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Dive into the research topics where George Jablonsky is active.

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Featured researches published by George Jablonsky.


The New England Journal of Medicine | 1985

Aspirin, sulfinpyrazone, or both in unstable angina. Results of a Canadian multicenter trial.

John A. Cairns; Michael Gent; Joel Singer; Keith J. Finnie; Gordon M. Froggatt; Douglas Holder; George Jablonsky; William J. Kostuk; Libardo J. Melendez; Martin G. Myers; David L. Sackett; Brian J. Sealey; Paul H. Tanser

We performed a randomized, double-blind, placebo-controlled trial in 555 patients with unstable angina who were hospitalized in coronary care units. Patients received one of four possible treatment regimens: aspirin (325 mg four times daily), sulfinpyrazone (200 mg four times daily), both, or neither. They were entered into the trial within eight days of hospitalization and were treated and followed for up to two years (mean, 18 months). The incidence of cardiac death and nonfatal myocardial infarction, considered together, was 8.6 per cent in the groups given aspirin and 17.0 per cent in the other groups, representing a risk reduction with aspirin of 51 per cent (P = 0.008). The corresponding figures for either cardiac death alone or death from any cause were 3.0 per cent in the groups given aspirin and 11.7 per cent in the other groups, representing a risk reduction of 71 per cent (P = 0.004). Analysis by intention to treat yielded smaller risk reductions with aspirin of 30 per cent (P = 0.072), 56 per cent (P = 0.009), and 43 per cent (P = 0.035) for the outcomes of cardiac death or nonfatal acute myocardial infarction, cardiac death alone, and all deaths, respectively. There was no observed benefit of sulfinpyrazone for any outcome event, and there was no evidence of an interaction between sulfinpyrazone and aspirin. Considered together with the results of a previous clinical trial, these findings provide strong evidence for a beneficial effect of aspirin in patients with unstable angina.


Journal of the American College of Cardiology | 1984

Clinically unrecognized ventricular dysfunction in young diabetic patients.

Richard R. Mildenberger; Ben Bar-Shlomo; Maurice N. Druck; George Jablonsky; John E. Morch; J. David Hilton; Anne B. Kenshole; Nicholas Forbath; Peter R. McLaughlin

Left ventricular function at rest and during supine bicycle exercise was assessed by gated radionuclide angiography in 20 diabetic patients and 18 normal control subjects without clinical evidence of heart disease. The diabetic patients were aged 21 to 44 years and all except one used insulin. No subject developed chest pain or electrocardiographic changes during exercise. Both groups had a similar rest and exercise heart rate and blood pressure, and both achieved similar work loads. The control group had an ejection fraction at rest of 65.4 +/- 6.2% (mean +/- SD) and only 1 of 18 showed a decrease with exercise; peak exercise ejection fraction averaged 77.1 +/- 7.8%. The diabetic group had a mean ejection fraction at rest of 63.7 +/- 6.5%, similar to that of the control group, but 7 of 20 showed a decrease during exercise; the exercise ejection fraction averaged 67.7 +/- 9.7%, significantly lower than that of the control group (p less than 0.01). The diabetic patients varied widely in ejection fraction response to exercise, ranging from an increase of 25% to a decrease of 21%. This response did not correlate with age, sex, duration of diabetes, smoking, retinopathy, exercise heart rate, blood pressure or rate-pressure product, work load attained or ejection fraction at rest. These data suggest that approximately one-third of patients with diabetes have subclinical left ventricular dysfunction without correlation to risk factors for atherosclerosis or other diabetic complications. Whether this is due to unrecognized coronary artery disease or primary myocardial disease remains unknown.


The Journal of Thoracic and Cardiovascular Surgery | 2008

Simultaneous integrated coronary artery revascularization with long-term angiographic follow-up

Bob Kiaii; R. Scott McClure; Peter Stewart; Reiza Rayman; Stuart A. Swinamer; Yoshihiro Suematsu; Stephanie A. Fox; Jennifer Higgins; Caroline Albion; William J. Kostuk; David Almond; Kumar Sridhar; Patrick Teefy; George Jablonsky; Pantelis Diamantouros; Wojciech B. Dobkowski; Philip M. Jones; Daniel Bainbridge; Ivan Iglesias; John M. Murkin; Davy Cheng; Richard J. Novick

OBJECTIVE Traditionally integrated coronary artery revascularization has been described as a 2-stage procedure. We evaluated the safety and feasibility of 1-stage, simultaneous, hybrid, robotically assisted coronary artery bypass grafting surgery and percutaneous coronary intervention. METHODS Fifty-eight patients underwent simultaneous, integrated coronary artery revascularization in an operating theater equipped with angiographic equipment. Forty-five patients were men. The mean age was 59 years. All internal thoracic arteries were harvested with robotic assistance. All anastomoses were manually constructed through a small anterior non-rib-spreading incision without cardiopulmonary bypass on the beating heart. Immediately after and within the same operative suite, both angiographic confirmation of graft patency and percutaneous coronary intervention were performed. In 52 patients therapeutic anticoagulation was achieved with the direct thrombin inhibitor bivalirudin. RESULTS There were no deaths or wound infections. There was 1 perioperative myocardial infarction. One patient had a stroke, and 3 patients required re-exploration for bleeding. The median lengths of intensive care and hospital stay were 1 and 4 days, respectively. All patients were alive and symptom free at follow-up (mean, 20.2 months; range, 1.1-40.8 months). Long-term angiographic follow-up in 54 patients showed 49 (91%) patent grafts (mean, 9.0 months; range, 4.3-40.8 months). There were 7 in-stent restenoses and 2 occluded stents. CONCLUSION For multivessel coronary artery disease, simultaneous integrated coronary artery revascularization with bivalirudin is safe and feasible. This approach enables complete multivessel revascularization with decreased surgical trauma and postoperative morbidity. Further studies are necessary to better determine patient selection and long-term outcomes.


Journal of the American College of Cardiology | 2001

Increased circulating monocyte activation in patients with unstable coronary syndromes

Christian V Zalai; M.Dean Kolodziejczyk; Linda M. Pilarski; Alexander Christov; Patric N. Nation; Marita Lundstrom-Hobman; Wayne Tymchak; Vladimir Dzavik; Dennis P. Humen; William J. Kostuk; George Jablonsky; Peter W. Pflugfelder; James E. Brown; Alexandra Lucas

OBJECTIVES The primary objective of this research was to assess the activation level of circulating monocytes in patients with unstable angina. BACKGROUND Markers of systemic inflammatory responses are increased in patients with unstable coronary syndromes, but the activation state and invasive capacity of circulating monocytes have not been directly assessed. METHODS Peripheral blood mononuclear cell (MC) activation in blood samples isolated from patients with stable and unstable coronary artery disease was measured in two studies. In study 1, a modified Boyden chamber assay was used to assess spontaneous cellular migration rates. In study 2, optical analysis of MC membrane fluidity was correlated with soluble CD14 (sCD14), a cellular activation marker. RESULTS Increased rates of spontaneous monocyte migration (p < 0.01) were detected in patients with unstable angina (UA) (Canadian Cardiovascular Society [CCS] angina class IV) on comparison to patients with acute myocardial infarction (MI), stable angina (CCS angina classes I to III) or normal donors. No significant increase in lymphocyte migration was detected in any patient category. Baseline MC membrane fluidity measurements and sCD14 levels in patients with CCS class IV angina were significantly increased on comparison with MCs from normal volunteers (p < 0.001). A concomitant reduction in the MC response to activation was detected (p < 0.05). CONCLUSIONS Using two complementary assays, activated monocytes with increased invasive capacity were detected in the circulation of patients with unstable angina. This is the first demonstration of increased monocyte invasive potential in unstable patients, raising the issue that systemic inflammation may both reflect and potentially drive plaque instability.


Circulation-cardiovascular Interventions | 2014

Remote Ischemic Postconditioning During Percutaneous Coronary Interventions Remote Ischemic Postconditioning–Percutaneous Coronary Intervention Randomized Trial

Shahar Lavi; Sabrina D’Alfonso; Pantelis Diamantouros; A. Camuglia; Pallav Garg; Patrick Teefy; George Jablonsky; Kumar Sridhar; Ronit Lavi

Background—Remote ischemic preconditioning may result in reduction in infarct size during percutaneous coronary intervention (PCI). It is unclear whether remote ischemic postconditioning (RIPost) will reduce the incidence of myocardial injury after PCI, and whether ischemic conditioning of a larger remote organ (thigh versus arm) would provide further myocardial protection. Methods and Results—We randomized 360 patients presenting with stable or unstable angina (28% of patients) and negative Troponin T at baseline to 3 groups: 2 groups received RIPost (induced by ischemia to upper or lower limb), and a third was the control group. RIPost was applied during PCI immediately after stent deployment, by three 5-minute cycles of blood pressure cuff inflation to >200 mm Hg in the arm or thigh (20 mm Hg in the control) with 5-minute breaks between each cycle. The primary end-point was the proportion of patients with Troponin T levels >3×ULN postprocedure (at 6 or 18–24 hours), where ULN stands for upper limit of normal. A total of 120 patients were randomized to each group. There were no differences in baseline characteristics between the 3 groups. The primary outcome occurred in 30%, 35%, and 35% of the arm, thigh, and control groups, respectively (P=0.64). There were no differences in creatine kinase or high sensitivity C-reactive protein levels after PCI or in the incidence of acute kidney injury between the groups. Conclusions—RIPost during PCI did not reduce the incidence of periprocedural myocardial injury. Similar effect was obtained when remote ischemia was induced to the upper or lower limb. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifier: NCT00970827.


American Journal of Cardiology | 1988

Nuclear magnetic resonance and radionuclide angiographic assessment of acute myocardial infarction in a randomized trial of intravenous streptokinase

Gerald Wisenberg; Keith J. Finnie; George Jablonsky; William J. Kostuk; Tara C. Marshall

Sixty-six patients presenting with their first evolving transmural acute myocardial infarction (AMI) were randomized to receive either streptokinase (n = 41) or placebo therapies (n = 25) within 6 hours of the onset of chest pain. These patients then underwent supine rest, exercise and after-nitroglycerin radionuclide angiography 3 weeks after AMI. Nuclear magnetic resonance (NMR) imaging was performed at 3 weeks as a more direct estimate of AMI size. Although peak creatine kinase values were comparably elevated between groups (2,367 +/- 1,486 IU/liter for streptokinase vs 2,637 +/- 1,305 IU/liter for placebo), there was a significant reduction in NMR-measured AMI size in the streptokinase group (3 +/- 2% of left ventricular volume vs 10 +/- 4% in the placebo group, p less than 0.05). This occurred despite comparable resting (54 +/- 11 vs 47 +/- 10% and exercise (53 +/- 12 vs 49 +/- 11%) global ejection fractions. However, following nitroglycerin, there was an improvement in global ejection fraction in the streptokinase-treated group that was not observed with placebo (61 +/- 13 vs 48 +/- 10%, p less than 0.05). A similar pattern was also observed with regional functional analysis. Thus, streptokinase therapy leads to a significant reduction in NMR-measured AMI size and to a greater degree of reversible left ventricular dysfunction.


American Heart Journal | 1990

Hemodynamic effects of intravenous procainamide during ventricular tachycardia.

Arjun D. Sharma; Paul Purves; Raymond Yee; George Klein; George Jablonsky; William J. Kostuk

Radionuclide angiography was used to study the hemodynamic effects of intravenous procainamide during stable monomorphic ventricular tachycardia. In four patients studied without procainamide, the ejection fraction was 25% +/- 2.4% during normal sinus rhythm, dropped to 11.3% +/- 2.2% (p less than 0.05) at the onset of ventricular tachycardia, increased to 16.7% +/- 1.7% after remaining in ventricular tachycardia for 10 minutes, and returned to 25.3% +/- 3.7% in sinus rhythm. In the 10 study patients, ejection fraction dropped from 36% +/- 5.8% in sinus rhythm to 25% +/- 5.1% in ventricular tachycardia (p less than 0.2). Ejection fraction decreased further (23% +/- 5.0%) following low doses of procainamide (140 +/- 52 mg) despite cycle length prolongation (354 +/- 18 msec versus 373 +/- 21 msec, p less than 0.5). In 8 of 10 patients, there was a progressive increase in the ejection fraction (28.8% +/- 4.1%). Ventricular tachycardia onset also resulted in a decrease in cardiac output and end-diastolic and end-systolic volumes. Two patients who tolerated procainamide in sinus rhythm showed hemodynamic collapse secondary to procainamide during ventricular tachycardia. We conclude that in some patients hemodynamic intolerance to an antiarrhythmic drug may only become evident during ventricular tachycardia.


Surgical Laparoscopy Endoscopy & Percutaneous Techniques | 2002

Early experience with robotically assisted internal thoracic artery harvest

W. Douglas Boyd; Bob Kiaii; Kojiro Kodera; Reiza Rayman; Walid Abu-Khudair; Shafie Fazel; Wojciech B. Dobkowski; Sugantha Ganapathy; George Jablonsky; Richard J. Novick

We sought to determine the efficacy of using robotic assistance to facilitate endoscopic harvesting of internal thoracic arteries (ITAs). A total of 104 patients had ITAs harvested endoscopically with use of both the AESOP 3000 system (Computer Motion, Goleta, CA, U.S.A.) and Zeus robotic telesurgical system (Computer Motion). All ITAs were harvested with a harmonic scalpel (Ethicon Endosurgery, Cincinnati, OH, U.S.A.). With the left lung collapsed, ITAs were harvested with CO2 insufflation through three 5-mm ports in the left chest. All patients tolerated insufflation without hemodynamic compromise. Average ITA harvest time was 61.3 ± 20.9 minutes. Intraoperative graft flows averaged 36.3 ± 22.4 mL/min. There were three distal ITA injuries; all other vessels were patent after harvesting and demonstrated no angiographic evidence of injury. This article demonstrates a technique by which ITA can be safely harvested totally endoscopically with use of computer-enhanced robotic systems and a harmonic scalpel, allowing complete pedicle dissection through 5-mm ports with minimal ITA manipulation.


American Journal of Cardiology | 1981

Radionuclide angiography and endomyocardial biopsy in the assessment of doxorubicin cardiotoxicity

Maurice N. Druck; Ben-Zion Bar-Shlomo; Karen Y. Gulenchyn; David Hilton; George Jablonsky; Avrum I. Gotlieb; Malcolm D. Silver; Patricia McEwan; David H. Feiglin; John E. Morch; Wm. Evans; Peter R. McLaughlin

Thirty-eight patients with a mean age of 53.2 years (19 to 75 years of age), who were receiving doxorubicin (D) for malignant disease, were studied in order to determine the relationship between functional and morphologic myocardial changes at different dose levels. Serial patient evaluations included physical examination, chest x-ray, electrocardiogram (ECG), endomyocardial biopsy (EMB), and rest-exercise gated nuclear angiography (GNA), at doses of D ranging from 144 to 954 mg/m2 (mean, 426 mg/m2). Physical examination, chest x-ray, and ECG proved to be insensitive predictors of D cardiotoxicity. Correlation of GNA and EMB in 31 patient evaluations, exclusive of known heart disease, did not reveal any false-positive angiograms, and all abnormal GNAs were associated with abnormal biopsies. Use of stress GNA uncovered six abnormal ventricles which could have been missed with a rest GNA alone. It has been suggested that: (1) GNA is a reliable monitor of D therapy; (2) an exercise study should be performed when the rest ejection fraction is normal, but is unnecessary when the rest EF is abnormal; (3) all patients with a resting ejection fraction of less than 45%, exclusive of other cardiac disease, should have D discontinued; and (4) endomyocardial biopsy is useful in assessing D cardiotoxicity in patients with other possible causes of an abnormal GNA.


American Journal of Cardiology | 1987

Comparison of bepridil with nadolol for angina pectoris.

Peter W. Pflugfelder; Dennis P. Humen; Pam A. O'Brien; Paul D. Purves; George Jablonsky; William J. Kostuk

Bepridil hydrochloride is a unique calcium channel-blocking drug with anti-ischemic and type 1 antiarrhythmic properties. With a half-life of more than 40 hours, once-daily therapy is possible. Twenty-four patients (22 men, 2 women), mean age 58 years (range 43 to 72), with stable exertional angina were assigned to therapy with bepridil and nadolol in a randomized, double-blind, crossover trial. Antianginal efficacy was assessed by a diary of angina frequency and nitroglycerin consumption as well as by treadmill exercise testing. The effect of therapy on ventricular function was assessed by symptom-limited equilibrium gated exercise radionuclide angiography. During therapy with both nadolol and bepridil, the number of episodes of angina per week was significantly reduced and nitroglycerin consumption decreased compared with baseline evaluation. Exercise duration was prolonged by both therapies (baseline 281 +/- 122 seconds, nadolol 377 +/- 96 seconds, bepridil 400 +/- 109 seconds; p less than 0.005 for nadolol and bepridil vs baseline). Time to the onset of angina was similarly prolonged, 50% by nadolol and 65% by bepridil (p less than 0.005). Bepridil had no effect on PR and QRS durations, although QTc was significantly prolonged (baseline 0.43 +/- 0.03, nadolol 0.42 +/- 0.03, bepridil 0.45 +/- 0.04; p less than 0.005 for bepridil vs baseline and nadolol). By radionuclide angiography, neither nadolol nor bepridil had an adverse effect on left ventricular function at rest or during exercise. Bepridil therefore provides effective therapy for angina without adverse effects on left ventricular function, comparable to the effects of beta blockade with nadolol.

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William J. Kostuk

London Health Sciences Centre

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Pantelis Diamantouros

University of Western Ontario

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Bob Kiaii

London Health Sciences Centre

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Patrick Teefy

London Health Sciences Centre

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Reiza Rayman

University of Western Ontario

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Richard J. Novick

University of Western Ontario

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Shahar Lavi

University of Western Ontario

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Wojciech B. Dobkowski

University of Western Ontario

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Sugantha Ganapathy

University of Western Ontario

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Alexander Christov

University of Western Ontario

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