electrocardiogram /elec·tro·car·dio·gram/ (-kahr´de-o-gram″) a graphic tracing of the variations in electrical potential caused by the excitation of the heart muscle and detected at the body surface. The normal electrocardiogram is a scalar representation that shows deflections resulting from cardiac activity as changes in the magnitude of voltage and polarity over time and comprises the P wave, QRS complex, and T and U waves. Abbreviated ECG or EKG. See also electrogram. 
Electrocardiogram (ECG, EKG)
electrocardiogram (ECG)
electrocardiogram (ECG, EKG) [e-lek″tro-kahr´de-o-gram″]
)
Normal electrocardiogram.
scalar electrocardiogram see electrocardiogram.
e·lec·tro·car·di·o·gram ( -l k tr -kär d - -gr m)n. Abbr. ECG, EKG The curve traced by an electrocardiograph. Also called cardiogram. |
Electrocardiogram (ECG, EKG)
A record of the electrical activity of the heart showing certain waves called P, Q, R, S, and T waves. The Q, R, S, T waves are associated with contraction of the ventricles, the lower two chambers of the heart.
Mentioned in: Arrhythmias, Bundle Branch Block, Cardiac Blood Pool Scan, Coarctation of the Aorta, Electrophysiology Study of the Heart, Heart Murmurs, Heart Transplantation, Multiple-Gated Acquisition (MUGA) Scan, Myocarditis, Myotonic Dystrophy, Pacemakers, Patent Ductus Arteriosus, Pericardiocentesis, Pericarditis, Prolonged QT Syndrome, Sydenham's Chorea, Technetium Heart Scan, Ventricular Fibrillation, Ventricular Septal Defect, Ventricular Tachycardia, Women's Health
electrocardiogram (ECG)
[-kär′dē·əgram′]
Etymology: Gk, elektron + kardia, heart, gramma, record
a graphic record produced by an electrocardiograph, a device for recording electrical conduction through the heart.
electrocardiogram (ECG, EKG) [e-lek″tro-kahr´de-o-gram″]
the record produced by electrocardiography; a tracing representing the heart's electrical action derived by amplification of the minutely small electrical impulses normally generated by the heart.
Normal electrocardiogram. Heart action during P-R interval: (1) Atrial contraction begins at peak of P wave. (2) P-R interval—atrial contraction. (3) Ventricles relaxed. Heart action during QRS complex: (1) Ventricular contraction begins at peak of R. (2) A-V (mitral and tricuspid) valves close, causing S1 sound. (3) Ventricles contract. (4) Atrial relaxation begins. Heart action during S-T segment: (1) Semilunar valves open (aortic and pulmonic). (2) Ejection of blood from ventricles–systole. Heart action during T wave: (1) Slowing of ejection from ventricles. (2) Closure of semilunar valves (aortic and pulmonic) causing S2 sound. Heart action during T-P interval: (1) Relaxation of ventricles. (2) A-V valves open. (3) Filling of ventricles, causing S3 sound.
electrocardiogram (
·lekˈ·trō·kärˑ·dē··gramˈ),n recording of the electrical activity of the heart. Often used to identify heart problems; routinely performed in patients complaining of chest pain to rule out heart disease. Also called
EKG.
EKG.
electrocardiogram
the record produced by electrocardiography; a tracing representing the heart's electrical action derived by amplification of the minutely small electrical impulses normally generated by the heart. Called also ECG and EKG.
electrocardiogram
ECG, EKG Cardiology A non-invasive test of the electrical activity of heart's conduction system, which is transformed into recordings on graph paper–an electrocardiograph; in an EKG, electrodes–leads are
placed on 12 specific sites of the body: standard limb leads–I, II, III, augmented limb leads–aVr , aVl, and aVf, and precordial or chest leads–V1 to V6; EKG tracings consist
of 3 major components: the P wave, which indicates atrial depolarization, the QRS complex–ventricular depolarization, and the T wave–ventricular repolarization; the Holter monitor is a portable EKG recording device worn by an individual
for continuous monitoring; the EKG is used to detect cardiac damage by evaluating alterations in the electrical conduction the heart, and can be performed at rest or during excercise–eg thallium stress test; the Holter monitor is a portable
device worn by a Pt for continuous cardiac monitoring; the EKG is used to detect the presence and location of myocardial ischemia or infarction, cardiac hypertrophy, arrhythmias, conduction defects. See His bundle electrocardiography, Signal-averaged electrocardiography, Sleep electrocardiography.
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