患者男,6岁,因“活动后口唇、指端发绀3年”入院,既往曾多次在各级医院检查未明确诊断。体格检查:一般情况可,皮肤巩膜无黄染,口唇紫绀,双肺呼吸音清晰,未闻及干湿啰音,心尖搏动位于第五肋间锁骨中线处,胸骨左缘闻及2~3级收缩期杂音。心率112次/min,律齐,双下肢无水肿,杵状指(趾)。四肢血压和血氧饱和度:左上肢95/61 mm Hg(1 mm Hg=0.133 kPa)、92%,右上肢100/62 mm Hg、92%,左下肢115/52 mm Hg、89%, Patient male, 6 years old, because of “activity after the lips, finger cyanosis 3 years ” admission, past many times at all levels of the hospital did not have a clear diagnosis. Physical examination: The general situation may be, the skin sclera without yellow dye, cyanosis of the lips, lungs breath sounds clear, no smell and wet and dry rales, apex beat in the fifth intercostal clavicle midline, sternal left edge smell and 2 to 3 Systolic murmur. Heart rate 112 beats / min, law Qi, no lower extremity edema, clubbing (toe). Extremity blood pressure and oxygen saturation: 95/61 mm Hg for left upper limb (92 mmHg = 0.133 kPa), 92% for right upper limb 100/62 mm Hg, 89% for left lower limb 115/52 mm Hg,