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Daniel B Kramer - One of the best experts on this subject based on the ideXlab platform.

  • exercise interventions in patients with Implantable Cardioverter Defibrillators and cardiac resynchronization therapy a systematic review and meta analysis
    Journal of Cardiopulmonary Rehabilitation and Prevention, 2019
    Co-Authors: Daniel A Steinhaus, Steven A Lubitz, Peter A Noseworthy, Daniel B Kramer
    Abstract:

    PURPOSE Physical activity improves outcomes across a broad spectrum of cardiovascular disease. The safety and effectiveness of exercise-based interventions in patients with Implantable Cardioverter-Defibrillators (ICDs) including cardiac resynchronization therapy Defibrillators (CRT-Ds) remain poorly understood. METHODS We identified clinical studies using the following search terms: "Implantable Cardioverter-Defibrillators"; "ICD"; "cardiac resynchronization therapy"; "CRT"; and any one of the following: "activity"; "exercise"; "training"; or "rehabilitation"; from January 1, 2000 to October 1, 2015. Eligible studies were evaluated for design and clinical endpoints. RESULTS A total of 16 studies were included: 8 randomized controlled trials, 5 single-arm trials, 2 observational cohort trials, and 1 randomized crossover trial. A total of 2547 patients were included (intervention groups = 1215 patients, control groups = 1332 patients). Exercise interventions varied widely in character, duration (median 84 d, range: 23-168 d), and follow-up time (median 109 d, range: 23 d to 48 mo). Exercise performance measures were the most common primary endpoints (87.5%), with most studies (81%) demonstrating significant improvement. Implantable Cardioverter-defibrillator shocks were uncommon during active exercise intervention, with 6 shocks in 635 patients (0.9%). Implantable Cardioverter-defibrillator shocks in follow-up were less common in patients receiving any exercise intervention (15.6% vs 23%, OR = 0.68; 95% CI, 0.48-0.80, P < .001). (Equation is included in full-text article.)O2 peak improved significantly in patients receiving exercise intervention (1.98 vs 0.36 mL/kg/min, P < .001). CONCLUSION In conclusion, exercise interventions in patients with ICDs and CRT-Ds appear safe and effective. Lack of consensus on design and endpoints remains a barrier to broader application to this important patient population.

  • joint shock death risk prediction model for patients considering Implantable Cardioverter Defibrillators
    Circulation-cardiovascular Quality and Outcomes, 2019
    Co-Authors: Harrison T Reeder, Changyu Shen, Alfred E Buxton, Sebastien Haneuse, Daniel B Kramer
    Abstract:

    Background The risk of death or appropriate therapy varies widely among recipients of Implantable Cardioverter-Defibrillators (ICDs). The goals of this study were to develop a risk prediction tool that jointly considers future outcome probabilities of ICD shock and death. Methods and results We performed a secondary analysis of patients receiving ICDs as part of the SCD-HeFT trial (Sudden Cardiac Death in Heart Failure Trial). We applied an illness-death regression model to jointly model both ICD shocks and death under the semi-competing risks framework, which predicts for each patient their probability of having received ICD shocks, dying, or both at any given point in time. Among 803 ICD recipients (mean age, 60 years; 23% women) followed for a median of 41.1 months, 430 (53.5%) patients completed the study without dying or receiving an ICD shock, 206 (25.7%) received at least 1 shock but survived, 113 (14.1%) died before experiencing a shock, and 54 (6.7%) received at least 1 shock and subsequently died. Predicted outcome probabilities based on baseline demographic and clinical variables reveal substantial heterogeneity in joint shock and death risks, both between patients at each time point and for each single patient across time. Overall, predictive performance for ICD shock and death individually was adequate, based on area under the curve at 5 years of 0.65 for shocks and of 0.79 for death. Conclusions Our analysis of outcomes after ICD implantation provides an alternative predictive model for individual risk of death or ICD shocks. If validated, this may provide a useful tool for individualized counseling regarding likely outcomes after device implantation, while also informing the design of further studies to focus the clinical effectiveness and cost-effectiveness of ICD therapy. Clinical trial registration URL: https://www.clinicaltrials.gov. Unique identifier: NCT00000609.

  • abstract 233 geographic variability in the utilization of remote monitoring for pacemakers and Implantable Cardioverter Defibrillators
    Circulation-cardiovascular Quality and Outcomes, 2019
    Co-Authors: Jessica N Holtzman, Rishi K Wadhera, Ariane M Fraiche, Eunhee Choi, Changyu Shen, Daniel B Kramer
    Abstract:

    Background: Remote monitoring (RM) of pacemakers (PMs) and Implantable Cardioverter-Defibrillators (ICDs) reduces the need for in-office visits, of particular importance to patients in rural areas....

  • characteristics and outcomes of patients receiving new and replacement Implantable Cardioverter Defibrillators results from the ncdr
    Circulation-cardiovascular Quality and Outcomes, 2013
    Co-Authors: Daniel B Kramer, Peter A Noseworthy, Alfred E Buxton, Kevin F Kennedy, Mark E Josephson, Sharonlise T Normand, John A Spertus, Peter Zimetbaum, Matthew R Reynolds, Susan L Mitchell
    Abstract:

    Background— Little is known about the clinical features, procedural risks, or survival of patients receiving replacement versus new Implantable Cardioverter-Defibrillators (ICDs). Methods and Results— Entries in the National Cardiovascular Data Registry (NCDR) ICD Registry from 2005 through 2010 were eligible for inclusion (n=463 978). Baseline demographic data, clinical information, and procedural variables were compared between patients receiving new (n=359 993; 77.6%) and replacement (n=103 985; 22.4%) ICDs and entered into a propensity match model to determine adjusted survival rates. Patients receiving replacement ICDs were older (70.7 versus 67.5 years of age) and more likely to have atrial fibrillation (41.8% versus 31.4%; P <0.001) and ventricular tachycardia (60.5% versus 33.9%; P <0.001) compared with patients receiving new ICDs. Median battery life was only 4.6 years (25%–75% interquartile range, 3.7–5.8) for all replaced devices, 5.8 (25%–75% interquartile range, 4.2–7.5) for single-chamber, 5.1 (25%–75% interquartile range, 4.1–6.1) for dual-chamber, and 3.9 (25%–75% interquartile range, 3.2–4.6) years for biventricular devices. Patients receiving replacement ICDs had lower rates of index admission complications (0.9% versus 3.2%; P <0.001) but greater risk for death compared receiving patients receiving new ICDs in unadjusted analysis (hazard ratio, 1.18; 95% confidence interval, 1.16–1.20; P <0.0001) and after propensity-score matching (hazard ratio, 1.28; 95% confidence interval, 1.25–1.30; P <0.0001). Conclusions— Patients receiving replacement ICDs are older and at greater risk for death compared with those receiving initial ICD implants. The battery life of initial ICDs is shorter than previously reported.

Fabrizio Veglia - One of the best experts on this subject based on the ideXlab platform.

Sonia Suchday - One of the best experts on this subject based on the ideXlab platform.

  • effects of acute mental stress and exercise on t wave alternans in patients with Implantable Cardioverter Defibrillators and controls
    Circulation, 2004
    Co-Authors: David S Krantz, Bruce D Nearing, John S Gottdiener, John F Quigley, Mark Ocallahan, Albert A Delnegro, Ted D Friehling, Pamela Karasik, Sonia Suchday, Joseph H Levine
    Abstract:

    Background— Malignant cardiac arrhythmias can be triggered by exercise and by mental stress in vulnerable patients. Exercise-induced T-wave alternans (TWA) is an established marker of cardiac electrical instability. However, the effects of acute mental stress on TWA have not been investigated as a vulnerability marker in humans. Methods and Results— TWA responses to mental stress (anger recall and mental arithmetic) and bicycle ergometry were evaluated in patients with Implantable Cardioverter Defibrillators (ICDs) and documented coronary artery disease (n=23, age 62.1±12.3 years) and controls (n=17, age 54.2±12.1 years). TWA was assessed from digitized ECGs by modified moving average analysis. Dual-isotope single photon emission computed tomography was used to assess myocardial ischemia. TWA increased during mental stress and exercise (P values <0.001), and TWA responses were higher in ICD patients than in controls (arithmetic Δ=8.9±1.4 versus 4.3±2.2 μV, P=0.043; exercise Δ=21.4±2.8 versus 13.8±3.2 μV, ...

  • effects of acute mental stress and exercise on t wave alternans in patients with Implantable Cardioverter Defibrillators and controls
    Circulation, 2004
    Co-Authors: Willem J Kop, David S Krantz, Bruce D Nearing, John S Gottdiener, John F Quigley, Mark Ocallahan, Albert A Delnegro, Ted D Friehling, Pamela Karasik, Sonia Suchday
    Abstract:

    Background— Malignant cardiac arrhythmias can be triggered by exercise and by mental stress in vulnerable patients. Exercise-induced T-wave alternans (TWA) is an established marker of cardiac electrical instability. However, the effects of acute mental stress on TWA have not been investigated as a vulnerability marker in humans. Methods and Results— TWA responses to mental stress (anger recall and mental arithmetic) and bicycle ergometry were evaluated in patients with Implantable Cardioverter Defibrillators (ICDs) and documented coronary artery disease (n=23, age 62.1±12.3 years) and controls (n=17, age 54.2±12.1 years). TWA was assessed from digitized ECGs by modified moving average analysis. Dual-isotope single photon emission computed tomography was used to assess myocardial ischemia. TWA increased during mental stress and exercise (P values <0.001), and TWA responses were higher in ICD patients than in controls (arithmetic Δ=8.9±1.4 versus 4.3±2.2 μV, P=0.043; exercise Δ=21.4±2.8 versus 13.8±3.2 μV, ...

Pamela Karasik - One of the best experts on this subject based on the ideXlab platform.

  • Effects of Acute Mental Stress and Exercise on T-Wave Alternans in Patients With Implantable Cardioverter Defibrillators and Controls
    2016
    Co-Authors: Willem J Kop, Phd David, S. Krantz, Phd Bruce, D. Nearing, Phd John, S. Gottdiener, Pamela Karasik
    Abstract:

    Background—Malignant cardiac arrhythmias can be triggered by exercise and by mental stress in vulnerable patients. Exercise-induced T-wave alternans (TWA) is an established marker of cardiac electrical instability. However, the effects of acute mental stress on TWA have not been investigated as a vulnerability marker in humans. Methods and Results—TWA responses to mental stress (anger recall and mental arithmetic) and bicycle ergometry were evaluated in patients with Implantable Cardioverter Defibrillators (ICDs) and documented coronary artery disease (n23, age 62.112.3 years) and controls (n17, age 54.212.1 years). TWA was assessed from digitized ECGs by modified moving average analysis. Dual-isotope single photon emission computed tomography was used to assess myocardial ischemia. TWA increased during mental stress and exercise (P values0.001), and TWA responses were higher in ICD patients than in controls (arithmetic 8.91.4 versus 4.32.2 V, P0.043; exercise 21.42.8 versus 13.83.2 V, P0.038). TWA increases with mental stress occurred at substantially lower heart rates (anger recall 9.77.7 bpm, arithmetic 14.313.3 bpm) versus exercise (53.722.7 bpm; P values0.001). After adjustment for heart rate increases, mental stress and exercise provoked increased TWA in ICD patients (P values0.05), but not in controls (P values 0.2). Ejection fraction and stress-induced myocardial ischemia were not associated with TWA. Conclusions—Mental stress can induce cardiac electrical instability, as assessed via TWA, among patients with arrhythmic vulnerability and occurs at lower heart rates than with exercise. Pathophysiological mechanisms of mental stress

  • effects of acute mental stress and exercise on t wave alternans in patients with Implantable Cardioverter Defibrillators and controls
    Circulation, 2004
    Co-Authors: David S Krantz, Bruce D Nearing, John S Gottdiener, John F Quigley, Mark Ocallahan, Albert A Delnegro, Ted D Friehling, Pamela Karasik, Sonia Suchday, Joseph H Levine
    Abstract:

    Background— Malignant cardiac arrhythmias can be triggered by exercise and by mental stress in vulnerable patients. Exercise-induced T-wave alternans (TWA) is an established marker of cardiac electrical instability. However, the effects of acute mental stress on TWA have not been investigated as a vulnerability marker in humans. Methods and Results— TWA responses to mental stress (anger recall and mental arithmetic) and bicycle ergometry were evaluated in patients with Implantable Cardioverter Defibrillators (ICDs) and documented coronary artery disease (n=23, age 62.1±12.3 years) and controls (n=17, age 54.2±12.1 years). TWA was assessed from digitized ECGs by modified moving average analysis. Dual-isotope single photon emission computed tomography was used to assess myocardial ischemia. TWA increased during mental stress and exercise (P values <0.001), and TWA responses were higher in ICD patients than in controls (arithmetic Δ=8.9±1.4 versus 4.3±2.2 μV, P=0.043; exercise Δ=21.4±2.8 versus 13.8±3.2 μV, ...

  • effects of acute mental stress and exercise on t wave alternans in patients with Implantable Cardioverter Defibrillators and controls
    Circulation, 2004
    Co-Authors: Willem J Kop, David S Krantz, Bruce D Nearing, John S Gottdiener, John F Quigley, Mark Ocallahan, Albert A Delnegro, Ted D Friehling, Pamela Karasik, Sonia Suchday
    Abstract:

    Background— Malignant cardiac arrhythmias can be triggered by exercise and by mental stress in vulnerable patients. Exercise-induced T-wave alternans (TWA) is an established marker of cardiac electrical instability. However, the effects of acute mental stress on TWA have not been investigated as a vulnerability marker in humans. Methods and Results— TWA responses to mental stress (anger recall and mental arithmetic) and bicycle ergometry were evaluated in patients with Implantable Cardioverter Defibrillators (ICDs) and documented coronary artery disease (n=23, age 62.1±12.3 years) and controls (n=17, age 54.2±12.1 years). TWA was assessed from digitized ECGs by modified moving average analysis. Dual-isotope single photon emission computed tomography was used to assess myocardial ischemia. TWA increased during mental stress and exercise (P values <0.001), and TWA responses were higher in ICD patients than in controls (arithmetic Δ=8.9±1.4 versus 4.3±2.2 μV, P=0.043; exercise Δ=21.4±2.8 versus 13.8±3.2 μV, ...

David S Krantz - One of the best experts on this subject based on the ideXlab platform.

  • effects of acute mental stress and exercise on t wave alternans in patients with Implantable Cardioverter Defibrillators and controls
    Circulation, 2004
    Co-Authors: David S Krantz, Bruce D Nearing, John S Gottdiener, John F Quigley, Mark Ocallahan, Albert A Delnegro, Ted D Friehling, Pamela Karasik, Sonia Suchday, Joseph H Levine
    Abstract:

    Background— Malignant cardiac arrhythmias can be triggered by exercise and by mental stress in vulnerable patients. Exercise-induced T-wave alternans (TWA) is an established marker of cardiac electrical instability. However, the effects of acute mental stress on TWA have not been investigated as a vulnerability marker in humans. Methods and Results— TWA responses to mental stress (anger recall and mental arithmetic) and bicycle ergometry were evaluated in patients with Implantable Cardioverter Defibrillators (ICDs) and documented coronary artery disease (n=23, age 62.1±12.3 years) and controls (n=17, age 54.2±12.1 years). TWA was assessed from digitized ECGs by modified moving average analysis. Dual-isotope single photon emission computed tomography was used to assess myocardial ischemia. TWA increased during mental stress and exercise (P values <0.001), and TWA responses were higher in ICD patients than in controls (arithmetic Δ=8.9±1.4 versus 4.3±2.2 μV, P=0.043; exercise Δ=21.4±2.8 versus 13.8±3.2 μV, ...

  • effects of acute mental stress and exercise on t wave alternans in patients with Implantable Cardioverter Defibrillators and controls
    Circulation, 2004
    Co-Authors: Willem J Kop, David S Krantz, Bruce D Nearing, John S Gottdiener, John F Quigley, Mark Ocallahan, Albert A Delnegro, Ted D Friehling, Pamela Karasik, Sonia Suchday
    Abstract:

    Background— Malignant cardiac arrhythmias can be triggered by exercise and by mental stress in vulnerable patients. Exercise-induced T-wave alternans (TWA) is an established marker of cardiac electrical instability. However, the effects of acute mental stress on TWA have not been investigated as a vulnerability marker in humans. Methods and Results— TWA responses to mental stress (anger recall and mental arithmetic) and bicycle ergometry were evaluated in patients with Implantable Cardioverter Defibrillators (ICDs) and documented coronary artery disease (n=23, age 62.1±12.3 years) and controls (n=17, age 54.2±12.1 years). TWA was assessed from digitized ECGs by modified moving average analysis. Dual-isotope single photon emission computed tomography was used to assess myocardial ischemia. TWA increased during mental stress and exercise (P values <0.001), and TWA responses were higher in ICD patients than in controls (arithmetic Δ=8.9±1.4 versus 4.3±2.2 μV, P=0.043; exercise Δ=21.4±2.8 versus 13.8±3.2 μV, ...