We report a case of an infant who presented in profound cardiovascular collapse with a normal sinus rhythm initially. A diagnosis of supraventricular tachycardia (SVT) was established only after hemodynamic stabilization. The possibility of SVT being masked because of severe metabolic derangements and/or painful therapeutic procedures should be kept in mind when managing cardiogenic shock in children. Such a consideration is of practical significance in planning therapy, such as the avoidance of digitalis in a patient with Wolf-Parkinson-White syndrome.