D George Wyse

The University of Calgary, Calgary, Alberta, Canada

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Publications (202)1531.88 Total impact

  • D. George Wyse
    The Canadian journal of cardiology 10/2014; · 3.12 Impact Factor
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    ABSTRACT: AimsTo investigate the association between baseline systolic blood pressure levels and mortality in patients with AF with or without LV dysfunction. Hypertension leads to cardiovascular disease but, in specific groups, low blood pressure has been associated with a paradoxical increase in mortality. In patients with AF and heart failure, the relationship between blood pressure and death remains largely unknown.Methods and resultsWe conducted a post-hoc combined analysis on pooled data from AFFIRM and AF-CHF trials and assessed the relationship between baseline systolic blood pressure (SBP) and mortality and hospitalizations. Patients were classified according to LVEF (>40%, ≤40%) and baseline SBP (<120 mmHg, 120–140 mmHg, >140 mmHg). A total of 5436 patients with non-permanent AF were followed for 41 ± 16 months. In patients with LVEF >40%, baseline SBP was not related to mortality using multivariate Cox regression analyses to adjust for baseline differences (P = 0.563). In contrast, in patients with LVEF ≤40% (n = 1980), SBP <120 mmHg and SBP >140 mmHg were both associated with a significant increase in total mortality compared with SBP 120–140 mmHg [hazard ratio (HR) 1.75, 95% confidence interval (CI) 1.41–2.17; and HR 1.40, 95% CI 1.04–1.90, respectively]. Hospitalizations were unrelated to SBP regardless of LVEF.Conclusions Mortality is modulated by baseline SBP levels in patients with AF and depressed EF but not in patients with normal EF. Targeted therapy of AF patients based on SBP merits further prospective investigation.
    European Journal of Heart Failure 10/2014; · 5.25 Impact Factor
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    ABSTRACT: Despite amiodarone's established safety profile in the setting of heart failure, it is unknown whether its impact on cardiovascular outcomes in patients with atrial fibrillation is modulated by left ventricular function.
    Journal of Cardiovascular Electrophysiology 09/2014; · 3.48 Impact Factor
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    ABSTRACT: The historical origin of the term ‘lone atrial fibrillation (AF)’ predates by 80 years our current understanding of the pathophysiology of AF, the multitude of known etiologies for AF, and our ability to image and diagnose heart disease. The term was meant to indicate AF in whom subsequent investigations could not demonstrate heart disease, but for many practitioners has become synonymous with ‘idiopathic AF’. As the list of heart diseases has expanded and diagnostic techniques have improved, the prevalence of ‘lone AF’ has fallen. The legacy of the intervening years is that definitions of ‘lone AF’ in the literature are inconsistent such that studies of ‘lone AF’ are not comparable Guidelines provide a vague definition of ‘lone AF’ but do not provide direction about how much or what kind of imaging and other testing are necessary to exclude heart disease. There has been an explosion in the understanding of the pathophysiology of AF in the last 20 years in particular. Nevertheless, there are no apparently unique mechanisms for AF in patients categorized as ‘lone AF’. In addition, the term ‘lone AF’ is not invariably useful in making treatment decisions, and other tools for doing so have been more thoroughly and carefully validated. It is therefore recommended that use of the term ‘lone AF’ be avoided.
    Journal of the American College of Cardiology 01/2014; · 15.34 Impact Factor
  • D George Wyse
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    ABSTRACT: Catheter ablation for atrial fibrillation (AF) is a procedural treatment option that has yet to find its final place in AF rhythm management. So far, other than pulmonary vein isolation, it does not have an indisputable mechanistic basis. It is empirical, not truly individualized on the basis of a diagnostic procedure. Success for the procedure is usually couched in terms of a measure of recurrence of AF. Existing data concerning recurrence have several confounders. Recurrence data are often subjective: They are based on surveys and symptoms rather than objective electrocardiogram (ECG) determination of recurrence, patients are highly selected, concurrent use of antiarrhythmic drugs is included or excluded, redo procedures may or may not be included, and follow-up is frequently a year or less. The nature of the AF (paroxysmal, persistent, long-standing persistent) greatly impacts success rates, which range from 20% to 85%. The procedure is probably infrequently a lifelong "cure" for AF. Best estimate of the risk of a complication from each procedure is about 4.5%, the commonest being tamponade (1.3%), vascular access complications (1.5%), and stroke or transient ischemic attach (1%). Risk of a fatal complication is estimated at 0.15%. There is no convincing evidence that the procedure decreases the risk of death, stroke, or hospitalization for heart failure, but the available randomized trials have enrolled patients inappropriate for assessment of impact on these clinical outcomes. Much remains to be done. Currently the procedure is indicated for relief of symptoms in selected patients, usually who have failed antiarrhythmic drug therapy.
    The Canadian journal of cardiology 05/2013; · 3.12 Impact Factor
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    ABSTRACT: The detection of undiagnosed atrial tachycardia/atrial fibrillation (AT/AF) among patients with stroke risk factors could be useful for primary stroke prevention. We analyzed newly detected AT/AF (NDAF) using continuous monitoring in patients with stroke risk factors but without previous stroke or evidence of AT/AF. NDAF (AT/AF >5 minutes on any day) was determined in patients with implantable cardiac rhythm devices and ≥1 stroke risk factors (congestive heart failure, hypertension, age ≥75 years, or diabetes). All devices were capable of continuously monitoring the daily cumulative time in AT/AF. Of 1,368 eligible patients, NDAF was identified in 416 (30%) during a follow-up of 1.1 ± 0.7 years and was unrelated to the CHADS(2) score (congestive heart failure, hypertension [blood pressure consistently >140/90 mm Hg or hypertension treated with medication], age ≥75 years, diabetes mellitus, previous stroke or transient ischemic attack). The presence of AT/AF >6 hours on ≥1 day increased significantly with increased CHADS(2) scores and was present in 158 (54%) of 294 patients with NDAF and a CHADS(2) score of ≥2. NDAF was sporadic, and 78% of patients with a CHADS(2) score of ≥2 with NDAF experienced AT/AF on <10% of the follow-up days. The median interval to NDAF detection in these higher risk patients was 72 days (interquartile range 13 to 177). In conclusion, continuous monitoring identified NDAF in 30% of patients with stroke risk factors. In patients with NDAF, AT/AF occurred sporadically, highlighting the difficulty in detecting paroxysmal AT/AF using traditional monitoring methods. However, AT/AF also persisted for >6 hours on ≥1 days in most patients with NDAF and multiple stroke risk factors. Whether patients with CHADS(2) risk factors but without a history of AF might benefit from implantable monitors for the selection and administration of anticoagulation for primary stroke prevention merits additional investigation.
    The American journal of cardiology 07/2012; 110(9):1309-14. · 3.58 Impact Factor
  • D George Wyse
    Europace 02/2012; 14(2):151-2. · 3.05 Impact Factor
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    ABSTRACT: Vernakalant is a novel, relatively atrial-selective antiarrhythmic agent for conversion of atrial fibrillation (AF) to sinus rhythm. This study examined the safety and efficacy of vernakalant in converting atrial flutter (AFL) to sinus rhythm. This was a phase 2/3, randomized, double-blind, placebo-controlled trial. Adults with AFL received either a 10 min infusion of 3.0 mg/kg vernakalant (n = 39) or placebo (n = 15). If AFL or AF persisted at the end of a 15 min observation period, a second 10 min infusion of 2.0 mg/kg vernakalant or placebo was administered. The primary efficacy outcome was the proportion of patients who had treatment-induced conversion of AFL to sinus rhythm for a minimum duration of 1 min within 90 min after the start of the first infusion. No patient in the placebo group met the primary outcome. Only one patient receiving vernakalant (1 of 39, 3%) converted to sinus rhythm. A reduced mean absolute ventricular response rate occurred within 50 min in patients receiving vernakalant (mean change from baseline -8.2 b.p.m.) vs. patients receiving placebo (-0.2 b.p.m.) (P = 0.037). A post-hoc analysis revealed that vernakalant increased AFL cycle length by an average of 55 ms, whereas the AFL cycle length was unchanged in the placebo group (P < 0.001). There was no occurrence of 1 : 1 atrio-ventricular conduction. Dysgeusia and sneezing were the most common treatment-related adverse events, consistent with previous reports. Vernakalant did not restore sinus rhythm in patients with AFL. Vernakalant modestly slowed AFL and ventricular response rates, and was well tolerated.
    Europace 01/2012; 14(6):804-9. · 3.05 Impact Factor
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    ABSTRACT: The impact of individual antiarrhythmic drugs (AADs) on mortality and hospital stay in atrial fibrillation (AF) was evaluated. Cardiovascular (CV) outcomes in AF patients receiving pharmacologic rhythm control therapy have not been compared with rate control therapy on the basis of AAD selection. We compared CV outcomes in the AFFIRM (Atrial Fibrillation Follow-Up Investigation of Rhythm Management) trial in subgroups defined by the initial AAD selected with propensity score matched subgroups from the rate arm (Rate). Seven hundred twenty-nine amiodarone patients, 606 sotalol patients, and 268 Class 1C patients were matched. The composite outcome of mortality or cardiovascular hospital stays (CVH) showed better outcomes with Rate compared with amiodarone (hazard ratio [HR]: 1.18, 95% confidence interval [CI]: 1.03 to 1.36, p = 0.02), sotalol (HR: 1.32, 95% CI: 1.13 to 1.54, p < 0.001), and Class 1C (HR: 1.22, 95% CI: 0.97 to 1.56, p = 0.10). There was a nonsignificant increase in mortality with amiodarone (HR: 1.20, 95% CI: 0.94 to 1.53, p = 0.15) with the risk of non-CV death being significantly higher with amiodarone versus Rate (HR: 1.11, 95% CI: 1.01 to 1.24, p = 0.04). First CVH event rates at 3 years were 47% for amiodarone, 50% for sotalol, and 44% for Class 1C versus 40%, 40%, and 36%, respectively, for Rate (amiodarone HR: 1.20, 95% CI: 1.03 to 1.40, p = 0.02, sotalol HR: 1.364, 95% CI: 1.16 to 1.611, p < 0.001, Class 1C HR: 1.24, 95% CI: 0.96 to 1.60, p = 0.09). Time to CVH with intensive care unit stay or death was shorter with amiodarone (HR: 1.22, 95% CI: 1.02 to 1.46, p = 0.03). In AFFIRM, composite mortality and CVH outcomes differed for Rate and AADs due to differences in CVH; CVH event rates during follow-up were high for all cohorts, but they were higher for all groups on AADs. Death, intensive care unit hospital stay, and non-CV death were more frequent with amiodarone.
    Journal of the American College of Cardiology 11/2011; 58(19):1975-85. · 15.34 Impact Factor
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    D George Wyse
    Journal of the American College of Cardiology 08/2011; 58(9):950-2. · 15.34 Impact Factor
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    ABSTRACT: The temporal relationship between atrial tachyarrhythmias (atrial tachycardia [AT] and atrial fibrillation [AF]) and cerebrovascular events/systemic emboli (CVE/SE) is unknown. The purpose of this study was to evaluate this relationship using stored AT/AF diagnostic data from implanted devices in patients with and those without AF. The TRENDS study enrolled 2,486 patients with an indication for an implantable device, at least one stroke risk factor, and available device data. The current study includes the subgroup of 40 (1.6%) patients enrolled in TRENDS who experienced CVE/SE. AT/AF was detected prior to CVE/SE in 20 (50%) of 40 patients. Other than average and maximum daily AT/AF burden and duration of device monitoring prior to CVE/SE, no statistically significant differences were found between patients with and those without AT/AF prior to CVE/SE. For the 20 patients with AT/AF detected prior to CVE/SE, 9 (45%) did not have any AT/AF in the 30 days prior to CVE/SE. Therefore, 29 (73%) of 40 patients with CVE/SE had zero AT/AF burden within 30 days prior to CVE/SE. Fourteen (70%) of the 20 patients with AT/AF detected prior to CVE/SE were not in AT/AF at diagnosis of CVE/SE. The last episode of AT/AF in these 14 patients was 168 ± 199 days (range 3-642 days) before CVE/SE. The majority of CVE/SE in this population did not occur proximal to recent AT/AF episodes. These data imply that the mechanisms of CVE/SE in patients with implantable devices may importantly involve mechanisms other than cardioembolism due to atrial tachyarrhythmias.
    Heart rhythm: the official journal of the Heart Rhythm Society 04/2011; 8(9):1416-23. · 4.56 Impact Factor
  • D George Wyse
    The Canadian journal of cardiology 01/2011; 27(1):14-8. · 3.12 Impact Factor
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    ABSTRACT: The objective of the present study was to assess the safety and effectiveness of vernakalant hydrochloride injection (RSD1235), a novel antiarrhythmic drug, for the conversion of atrial fibrillation (AF) or atrial flutter to sinus rhythm (SR). Patients with either AF or atrial flutter were randomized in a 1:1 ratio to receive vernakalant (n = 138) or placebo (n = 138) and were stratified by an arrhythmia duration of >3 hours to ≤7 days (short duration) and 8 to ≤45 days (long duration). The first infusion of placebo or vernakalant (3 mg/kg) was given for 10 minutes followed by a second infusion of placebo or vernakalant (2 mg/kg) 15 minutes later if the arrhythmia had not terminated. A total of 265 patients were randomized and received treatment. The primary end point was conversion of AF to SR for ≥1 minute within 90 minutes of the start of the drug infusion in the short-duration AF group. Of the 86 patients receiving vernakalant in the short-duration AF group, 44 (51.2%) demonstrated conversion to SR compared to 3 (3.6%) of the 84 in the placebo group (p <0.0001). The median interval to conversion of short-duration AF to SR in the responders given vernakalant was 8 minutes. Of the entire AF population (short- and long-duration AF), 47 (39.8%) of the 118 vernakalant patients experienced conversion of AF to SR compared to 4 (3.3%) of the 121 placebo patients (p <0.0001). Transient dysgeusia and sneezing were the most common adverse events in the vernakalant patients. One vernakalant patient who had severe aortic stenosis experienced hypotension and ventricular fibrillation and died. In conclusion, vernakalant demonstrated a rapid and high rate of conversion for short-duration AF and was well tolerated.
    The American journal of cardiology 11/2010; 106(9):1277-83. · 3.58 Impact Factor
  • Stroke 05/2010; 41(6). · 6.02 Impact Factor
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    ABSTRACT: The goal of this study was to evaluate the relationship between the presence of sinus rhythm and outcomes in patients with a history of congestive heart failure (CHF) and atrial fibrillation (AF). The value of sinus rhythm maintenance in patients with AF and heart failure (HF) is uncertain. A total of 1,376 patients with AF, ejection fraction < or =35%, and heart failure symptoms were randomized to a rhythm- or rate-control strategy. Detailed efficacy analyses were used to evaluate the independent effects of treatment strategy and the presence of sinus rhythm on cardiovascular outcomes. Overall, 445 (32%) patients died and 402 (29%) experienced worsening HF. The rhythm-control strategy was not predictive of cardiovascular mortality (hazard ratio [HR]: 0.90, 95% confidence interval [CI]: 0.70 to 1.16; p = 0.41), all-cause death (HR: 0.86, 95% CI: 0.69 to 1.08; p = 0.19), or worsening HF (HR: 0.86, 95% CI: 0.68 to 1.10; p = 0.23). In analyses devised to isolate the effect of underlying rhythm, sinus rhythm was not associated with cardiovascular mortality [HR: 1.22, 95% CI: 0.80 to 1.87; p = 0.35), total mortality [HR: 1.11, 95% CI: 0.78 to 1.58; p = 0.57), or worsening HF [HR: 0.62, 95% CI: 0.37 to 1.02; p = 0.059). A rhythm-control strategy or the presence of sinus rhythm are not associated with better outcomes in patients with AF and CHF.
    Journal of the American College of Cardiology 04/2010; 55(17):1796-802. · 15.34 Impact Factor
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    ABSTRACT: Evidence of atrial tachycardia/atrial fibrillation (AT/AF) is often sought in patients with ischemic stroke or transient ischemic attack. We studied patients with previous thromboembolic events (TE) who were implanted with devices capable of continuous arrhythmia monitoring to comprehensively quantify the incidence and duration of newly detected AT/AF. This study represents a subgroup analysis of the TRENDS trial, which included patients with clinical indications for pacemakers or defibrillators and >or=1 stroke risk factors (heart failure, hypertension, age 65 or older, diabetes, or previous TE). A history of AF was not required. All implanted devices were capable of continuously monitoring the cumulative time spent in AT/AF each day. This analysis focuses primarily on the incidence and duration of newly detected AT/AF (defined as >or=5 minutes of AT/AF on any day) in patients with previous TE, no documented history of AF, and no warfarin or antiarrhythmic drug use. A total of 319 patients had a history of TE and >or=1 day of device data. Patients with a documented history of AF (n=80), warfarin use (n=56), or antiarrhythmic drug use (n=20) were excluded from analysis. Of the remaining 163 patients, newly detected AT/AF was identified via the device in 45 patients (28%) over a mean follow-up of 1.1+/-0.7 years. AT/AF recurred infrequently, with only 12 patients experiencing AT/AF on >10% of follow-up days. Newly detected episodes of AT/AF were found via continuous monitoring in 28% of patients with previous TE. Most episodes would not have been detected by standard intermittent monitoring techniques.
    Stroke 02/2010; 41(2):256-60. · 6.02 Impact Factor
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    D George Wyse
    Journal of Interventional Cardiac Electrophysiology 10/2009; 25(3):163-5. · 1.39 Impact Factor
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    Elad Anter, David J Callans, D George Wyse
    Circulation 10/2009; 120(14):1436-43. · 14.95 Impact Factor
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    D George Wyse, Elad Anter, David J Callans
    Circulation 10/2009; 120(14):1444-52. · 14.95 Impact Factor
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    ABSTRACT: It is unknown if brief episodes of device-detected atrial fibrillation (AF) increase thromboembolic event (TE) risk. TRENDS was a prospective, observational study enrolling patients with > or = 1 stroke risk factor (heart failure, hypertension, age > or = 65 years, diabetes, or prior TE) receiving pacemakers or defibrillators that monitor atrial tachycardia (AT)/AF burden (defined as the longest total AT/AF duration on any given day during the prior 30-day period). This time-varying exposure was updated daily during follow-up and related to TE risk. Annualized TE rates were determined according to AT/AF burden subsets: zero, low (<5.5 hours [median duration of subsets with nonzero burden]), and high (> or = 5.5 hours). A multivariate Cox model provided hazard ratios including terms for stroke risk factors and time-varying AT/AF burden and antithrombotic therapy. Patients (n=2486) had at least 30 days of device data for analysis. During a mean follow-up of 1.4 years, annualized TE risk (including transient ischemic attacks) was 1.1% for zero, 1.1% for low, and 2.4% for high burden subsets of 30-day windows. Compared with zero burden, adjusted hazard ratios (95% CIs) in the low and high burden subsets were 0.98 (0.34 to 2.82, P=0.97) and 2.20 (0.96 to 5.05, P=0.06), respectively. The TE rate was low compared with patients with traditional AF with similar risk profiles. The data suggest that TE risk is a quantitative function of AT/AF burden. AT/AF burden > or = 5.5 hours on any of 30 prior days appeared to double TE risk. Additional studies are needed to more precisely investigate the relationship between stroke risk and AT/AF burden.
    Circulation Arrhythmia and Electrophysiology 10/2009; 2(5):474-80. · 5.95 Impact Factor

Publication Stats

7k Citations
1,531.88 Total Impact Points


  • 1984–2014
    • The University of Calgary
      • • Department of Medicine
      • • Department of Cardiac Sciences
      • • Department of Oncology
      • • Faculty of Medicine
      Calgary, Alberta, Canada
  • 2012
    • St George's, University of London
      Londinium, England, United Kingdom
  • 2004–2012
    • Medtronic
      Minneapolis, Minnesota, United States
  • 2009
    • Karl Jaspers Society of North America
      United States
    • University of Pennsylvania
      • Department of Medicine
      Philadelphia, PA, United States
  • 2006–2009
    • University of Toronto
      • Division of Cardiology
      Toronto, Ontario, Canada
  • 2005
    • University of Florida
      Gainesville, Florida, United States
    • Institut Universitaire de Cardiologie et de Pneumologie de Québec (Hôpital Laval)
      Québec, Quebec, Canada
  • 2003
    • University of Utah
      • Division of Cardiology
      Salt Lake City, UT, United States
    • Portland VA Medical Center
      Portland, Oregon, United States
    • The Clinical Trial Center, LLC
      Jenkintown, Pennsylvania, United States
  • 1999
    • The University of Hong Kong
      Hong Kong, Hong Kong
  • 1996
    • American Heart Association
      Dallas, Texas, United States
  • 1993
    • University of Alabama at Birmingham
      • Department of Medicine
      Birmingham, AL, United States
  • 1988
    • University of Alberta
      • Faculty of Pharmacy and Pharmaceutical Sciences
      Edmonton, Alberta, Canada