Y Sun · Susan Cooney · Jamie Ray · Brett D Atwater

    No preview · Article · Aug 2013 · Journal of Cardiovascular Electrophysiology
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    ABSTRACT: Dabigatran is approved for prevention of stroke or systemic embolism in patients with nonvalvular atrial fibrillation (AF). The safety and effectiveness of periprocedural dabigatran in ablation for AF are unknown. We performed a meta-analysis of all studies comparing periprocedural dabigatran with warfarin for anticoagulation in AF ablation. Studies of >100 patients with post-procedure follow-up were included. Outcomes were compared by calculating maximum likelihood estimates with confidence intervals. The co-primary endpoints were neurological events and major bleeding. Ten cohort studies were included, including a total of 1,501 patients receiving dabigatran and 2,356 receiving warfarin. The mean age was 59-64 years and inclusion of women varied (10-33 %). Intra-procedural unfractionated heparin and irrigated ablation catheters were used routinely. Adverse events were low overall; however, the dabigatran group demonstrated a numerical excess of neurological events (10/1,501 [0.7 %] versus 4/2,356 [0.2 %]), but equivalent major bleeding outcomes (24/1,501 [1.6 %] versus 40/2,356 [1.7 %]). In the meta-analysis, there was a nonsignificant trend towards higher rates of the composite primary endpoints (any neurological event or major bleeding) in the dabigatran group. Dabigatran demonstrated a significantly higher rate of neurological events (estimated absolute risk difference 0.0047, 95 % confidence interval 0.0007 to 0.0099). Compared with warfarin, dabigatran may be associated with a higher frequency of periprocedural neurological events following radiofrequency ablation of AF. Randomized clinical trials are needed to definitively assess the safety and efficacy of novel oral anticoagulant use for periprocedural anticoagulation for ablation of AF.
    No preview · Article · Jul 2013 · Journal of Interventional Cardiac Electrophysiology

  • No preview · Article · Mar 2013 · Dermatitis
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    ABSTRACT: Background: Proper positioning of the left ventricular (LV) lead improves clinical outcomes and survival in patients receiving cardiac resynchronization therapy (CRT). Techniques of LV lead insertion using contrast injection and a telescoping system of delivery catheters to support advancement of the lead into the target branch may allow more efficient, targeted lead placement. We sought to evaluate the impact of an LV lead implant approach using telescoping-support catheters (group TS) on success rate, lead location, and procedural time compared to standard over-the-wire implant techniques (group OTW). Methods: Four hundred thirty-seven consecutive patients undergoing CRT implantation were divided into group TS (n = 105) or group OTW (n = 332) based upon a review of the operative technique used for LV lead implantation. The primary outcome was success of LV lead implantation at the index procedure. Secondary endpoints included optimal positioning of the LV lead and reduction in procedural fluoroscopy time. Results: Failed LV lead placement was lower (1.9% vs 8.1%, P = 0.02) and optimal lead positioning was achieved more often for group TS than group OTW (87% vs 75%, P = 0.01). In addition, there were significantly shorter fluoroscopy times for group TS versus group OTW (29.6 minutes vs 41.9 minutes, P < 0.01). Conclusion: A CRT-implant approach using contrast injection and a telescoping-support catheter system results in fewer failed LV lead implants, improved LV lead location, and shorter procedure times.
    No preview · Article · Feb 2013 · Pacing and Clinical Electrophysiology
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    ABSTRACT: Several studies based on claims data have reported underutilization of evidence-based heart failure (HF) therapies. The degree to which these estimates fail to account for therapeutic contraindications is unclear. We identified patients with HF and left ventricular ejection fraction ≤45% seen between January 1, 2010, and July 1, 2010, at a tertiary care Veterans Affairs Medical Center. Medical records were abstracted to evaluate utilization of and contraindications to β-blocker, angiotensin-converting enzyme inhibitor, aldosterone antagonist, anticoagulation for atrial fibrillation, implantable cardioverter-defibrillator, and cardiac resynchronization therapies. Of the 178 patients with HF and an ejection fraction ≤45%, 78 (44%) received every guideline-recommended therapy. After accounting for medical contraindications, 77 (72%) of 107 patients received every guideline-recommended therapy. Adherence to recommendations for β-blocker (98%), angiotensin-converting enzyme inhibitor/angiotensin blocker (95%), and anticoagulation (97%) were better than adherence to implantable cardioverter-defibrillator (82%), cardiac resynchronization therapy (59%), or aldosterone antagonist (51%) recommendations. In adjusted analysis, lower New York Heart Association functional class and care by a cardiologist were associated with improved guideline adherence (P < .001). Many patients with HF have therapeutic contraindications, and a failure to account for these may lead to a large underestimation of the true guideline adherence rates.
    No preview · Article · Nov 2012 · American heart journal
  • Brett D Atwater · James P Daubert
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    ABSTRACT: Sudden cardiac arrest is the one of the most common causes of death in developed countries and accounts for between 180,000 and over 450,000 per year in the USA. Antiarrhythmic drug approaches to prevention of sudden cardiac death have been resoundingly ineffective. The implantable cardioverter defibrillator (ICD) constitutes one of the most important and well validated therapeutic advances in modern cardiovascular medicine. Consequently, ICD use has increased exponentially, although implementation has been quite variable geographically and with respect to other measures. In view of the expanded use of ICDs, the potential shortcomings and risks of ICD therapy have attracted attention. This commentary summarises the weaknesses, disadvantages and risks of the ICD in a balanced fashion in light of their proven life-saving benefits.
    No preview · Article · Mar 2012 · Heart (British Cardiac Society)
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    ABSTRACT:   Cardiovascular magnetic resonance imaging (cMRI) may provide a noninvasive method to test for pulmonary vein (PV) isolation after ablation for atrial fibrillation (AF) by detecting changes in PV contraction. PV contraction (the maximal percentage change in PV cross-sectional area [CSA] during the cardiac cycle) measured 1 month before and 2 months after PV isolation was compared in 63 PVs from 16 patients with medically refractory AF. Repeat cMRI imaging and invasive catheter mapping was performed prior to repeat PV ablation in 50 PVs from 14 additional patients with recurrent AF. Contraction in PVs with sustained isolation after the initial ablation was compared to contraction in PVs with electrical reconnection to adjacent atrium. Receiver operating characteristic (ROC) curve analysis was performed to determine the optimal cutoff PV contraction value for prediction of PV-atrial reconnection after ablation. The cutoff value was then prospectively tested in 40 PVs from 12 additional patients. PV contraction decreased after AF ablation (22.4 ± 10% variation in CSA before ablation vs 10.1 ± 8% variation in CSA after ablation, P < 0.00001). PVs with sustained isolation on invasive mapping contracted less than PVs with electrical reconnection to adjacent atrium (13.7 ± 10.6% vs 21.4 ± 9.3%, P = 0.021). PV contraction produced a c-index of 0.74 for prediction of PV-atrial reconnection after ablation and >17% variation in PV CSA predicted reconnection with a sensitivity of 84.6% and specificity of 66.7%. PV contraction is reduced by ablation. PV contraction measurement may provide a noninvasive method to test for PV isolation after ablation procedures.
    No preview · Article · Feb 2011 · Journal of Cardiovascular Electrophysiology
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    ABSTRACT: Several studies that used claims and registry data have reported that 40% to 80% of patients eligible for an implantable cardioverter defibrillator (ICD) fail to receive one in clinical practice, and the rates are especially high among women and blacks. The extent and documented reasons for nonuse of ICDs among patients with left ventricular systolic dysfunction are unknown. Using hospital claims and clinical data, we identified patients hospitalized with a heart failure diagnosis and left ventricular ejection fraction ≤30% between January 1, 2007, and August 30, 2007, at a tertiary-care center. Using claims data, we determined placement of an ICD or cardiac resynchronization therapy with defibrillation device at any time up to 1 year after hospitalization. Medical records for patients without an ICD were abstracted to determine reasons for nonuse. Patients with an ICD were compared with patients without an ICD and also with patients without an ICD who did not have any contraindication for an ICD as identified through chart abstraction. Of the 542 potentially eligible patients identified, 224 (41%) did not have an ICD. In the initial adjusted analysis, female sex (odds ratio=1.90; 95% CI, 1.28 to 2.81) and increasing age (odds ratio=1.07; 95% CI, 1.04 to 1.11) were associated with a higher likelihood of not having an ICD. After detailed chart review, of the 224 patients without an ICD, 117 (52%) were ineligible for the device and 38 (17%) patients refused the device, resulting in only 69 (13%) patients eligible for an ICD who failed to receive one. In this subsequent adjusted analysis, remaining factors associated with a higher likelihood of not having an ICD were absence of ventricular arrhythmias (odds ratio=4.93; 95% CI, 2.56 to 9.50), noncardiology hospital service (odds ratio=3.73; 95% CI, 1.98 to 7.04), and lack of health insurance (odds ratio=3.10; 95% CI, 1.48 to 6.46). On the basis of a detailed chart review, the true rate of ICD underuse may be substantially lower than previous estimates. In addition, after accounting for ICD eligibility criteria, patient sex and age disparities in ICD therapy were no longer present.
    Preview · Article · Feb 2011 · Circulation Cardiovascular Quality and Outcomes
  • Brett D Atwater · James P Daubert

    No preview · Article · Feb 2010 · Journal of Cardiovascular Electrophysiology
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    ABSTRACT: Catheter-directed atrial fibrillation (AF) ablation is contraindicated among patients with left atrial appendage (LAA) thrombus. The prevalence of LAA thrombus among fully anticoagulated patients undergoing AF ablation is unknown. We retrospectively evaluated the prevalence of LAA thrombus among 192 consecutive patients undergoing AF ablation between July 2006 and January 2009. Seven of 192 patients (3.6%) had evidence of thrombus on transesophageal echocardiogram (TEE) despite being fully anticoagulated on warfarin (international normalized ratio [INR] 2-3) for 4 consecutive weeks prior to echocardiogram. Univariate analysis demonstrated that structural heart disease, large left atrial dimension, and number of AF ablations were associated with thrombus. Three patients with thrombus had paroxysmal AF with normal LV function. Despite full anticoagulation, 3.6% of patients undergoing AF ablation had LAA thrombus. We recommend that all patients, regardless of LV function or left atrial size, should undergo preprocedural TEE to exclude the presence of LAA thrombus.
    No preview · Article · Feb 2010 · Journal of Cardiovascular Electrophysiology
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    ABSTRACT: The currently available sudden cardiac death (SCD) risk prediction tools fail to identify most at-risk patients and cannot delineate a specific patient's SCD risk. We sought to develop a tool to improve the risk stratification of patients with coronary artery disease. Clinical, demographic, and angiographic characteristics were evaluated among 37,258 patients who had undergone coronary angiography from January 1, 1985 to May 31, 2005, and who were found to have at least one native coronary artery stenosis of > or =75%. After a median follow-up of 6.2 years, SCD had occurred in 1,568 patients, 14,078 patients had died from other causes, and 21,612 patients remained alive. A Cox proportional hazards model identified 10 independent patient characteristic variables significantly associated with SCD. A simplified model accounting for 97% of the predictive capacity of the full model included the following 7 variables: depressed left ventricular ejection fraction, number of diseased coronary arteries, diabetes mellitus, hypertension, heart failure, cerebrovascular disease, and tobacco use. The Duke SCD risk score was created from the simplified model to predict the likelihood of SCD among patients with coronary artery disease. It was internally validated with bootstrapping (c-index = 0.75, chi-square = 1,220.8) and externally validated in patients with ischemic cardiomyopathy from the Sudden Cardiac Death Heart Failure Trial (SCD-HeFT) database (c-index = 0.64, chi-square = 14.1). In conclusion, the Duke SCD risk score represents a simple, validated method for predicting the risk of SCD among patients with coronary artery disease and might be useful for directing treatment strategies designed to mitigate the risk of SCD.
    No preview · Article · Dec 2009 · The American journal of cardiology

Publication Stats

151 Citations
63.79 Total Impact Points


  • 2009-2015
    • Duke University
      • Department of Medicine
      Durham, North Carolina, United States
  • 2009-2014
    • Duke University Medical Center
      • Duke Clinical Research Institute
      Durham, North Carolina, United States
  • 2008
    • University of Wisconsin–Madison
      • Department of Medicine
      Madison, Wisconsin, United States
  • 2005
    • North Carolina Clinical Research
      Raleigh, North Carolina, United States