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Dive into the research topics where Cathy MacDonald is active.

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Featured researches published by Cathy MacDonald.


The New England Journal of Medicine | 1998

Myocardial Bridging in Children with Hypertrophic Cardiomyopathy — A Risk Factor for Sudden Death

Anji T. Yetman; Brian W. McCrindle; Cathy MacDonald; Robert M. Freedom; Robert M. Gow

BACKGROUND Myocardial bridging may cause compression of a coronary artery, and it has been suggested that myocardial ischemia may result. The clinical significance and prognostic value of myocardial bridging of the left anterior descending coronary artery in children with hypertrophic cardiomyopathy are unknown. We sought to determine the prevalence and clinical effects of myocardial bridging in children with hypertrophic cardiomyopathy who underwent cardiac catheterization. METHODS Angiograms from 36 children with hypertrophic cardiomyopathy were reviewed to determine whether myocardial bridging was present and, if so, to assess the characteristics of systolic narrowing of the left anterior descending coronary artery caused by myocardial bridging and the duration of residual diastolic compression. We also reviewed clinical data on these patients. RESULTS Myocardial bridging was present in 10 (28 percent) of the patients. Compression of the left anterior descending coronary artery persisted for a mean (+/-SD) of 50+/-17 percent of diastole. As compared with patients without bridging, patients with bridging had a greater incidence of chest pain (60 percent vs. 19 percent, P=0.04), cardiac arrest with subsequent resuscitation (50 percent vs. 4 percent, P=0.004), and ventricular tachycardia (80 percent vs. 8 percent, P<0.001). On average, the patients with bridging had a reduction in systolic blood pressure with exercise of 17+/-27 mm Hg, as compared with an elevation of 43+/-31 mm Hg in those without bridging (P<0.001). The patients with bridging also had greater ST-segment depression with exercise (median, 5 vs. 0 mm, P=0.004) and a shorter duration of exercise (mean, 6.6+/-2.4 vs. 9.1+/-1.4 minutes, P=0.008). The degree of dispersion of the QT interval corrected for heart rate on the electrocardiogram was greater in patients with bridging than in those without bridging (104+/-46 vs. 48+/-31 msec, P=0.002). Kaplan-Meier estimates of the proportions of patients who had not died or had cardiac arrest with subsequent resuscitation five years after the diagnosis of hypertrophic cardiomyopathy were 67 percent among patients with bridging and 94 percent among those without bridging (P=0.004). CONCLUSIONS Myocardial bridging is associated with a poor outcome in children with hypertrophic cardiomyopathy. Our observations suggest that bridging is associated with myocardial ischemia


Pediatric Cardiology | 2000

Selected Aspects of Cardiac Tumors in Infancy and Childhood

Robert M. Freedom; Kyong-Jin Lee; Cathy MacDonald; Glenn Taylor

Abstract. Considerable literature concerning cardiac tumors in infancy and childhood has accumulated summarizing the prevalence, histologic types, clinical presentation and outcome, and changing imaging algorithms [1, 7, 10, 14, 20, 24, 33, 37, 43, 48, 57, 58, 60–62, 67, 69, 70, 90, 105, 106, 110, 124, 139, 140, 142, 143, 149]. In this review, we focus on selected aspects of cardiac tumors in the neonate, infant, and child, with an emphasis on imaging modalities [6, 13, 15, 18, 21–23, 60, 71, 77, 80, 92, 98, 99, 103, 107, 112, 114, 119, 146]. Various types of primary cardiac tumors in childhood are discussed in this article.


Journal of the American College of Cardiology | 2000

Balloon Angioplasty of Native Coarctation: Clinical Outcomes and Predictors of Success

Caroline Ovaert; Brian W. McCrindle; David Nykanen; Cathy MacDonald; Robert M. Freedom; Lee N. Benson

OBJECTIVES We sought to investigate the clinical impact of balloon angioplasty for native coarctation of the aorta (CoA) and determine predictors of outcome. BACKGROUND Balloon dilation of native CoA remains controversial and more information on its long-term impact is required. METHODS Hemodynamic, angiographic and follow-up data on 69 children who underwent balloon angioplasty of native CoA between 1988 and 1996 were reviewed. Stretch, recoil and gain of CoA circumference and area were calculated and related to outcomes. RESULTS Initial systolic gradients (mean +/- SD, 31+/-12 mm Hg) fell by -74+/-27% (p < 0.001), with an increase in mean CoA diameters of 128+/-128% in the left anterior oblique and 124+/-87% in the lateral views (p < 0.001). Two deaths occurred, one at the time of the procedure and one 23 months later, both as a result of an associated cardiomyopathy. Seven patients had residual gradients of >20 mm Hg. One patient developed an aneurysm, stable in follow-up, and four patients had mild dilation at the site of the angioplasty. Freedom from reintervention was 90% at one year and 87% at five years with follow-up ranging to 8.5 years. Factors significantly associated with decreased time to reintervention included: a higher gradient before dilation, a smaller percentage change in gradient after dilation, a small transverse arch and a greater stretch and gain, but not recoil. CONCLUSION Balloon dilation is a safe and efficient treatment of native CoA in children. Greater stretch and gain are factors significantly associated with reintervention, possibly related to altered elastic properties and vessel scarring.


Pediatric Radiology | 2003

Contrast-enhanced MR angiography of pulmonary venous abnormalities in children

Emanuela R. Valsangiacomo; Stéphanie Levasseur; Brian W. McCrindle; Cathy MacDonald; Jeffrey F. Smallhorn; Shi-Joon Yoo

Abstract Background. Echocardiography and X-ray angiography have been considered as gold standards for evaluation of pulmonary venous abnormalities. However, each technique has its own limitations, such as limitation in visualization of the pulmonary veins within the lungs by echocardiography, and the invasive nature of and use of ionizing radiation in X-ray angiography. Contrast-enhanced MR angiography (MRA) is a fast noninvasive method of visualization of the vessels including the pulmonary arteries and veins. Objectives. To evaluate the utility of contrast-enhanced MRA in the evaluation of pulmonary venous abnormalities in pediatric patients and to compare its diagnostic accuracy with that of transthoracic echocardiography. Materials and methods. In 30 pediatric patients 31 contrast-enhanced MRA studies were performed for evaluation of pulmonary venous abnormalities. Each of 124 pulmonary veins was evaluated for site of connection, course within the lung, presence of obstruction, and topographic relationship with the adjacent structures. The findings of MRA were compared with echocardiographic findings for 116 veins in 29 studies in 28 patients. Results. Contrast-enhanced MRA visualized 99% (123 of 124) of the pulmonary veins investigated, while echocardiography visualized 89% (103 of 116). Exact agreement was found between the two methods in 72% of the veins with a weighted kappa of 0.60 (0.47–0.73, 95% CI). Echocardiography failed to diagnose an abnormal connection in 2 of 15 pulmonary veins, a discrete stenosis in 2 of 19 veins, and diffuse hypoplasia in 10 of 14 veins. In 29% of patients, MRA made the uncertain echocardiographic findings clear. In another 29%, MRA provided a new diagnosis. Conclusions. Contrast-enhanced MRA is a powerful, safe, and accurate fast-imaging technique for the anatomical evaluation of pulmonary venous abnormalities. MRA may obviate the need for conventional X-ray angiography. Cardiac catheterization may be reserved for those patients in whom pulmonary vascular resistance needs to be determined.


Circulation | 1994

Magnetic resonance imaging of the iliofemoral arteries after balloon dilation angioplasty of aortic arch obstructions in children.

P E Burrows; Lee N. Benson; P Babyn; Cathy MacDonald

BackgroundWe wished to determine the nature and incidence of changes in the iliofemoral arteries after balloon dilation angioplasty (BDA) for aortic arch obstruction in children and to determine the reliability of gradient magnetic resonance imaging (MRI) in their detection. Methods and ResultsSixty-three children, including 62 with and 1 without arch obstruction, underwent MRI of the iliofemoral vessels. Of these, 36 patients had undergone transfemoral BDA (7 after previous transfemoral diagnostic catheterization), 12 had undergone diagnostic transfemoral catheterization but not BDA, and 15 had no history of femoral arterial catheterization. The iliofemoral arteries were normal on MRI in all 15 children without catheterization. Among the 36 children who had undergone BDA, the ipsilateral iliofemoral artery was normal in 15, mildly narrowed in 7, and severely stenotic or occluded in 14 (39%), including 6 of 9 patients treated for acute femoral artery thrombosis and 8 with no history of femoral artery thrombosis. Two patients had documentation of progressive obstruction. Six patients had concordant conventional angiography. There was a significant correlation between the number of balloon catheters used for the angioplasty and severe occlusive changes. Nine of 19 patients who had undergone diagnostic transfemoral catheterization had severe obstructive changes on MRI; 8 of 9 weighed <10 kg at catheterization. ConclusionsObstructive lesions of the iliofemoral arteries are common after transfemoral BDA of arch obstructions (58%) and can be reliably evaluated with gradient MRI. Catheter size and manipulation are the main contributing factors.


Psychiatry Research-neuroimaging | 1989

Live events and mania: A case-controlled study

Russell T. Joffe; Cathy MacDonald; Stanley P. Kutcher

Life events were evaluated in 14 patients with bipolar affective disorder in the year preceding a mania as well as in 14 patients with bipolar affective disorder without a mania matched for age, sex, and time of recall. There were a significantly greater number of uncontrolled and unanticipated life events in the patients with as compared to those without a mania. However, neither the total number of life events nor measures of distress and stress distinguished bipolar patients with as compared to those without mania.


Journal of Affective Disorders | 1993

Anxiety disorders and anxiety symptoms in a clinic sample of seasonal and non-seasonal depressives

Anthony J. Levitt; Russell T. Joffe; Diana Brecher; Cathy MacDonald

Thirty-eight patients with seasonal affective disorder (SAD) were compared with 33 non-seasonal recurrent major depressives (non-SAD) who presented during the winter months for differences in the prevalence of concurrent anxiety disorders and the impact of anxiety on treatment response. SAD patients received light therapy, whereas non-SAD patients received antidepressant medications. There was no differences in the prevalence of any anxiety disorder, or on scores of anxiety on the Hamilton Rating Scale for Depression between the SAD and non-SAD groups. The presence of any anxiety disorder was associated with a better response rate in SAD patients, and an inferior response rate in non-SAD patients. The findings refute previous suggestions that anxiety is more common in SAD than in non-SAD, but suggest that the presence of anxiety may be associated with differential treatment response rates.


Pediatric Radiology | 2000

Fluoroscopic landmark for SVC-RA junction for central venous catheter placement in children.

Bairbre Connolly; John B. Mawson; Cathy MacDonald; Peter Chait; Haverj Mikailian

Background. Vascular access devices are commonly placed under image guidance. The usual aim is to place the tip at the superior vena cava-right atrial juntion (SVC-RA).¶Objective. To identify a radiographic landmark for the SVC-RA junction that would be useful for accurate central venous catheter tip placement in children.¶Materials and methods. Images from 56 children undergoing contrast studies of their upper limb venous systems were examined for location of the SVC-RA in relation to a radiographic landmark.¶Results. Most patients (92.5 %) showed the SVC-RA junction to lie at the sixth thoracic vertebral level or the interspace above or below. The SVC-RA junction lay lower than the right main bronchus and the notch on the right cardiomediastinal contour.¶Conclusion. The vertebral body provides a useful and radiographically visible landmark for accurate central catheter tip placement.


Psychiatry Research-neuroimaging | 2002

Utility scores of symptom profiles in major depression.

Ayal Schaffer; Anthony J. Levitt; Susan K. Hershkop; Paul Oh; Cathy MacDonald; Krista L. Lanctôt

Utility is a measure of undesirability for a specific health state. This study determines the utility scores for the individual symptoms of depression, and examines the impact that personal experience with depression has on these scores. Seventy-five subjects (19 with current depression, 21 with past depression, and 35 healthy controls) assigned utility scores to each of 10 individual symptoms of depression, and three depression severity profiles. Utility scores were measured using the standard gamble technique. Mean utility scores were used to list the symptoms of depression from most to least undesirable. The three diagnostic groups were compared with respect to the magnitude of undesirability of the depressive symptoms. The results of this study found that individuals assigned different utility scores to different symptoms of depression. The psychological symptoms of depression such as suicidal ideation, guilt and depressed mood were ranked as more undesirable than the somatic symptoms of depression. Each diagnostic group ranked the symptoms of depression in a similar manner. Patients with a current depression were willing to accept a greater risk of death to avoid suffering from lifelong depressive symptoms as compared to patients with a past depression or healthy controls.


Pediatric Cardiology | 1996

Right Aortic Arch with Retroesophageal Left Aberrant Innominate Artery

C.A.F. Moes; J.B. Mawson; Cathy MacDonald; Jeffrey S. Smallhorn

Abstract. Right aortic arch with a left retroesophageal innominate artery (type D double aortic arch) is rare. The diagnosis is made by aortography. The present case is the first known patient to undergo a magnetic resonance imaging study that outlined the anomaly clearly.

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Paul Babyn

University of Saskatchewan

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Anthony J. Levitt

Sunnybrook Health Sciences Centre

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