Pulmonary embolism and left heart failure, although both may have dyspnea and hemoptysis, are not the same. The main points of differentiation are as follows: i. Pulmonary embolism generally has very high D-dimer, while left heart failure D-dimer is not necessarily high. Second, most pulmonary embolism has a history of venous thrombosis in the lower or upper extremities, that is, a history of swelling of the extremities, while left heart failure does not. Third, pulmonary embolism and left heart failure are visible by ultrasound, that is, pulmonary tethering usually has pulmonary hypertension, while left heart failure usually has a significantly decreased ejection fraction. The difference between pulmonary embolism and left heart failure is also that BNP is usually normal or mildly elevated in pulmonary embolism, while BNP is higher in left heart failure. V. Pulmonary embolism can be diagnosed by pulmonary artery CTA