In the 13 years since the first edition of ECG Tutor, much has changed in the world of medicine. The detailing of the human genome and the ability to modify genes has ushered in a new era of genomic medicine at the most basic and most clinical levels. Technological sophistication has provided us with increasingly powerful imaging modalities, while computer technology has provided us with electronic medical records, automated interpretations of electrocardiograms and x-rays and algorithms that can take a history, provide differential diagnoses, review the literature and suggest further diagnostic tests and therapies. Robotic examinations and surgeries have extended the reach of medicine into increasingly remote areas. At the same time, social and economic factors have lead to questions regarding the accessibility, affordability and accountability of medical care at local, national and international levels.
The electrocardiogram, on the other hand has not changed. The basic electrophysiologic properties that underlie the depolarization and repolarization of cardiac cells remain the same as do the recording techniques, even as the ECG machines themselves have been miniaturized. One can argue, however, that the informational content of the ECG has expanded as the result of our understanding of the genetic factors that may influence the ECG waveform and the correlation of the ECG wave form to the information provided by the newer imaging modalities. One can also argue that at the same time, the emphasis placed on ECG teaching during medical school and residency training has decreased, the result of the increased reliance on the imaging capabilities. Moreover, the speed with which medical decisions are made and interventions performed has made only the initial reading of the ECG at the bedside, or in the Emergency Department truly relevant to the care of the patient.
It is our hope that this updated and revised edition of ECG tutor will take advantage of current web-based capabilities to make an understanding of the electrocardiogram and its importance and utility in the diagnosis and treatment of patients with heart disease, more readily accessible to medical students, residents and practicing physicians with an interest in the electrocardiogram. Readers are encouraged to communicate directly with the author via email at lgettes@med.unc.edu, if they wish to question or discuss issues pertinent to the ECG. They are also encouraged to submit ECGs they wish to discuss or interpret. Other members of the Electrophysiology faculty at UNC will assist, as appropriate, in the discussion of pertinent issues and the analysis of submitted tracings.
The most recent edition of the text by Surawicz, Knilans: Chou’s Electrocardiography in Clinical Practise 6th edition, Saunders, Philadelphia, 2008, as well as those previously referred to, were used as primary reference sources.