ELECTROCARDIOGRAPHY

It is generally known that heart works very effectively during rest condition; however it can increase its output according to tissue oxygen and substrate demand in couple of seconds. This quick and effective process is an evidence of perfect nervous and humoral regulation. Regulation of the heart activity is fascinating. Detailed study of the heart physiology clearly points out the perfection of this phenomenon at one side, but also a complexity of it at the other side. Complexity of this regulation may be also the background for the delicacy of these processes. One of the manifestations of “imperfections” in this complex process could be quite common presence of disturbances of electrical and/or mechanical work of the heart.
During our entire practice as a teacher of pathophysiology, we frequently faced the lack of knowledge in students on the heart function during pathological and even during physiological conditions.
The most problematic part seems to be interpretation of ECG curve caused by disturbances of the impulse production or conduction and many more processes. Many of our students managed to understand the ECG thanks to their endurance and the help from the teachers during the pre-gradual study. Some of them, however, never broke the barrier of understanding of ECG and they only relied on their ability to memorize and remember the most important changes of the electrocardiogram. Memory used to be bad servant sometimes, and it may happen that the remembered figures vanish with the time. Memorizing instead of understanding ECG is not the best way how to manage one of the most important examination methods in cardiology, and it was frustrating for both students and teachers. The lack of knowledge at the student side was frequently explained as a consequence of not well written literature (textbooks) that would be student-friendly and that would explain electrophysiological processes in the heart with their manifestation on the ECG curve. The retention of knowledge can only be achieved by understanding of the task rather than the memorizing textbooks. This was main motivation for preparing better teaching textbook on ECG.
The main objective of this textbook is to explain the mechanisms leading to the typical electrophysiological changes in the heart in physiological and pathological conditions and also to show the manifestation of these processes on the ECG curve.
The authors tried to avoid using mathematical and electrophysiological terms in the text. This will lead to some degree of simplification of all tasks; however, the authors do believe that simple explanations can be more effective for understanding than sophistically written text. The authors do believe that this small textbook can be useful and can help the students to “read” electrocardiogram properly. We all know the situations in cardiology when quick decision is necessary to save a life.