Cardiac dyspnea, which is more common in clinical practice, is mainly considered for two reasons: first, the onset of coronary heart disease, such as angina pectoris and myocardial infarction, can be manifested as dyspnea, dyspnea in angina pectoris lasts from a few minutes to ten minutes, rarely more than half an hour, dyspnea in acute myocardial infarction, which lasts more than half an hour, especially in elderly people who have no previous special medical history and suddenly occur dyspnea, showing persistence, pay attention to acute myocardial infarction. Second, heart failure, especially left heart failure, manifested as varying degrees of dyspnea, the initial manifestation is mainly activity-related dyspnea, with the aggravation of the disease, can appear paroxysmal dyspnea at night, the disease continues to progress will appear telescopic breathing, dyspnea can also occur at rest, do cardiac ultrasound, to help clarify the diagnosis.