Chapter 20 Treatment of Arrhythmia PDF

Chapter 20 Treatment of Arrhythmia Copyright © 2019 by Elsevier, Inc. All rights reserved.  Lesson 20.1 Treatment of Arrhythmia 1. Learn the terminology associated with arrhythmias. 2. List risk factors for arrhythmias. 3. Describe the types of arrhythmias. 4. List and...

Chapter 20 Treatment of Arrhythmia Copyright © 2019 by Elsevier, Inc. All rights reserved.  Lesson 20.1 Treatment of Arrhythmia 1. Learn the terminology associated with arrhythmias. 2. List risk factors for arrhythmias. 3. Describe the types of arrhythmias. 4. List and categorize medications used to treat arrhythmias. 5. Describe mechanism of action for each class of drugs used to treat arrhythmias. 6. Identify significant drug look-alike/sound-alike issues. 7. Identify warning labels and precautionary messages associated with medications used to treat arrhythmias. Copyright © 2019 by Elsevier, Inc. All rights reserved. 2  Key Terms  Review Chapter Key Terms Copyright © 2019 by Elsevier, Inc. All rights reserved. 3  Arrythmia  Normally HR -between 60 and 100 beats/min or approximately 100,000 beats/day.  Blood is pumped throughout the body, supplying oxygen and nutrients to cells and organs, including the heart.  Arrhythmia -an irregular heart rhythm or a heart rate that is too rapid or too slow. Exceed 600 beats/min Copyright © 2019 by Elsevier, Inc. All rights reserved. 4  Heart rhythm Depolarization- Sodium and Calcium enter the heart Cause firing of the cells leading to contractions Repolarization Cells return to their resting state Refractory period The time for repolarization, following which depolarization occurs Copyright © 2019 by Elsevier, Inc. All rights reserved. 5  Arrythmia formation  Cardiac ion exchange channels function improperly: Excessive firing Extra currents in refractory period Establishment of sinus rhythm by non-pacemaker cells  Arrhythmias may stimulate formation of more arrythmias Copyright © 2019 by Elsevier, Inc. All rights reserved. 6  Symptoms of Arrythmia  Palpitations or fluttering in the chest  Rapid, irregular heart rate  Sweating or nausea  Chest pain  Shortness of breath  Light-headedness or dizziness  Fainting Copyright © 2019 by Elsevier, Inc. All rights reserved. 7  Types of Arrhythmias  Atrial flutter: Heart rate of 160 to 350 beats per minute More contractions in atrium than in ventricle Usually occurs in the right atrium Treated by inserting a catheter into the atrium (catheter ablation) rather than by drug therapy. Normal Heart rhythm Copyright © 2019 by Elsevier, Inc. All rights reserved. 8  Types of Arrhythmias  Atrial fibrillation: Rapid, uncoordinated contractions of atria Most common arrhythmia; not usually life threatening Heart rate of 300 to 400 beats per minute Temporary, recurrent (paroxsysmal), persistent (>7 days), and permanent (>1 year). Normal Heart rhythm Copyright © 2019 by Elsevier, Inc. All rights reserved. 9  Types of Arrhythmias  Supraventricular tachycardia: In regions above the ventricles Heart rate up to 200 beats per minute Intermittently (paroxysmal) or frequently Normal Heart rhythm Supraventricular tachycardia Copyright © 2019 by Elsevier, Inc. All rights reserved. 10  Types of Arrhythmias  Ventricular tachycardia: Ventricles beat faster than 200 beats per minute May occur when the spread of electrical impulses between heart chambers is “short-circuited” across scar tissue caused by a heart attack. Normal Heart rhythm Copyright © 2019 by Elsevier, Inc. All rights reserved. 11  Types of Arrhythmias  Ventricular fibrillation: Ventricles beat faster than 600 beats per minute Life threatening: Ventricles unable to fill with blood Blood cannot be pumped throughout body Reversed only after electrical cardioversion  process of applying an electrical shock to the heart with a defibrillator to return the heart to a normal rhythm. Normal Heart rhythm Copyright © 2019 by Elsevier, Inc. All rights reserved. 12 Poll question 1 Copyright © 2019 by Elsevier, Inc. All rights reserved. 13  Overview (1 of 2)  Nonmodifiable risk factors: Age, gender, low heart rate, emotional stress  Modifiable risk factors: Obesity, smoking, excessive alcohol consumption, stimulant use Copyright © 2019 by Elsevier, Inc. All rights reserved. 14  Overview (2 of 2)  Diseases as risk factors: Hypertension Heart failure CHD Stroke Infection Diabetes Thyroid disease Obstructive sleep apnea Copyright © 2019 by Elsevier, Inc. All rights reserved. 15 Poll question 2 Copyright © 2019 by Elsevier, Inc. All rights reserved. 16  Treatment of Arrhythmia  Antiarrhythmic drugs are used to treat irregular heart rhythms and rate. Their use is declining  Antiarrhythmic drugs are categorized into four classes (classes I, II, III, and IV) according to their mechanisms of action and structural similarities. Class 1 are further subdivided into 1A, 1B and 1C Copyright © 2019 by Elsevier, Inc. All rights reserved. 17  Mechanism of Action  Class I, Na+ channel blockers: Slow rate of depolarization Reduce automaticity Delay conduction Prolong time between contractions Copyright © 2019 by Elsevier, Inc. All rights reserved. 18  Mechanism of Action  Class II, beta blockers: Block stimulation of the atrioventricular (AV) and sinoatrial (SA) nodes Increase the refractory period Decrease automaticity Slow conduction velocity Copyright © 2019 by Elsevier, Inc. All rights reserved. 19  Mechanism of Action  Class III, K+ channel blockers: Prolong depolarization and refractory period Suppresses both supraventricular and ventricular arrhythmia (amiodarone)  Class IV, Ca2+ channel blockers: Treat supraventricular arrhythmias, atrial fibrillation, and atrial flutter Copyright © 2019 by Elsevier, Inc. All rights reserved. 20 Summary of Antiarrhythmic drugs 21  Adverse effects of antiarrhythmic agents  Bradycardia  Hypotension  Dizziness  Nausea and vomiting  Diarrhea or constipation Copyright © 2019 by Elsevier, Inc. All rights reserved. 22  Treatment of Arrhythmia  Cardioglycoside (digoxin)  Angiotensin-converting enzyme inhibitors (ACEIs)  Angiotensin II type 1 receptor blockers (ARBs) Copyright © 2019 by Elsevier, Inc. All rights reserved. 23  Mechanism of Action  Cardioglycoside (digoxin): Slows conduction velocity and prolongs the refractory period  ACEIs and ARBs: Lengthen refractory period and shorten conduction time Decrease dilation of coronary arteries and reduce blood pressure Reduce inflammation and structural changes in atria (ARBs) Copyright © 2019 by Elsevier, Inc. All rights reserved. 24  Look-Alike/Sound-Alike Drugs  Procan SR and Proscar  Procardia and Provera  Quinidine and quinine Copyright © 2019 by Elsevier, Inc. All rights reserved. 25 Drug Used to Prevent Arrhythmias  Angiotensin-converting enzyme inhibitors (ACEIs)  Angiotensin II type 1 receptor blockers (ARBs)  Drugs used to treat hypertension Hypertension doubles the risk for A Fib Copyright © 2019 by Elsevier, Inc. All rights reserved. 26 Poll question 3 Copyright © 2019 by Elsevier, Inc. All rights reserved. 27  Prevention of stroke  Afib is a risk factor for stroke Poll question 4  Medications used to prevent stroke in patients with A Fib Anticoagulants Copyright © 2019 by Elsevier, Inc. All rights reserved. 28  Look-Alike/Sound-Alike Drugs ( 1 of 2)  Acebutolol and albuterol  Esmolol and Osmitrol  Brevibloc and Brevital  Propranolol and Pravachol  Inderal, Adderall, Isordil, and Toradol Copyright © 2019 by Elsevier, Inc. All rights reserved. 29  Look-Alike/Sound-Alike Drugs ( 2 of 2)  Amiodarone, amantadine, and trazodone  Cordarone, Cardura, and Coumadin  Betapace AF and Betapace  Verapamil and Verelan  Calan SR and Calan Copyright © 2019 by Elsevier, Inc. All rights reserved. 30  Warning Labels: Class I Antiarrhythmics  May cause dizziness or drowsiness (Ia and Ib)  Swallow whole; don’t crush or chew (Ia and Ic)  Take on an empty stomach (Ia and Ic)  Avoid grapefruit juice (quinidine and Ic)  Refrigerate; do not freeze (Ia)  Take with food (Ib)  Don’t skip or exceed dose (Ic)  Wear sunglasses (propafenone) Copyright © 2019 by Elsevier, Inc. All rights reserved. 31  Warning Labels: Class II Antiarrhythmics  May cause dizziness or drowsiness  Concentrate; must be diluted (esmolol)  Swallow whole; don’t crush or chew (extended release)  Don’t skip doses Copyright © 2019 by Elsevier, Inc. All rights reserved. 32  Warning Labels: Class III Antiarrhythmics  Avoid prolonged exposure to sunlight (amiodarone)  May cause dizziness or drowsiness  Avoid grapefruit juice (amiodarone, dofetilide)  Should not be administered during pregnancy (ibutilide)  Avoid salt substitutes (sotalol)  Take on an empty stomach (sotalol)  Protect from moisture (dofetilide) Copyright © 2019 by Elsevier, Inc. All rights reserved. 33  Warning Labels: Class IV Antiarrhythmics  Take with food  Swallow whole; don’t crush or chew (extended release) Copyright © 2019 by Elsevier, Inc. All rights reserved. 34  Questions? Copyright © 2019 by Elsevier, Inc. All rights reserved.