normal vector cardiogram

例句：

1. 1. The NVECG is used to diagnose heart disease in patients with chest pain or shortness of breath.
   NVECG用于诊断有胸痛或呼吸困难的患者中的心脏病。
2. 2. During the test, a small electrode is placed on the patient's chest and connected to the machine.
   测试期间，一个小电极被放置在患者的胸部并连接到机器上。
3. 3. The results of the NVECG can help doctors determine the cause of the patient's symptoms and recommend appropriate treatment.
   NVECG的结果可以帮助医生确定患者症状的原因并推荐适当的治疗。