Warren M Jackman

University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States

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Publications (193)1141.76 Total impact

  • Benjamin J Scherlag, Warren M Jackman
    Circulation Arrhythmia and Electrophysiology 08/2014; 7(4):570-2. · 5.95 Impact Factor
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    ABSTRACT: -Ablation of epicardial posteroseptal accessory pathways (EpiPSAP) requires ablation within the coronary venous system. We assessed the risk of coronary artery (CA) injury with radiofrequency ablation (RFA) within the coronary venous system as a function of the distance between the CA and ablation site. We also examined the efficacy and safety of cryoablation close to a CA. -Two-hundred-forty patients underwent ablation for EpiPSAP. Coronary angiography was performed prior to ablation in the last 169 patients and was repeated after ablation if performed in the coronary venous system within 5mm of a significant CA. The distance between the ideal ablation site and closest CA was <2mm in 100 (59%), 3-5mm in 28 (16%) and >5mm in 41 of 169 (25%) patients. CA injury was observed in 11 of 22 (50%) and 1 of 15 (7%) patients when RFA was performed within 2mm and 3-5mm of a CA, respectively. Cryoablation was performed in 26 patients with a significant CA located within 5mm. Cryoablation alone eliminated EpiPSAP conduction in 17 of 26 (65%) patients and in 8 patients with additional RFA without CA narrowing in any patient. Over a follow-up period of 3-6 months, single procedure success rates were 90% and 77% for RFA and cryoablation at the ideal site, respectively. -The risk of CA injury with RFA is correlated inversely with the distance from the ablation site. Cryoablation is a safe and reasonably effective alternative when a significant CA is located close to the ideal ablation site.
    Circulation Arrhythmia and Electrophysiology 12/2013; · 5.95 Impact Factor
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    ABSTRACT: -During radiofrequency (RF) ablation, high electrode-tissue contact force (CF) is associated with increased risk of steam pop and perforation. The purpose of this study, in patients undergoing ablation of paroxysmal atrial fibrillation (AF), was to: 1) identify factors producing high CF during left atrial (LA) and pulmonary vein (PV) mapping; 2) determine the ability of atrial potential amplitude (Amp) and impedance to predict CF; and 3) explore the feasibility of controlling RF power based on CF. -A high-density map of LA/ PVs (median 328 sites) was obtained in 18 patients undergoing AF ablation using a 7.5F irrigated mapping/ablation catheter to measure CF. Average CF was displayed on the 3D map. For 5,682 mapped sites, CF ranged 1-144g (median 8.2g). High CF (≥35g) was observed at only 118/5,682 (2%) sites, clustering in 6 LA regions. The most common high CF site (48/113 sites in 17/18 patients) was located at the anterior/rightward LA roof, directly beneath the ascending aorta (confirmed by merging the CT image and map). Poor relationship between CF and either unipolar-Amp, bipolar-Amp or impedance was observed. During ablation, RF power was modulated based on CF. All PVs were isolated without steam pop, impedance rise, or pericardial effusion. -High CF often occurs at anterior/rightward roof, where the ascending aorta provides resistance to the LA. Atrial potential Amp and impedance are poor predictors of CF. Controlling RF power based on CF appears to prevent steam pop and impedance rise without loss of lesion effectiveness.
    Circulation Arrhythmia and Electrophysiology 07/2013; · 5.95 Impact Factor
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    ABSTRACT: The distal insertion of right atriofascicular pathways remains a source of debate. Moreover, there are various morphologies of preexcited QRS complexes involving atriofascicular pathways that have been poorly characterized. To characterize the distal insertion of atriofascicular accessory pathways and to provide a mechanism for the change in QRS morphology observed between short and long V-H antidromic AVRT in the same patient. 13 patients with atriofascicular pathways and preexcited AVRT with short V-H and long V-H intervals were studied. For each patient the tachycardia cycle length, V-H interval, QRS width, and axis were compared. A baseline H-V interval was also recorded. The baseline H-V interval was significantly longer than the V-H interval during antidromic AVRT (medial 50 msec vs. -10 msec, p<.0001). Retrograde RBBB increased the V-H interval (median -10 msec vs. 85 msec, p <.0001), the tachycardia CL (median of 302.5 msec vs. 350 msec, p <.0001) and the QRS width (median 120msec vs. 140msec, p<.0002). At least subtle changes in the QRS morphology, axis, or QRS width were seen in all patients. The distal insertion of right atriofascicular pathways fuses with the right bundle branch. The various QRS morphologies seen during the change from short V-H to long V-H antidromic AVRT can be explained by fusion, particularly over the left anterior fascicle.
    Heart rhythm: the official journal of the Heart Rhythm Society 07/2013; · 4.56 Impact Factor
  • Vincent P Keating, Ryan Cooley, Warren M Jackman
    Heart rhythm: the official journal of the Heart Rhythm Society 06/2013; · 4.56 Impact Factor
  • Journal of Cardiovascular Electrophysiology 03/2013; · 3.48 Impact Factor
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    ABSTRACT: Background: The open-irrigated catheter is used most frequently for atrial and ventricular radiofrequency ablation (RFA), and is often considered as the standard by which new ablation systems are compared. But few data have been published concerning its safety. This report provides a comprehensive safety analysis of the use of an open-irrigated catheter for RFA of atrial flutter, ventricular tachycardia, and atrial fibrillation in 1,275 patients in six rigorously monitored, prospective, multicenter studies. Methods: This analysis is of data from six studies conducted as part of both Food and Drug Administration-mandated investigational device exemption studies and postapproval studies. The six studies span a period of more than 10 years. All serious RFA complications and vascular access complications that occurred within seven days postprocedure were included. Results: The number of patients who experienced any acute serious RFA complication in these studies combined was 4.9% (63/1,275). The two earliest studies were conducted when the open-irrigated catheter was first introduced, and accounted for 55.6% of the complications. In the first atrial flutter ablation study, RFA complications decreased by 60% (15.4%-6.2%) after a proctoring program was initiated during the study. For all studies, vascular access complications ranged between from 0.5%-4.7%, and no stroke or transient ischemic attack was reported within 7 days postprocedure. No significant pulmonary vein stenosis was reported from the atrial fibrillation studies. Conclusion: A proctoring program, careful fluid management, and absence of char and coagulum contributed to the safe use of the open-irrigated RFA catheter. (PACE 2012; 35:1081-1089).
    Pacing and Clinical Electrophysiology 07/2012; 35(9):1081-9. · 1.75 Impact Factor
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    ABSTRACT: There has been a long-standing controversy regarding the mechanism(s) to explain the irregular ventricular response during atrial tachycardia (AT) or atrial fibrillation (AF) and where the site of block, if any, resides in the atrioventricular (AV) junction. We studied 12 Langendorff preparations perfused with modified Tyrode's solution containing 5-10 mM diacetyl monoxime which suppressed contractility but allowed the use of intracellular action potential (AP) recordings. Octapolar catheters (2-mm rings, 2-mm spacing) were secured along the tricuspid annulus from the apex to the base of the triangle of Koch and along the anterior limbus of the fossa ovalis to record extracellular, slow pathway, fast pathway, His bundle (Hb) and AV nodal (AVN) extracellular potentials as well as intracellular action potentials. AT or AF induced by rapid atrial pacing showed a variety of irregular responses due to: (1) Wenckebach conduction showing decrement within the AVN and progressive diminution of extracellular AVN potentials (n = 5); (2) repetitive concealed conduction proximal to the AVN (n = 3); (3) ectopic beats arising within the AVN (n = 2); (4) ectopic beats arising at the Hb (n = 2). In this experimental preparation, extracellular and intracellular recordings provided presumptive evidence for the mechanisms causing the irregularities of the ventricular response such as repetitive concealed conduction, enhanced automaticity or electrotonically triggered activity. Also more definitive determinations of the site of block in the AV junction were also obtained.
    Acta cardiologica 04/2012; 67(2):221-9. · 0.61 Impact Factor
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    ABSTRACT: A canine right atrial (RA) linear lesion model was used to produce a complex pattern of RA activation to evaluate a novel mapping system for rapid, high resolution (HR) electroanatomical mapping. The mapping system (Rhythmia Medical, Incorporated) uses an 8F deflectable catheter with a minibasket (1.8 cm diameter), containing 8 splines of 8 electrodes (total 64 electrodes, 2.5 mm spacing). The system automatically acquires electrograms and location information based on electrogram stability and respiration phase. In 10 anesthetized dogs, HR-RA map was obtained by maneuvering the minibasket catheter during sinus rhythm and coronary sinus pacing. A right thoracotomy was performed, and either 1 or 2 (to create a gap) epicardial linear lesions were created on the RA free wall (surgical incision or epicardial radiofrequency lesions). RA maps during RA pacing close to the linear lesions were obtained. A total of 73 maps were created, with 44 to 729 (median 237) beats and 833 to 12 412 (median 3589) electrograms (≤2 to ≤5 mm from surface geometry), resolution 1.8 to 5.3 (median 2.7) mm, and 2.6 to 26.3 (median 7.3) minutes mapping time. Without manual annotation, the system accurately created RA geometry and demonstrated RA activation, identifying the location of lines of block and presence or absence of a gap in all 10 dogs. Endocardial radiofrequency catheter ablation of a gap (guided by activation map) produced complete block across the gap in all 3 dogs tested. The new HR mapping system accurately and quickly identifies geometry and complex patterns of activation in the canine RA, with little or no manual annotation of activation time.
    Circulation Arrhythmia and Electrophysiology 03/2012; 5(2):417-24. · 5.95 Impact Factor
  • Heart rhythm: the official journal of the Heart Rhythm Society 03/2012; 9(4):632-696.e21. · 4.56 Impact Factor
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    ABSTRACT: This is a report of the Heart Rhythm Society (HRS) Task Force on Catheter and Surgical Ablation of Atrial Fibrillation, developed in partnership with the European Heart Rhythm Association (EHRA), a registered branch of the European Society of Cardiology and the European Cardiac Arrhythmia Society (ECAS), and in collaboration with the American College of Cardiology (ACC), American Heart Association (AHA), the Asia Pacific Heart Rhythm Society (APHRS), and the Society of Thoracic Surgeons (STS). This is endorsed by the governing bodies of the ACC Foundation, the AHA, the ECAS, the EHRA, the STS, the APHRS, and the HRS.
    Europace 03/2012; 14(4):528-606. · 2.77 Impact Factor
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    ABSTRACT: This is a report of the Heart Rhythm Society (HRS) Task Force on Catheter and Surgical Ablation of Atrial Fibrillation, developed in partnership with the European Heart Rhythm Association (EHRA), a registered branch of the European Society of Cardiology and the European Cardiac Arrhythmia Society (ECAS), and in collaboration with the American College of Cardiology (ACC), American Heart Association (AHA), the Asia Pacific Heart Rhythm Society (APHRS), and the Society of Thoracic Surgeons (STS). This is endorsed by the governing bodies of the ACC Foundation, the AHA, the ECAS, the EHRA, the STS, the APHRS, and the HRS.
    Journal of Interventional Cardiac Electrophysiology 03/2012; 33(2):171-257. · 1.39 Impact Factor
  • Warren M Jackman, Benjamin J Scherlag
    Circulation Arrhythmia and Electrophysiology 02/2012; 5(1):5-7. · 5.95 Impact Factor
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    ABSTRACT: The mechanism(s) underlying the maintenance of atrial fibrillation (AF) during the first few hours after AF was initiated remains poorly understood. To investigate the roles of the intrinsic cardiac autonomic nervous system in the maintenance of AF at the early stage. In 10 anesthetized dogs, we attached multielectrode catheters on atria and pulmonary veins. Microelectrodes inserted into the anterior right ganglionated plexi recorded neural activity. At baseline, programmed stimulation determined the effective refractory period (ERP) and window of vulnerability (WOV), a measure of AF inducibility. For the next 6 hours, AF was simulated by rapid atrial pacing (RAP) and the same parameters were measured hourly during sinus rhythm. A circular catheter was positioned in the superior vena cava for high-frequency stimulation (20 Hz) of the adjacent vagal preganglionics. During 4-6 hours of RAP, we delivered low-level vagal stimulation in the superior vena cava (LL-SVCS), 50% below that which induced slowing of the sinus rate. During the 6-hour RAP, there was a progressive decrease in the ERP and an increase in ERP dispersion, WOV, and neural activity. With LL-SVCS during 4-6-hour RAP, ERP, WOV, and neural activity returned toward baseline levels (all P <.05, compared with the third-hour RAP values). RAP not only induces atrial electrical remodeling but also promotes autonomic remodeling. These 2 remodeling processes may form a vicious cycle and each may perpetuate the other. These findings may help to explain how AF maintains itself in its very early stage. LL-SVCS both reversed remodeling processes and can potentially break the vicious cycle of "AF begets AF" in the first few hours of AF.
    Heart rhythm: the official journal of the Heart Rhythm Society 12/2011; 9(5):804-9. · 4.56 Impact Factor
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    ABSTRACT: Totally thoracoscopic epicardial pulmonary vein ablation is an emerging treatment of atrial fibrillation (AF). A hybrid surgical-electrophysiological procedure with periprocedural confirmation of conduction block might reduce recurrences of AF or atrial tachycardia and improve surgical success. We report our joint surgical-electrophysiological approach for confirmation of conduction block across pulmonary vein ablation lines and those compartmentalizing the left atrium during totally thoracoscopic surgery. A diagnostic electrophysiology (EP) catheter positioned under the left atrium is used as reference and a custom-made multi-electrode for recording. Determination of conduction block across the pulmonary vein (PV) ablation lines requires measurement of activation time differences of milliseconds. Second, a stable reference electrogram to which to relate local activation time is required. Third, the recording electrode terminals and the inter-electrode distance should be small to prevent recording of far field activity and to allow recording of very small electrograms. We confirm entry and exit block and determine conduction block across linear ablation lines with differential pacing. A joint surgical-electrophysiological protocol for confirmation of conduction block across PV isolation lines and left atrial ablation lines is feasible and might prevent recurrences and further improve the success of minimally invasive surgery for AF.
    Minimally invasive therapy & allied technologies: MITAT: official journal of the Society for Minimally Invasive Therapy 10/2011; 21(4):293-301. · 1.33 Impact Factor
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    ABSTRACT: Patients undergo ablation for focal atrial fibrillation (AF) as a result of failure of anti-arrhythmic drugs. Our basic studies have implicated cholinergic and adrenergic neurotransmitter release as the underlying mechanism for focal AF. Therefore, we tested the efficacy of a combination of sodium channel-blocking agents with additional vagolytic properties and a β-blocker to terminate and prevent focal AF. In 18 Na-pentobarbital-anaesthetized dogs, after a right or left thoracotomy, acetylcholine (Ach, 0.5 cc, 100 mM) was injected into a fat pad containing ganglionated plexi (GP) or applied on an atrial appendage (AA) to induce focal firing at the pulmonary veins (PVs) or AA, respectively. Disopyramide (2-4 mg/kg, n= 6) or quinidine (3-6 mg/kg, n= 12) combined with esmolol or propranolol (1 mg/kg, n= 13 and 5, respectively) were slowly injected to terminate (Group I, n= 12) or prevent (Group II, n= 6) Ach-induced sustained focal AF. In another four dogs, only the sodium channel-blocking agents with additional vagolytic properties or only the β-blocker was injected prior to or after the initiation of focal AF. At baseline, the mean duration of AF induced by Ach was 26 ± 4 min. Group I: After drugs, Ach-induced AF duration was 3 ± 1 min (P< 0.001). Group II: Prior to drugs, Ach-induced AF lasted for 19 ± 3 min. With the drug combination the duration of Ach-induced AF, decreased to 6 ± 1/min, P< 0.001. Either quinidine or propranolol alone did not change the duration of Ach-induced AF, mean 25 ± 10 min compared with Ach alone, 28 ± 16 min, P= 0.2. Type IA (cholinergic antagonist) plus Type II (β-adrenergic antagonist) provides significant prevention and suppression of focal AF arising at PV and non-PV sites.
    Europace 09/2011; 14(3):426-30. · 2.77 Impact Factor
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    ABSTRACT: Pulmonary vein (PV) antrum isolation with ganglionated plexi (GP) ablation is a novel atrial fibrillation (AF) ablation technique. The aim of this study was to evaluate acute changes in left atrial and PV flow velocities following PV antrum isolation with GP ablation using transesophageal echocardiography (TEE). TEE was performed before and after PV antrum isolation with GP ablation in 88 consecutive patients. All four PVs, when possible, were analyzed with regard to peak systolic and diastolic pulsed-wave Doppler flow velocities. Left atrial appendage emptying velocities were also obtained. PV stenosis was defined as a peak PV Doppler flow velocity of ≥110 cm/sec with spectral broadening (turbulence). All but four right inferior and four left inferior PVs were visualized. Compared to preablation values, both PV systolic and diastolic velocities increased after ablation (P < 0.05 for each of the four PVs). However, the systolic to diastolic ratio decreased significantly after ablation in all PVs (1.3 ± 0.6 to 0.9 ± 0.4, P < 0.0001, 1.2 ± 0.7 to 0.9 ± 0.4, P < 0.0001, 1.2 ± 0.6 to 1.0 ± 0.6, P = 0.035 and 1.1 ± 0.5 to 0.9 ± 0.5, P = 0.0001, for left superior, left inferior, right superior and right inferior PV, respectively). Left atrial appendage emptying velocities showed a trend towards higher values following ablation (62.7 ± 26.1 cm/sec vs. 67.5 ± 23.2 cm/sec, P = 0.07). Asymptomatic PV stenosis occurred in seven patients (seven PVs). PV antrum isolation with GP ablation acutely increased PV flow velocities and altered the pattern of PV Doppler flow signal, likely correlating with increased left atrial pressures, but did not appear to adversely impact on left atrial appendage physiology.
    Echocardiography 08/2011; 28(7):775-81. · 1.26 Impact Factor
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    ABSTRACT: Article Title: Transesophageal Echocardiographic Assessment of Pulmonary Veins and Left Atrium in Patients Undergoing Atrial Fibrillation Ablation (Echocardiography 2011;28:774).
    Echocardiography 08/2011; 28(7):774. · 1.26 Impact Factor
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    ABSTRACT: Thoracoscopic pulmonary vein isolation (PVI) and ganglionated plexus ablation is a novel approach in the treatment of atrial fibrillation (AF). We hypothesize that meticulous electrophysiological confirmation of PVI results in fewer recurrences of AF during follow-up. Surgery was performed through 3 ports bilaterally. Ganglionated plexi were localized and subsequently ablated. PVI was performed and entry and exit block was confirmed. Additional left atrial ablation lines were created and conduction block verified in patients with nonparoxysmal AF. The left atrial appendage was removed. Freedom of AF was assessed by ECGs and Holter monitoring every 3 months or during symptoms of arrhythmia. Antiarrhythmic drugs were discontinued after 3 months and oral anticoagulants were discontinued according to the guidelines. Thirty-one patients were treated (16 paroxysmal AF, 13 persistent AF, 2 long-standing persistent AF). Thirteen patients with nonparoxysmal received additional left atrial ablation lines. After 1 year, 19 of 22 patients (86%) had no recurrences of AF, atrial flutter, or atrial tachycardia and were not using antiarrhythmic drugs (11/12 paroxysmal, 7/9 persistent, and 1/1 long-standing persistent). Three patients had a sternotomy because of uncontrolled bleeding during thoracoscopic surgery. Four adverse events were 1 hemothorax, 1 pneumothorax, and 2 pneumonia. No thromboembolic complications or mortality occurred. Thoracoscopic surgery with PVI and ganglionated plexus ablation for AF is a safe and successful procedure with a single procedure success rate of 86% at 1 year. Electrophysiological guided thorough PVI and additional left atrial ablation line creation presumably contributes in achieving a high success rate in the surgical treatment of AF.
    Circulation Arrhythmia and Electrophysiology 06/2011; 4(3):262-70. · 5.95 Impact Factor
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    ABSTRACT: We sought to extend the use of low-level vagal stimulation by applying it only to the right vagus nerve (LL-RVS) to suppress atrial fibrillation (AF). In 10 pentobarbital anesthetized dogs, LL-RVS (20 Hz, 0.1 ms pulse width) was delivered to the right vagal trunk via wire electrodes at voltages 50% below that which slowed the sinus rate (SR) or atrio-ventricular conduction. Electrode catheters were sutured at multiple atrial and pulmonary vein (PV) sites to record electrograms. LL-RVS continued for 3 hours. At the end of each hour, 40 ms of high-frequency stimulation (HFS; 100 Hz, 0.01 ms pulse width) was delivered 2 ms after atrial pacing (during the refractory period) to determine the AF threshold (AF-TH) at each site. Other electrodes were attached to the superior left ganglionated plexi (SLGP) and right stellate ganglion (RSG) so that HFS (20 Hz, 0.1 ms pulse width) to these sites induced SR slowing and acceleration, respectively. Microelectrodes inserted into the anterior right ganglionated plexi (ARGP) recorded neural activity. (1) Three hours of LL-RVS induced a progressive increase in AF-TH at all sites (all P < 0.05). (2) The SR slowing and acceleration response induced by SLGP and RSG stimulation, respectively, was blunted by LL-RVS. (3) The frequency and amplitude of the neural activity recorded from the ARGP were markedly inhibited by LL-RVS. LL-RVS suppressed AF inducibility and the chronotropic responses to parasympathetic and sympathetic stimulation. Inhibition of neural activity in the GP may be a mechanism underlying these results.
    Journal of Cardiovascular Electrophysiology 04/2011; 22(10):1147-53. · 3.48 Impact Factor

Publication Stats

9k Citations
1,141.76 Total Impact Points


  • 1988–2014
    • University of Oklahoma Health Sciences Center
      • • Heart Rhythm Institute (HRI)
      • • Department of Internal Medicine
      • • Section of Cardiovascular Diseases
      Oklahoma City, Oklahoma, United States
  • 2013
    • Aurora St. Luke's Medical Center
      Milwaukee, Wisconsin, United States
  • 2001–2013
    • Oklahoma City University
      Oklahoma City, Oklahoma, United States
  • 2012
    • Johns Hopkins Medicine
      Baltimore, Maryland, United States
    • Case Western Reserve University
      Cleveland, Ohio, United States
  • 2011
    • Maastricht University
      • Cardiologie
      Maastricht, Provincie Limburg, Netherlands
  • 2008–2011
    • Renmin University of China
      Peping, Beijing, China
    • Research Institute of Science and Technology
      Ann Arbor, Michigan, United States
  • 2010
    • Oklahoma Heart Hospital
      Oklahoma City, Oklahoma, United States
  • 2009
    • Baylor Hamilton Heart and Vascular Hospital
      Dallas, Texas, United States
    • Arkansas Heart Hospital
      Little Rock, Arkansas, United States
    • Beijing Fuwai Hospital
      Peping, Beijing, China
  • 2007–2009
    • Fudan University
      Shanghai, Shanghai Shi, China
    • Shandong Qianfoshan Hospital
      Chi-nan-shih, Shandong Sheng, China
    • Beijing Medical University
      • Department of Cardiology
      Peping, Beijing, China
  • 1995–2005
    • University of Oklahoma
      • School of Electrical and Computer Engineering
      Oklahoma City, OK, United States
  • 2004
    • Ocala Heart Institute
      Florida, United States
    • KU Leuven
      • Department of Cardiovascular Sciences
      Leuven, VLG, Belgium
  • 2003
    • Seattle Institute for Cardiac Research
      Seattle, Washington, United States
  • 1996
    • University Medical Center Utrecht
      • Department of Cardiology
      Utrecht, Provincie Utrecht, Netherlands
    • Correctional Service of Canada
      Ottawa, Ontario, Canada
  • 1989–1990
    • University of Hamburg
      • University Heart Center
      Hamburg, Hamburg, Germany
  • 1983
    • Indiana University-Purdue University School of Medicine
      • Department of Medicine
      Indianapolis, IN, United States