Drugs Used to Treat Dysrhythmias Chapter 24 Drugs Used to Treat Dysrhythmias Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Chapter 24 Lesson 24.1 Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Objectives Describe the anatomic structures and conduction systems of the heart Differentiate the common dysrhythmias Describe the therapeutic response that should be observable when an antidysrhythmic drug is administered Identify baseline nursing assessments that should be implemented during the treatment of dysrhythmias Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Dysrhythmias (cont’d) Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Dysrhythmias (cont’d) Stress, ischemia, heart failure can cause irregular muscular contraction Normal conduction pathway could be partially obstructed, causing an irregular flow of electrical impulses, resulting in an irregular pattern of muscle contractions Electrical impulses are conducted by sodium, calcium, and potassium ions. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Classification of Dysrhythmias Supraventricular Develop above the bundle of His Atrial flutter, atrial fibrillation Premature atrial contractions Sinus tachycardia, sinus bradycardia Paroxysmal supraventricular tachycardia Ventricular Develop below the bundle of His Premature ventricular contractions Ventricular tachycardia Ventricular fibrillation Dysrhythmias can be the result of blocked pathways and are classified by degree of block. First degree is partial block with delayed response, second degree is occasional blockage, and third degree is complete block. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

EKG Strips (V-Fib, & V-Tach) Mosby items and derived items © 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Assessment of Patients with Dysrhythmias Initially monitor with ECG Past medication history Presence of six cardinal signs of cardiovascular disease Basic mental status Baseline vital signs Blood pressure, pulse, respirations, temperature, oxygen saturation Auscultation and percussion of heart and lung sounds Laboratory tests: electrolytes, blood gases Six cardinal signs of cardiovascular disease: dyspnea, chest pain, fatigue, edema, syncope, palpitations. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Drug Therapy for Dysrhythmias Class I: myocardial depressant inhibits sodium ion movement Class Ia agents – prolong duration of electrical stimulation Class Ib agents – shorten duration of electrical stimulation Class Ic agents – potent myocardial depressants, slow conduction rate Class II: beta-adrenergic blocking agents Class III: slow rate of electrical conduction Class IV: block calcium ion flow Antidysrhythmic agents classified according to effects on the heart’s electrical conduction system. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Chapter 24 Lesson 24.2 Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Objectives Cite common adverse effects that may be observed with the administration of amiodarone, sotalol, diltiazem, verapamil, lidocaine, and quinidine List the dosage forms and precautions needed when preparing IV amiodarone for the treatment of dysrhythmias Identify the potential effects of muscle relaxants used during surgical intervention when combined with antidysrhythmic drugs Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Drug Class: Class Ia Antidysrhythmic Agents Actions Prolong the duration of electrical stimulation Uses Treat atrial fibrillation, Wolff-Parkinson-White syndrome, paroxysmal supraventricular tachycardia, premature ventricular tachycardia, ventricular tachycardia Common adverse effects Dry mouth, nose, throat Serious adverse effects Myocardial toxicity, urinary hesitancy, constipation with distension and flatus For specific drugs, see Table 24-1. Therapeutic outcomes: conversion of dysrhythmia to normal sinus. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Drug Class: Class Ib Antidysrhythmic Agents Drug: IV lidocaine (Xylocaine) Actions: shorten the duration of electrical stimulation Uses: treat premature ventricular contractions, ventricular tachycardia, ventricular fibrillation Common adverse effects Lightheadedness, muscle twitching, hallucinations, agitation, euphoria; respiratory depression Serious adverse effects Dysrhythmias, neurotoxicity, seizures, confusion For specific drugs, see Table 24-1. Lidocaine used for dysrhythmias is different from lidocaine used for local anesthesia; the label must read “Lidocaine for Dysrhythmia.” Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Drug Class: Class Ic Antidysrhythmic Agents Actions: potent myocardial depressants, slow conduction rate Uses: treat ventricular tachycardias, supraventricular tachyarrhythmia, frequent premature ventricular contractions Common adverse effects Dizziness, lightheadedness, faintness, unsteadiness, blurred vision, headaches, constipation, nausea Serious adverse effects Visual disturbances, increasing dyspnea, exercise intolerance edema, dysrhythmias For specific drugs, see Table 24-1. Propafenone recommended for treatment of paroxysmal atrial fibrillation and life-threatening ventricular dysrhythmias. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Drug Class: Class II Antidysrhythmic Agents (Beta Blockers) Drugs: esmolol (Brevibloc), metoprolol (Lopressor), Toprol) Actions Inhibit cardiac response to sympathetic nerve stimulation to reduce heart rate, systolic blood pressure, cardiac output Uses Treat ventricular dysrhythmias, sinus tachycardia, paroxysmal supraventicular tachycardia, premature ventricular contractions, tachycardia-associated atrial fibrillation or flutter See Chapter 13 for further discussion For specific drugs, see Table 24-1. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Drug Class: Class III Antidysrhythmic Agents Drugs: amiodarone hydrochloride (Cordarone, Pacerone) Actions Prolong the action potential of atrial and ventricular tissue by increasing the refractory period Uses Treat life-threatening supraventricular tachycardia, atrial fibrillation, atrial flutter Serious adverse effects Fatigue, tremors, involuntary movements, sleep disturbances, numbness and tingling, dizziness, ataxia, and confusion, thyroid disorders, hepatotoxicity, dysrhythmias For specific drugs, see Table 24-1. Successful in treating many dysrhythmias where other antidysrhythmics fail but have many adverse effects, some of which are severe and potentially fatal. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Drug Class: Class IV Antidysrhythmic Agents (Calcium Channel Blockers, dipine’s) Drugs Verapamil (Calan, Isoptin), diltiazem (Cardizem) Actions Slow AV conduction, prolong refractoriness, decrease automaticity Uses Treat automatic and re-entrant tachycardias See Chapter 23 for further discussion Contraindicated in heart failure patients. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Miscellaneous Antidysrhythmic Agents Drug: adenosine (Adenocard) Actions Naturally occurring chemical in the body; strong depressant effects on the SA and AV nodes Uses Convert supraventricular tachycardia to normal sinus rhythm Common adverse effects Flushing of the face, shortness of breath, chest pressure, nausea, headache Administered as a rapid IV bolus. Variety of physiologic effects: promotes prostaglandin release, inhibits platelet aggregation, has antiadrenergic effects, suppresses heart rate, and dilates coronary arteries. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Miscellaneous Antidysrhythmic Agents (cont’d) Drug: digoxin (Lanoxin) Actions Slow conduction through the AV node, reducing conduction velocity and automaticity; increase cardiac output Uses Treat atrial fibrillation, atrial flutter, paroxysmal tachycardia See Chapter 28 for further information Don’t for get to check apical pulse for one full minute when pt is on this medication!!!!! Slide 19 Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. 19