heart surgery

heart surgery,

any surgical procedure involving the heart, performed to correct acquired or congenital defects, replace diseased valves, open or bypass blocked vessels, or graft a prosthesis or a transplant. Two major types of heart surgery are performed: closed and open. The closed technique is done through a small incision, without use of the heart-lung machine. In the open technique the heart chambers are open and fully visible, and blood is detoured around the surgical field by the heart-lung machine. Preoperative care focuses on correcting metabolic imbalances and cardiac and pulmonary ailments and on performing diagnostic and laboratory tests. General anesthesia is used, the chest cavity is opened, and the heart-lung machine is connected. Hypothermia also is used to decrease the metabolic rate and the need of the tissues for oxygen. After surgery, constant observation is required in an intensive care unit for signs of hemorrhage and shock, cardiac arrhythmias, sudden chest pain, organ failure, and pulmonary edema. The blood pressure and all pulses, respirations, and venous and pulmonary artery pressures and cardiac rhythm (ECG) are monitored. If the blood pressure is high enough to ensure cerebral profusion, the head of the patient's bed is elevated to a semi-Fowler's position to encourage chest drainage and lung expansion. The patient is quickly extubated. Oxygen is provided. Chest tube drainage, urinary output, and temperature are noted hourly; IV infusions and sometimes blood transfusions are given. Narcotics help control pain so the patient can effectively cough, deep breathe, and become quickly mobile. Antibiotics are given to prevent infection. Mortality rate is highest during the first 48 hours after surgery. Common kinds of heart surgery include coronary bypass and endarterectomy. See also arrhythmia, fibrillation, heart-lung machine, hypothermia, pulmonary edema.

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heart,

n the muscular pump that maintains and regulates the flow of blood through the body.

heart, artificial,

n a mechanical device that acts to pump blood to and from the body tissues during repair of the heart.

heart attack,

n See myocardial infarction; thrombosis, coronary; or occlusion, coronary.

heart block,

n the condition in which the muscular interconnection between the auricle and ventricle is interrupted so that the auricle and ventricle beat independently of each other.

heart, compression of,

n See massage, cardiac.

heart defect,

n a fault in the structural integrity of the heart.

heart defect, congenital,

n the structural errors in the heart formed during embryonic and fetal life.

heart disease,

n a disorder in the normal functioning of the heart.

heart disease, dental concerns,

n.pl the special considerations taken to eliminate oral disease by maintaining an elevated level of oral health and prevent infective endocarditis, an infection of the heart valves that may be caused by bacteremia created during dental treatments. Heart disease has also been linked with increased levels of periodontal disease.

heart disease, ischemic,

n See disease, heart, ischemic.

heart disease risk factors,

n.pl the hereditary, lifestyle, and environmental influences that increase one's chances of developing heart disease.

heart massage,

n See massage, cardiac.

heart murmur,

n the sound of blood flowing back through a defective heart valve. Two types are possible: organic or functional.

heart, normal,

n a heart without anatomic defects that could cause an impairment in the function of the organ.

heart rate,

n the rate or tempo of heart contractions recorded in beats per minute.

heart sounds,

n.pl the normal noises produced within the heart during the cardiac cycle that can be heard over the precordium and may reveal abnormalities in cardiac structure or function. The use of the stethoscope over the left side of the chest is a common clinical technique to assess heart function. The typical sounds are a rythmic lub dup; abnormal sounds include clicks, murmurs, rubs, snaps, and gallops.

heart surgery,

n a surgical procedure involving the heart, performed to correct acquired or congenital defects, to replace diseased valves, to open or bypass blocked vessels, or to graft a prosthesis or a transplant in place.

heart valves,

n.pl one of the four structures within the heart that prevent backflow of blood by opening and closing with each heartbeat. They include two semilunar valves, the aortic and pulmonary; the mitral, or bicuspid, valve; and the tricuspid valve. They permit the flow of blood in only one direction, and any one of the valves may become defective, permitting the backflow associated with heart murmurs.