If a patient has an accelerated heartbeat accompanied by dyspnea, the specific causes are as follows: 1. Consider whether it is cardiac neurosis, certain patients may have an accelerated heartbeat accompanied by dyspnea due to anger, anxiety, etc. when there is a disorder of the vegetative nerves. 2. If a patient is poisoned, such as acute organophosphorus poisoning or poisoning by undesirable gases, an accelerated heartbeat accompanied by dyspnea may also occur. 3. Cardiogenic diseases, such as coronary atherosclerotic heart disease, unstable angina, arrhythmia, myocarditis, pericarditis, heart valve disease, hypertrophic obstructive cardiomyopathy, and infective endocarditis, may also cause an accelerated heartbeat with dyspnea. 4. Pleural effusion may also present with the above-mentioned typical symptoms.