Basic Dysrhythmia interpretation Exam Review Update

Basic Dysrhythmia interpretation Exam Review Update General Rules - ANS-First and most important, look at your patient. Read left to right. Apply the systematic approach. Avoid shortcuts and assumptions. Ask and answer each question in the ECG analysis approach. ECG Rhythm Analysis - ANS-Analyze P waves (P wave is present, shape is consistent, must be before each QRS), Analyze QRS complex (present and consistent), Determine atrial rhythm or regularity (assessing P-P interval or R-R interval), Determine ventricular rhythm or regularity (assessing R-R interval), Determine Heart Rate, Measure the PR interval (measurement should be constant and should be between 0.12-0.20 sec), Measure the QRS duration (measurement should be constant and should be between 0.04-0.10 sec), interpret the rhythm Artifacts - ANS-Wave-forms outside the heart-interference. Caused by: Patent movement, loose or defective electrodes, improper grounding, faulty ECG apparatus. Sinus Rhythms - ANS-Normal, Sinus Bradycardia, Sinus Tachycardia, Sinus Arrhytmia, Normal Sinus Rhythms - ANS-SA node generates impulse that followed a normal pathway. heart rate fall within 60-100 BPM, atrial and ventricular rhythms are normal, p wave precedes every QRS, PR interval is within 0.12-0.20, QRS is within 0.12 seconds. Atrial Rhythms - ANS-Atrial Dysrhythmias, Premature Atrial Contractions (PAC), Atrial Tachycardia (unifocal, multifocal), Atrial Flutter, Atrial Fibrillation Sinus Bradycardia features - ANS-SA node fires slower than normal HR (<60 bpm), rhythm is regular, P wave upright and same shape, PR is constant 0.12-0.20, QRS -normal <0.12 sec Sinus Bradycardia information - ANS-Causes: vagal stimulation, MI, Hypoxia, Digitalis toxicity (herbal meds), Medication side effects, normal to elite aerobically fit athletes (pumps more blood/beat) Adverse effects: Dizziness, weakness, syncope, diaphoresis, pallor, hypotension Treatment: According to symptoms, atropine to speed up heart rate, pacemaker Sinus Tachycardia features - ANS-SA node fires at a rate faster than normal, >100 bpm but conduction pathway is normal. All criteria for interpretation are the same except that the heart rate is faster. Sinus Tachycardia information - ANS-Causes: emotionally upset, pain, fever, thyrotoxicosis (hyperthyroid), hypoxia, hypovolemia, inhibition of vagus nerve (parasympathetic) Adverse effects: Angina, dizziness, hypotension, increased in cardiac workload Treatment: Treat the cause, medications may be given (b-blockers) Sinus Arrhythmia - ANS-The only irregular rhythm from the sinus node and has a cyclic pattern that usually corresponds with breathing, Rate= varies with respiratory pattern, Regularity= irregular in a repetitive pattern, P wave= upright in most leads, same shape and one to each QRS;P-P interval is irregular, QRS= <0.12, Cause= usually breathing pattern but can also be heart disease, Tx= Usually non required Atrial Dysrhythmias - ANS-SA node fails to generate an impulse (atrial tissue takes over), Atrial nodes or internodal pathways may initiate an impulse and follows the conduction pathway, Dysrhythmias of this type are not lethal, Accessory pathway (an additional electrical conduction pathway b/w 2 parts of the heart; may alter electrical conduction system of the heart) Premature Atrial Contractions (PAC) Information - ANS-Early ectopic beat that originates outside the SA node, Causes= atria becomes hyper and fire early caused by medications, caffeine, tobacco, hypoxia, or heart disease, Adverse effects= if freq can be a sign of impending heart failure or atrial tachycardia or fibrillation, Tx= 02, omit caffeine, tobacco or other stimulants. Give digitalis or quinidine, treat heart failure Premature Atrial Contractions (PAC) features - ANS-Normal rate, usually regular in rhythm except for PAC, P waves shaped differently from a normal P wave or hidden in preceding T wave (P and T fire at same time), PR interval = 0.12-0.20 sec, QRS= 0.12 sec, Produce an irregularity in the rhythm (P-P and PR intervals are shorter than the P-P and R-R intervals of underlying rhythm), Have P waves that are upright (in lead II) preceding each QRS complex but have a different morphology (appearance) than the P waves of underlying rhythm. Bigeminal, trigeminal, quadrigeminal ( N/PAC, N/N/PAC, N/N/N/PAC)