A young man nearing the end of his second decade with no significant medical history presented to the emergency department with a 1-day history of intermittent palpitations and chest pain associated with shortness of breath. On presentation, the patient appeared anxious with a heart rate of 101 beats per minute, respiratory rate of 20 breaths per minute, blood pressure of 151/79 mm Hg, and pulse oximetry of 96% in room air. His cardiopulmonary examination results, complete blood cell count, basic metabolic panel, and cardiac troponins were all within normal limits. His electrocardiogram on presentation and echocardiogram are shown in Figure 1 and the Video.

一名接近第二个 10 岁的年轻人，没有明显的病史，因 1 天的间歇性心悸和胸痛伴呼吸短促而到急诊科就诊。就诊时，患者出现焦虑，心率为每分钟 101 次，呼吸频率为每分钟 20 次，血压为 151/79 mm Hg，室内空气中脉搏血氧饱和度为 96%。他的心肺检查结果、全血细胞计数、基本代谢组和心肌肌钙蛋白均在正常范围内。他的心电图和超声心动图如图 1 和视频所示。