Takotsubo syndrome is a potentially reversible cause of acute systolic dysfunction. Takotsubo syndrome is rare in children, with no reported dobutamine-induced cases to date. We present a 14-year-old male with prior history of heart transplantation, who developed Takotsubo syndrome during dobutamine stress echocardiography. We highlight the importance of its early recognition to ensure supportive measures with avoidance of inotropic medications.

In patients with coronary arterial disease, stress imaging is able to demonstrate abnormalities in the motion of the ventricular walls, and abnormalities in coronary arterial perfusion not apparent at rest. It can also provide information on prognostic factors. In patients with congenitally malformed hearts, stress imaging is used to determine contractile reserve, abnormalities of mural motion, and global systolic function, but also to assess diastolic and vascular function. In most of these patients, stress is usually induced using pharmacological agents, mainly dobutamine given in varying doses. The clinical usefulness of abnormal responses to the stress induced in such patients has to be addressed in follow-up studies. The abnormal stress might serve as surrogate endpoints, predicting primary endpoints at an early stage, which are useful for stratification of risk in this population of growing patients. We review here the stress imaging studies performed to date in patients with congenitally malformed hearts, with a special emphasis on echocardiography and cardiac magnetic resonance imaging.

We recently reported our experience with exercise stress echocardiography in children with prior history of Kawasaki disease and coronary arterial involvement. Dobutamine stress echocardiography has been used in adults (doses up to 50 μg/kg/min) for diagnosis and risk stratification of coronary arterial disease. To date, no studies have assessed the safety and utility of high-dose dobutamine for the detection of abnormalities of wall motion in children, although low dose dobutamine (5 μg/kg/min) has been used to assess left ventricular function after use of anthracycline in children. Our study group consisted of 10 children known to have Kawasaki disease, and 16 children who had undergone heart transplantation. After baseline transthoracic echocardiographic imaging, dobutamine was infused in an incremental fashion, 10–40 μg/kg/min intravenously, to attain peak heart rate. Heart rate and blood pressure were monitored continuously, and 4 standard echocardiographic images were acquired at each stage of dobutamine infusion and at recovery. Images were digitized, and the left ventricular segments were reviewed to assess wall motion. No patients suffered serious side effects such as arrhythmias or hypotension. Studies were complete in all 26 patients. One study proved positive, with a new abnormality of wall motion identified corresponding to a critical right coronary arterial stenosis. Peak heart rate and blood pressure were similar for the 2 groups. High dose dobutamine stress echocardiography, therefore, is feasible and safe in children, and may detect flow-limiting coronary arterial stenoses noninvasively. The technique may safely be applied to other subsets of children where assessment of ischemia and contractile reserve is warranted.