Massive gas interference on cardiac ultrasound refers to the phenomenon where the gas in the lungs interferes with the conduction of the ultrasound waves when performing a cardiac ultrasound, resulting in an unclear view of the heart structure. Normally, there is a small amount of lung tissue in the peripheral portion of the heart between the heart and the chest wall, which can interfere with the ultrasound cardiac examination, but the area of interference can usually be avoided by repositioning the ultrasound probe. In pathological conditions, such as when a pneumothorax or emphysema has occurred, the amount of air-containing tissue between the heart and the chest wall is greatly increased, and interference with the ultrasound cardiac examination increases. Therefore, if there is a lot of gas interference during the cardiac ultrasound examination, it is best to do a chest fluoroscopy or chest X-ray to see if there is a pneumothorax or emphysema, and if not, it may be a problem with the sonographer’s operation, and the ultrasound probe can be adjusted or a new experienced sonographer can perform the examination.