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 ThS. Lê Hoài Nam Bộ môn Nội – ĐHYD TPHCM History of the ECG/EKG • During the late 1800’s and early 1900’s, Dutch physiologist Willem Einthoven developed the early electrocardiogram He won the Nobel prize. ! • Hubert Mann first uses the electrocardiogram to describe electrographic changes associated with a heart attack in 1920 ! • Electrocardiograms must be viewed in the context of demographics, health history, and other clinical test correlates. They are especially useful when compared across time to see how electrical activity of the heart has changed (perhaps as the result of some pathology).
 1887 British physiologist Augustus D. Waller of St Mary's Medical School, London publishes the first human electrocardiogram. It is recorded with a capilliary electrometer from Thomas Goswell, a technician in the laboratory. Waller AD. A demonstration on man of electromotive changes accompanying the heart's beat. J Physiol (London) 1887;8:229-234 1889 Dutch physiologist Willem Einthoven sees Waller demonstrate his technique at the First International Congress of Physiologists in Bale. Waller often demonstrated by using his dog "Jimmy" who would patiently stand with paws in glass jars of saline. 1889 ! R.E.Mason., I.Likar ( 1966) Augustus waller first to His electrocardiograph machine consisted of a Lippmann capillary electrometer fixed to a projector. The trace from the heartbeat was projected onto a photographic plate which was itself fixed to a toy train. This allowed a heartbeat to be recorded in real time. In 1911 he still saw little clinical application for his work. An initial breakthrough came when Willem Einthoven, working in Leiden, Netherlands, used the string galvanometer that he invented in 1903. [8] This device was much more sensitive than both the capillary electrometer that Waller used and the string galvanometer that had been invented separately in 1897 by the French engineer Clément Ader. [9] . Rather than using today's self-adhesive electrodes Einthoven's subjects would immerse each of their limbs into containers of salt solutions from which the ECG was recorded. Einthoven assigned the letters P, Q, R, S and T to the various deflections, and described the electrocardiographic features of a number of cardiovascular disorders. In 1924, he was awarded the Nobel Prize in Medicine for his discovery limb leads Many advancements such as Goldbergers chest leads Electrocardiography • A recording of the electrical activity of the heart over time • Gold standard for diagnosis of cardiac arrhythmias • Helps detect electrolyte disturbances (hyper- & hypokalemia), arrhythmias, myocardial ischemia and infarction, pericarditis, chamber hypertrophy, drug toxicity (i.e. digoxin and drugs which prolong the QT interval) • Allows for detection of conduction abnormalities • Screening tool for ischemic heart disease during stress tests • Helpful with non-cardiac diseases (e.g. pulmonary embolism or hypothermia) Cardiac Electrical Activity • SA Node - Dominant pacemaker with an intrinsic rate of 60 - 100 beats/minute. ! • AV Node - Back-up pacemaker with an intrinsic rate of 40 - 60 beats/minute. ! • Ventricular cells - Back- up pacemaker with an intrinsic rate of 20 - 40 bpm. Lead “Views” EKG Leads Leads are electrodes which measure the difference in electrical potential between either: 1. Two different points on the body (bipolar leads) ! 2. One point on the body and a virtual reference point with zero electrical potential, located in the center of the heart (unipolar leads) EKG Leads The standard EKG has 12 leads: 3 Standard Limb Leads 3 Augmented Limb Leads 6 Precordial Leads The axis of a particular lead represents the viewpoint from which it looks at the heart. Standard Limb Leads . Vai trò của điện tâm đồ Điện tâm đồ bình thường
 ThS. Lê Hoài Nam Bộ môn Nội – ĐHYD TPHCM History of the ECG/EKG •