query: medical_specialty premature atrial contraction
supports: Electrocardiography (ECG or EKG*) is the process of recording the electrical activity of the heart over a period of time using electrodes placed on the skin. These electrodes detect the tiny electrical changes on the skin that arise from the heart muscle's electrophysiologic pattern of depolarizing during each heartbeat. It is a very commonly performed cardiology test. In medicine, a Holter monitor (often simply "Holter" or occasionally ambulatory electrocardiography device) is a portable device for continuously monitoring various electrical activity of the cardiovascular system for at least 24 hours (often for two weeks at a time). A disease is a particular abnormal condition, a disorder of a structure or function, that affects part or all of an organism. The study of disease is called pathology which includes the causal study of etiology. Disease is often construed as a medical condition associated with specific symptoms and signs. It may be caused by external factors such as pathogens, or it may be caused by internal dysfunctions particularly of the immune system such as an immunodeficiency, or a hypersensitivity including allergies and autoimmunity. A subclinical infection (sometimes called a preinfection) is an infection that, being subclinical, is nearly or completely asymptomatic (no signs or symptoms). A subclinically infected person is thus an asymptomatic carrier of a microbe, intestinal parasite, or virus that usually is a pathogen causing illness, at least in some individuals. Many pathogens spread by being silently carried in this way by some of their host population. Such infections occur both in humans and nonhuman animals. An example of an asymptomatic infection is a mild common cold that is not noticed by the infected individual. Since subclinical infections often occur without eventual overt sign, their existence is only identified by microbiological culture or DNA techniques such as polymerase chain reaction. Medicine (British English ; American English ) is the science and practice of the diagnosis, treatment, and prevention of disease. The word "medicine" is derived from Latin "medicus", meaning "a physician". Medicine encompasses a variety of health care practices evolved to maintain and restore health by the prevention and treatment of illness. Contemporary medicine applies biomedical sciences, biomedical research, genetics, and medical technology to diagnose, treat, and prevent injury and disease, typically through pharmaceuticals or surgery, but also through therapies as diverse as psychotherapy, external splints and traction, medical devices, biologics, and ionizing radiation, amongst others. Premature atrial contractions ( PACs ) , also known as atrial premature complexes ( APC ) or atrial premature beats ( APB ) , are a common cardiac dysrhythmia characterized by premature heartbeats originating in the atria . While the sinoatrial node typically regulates the heartbeat during normal sinus rhythm , PACs occur when another region of the atria depolarizes before the sinoatrial node and thus triggers a premature heartbeat.The exact cause of PACs is unclear ; while several predisposing conditions exist , PACs commonly occur in healthy young and elderly people without heart disease , and by themselves are not considered an abnormal finding . PACs are often completely asymptomatic and may be noted only with Holter monitoring , but occasionally they can be perceived as a skipped beat or a jolt in the chest . In most cases , no treatment other than reassurance is needed for PACs , although medications such as beta blockers can reduce the frequency of symptomatic PACs . In medicine, a disease is considered asymptomatic if a patient is a carrier for a disease or infection but experiences no symptoms. A condition might be asymptomatic if it fails to show the noticeable symptoms with which it is usually associated. Asymptomatic infections are also called subclinical infections. Other diseases (such as mental illnesses) might be considered subclinical if they present some but not all of the symptoms required for a clinical diagnosis. The term clinically silent is also used.
candidates: cardiology genetics infection pathology surgery
answer: cardiology