MAIN ELECTROCARDIOGRAPHIC CHANGES (Atena Editora)

Abstract

INTRODUCTION: The cardiac conduction system is formed by the sinoatrial (SA) node, interatrial and internodal bundles, atrioventricular (AV) node, bundle of His (atrioventricular) and Purkinje fibers. In the SA node, rhythmic impulses are generated that pass through the internodal pathways, reaching the AV node. In it, the impulse is conducted to the bundle of Hiss to finally reach the Purkinje fibers that will stimulate the entire cardiac ventricle. When evaluating an ECG, it is necessary to pay attention to both the way the stimulus is being conducted, that is, the morphology of the emitted waves, as well as the rhythm and frequency. METHODOLOGY: A systematic review of books on how to evaluate the ECG and its alterations was carried out, in addition to physiology treaties and guidelines on the same. This article aims to list the electrocardiographic changes in the main cardiac arrhythmias. RESULTS: Cardiac arrhythmia is a condition identified by abnormalities or lack of rhythm in the heartbeat. Monitoring systems capture a non-stationary physiological signal formed by a sequence of waves that reflect the electrical activity of the heart. In electrophysiology, the genesis of cardiac arrhythmias is related to changes in both the formation and conduction of the cardiac electrical impulse. Bradyarrhythmias are disturbances of the heart rhythm that accompany the decrease in HR and result either from the reduction in the generation of the electrical stimulus, or from the disturbance of conduction by the cardiac tissue. Tachyarrhythmias are defined when the HR is above 100bpm, whether sinus or not. CONCLUSION: The ECG is a practical and low-cost exam, being a complementary exam to the clinical history and exam in emergency rooms and outpatient consultations. Arrhythmias present peculiarities of the electrocardiographic tracings, being necessary to evaluate the same in order to choose the best therapeutic plan and prognosis for the patient.