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Featured researches published by David A. Harrison.


Journal of the American College of Cardiology | 1997

Sustained Ventricular Tachycardia in Adult Patients Late After Repair of Tetralogy of Fallot

David A. Harrison; Louise Harris; Samuel C. Siu; Cynthia J MacLoghlin; Michael S. Connelly; Gary Webb; Eugene Downar; Peter R. McLaughlin; William G. Williams

OBJECTIVES We sought to determine the features associated with sustained monoform ventricular tachycardia (VT) in adult patients late after repair of tetralogy of Fallot (TOF) and to review their management. BACKGROUND Patients with repair of TOF are at risk for sudden death. Risk factors for ventricular arrhythmia have been identified from patients with ventricular ectopic beats because of the low prevalence of sustained VT. METHODS From a retrospective chart review of patients assessed between January 1990 and December 1994, 18 adult patients with VT were identified and compared with 192 with repaired TOF free of sustained arrhythmia. RESULTS There was no significant difference in age at repair, age at follow-up or operative history. Patients with VT had frequent ventricular ectopic beats (6 of 9 vs. 21 of 101), low cardiac index ([mean +/- SD] 2.4 +/- 0.4 vs. 3.0 +/- 0.8) and more structural abnormalities of the right ventricle (outflow tract aneurysms and pulmonary or tricuspid regurgitation) than control patients. Electrophysiologic map-guided operation was performed in 10 of 14 patients who required reoperation. VT has reoccurred in three of these patients. Four patients did not undergo operation (three received amiodarone; one underwent defibrillator implantation). Two patients with VT also had severe heart failure and died. CONCLUSIONS Most patients with VT late after repair of TOF have outflow tract aneurysms or pulmonary regurgitation, or both. These patients have a greater frequency of ventricular ectopic beats than arrhythmia-free patients after repair of TOF. A combined approach of correcting significant structural abnormalities (pulmonary valve replacement or right ventricular aneurysmectomy, or both) with intraoperative electrophysiologic-guided ablation may reduce the potential risk of deterioration in ventricular function and enable arrhythmia management to be optimized.


The Journal of Thoracic and Cardiovascular Surgery | 1999

Reoperation in adults with repair of tetralogy of fallot: indications and outcomes.

Erwin Oechslin; David A. Harrison; Louise Harris; Eugene Downar; Gary Webb; Samuel S. Siu; William G. Williams

OBJECTIVE The purpose of this study is to review indications, surgical procedures, and outcomes in adults with repaired tetralogy of Fallot referred for reoperation. METHOD Sixty consecutive adults (age >/= 18 years) who underwent reoperation between 1975 and 1997 after previous repair of tetralogy of Fallot were reviewed. Mean age at corrective repair was 13.3 +/- 9.6 years and at reoperation 33.3 +/- 9.6 years. Mean follow-up after reoperation is 5.0 +/- 4.9 years. RESULTS Long-term complications of the right ventricular outflow tract (n = 45, 75%) were the most common indications for reoperation: severe pulmonary regurgitation (n = 23, 38%) and conduit failure (n = 13, 22%) were most frequent. Less common indications were ventricular septal patch leak (n = 6) and severe tricuspid regurgitation (n = 3). A history of sustained ventricular tachycardia was present in 20 patients (33%) and supraventricular tachycardia occurred in 9 patients (15%). A bioprosthetic valve to reconstruct the right ventricular outflow tract was used in 42 patients. Additional procedures (n = 115) to correct other residual lesions were required in 46 patients (77%). There was no perioperative mortality. Actuarial 10-year survival is 92% +/- 6%. At most recent follow-up, 93% of the patients are in New York Heart Association classification I or II. Sustained ventricular tachycardia occurred in 4 patients (7%) during follow-up. CONCLUSIONS Long-term complications of the right ventricular outflow tract were the main reason for reoperation. Mid-term survival and functional improvement after reoperation are excellent.


American Journal of Cardiology | 1999

Determinants of Survival and Length of Survival in Adults With Eisenmenger Syndrome

Warren J. Cantor; David A. Harrison; Jack S. Moussadji; Michael S. Connelly; Gary Webb; Peter Liu; Peter R. McLaughlin; Samuel C. Siu

A retrospective study of adults with Eisenmenger syndrome assessed at a tertiary referral center was performed to identify clinical characteristics and establish prognostic determinants. Mortality and cause of death are reported with baseline clinical data correlated with mortality to identify predictors of death. Clinical events during follow-up, including heart failure, atrial arrhythmia, hemoptysis, and syncope were also reviewed. A total of 109 adults with Eisenmenger syndrome (mean +/- SD age 29 +/- 11 years, 43% men) were followed for a median of 6.3 years. Sixty-six patients (61%) had simple cardiac anatomy (13 atrial septal defect, 43 ventricular septal defect, 10 patent ductus arteriosus). The remainder (43 patients) had complex cardiac anatomy (including atrioventricular septal defect, truncus arteriosus, univentricular heart, and transposition of the great arteries). There were 33 deaths and 9 transplantations during follow-up. Median survival was 53 years. Multivariate Cox regression analysis identified age at presentation (hazard ratio [HR] 0.90), supraventricular arrhythmia (HR 3.44), precordial electrocardiogram voltage (HR 1.61/mV increase), and poor New York Heart Association functional class (HR 2.60) as independent predictors of mortality. There is a large variation in the life expectancy for adults with Eisenmenger syndrome. Baseline characteristics associated with increased mortality include younger age at presentation (associated with complex anatomy), functional class, supraventricular arrhythmia, and an electrocardiogram index for right ventricular hypertrophy.


The Annals of Thoracic Surgery | 1997

Pulmonary valve replacement late after repair of tetralogy of Fallot.

Ilya Yemets; William G. Williams; Gary Webb; David A. Harrison; Peter R. McLaughlin; George A. Trusler; John G. Coles; Ivan M. Rebeyka; Robert M. Freedom

BACKGROUND Pulmonary valve incompetence is usually well tolerated after tetralogy of Fallot repair but may result in late progressive right heart failure as manifested by increasing fatigue, dyspnea, and frequently arrhythmias. METHODS All patients who underwent pulmonary valve replacement in our center late after repair of tetralogy of Fallot were reviewed. RESULTS Eighty-five patients had elective pulmonary valve replacement late (median, 9.3 years) after repair. Operative risk was low (1.1%). Ninety percent of survivors are in New York Heart Association class I. Survival 10 years after pulmonary valve replacement is 95%, with 86% of the patients free of reoperation for valve failure. CONCLUSIONS Pulmonary valve replacement is infrequently required after repair of tetralogy of Fallot. Pulmonary valve replacement may be performed electively with little risk; it improves symptoms of right heart failure and provides satisfactory long-term survival with low risk of early valve failure. As the population of patients who have had repair of tetralogy of Fallot ages, pulmonary valve replacement will become a more frequent consideration.


American Journal of Cardiology | 1996

Percutaneous catheter closure of the persistently patent ductus arteriosus in the adult

David A. Harrison; Lee N. Benson; Charles Lazzam; Janice E. Walters; Samuel Siu; Peter R. McLaughlin

The USCI patent ductus occluder has been shown to be an effective nonsurgical technique for closure of the persistently patent ductus in a primarily pediatric population. Its clinical impact in the adult has been reported only within small subgroups of larger pediatric studies or for a small population. This study was conducted to determine the feasibility, success rate, and complications of device closure for the persistently patent ductus arteriosus (PDA) in the adult. The population consisted of 55 patients (4 men and 51 women; mean age 38.8 +/- 15.0 years) with follow-up of 2.2 +/- 2.1 years. All patients underwent echocardiography obtained as part of their follow-up assessment. The device was successfully placed in 54 patients, with 75% clinical and echocardiographic closure at the first follow-up assessment 2.4 +/- 2.6 months). One patient with initial clinical and echocardiographic evidence of closure was subsequently found to have an open ductus. Spontaneous closure (2 patients) or second implant (6 patients) resulted in 86% closure at the most recent assessment. Thus, the percutaneous PDA double-umbrella occluder device is a feasible and effective technique for closing persistent PDA in the adult and will result in occlusion of the shunt in most patients without the need for thoracotomy.


Journal of the American College of Cardiology | 1998

Ten-year follow-up of adults with repaired tetralogy of fallot using serial radionuclide angiography

J.T. Elliott; V. Guru; M.A. Gatzoulis; David A. Harrison; Erwin Oechslin; Samuel Siu; Gary D. Webb; William G. Williams; Peter Liu; Peter R. McLaughlin


Catheterization and Cardiovascular Diagnosis | 1994

Right-to-left shunt following repair of partial anomalous pulmonary venous connection: a novel use of the Rashkind double-umbrella occlusion device.

David A. Harrison; Leland N. Benson; R. J. Cusimano; P. R. McLaughlin


/data/revues/00029149/v83i7/S0002914999000193/ | 2011

Arrhythmia and survival in patients >18 years of age after the Mustard procedure for complete transposition of the great arteries

Geoff Puley; Samuel Siu; Michael S. Connelly; David A. Harrison; Gary Webb; William G. Williams; Louise Harris


Archive | 2010

with congenital heart disease Outcome of previous tricuspid valve operation and arrhythmias in adult patients

Gary Webb; Louise Harris; Christopher B. Overgaard; David A. Harrison; Samuel C. Siu; William G. Williams


Journal of the American College of Cardiology | 1996

Long term survival in patients with Eisenmenger's syndrome

Jack S. Moussadji; David A. Harrison; Warren J. Cantor; Michael S. Connelly; Gary Webb; Peter Liu; Peter R. McLaughlin; Samuel C. Siu

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Gary Webb

Cincinnati Children's Hospital Medical Center

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Louise Harris

University Health Network

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Samuel C. Siu

University of Western Ontario

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Samuel Siu

University of Western Ontario

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Erwin Oechslin

University Health Network

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