Cardiac first aid is mostly used for cardiogenic asthma, also known as paroxysmal nocturnal dyspnea, which is more common in middle-aged and elderly people. Most patients have a history of hypertension, coronary heart disease, secondary valve stenosis, aortic insufficiency and acute nephritis. Asthma attacks at night often lead to frequent coughing, obvious difficulty in exhaling and inhaling, and wheezing.
The main function of the heart is to provide power for blood flow and deliver blood to all parts of the body. The human heart is located in the lower left of the middle of the chest, about the size of a fist and weighs about 250 grams. Women's hearts are usually smaller and lighter than men's. The human heart looks like a peach, located above the diaphragm, between the lungs and on the left.