Cardiac Arrest following a Myocardial Infarction in a Child Treated with Methylphenidate

Abstract

The use of psychostimulants labeled to treat attention deficit/hyperactivity disorder increases. Among side effects these drugs raise blood pressure and heart rate, and the safety has been scrutinised in recent years. Data from large epidemiological studies, including over a million person-years, did not report any cases of myocardial infarction in current users of methylphenidate, and the risk of serious adverse cardiac events was not found to be increased. We present a case with an 11-year-old child, treated with methylphenidate, who suffered cardiac arrest and was diagnosed with a remote myocardial infarction. This demonstrates that myocardial infarction can happen due to methylphenidate exposure in a cardiac healthy child, without cardiovascular risk factors.

Figure 1

12-lead electrocardiogram obtained on day five of the index admission. Abnormal Q-waves are seen in the left sided leads I, aVL, and V4–V6. The QTc interval was normal at 395 msec (Fredericia correction).

Figure 2

Cardiac magnetic resonance (CMR) imaging showing short-axis views in diastole (a) by cine CMR and (b) by late gadolinium enhancement imaging. Arrows indicate myocardial wall thinning and late gadolinium enhancement in the circumflex artery area consistent with myocardial necrosis and scar formation.

Figure 3

Reading from the implantable cardioverter defibrillator showing onset of ventricular fibrillation (arrow) at an average cycle length of 210 ms corresponding to a rate of 285 per minute. After the first shock (HV) delivered by the defibrillator, sinus rhythm is restored.