NUR 425 Med Surg 2 - Exam 3: Cardiac Dysrhythmias and ECG Waveforms Latest Update with complete solutions

Coordinating Care for Patients with Cardiac Dysrhythmias Electrocardiogram ● Electrical Conduction System: With specialized muscle cells is necessary for the cardiac action potential that generates a heartbeat and thus cardiac output Waveforms ● P Wave: SA node sending out an electrical impulse and represents atrial depolarization ● PR Interval: Movement of electrical activity from atria to ventricles ● QRS Complex: Ventricular depolarization/contraction ● T Wave: Ventricular repolarization/rest (Helpful in monitoring electrolyte imbalances such as hypo/hyperkalemia) ● U Wave: Purkinje fibers repolarize and is rarely seen (Digoxin toxicity, hypokalemia) Sinus Bradycardia (Picture = 4 QRS → 40 BPM) ● Sinus rhythm with rate 60 BPM and a regular rate ● Causes: Hypoxia, hypothermia, normal rate in athletes (Nonsymptomatic) ● Symptomatic: Syncope, angina, hypotension, SOB, diaphoresis ● Treatment: Atropine IV push, pacemaker Sinus Tachycardia (Picture = 12.5 QRS → 125 BPM) ● Sinus rhythm with rate 100 BPM and a regular rate ● Causes: Fever, anemia, hypovolemia, hypotension, alcoholism, HTN, PE, MI ● Treatment: Treat cause (RBCs, IV fluids), beta blockers, calcium channel blockers Premature Atrial Contractions (PACs) ● Usually non-life threatening, can be seen in normal sinus rhythm ● Pacemaker close to SA node fires earlier than expected = Irregular rate ● Causes: Hypoxia, excessive stimulant ingestion, infection, CAD, Digoxin toxicity ● Treatment: Monitor frequency, look at causes/eliminate them to see if PACs resolve