Usefulness of Cardiac Magnetic Resonance Imaging Combined With Low-Dose Dobutamine Stress to Detect an Abnormal Ventricular Stress Response in Children and Young Adults After Fontan Operation at Young Age

• Published in: The American journal of cardiology Vol. 101; no. 11; pp. 1657 - 1662
• Main Authors: Robbers-Visser, Daniëlle, MD, Jan ten Harkel, Derk, MD, PhD, Kapusta, Livia, MD, PhD, Strengers, Jan L., MD, PhD, Dalinghaus, Michiel, MD, PhD, Meijboom, Folkert J., MD, PhD, Pattynama, Peter M., MD, PhD, Bogers, Ad J., MD, PhD, Helbing, Willem A., MD, PhD
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.06.2008; Elsevier; Elsevier Limited
• Subjects: Adolescent; Adult; Biological and medical sciences; Cardiology; Cardiology. Vascular system; Cardiotonic Agents - administration & dosage; Cardiovascular; Cardiovascular disease; Child; Children & youth; Cross-Sectional Studies; Dobutamine - administration & dosage; Dose-Response Relationship, Drug; Drug dosages; Echocardiography, Stress - methods; Female; Follow-Up Studies; Fontan Procedure - methods; Heart; Heart Defects, Congenital - diagnosis; Heart Defects, Congenital - physiopathology; Heart Defects, Congenital - surgery; Heart Rate - physiology; Heart Ventricles - abnormalities; Heart Ventricles - diagnostic imaging; Heart Ventricles - physiopathology; Humans; Injections, Intravenous; Magnetic Resonance Imaging - methods; Male; Medical sciences; Myocardial Contraction - physiology; NMR; Nuclear magnetic resonance; Prognosis; Reproducibility of Results; Retrospective Studies; Severity of Illness Index; Young adults; Human; Heart; Pharmacologic test; Low dose; Nuclear magnetic resonance imaging; Fontan operation; Stress; Response; Young adult; Medical imagery; Circulatory system; Cardiology; Child; Age
• ISSN: 0002-9149; 1879-1913
• DOI: 10.1016/j.amjcard.2008.01.050

After Fontan operation, patients are limited in increasing cardiac output and in exercise capacity. This has been related to impaired preload or other factors leading to decreased global ventricular performance with stress. To study these factors, the stress responses of functionally univentricular hearts were assessed at rest and during low-dose dobutamine stress using cardiovascular magnetic resonance imaging. Thirty-two patients after Fontan completion at young age were included (27 with total cavopulmonary connection, 5 with atriopulmonary connection; mean age 13.3 years, range 7.5 to 22.2; 23 male patients; median follow-up after Fontan operation 8.1 years, range 5.2 to 17.8). A multiphase short-axis stack of 10 to 12 contiguous slices of the systemic ventricle was obtained at rest and during low-dose dobutamine stress cardiovascular magnetic resonance imaging (maximum 7.5 μg/kg/min). With stress-testing, heart rate, ejection fraction, and cardiac index increased adequately (p <0.001). There was an abnormal decrease in end-diastolic volume and an adequate decrease in end-systolic volume (p <0.001). Stroke volume did not change with stress testing (p = 0.15). At rest, dominant left ventricles had higher ejection fractions than dominant right ventricles (p = 0.01), but this difference disappeared with stress testing. In conclusion, a functionally univentricular heart after Fontan completion at young age has an adequate increase in ejection fraction with β-adrenergic stimulation. However, as a result of impaired preload with stress, cardiac output can be increased only by increasing heart rate.