Evidence of Early Impairments in Both Right and Left Ventricular Inotropic Reserves in Children With Duchenne’s Muscular Dystrophy Gilles Bosser, MD, Hugues Lucron, MD, Jean-Paul Lethor, MD, Guillaume Burger, MD, Franc ¸oise Beltramo, MD, Pierre-Yves Marie, MD, and Franc ¸ois Marc ¸on, MD In Duchenne’s muscular dystrophy (DMD), cardiac func- tion deteriorates with time and heart failure is one of the major causes of death. The aim of the study was to determine if a decrease in the ventricular inotropic re- serves could be an early sign of cardiac dysfunction in these children. Nineteen children with DMD (aged 9 to 18 years, mean age 13.6  2.4) underwent equilibrium radionuclide angiography at rest and during an inotro- pic stimulation with low-dose dobutamine perfusion (7.5 to 15 g · kg 1 · min 1 ). In all patients, this investiga- tion was short (<30 minutes), successful, and uncompli- cated. At rest, left ventricular (LV) ejection fraction (EF) was normal (>0.50) in 79% of patients, and right ven- tricular (RV) EF was normal (>0.45) in 95%. There was a trend toward a decrease with age for rest LVEF (p  0.051) but not for rest RVEF (p  0.8). By contrast, marked declines with age could be documented for the increases () in LVEF and RVEF during dobutamine per- fusion (p  0.002 for LVEF and p  0.015 for RVEF). Thus, by multivariate analysis, the sole best indicator of decline in cardiac function with age was LVEF deter- mined with dobutamine. In children with DMD, low-dose dobutamine radionuclide angiography gives evidence of an early decline with age of the inotropic reserves of both ventricles. 2004 by Excerpta Medica, Inc. (Am J Cardiol 2004;93:724 –727) I n young children with Duchenne’s muscular dys- trophy (DMD) the first signs of cardiac disease (characteristic electrocardiographic pattern) appear early in life. 1–3 The local abnormalities of contractility frequently seen in the posterior, lateral, or apical seg- ments of the left ventricle on echocardiography, 1,2,4,5 are consecutive to a degenerative process, involving fibrosis and fatty replacement that predominates in these regions. 6,7 However, global cardiac function re- mains normal at rest for many years in children with DMD, 2 and clinical signs of heart failure appear late in life because they are often confined to a wheelchair. 4,8 The aim of this study was to evaluate if an abnormal inotropic reserve (a parameter known to decrease much earlier than cardiac function at rest in cardio- myopathies of other origins 9 –11 ) might constitute an early sign of cardiac dysfunction in young children with DMD. For this purpose, we have retrospectively analyzed the data collected from children with DMD who underwent a first low-dose dobutamine (pharma- cologic stress is of major interest in these children unable to perform exercise) radionuclide angiography as a part of their systematic cardiac evaluation. METHODS Patients: In our institution, children with DMD have a systematic annual evaluation, which includes standard physical examination, muscular testing, and cardiac investigations; 12-lead electrocardiography, echocardiography, and also 24-hour Holter electrocar- diography because of the high rate of atrial tachyar- rhythmias. Cardiac radionuclide angiography is sys- tematically performed both at rest and during low- dose dobutamine infusion, before spine surgery, or when echocardiography becomes difficult to perform. For the present study, we selected the 19 consecutive children who underwent a first dobutamine radionu- clide angiographic study between 1992 and 2001. No patient had any sign or symptom of heart failure and none had nocturnal hypoxemia. In all cases, electro- cardiograms were abnormal with at least some ele- ments of the characteristic pattern (sinus tachycardia, tall R waves in the right precordium, and Q waves in leads I, V l , and V 5 to V 6 ), 1 but no arrhythmia was evidenced by the Holter-electrocardiograms. Muscular testing: During the same time period, the wasting of skeletal muscles was scored using 2 differ- ent tests: (1) the minitest, which is based on analysis of 5 different groups of muscles and provides a global score ranging from 5 (severely abnormal) to 25 (nor- mal), 12 and (2) Brooke functional score, which pro- vides separate analyses of the upper limbs (Brooke up), with a score ranging from 1 (normal) to 6 (se- verely abnormal), and of the lower limbs (Brooke low), with a score ranging from 1 (normal) to 10 (severely abnormal). 12,13 Echocardiography: One to 7 days before radionu- clide angiography imaging, transthoracic echocardi- ography was performed using an Acuson 128 XP/10 apparatus (Acuson Corporation, Mountain View, Cal- ifornia) and with a 5- or 3-MHz transducer where From the Departments of Pediatric Cardiology, Physical Medicine and Rehabilitation, and Nuclear Medicine, Children’s Hospital, Chu- Nancy, France. Manuscript received July 8, 2003; revised manuscript received and accepted December 2, 2003. Address for reprints: Gilles Bosser, MD, Service de Cardiope ´dia- trie, Ho ˆpital d’Enfants, Chu Nancy-Brabois, Alle ´ e du Morvan, 54511 Vandoeuvre Cedex, France. E-mail: g.bosser@chu-nancy.fr. 724 ©2004 by Excerpta Medica, Inc. All rights reserved. 0002-9149/04/$–see front matter The American Journal of Cardiology Vol. 93 March 15, 2004 doi:10.1016/j.amjcard.2003.12.005