AV Conduction Blocks, First-Degree Block, Second-Degree Type I (Wenckebach), Second-Degree Type II (Mobitz II), Third-Degree Heart Block, PR Interval Changes, Bradycardia, Decreased Cardiac Output, Myocardial Infarction Etiology, Drug Toxicity, Pacemaker

AV Conduction Blocks, First-Degree Block, Second-Degree Type I (Wenckebach), Second-Degree Type II (Mobitz II), Third-Degree Heart Block, PR Interval Changes, Bradycardia, Decreased Cardiac Output, Myocardial Infarction Etiology, Drug Toxicity, Pacemaker Therapy, Temporary Pacing, Permanent Pacemaker, Transvenous Pacing, Transcutaneous Pacing, Implantable Cardioverter-Defibrillator (ICD), Cardiac Resynchronization Therapy (CRT), Synchronized Cardioversion, Defibrillation, Ventricular Tachycardia, Ventricular Fibrillation, Failure to Capture, Failure to Sense, Electrical Countershock, Dysrhythmia Management Exam Questions Verified and Complete A+ Graded Rationales Latest Updated 2026 What is a block? Conduction defects that delay or block transmission of the sinus impulse through the AV node are called AV conduction blocks. What is a 1st degree AV block? Conduction between the atrium & ventricles is prolonged What is the PR interval for a 1st degree block? 0.20 What are the signs & symptoms of a 1st degree block? Benign conduction delay that generally poses no threat, no symptoms, & requires no treatment. Assess current medications. What is a 2nd degree AV block type 1? Repeating pattern of increasing AV conduction delays until an impulse fails to conduct to the ventricles (More P than QRS) What causes 2nd degree AV block type 1? (2) - MI - Drug intoxication What medication is given for 2nd degree AV block type 1? Atropine may be used for slow rates if client is symptomatic Does 2nd degree block type 1 progress to a complete heart block? Rarely What does a 2nd degree block type 1 ECG look like? - Rhythm: irregular - More P than QRS - PR interval elongates What is 2nd degree block type 2? multiple P waves; AV node refuses to allow impulses through; Numerous QRS's are blocked; usually bradycardic; can evolve to 3rd degree What are present PR intervals in 2nd degree block type 2? Constant What is the pathophysiology for 2nd degree block type 2? Intermittent failure of the AV node to conduct an impulse to the ventricles without delays in conduction. What are the causes for 2nd degree block type 2? - CAD - Drug toxicity - MI What are signs & symptoms of 2nd degree block type 2? Decreased CO How is 2nd degree block type 2 treated? Pacemaker What does a 2nd degree block type 2 ECG look like? - Rate: Arterial (60-100); Ventricular (60) - Rhythm: regular or irregular - More P than QRS - PR: constant What is a 3rd degree AV block? At