ECG Characteristics Latest Update 100% Solved

ECG Characteristics Latest Update 100% Solved P wave caused by depolarization of the atria PR Interval extends from the beginning of the P wate to the beginning of th QRS - Represents the time the impulse takes to travel from the SA node through the AV node - Normally 0.12-0.20 seconds QRS Complex Represents ventricular depolarization - Normally < 0.12 seconds T Wave Represents ventricular repolarization U Wave Usually not seen - Represents repolarization of purkinje fibers QT Interval Beginning of the QRS to the end of T wave - Represents ventricular depolarization and repolarization - Normally 0.36 to 0.44 seconds Prolonged Q-T Syndrome Genetic bases -symptoms include syncope an dsuddent cardiac death (runners death) may be first sign - abnormality in cardiac repolarization - may cause Torsade de Pointes Causes of Cardiac Arrhythmias Disturbance of Autpmaticity ~ Disturbance of Conduction ~ Combination of Altered Automaticity and Conduction Automaticity the ability of the cell to depolarize itself, reach threshold. and produce a propagated action potential Distubance in Automaticity Speeding up or slowing down areas of automaticity (SA node, AV node, or myocardium) ~ Abnormal depolarization from the atria, AV junction, or the ventricles (premature beats) ~ irritability Disturbance in Conduction too rapid conduction ~ slow conduction or blocks in conduction ~ failure ot do the job Rate < 60bpm-Bradycardia ~ 60-100bpm-normal ~ >100bpm Tachycardia Rhythm Regular-sinus, junctional, Ventricular ~ Irregular-premature beats, Afib/Aflutter, escape beats P-QES Relationship 1 P for q QRS (1:1)-sinus, atrial, junctional ~ Fewer P's than QRS's-ectopy, ventricular ~ More P's than QRS-blocks