Cardiology: the study of the heart, its physiology, and its functions. (MeSH) The science concerned with the structure, function, and diseases of the heart. (OxfordMed)

A branch of medicine that specializes in diagnosing and treating diseases of the "heart," “blood vessels,” and “circulatory system.” These diseases include “coronary artery disease,” heart rhythm problems, and" heart failure." (NCI1) The developed world led an “epidemic” in “artery” disease related to a diet high in animal fats, smoking, and a more sedentary lifestyle. Changes in lifestyle and the development of “cholesterol” lowering drugs have reduced the incidence of (heart surgery). (Bynum, 245)

Arrhythmia Treatments: the underlying cause of an arrhythmia provides the basis for selecting the best treatment. Treatments fall into several main categories along a continuum from the least to most invasive. In general, the least invasive treatment that effectively controls the arrhythmia is the treatment of choice. Medications can control abnormal heart rhythms or treat related conditions such as high "blood pressure," coronary artery disease, heart failure, and "heart attack. Drugs also may be administered to reduce the risk of "blood clots" in patients with certain types of arrhythmias. (HRS, Heart Rhythm Disorders Facts) If (there are) no symptoms, treatment may not be required. (The) doctor may choose to have regular follow-up without treatment. (Cleveland Clinic, Diseases & Conditions) Although surgery is sometimes used to treat abnormal heart rhythms, it is more commonly elected to treat other cardiac problems, such as coronary artery disease and heart failure. Correcting these conditions may reduce the likelihood of arrhythmias. (HRS, Heart Rhythm Disorders Facts)

Cardiac Ablation: procedure (where) one or more flexible, thin tubes ('catheters') are guided via "x-ray" into the "blood vessels" and directed to the heart muscle. A burst of radio frequency energy destroys very small areas of tissue that give rise to abnormal electrical signals. (HRS, Heart Rhythm Disorders Facts) During ablation, energy is delivered through a catheter to tiny areas of the heart muscle. The energy can either ‘disconnect’ the pathway of the abnormal rhythm, block the abnormal pulses and promote normal conduction of impulses, or disconnect the electrical pathway between the "atria" and the "ventricles." Most often used to treat “PSVT,” “atrial fibrillation,” “atrial flutter,” "AV nodal re-entrant tachycardia,” and “ventricular tachycardia.” May be combined with other procedures to achieve optimal treatment. (Cleveland Clinic, Diseases & Conditions)

Cardiac Electronic Devices: by delivering a controlled electric shock to the heart, ‘defibrillators,’ or ‘cardioverters’ shock the heart back into a normal heart rhythm. Sometimes the devices are external, such as in an emergency situation. Often, the electronics are implanted in the patient’s chest. (HRS, Heart Rhythm Disorders Facts)

Cardiac Resynchronization Therapy: U.S. Food and Drug Administration approved (this) special type of pacemaker for certain patients with heart failure. An implanted device paces both the left and right ventricles simultaneously. This resynchronizes muscle contractions and improves the efficiency of the weakened heart. (HRS, Heart Rhythm Disorders Facts)

Implanted Cardioverter Defibrillator (ICD): pacemaker-like device that is implanted under the skin. Continually monitors the heart, and automatically delivers an electric shock if it detects "ventricular fibrillation" or "ventricular tachycardia." (HRS, Medical Device Facts.) Automatically functions as a pacemaker for heart rates that are too slow, and delivers life-saving shocks if a dangerously fast heart rhythm is detected. 99 percent effective in stopping life-threatening arrhythmias. Most successful therapy to treat ventricular fibrillation, the major cause of sudden cardiac arrest. (HRS, Heart Rhythm Disorders Facts)

Pacemaker: a device that 'paces' the heart rate when it is too slow (and) can take over for the heart’s natural pacemaker, the “sinoatrial node,” when it is functioning improperly. Pacemakers monitor and regulate the rhythm of the heart and transmit electrical impulses to stimulate the heart if it is beating too slowly. (HRS, Heart Rhythm Disorders Facts)

Heart Diagnostics: procedures used to determine whether an individual is in a group that is at high risk for “sudden cardiac arrest” or other cardiovascular diseases. (HRS, Electrophysiology Facts)

Echocardiography: the use of ultrasound waves to investigate and display the action of the heart as it beats. Used in the diagnosis and assessment of congenital and acquired heart diseases. The image produced is not anatomical but permits precise measurement of cardiac dimensions. (OxfordMed, 231)

Echocardiogram: a painless, noninvasive test, in which a device called a 'transducer' is placed on the chest and sound waves are bounced off the heart. This provides a moving picture of the heart. (HRS, Electrophysiology Facts) Also referred to as 'echo' and 'cardiac echo.’

Electrocardiography: a technique for recording the electrical activity of the heart. Electrodes connected to the recording apparatus are paced on the skin of the four limbs and chest wall. (OxfordMed, 236)

Electrocardiogram (ECG): the visualization of the electrical activity of the heart, which can be stored as a permanent record. (Bynum, 292) A tracing of the electrical activity of the heart recorded by electrocardiography. (OxfordMed) A picture of the electrical impulses traveling through the heart muscle. Recorded on graph paper, through the use of electrodes that are attached to the skin on the chest, arms, and legs. (Cleveland Clinic, Diseases & Conditions) Also referred to as 'ECG' and ‘EKG.'

QT Interval: the area on the ECG that represents the time it takes for the heart muscle to contract and then recover, or for the electrical impulse to fire and then recharge. (Cleveland Clinic, Diseases & Conditions)

Electrophysiology Study (EPS): a test that can help predict if an individual is at high risk for (heart arrhythmia). Signals are administered to the heart muscle in patterns to see if they will stimulate "ventricular tachycardia." The test is performed in a safe and controlled electrophysiology laboratory at a hospital or clinic and the patient is in no danger. In an EPS, local anesthetics are used to numb areas in the groin or near the neck, and small catheters are passed into the heart to record its electrical signals. During the study, the physician studies the speed and flow of electrical signals through the heart, identifies rhythm problems, and pinpoints areas in the heart's muscle that give rise to abnormal electrical signals. (HRS, Electrophysiology Facts) During the test, the arrhythmia can be safely reproduced and terminated. (Cleveland Clinic, Diseases & Conditions) Also referred to as 'intracardiac electrophysiology study.'

Event Monitor: a small, pager-sized device that also records the electrical activity of the heart. Unlike a “Holter monitor,” it does not operate continuously, but instead is activated by the individual whenever he or she feels the heart begin to beat too fast or chaotically. After the device is activated to record the heart rhythm, the patient can report the event and transmit the recording by phone to his doctor or other health care provider. (HRS, Electrophysiology Facts)

Holter Monitor: external device that is worn by an individual who may be at risk for heart disease. The monitor automatically records a continuous electrocardiogram of the heart's electrical activity; it is usually worn for 24 to 48 hours. (HRS, Electrophysiology Facts)