Journal of Pediatric Cardiology and Cardiac Surgery

We report a 4-month-old male diagnosed with a tachycardia attack during an echocardiographic examination. While undergoing the procedure at a previous clinic, the infant was crying violently, complicating differentiation between sinus tachycardia and a tachycardia attack. Doppler echocardiography revealed a heart rate over 300 beats/minute, prompting transfer of the patient to our hospital on suspicion of tachyarrhythmia. Upon arrival at our hospital, the heart rate had decreased to 250 beats/minute and Δ waves were identified during this tachycardia. These findings suggested an atrial tachycardia (AT) with Wolff–Parkinson–White (WPW) syndrome. A limited heart rate variability during crying and at rest raised the suspicion of AT. Adenosine triphosphate (ATP) was administered. Based on the response to the agent and subsequent findings, the patient was ultimately diagnosed as having AT with bystander WPW syndrome. Neonates and infants frequently experience tachycardias triggered by crying. When tachycardia does not align with clinical symptoms, tachyarrhythmia must be suspected and investigated thoroughly. When differentiation of AT from sinus tachycardia proves challenging, a multifaceted approach is essential including monitoring the response to ATP and observing the changes in the electrocardiographic waveform over time.