Cardiac Glycosides, Antianginals, and Antidysrhythmics Chapter 42 Cardiac Glycosides, Antianginals, and Antidysrhythmics Copyright © 2015, 2012, 2009, 2006, 2003, 2000, 1997, 1993 by Saunders, an imprint of Elsevier Inc.

Heart Failure Heart failure Pathophysiology Right-sided Left-sided Preload Afterload Right-sided Blood backs up in periphery Left-sided Blood backs up in lungs Copyright © 2015, 2012, 2009, 2006, 2003, 2000, 1997, 1993 by Saunders, an imprint of Elsevier Inc.

ACC/AHA Stages of Heart Failure Stages Characteristics 1 (A) High risk for HF without symptoms or structural disease 2 (B) Some levels of cardiac changes (e.g., decrease ejection fraction without symptoms of heart failure) 3 (C) Structural heart disease with symptoms of HF (e.g., fatigue, SOB, edema, decreased physical activity) 4 (D) Severe structural heart disease and marked symptoms of HF at rest Copyright © 2015, 2012, 2009, 2006, 2003, 2000, 1997, 1993 by Saunders, an imprint of Elsevier Inc.

Heart Failure (Cont.) Nonpharmacologic treatment Laboratory tests Limit salt intake. Limit or avoid alcohol intake. Stop smoking. Decrease saturated fat intake. Perform mild exercise as possible. Laboratory tests Atrial natriuretic peptide (ANP)–20 to 77 pg/mL; 20 to 77 ng/L (SI units) Brain natriuretic peptide (BNP)–Desired value: less than 100 pg/mL; positive value: greater than 100 pg/mL Copyright © 2015, 2012, 2009, 2006, 2003, 2000, 1997, 1993 by Saunders, an imprint of Elsevier Inc.

Cardiac Glycosides Digitalis preparations (digoxin) Actions Positive inotropic Increases myocardial contractility Negative chronotropic Decreases heart rate Negative dromotropic Decreases conduction Increase stroke volume Increases cardiac output Copyright © 2015, 2012, 2009, 2006, 2003, 2000, 1997, 1993 by Saunders, an imprint of Elsevier Inc.

Cardiac Glycosides (Cont.) Atrial fibrillation Atrial flutter Other drugs used if digoxin not effective: Calcium channel blocker: verapamil (Calan) Warfarin (Coumadin) Copyright © 2015, 2012, 2009, 2006, 2003, 2000, 1997, 1993 by Saunders, an imprint of Elsevier Inc.

Cardiac Glycosides (Cont.) Digoxin Drug interactions Diuretics Glucocorticoids Antacids Herbal interactions Hypokalemia Digitalis toxicity Anorexia, diarrhea, nausea and vomiting, bradycardia, premature ventricular contractions, cardiac dysrhythmias, headaches, malaise, blurred vision, visual illusions, confusion, and delirium Copyright © 2015, 2012, 2009, 2006, 2003, 2000, 1997, 1993 by Saunders, an imprint of Elsevier Inc.

Cardiac Glycosides (Cont.) Antidote for digitalis toxicity: digoxin immune Fab (ovine, Digibind) Treatment cardiotoxicity Phenytoin Lidocaine Copyright © 2015, 2012, 2009, 2006, 2003, 2000, 1997, 1993 by Saunders, an imprint of Elsevier Inc.

Nursing Process: Digoxin Assessment Nursing diagnoses Planning Nursing interventions Patient teaching Cultural considerations Evaluation Copyright © 2015, 2012, 2009, 2006, 2003, 2000, 1997, 1993 by Saunders, an imprint of Elsevier Inc.

Phosphodiesterase Inhibitors Milrinone lactate (Primacor) Positive inotrope Used to treat acute HF Action Increase stroke volume and cardiac output and promote vasodilation Caution: Administered IV for no longer than 48 to 72 hours to avoid severe cardiac dysrhythmias Copyright © 2015, 2012, 2009, 2006, 2003, 2000, 1997, 1993 by Saunders, an imprint of Elsevier Inc.

Other Agents Used to Treat Heart Failure Vasodilators Angiotensin-converting enzyme (ACE) inhibitors Angiotensin II receptor antagonists Diuretics (thiazides, furosemide), spironolactone (Aldactone) Some beta blockers Copyright © 2015, 2012, 2009, 2006, 2003, 2000, 1997, 1993 by Saunders, an imprint of Elsevier Inc.

Vasodilators Decrease venous blood return to the heart Decrease preload Decrease oxygen demand on the heart Arteriolar dilators Reduce cardiac afterload Improve renal perfusion Improve circulation to skeletal muscles Copyright © 2015, 2012, 2009, 2006, 2003, 2000, 1997, 1993 by Saunders, an imprint of Elsevier Inc.

ACE Inhibitors and ARBs Dilate venules and arterioles, improving renal blood flow and decreasing blood fluid volume Decrease release of aldosterone Angiotensin II receptor blocker (ARB) agents Valsartan (Diovan) and candesartan (Atacand) approved for HF in patients who cannot tolerate an ACE inhibitor. Copyright © 2015, 2012, 2009, 2006, 2003, 2000, 1997, 1993 by Saunders, an imprint of Elsevier Inc.

Diuretics First-line drug treatment for reducing fluid volume Spironolactone (Aldactone) Blocks production of aldosterone; improves heart rate variability; decreases myocardial fibrosis cardioprotective effect of blocking aldosterone in the heart and blood vessels to promote cardiac remodeling Copyright © 2015, 2012, 2009, 2006, 2003, 2000, 1997, 1993 by Saunders, an imprint of Elsevier Inc.

Beta Blockers Carvedilol (Coreg) Metoprolol tartrate (Toprol-XL) Bisoprolol (Zebeta) Doses should be low initially and gradually increased. Beneficial effect:1 to 3 months Copyright © 2015, 2012, 2009, 2006, 2003, 2000, 1997, 1993 by Saunders, an imprint of Elsevier Inc.

Atrial Natriuretic Peptide Nesiritide (Natrecor) Inhibits antidiuretic hormone (ADH) by increasing urine sodium loss Promotes vasodilation, natriuresis, and diuresis Used for treatment of acute decompensated HF with dyspnea at rest, dyspnea with little physical exertion Copyright © 2015, 2012, 2009, 2006, 2003, 2000, 1997, 1993 by Saunders, an imprint of Elsevier Inc.

BiDil Combination of hydralazine (for blood pressure) and isosorbide dinitrate (a dilator to relieve heart pain) FDA approval for treating HF, especially in African Americans Copyright © 2015, 2012, 2009, 2006, 2003, 2000, 1997, 1993 by Saunders, an imprint of Elsevier Inc.

Angina Classic (stable): Occurs with predictable stress or exertion Unstable (preinfarction): Occurs frequently with progressive severity unrelated to activity; unpredictable regarding stress/exertion and intensity Variant (Prinzmetal, vasospastic): Occurs during rest Copyright © 2015, 2012, 2009, 2006, 2003, 2000, 1997, 1993 by Saunders, an imprint of Elsevier Inc.

Types of Antianginal Drugs Nitrates: reduction of venous tone, decreased workload of the heart, vasodilation Beta blockers: decrease the workload of the heart and decrease oxygen demands Calcium channel blockers: decrease the workload of the heart and decrease oxygen demands Copyright © 2015, 2012, 2009, 2006, 2003, 2000, 1997, 1993 by Saunders, an imprint of Elsevier Inc.

Nitrates First agents used to relieve angina Action: Generalized vascular and coronary vasodilation Side effects and adverse reactions: Headache, hypotension, dizziness, weakness, and faintness Sublingual, topical (ointment, transdermal patch), buccal extended-release tablet, oral extended-release capsule and tablet, aerosol spray (inhalation), and IV Copyright © 2015, 2012, 2009, 2006, 2003, 2000, 1997, 1993 by Saunders, an imprint of Elsevier Inc.

Beta Blockers Block the action of the catecholamines (epinephrine and norepinephrine) Decrease heart rate and blood pressure Do not abruptly discontinue Selective beta blockers: atenolol (Tenormin), metoprolol (Lopressor, Toprol-XL) Copyright © 2015, 2012, 2009, 2006, 2003, 2000, 1997, 1993 by Saunders, an imprint of Elsevier Inc.

Calcium Channel Blockers Relax coronary artery spasm (variant angina) Relax peripheral arterioles (stable angina) Decrease cardiac oxygen demand Decrease cardiac contractility (negative inotropic effect that relaxes smooth muscle) Decrease afterload Decrease peripheral resistance Reduce the workload of the heart Copyright © 2015, 2012, 2009, 2006, 2003, 2000, 1997, 1993 by Saunders, an imprint of Elsevier Inc.

Antianginal Drugs Types of anginal pectoris with treatment Copyright © 2015, 2012, 2009, 2006, 2003, 2000, 1997, 1993 by Saunders, an imprint of Elsevier Inc.

Nursing Process: Antianginal Drugs Assessment Nursing diagnoses Planning Nursing interventions Patient teaching Evaluation Copyright © 2015, 2012, 2009, 2006, 2003, 2000, 1997, 1993 by Saunders, an imprint of Elsevier Inc.

Antidysrhythmic Drugs Dysrhythmia vs. arrhythmia Cardiac action potentials Phase 0 to phase 4 Copyright © 2015, 2012, 2009, 2006, 2003, 2000, 1997, 1993 by Saunders, an imprint of Elsevier Inc.

Antidysrhythmic Drugs (Cont.) Mechanism of drug action Class I Sodium channel blockers 1A: slow conduction, prolongs repolarization (quinidine, procainamide, disopyramide) 1B: slow conduction, shortens repolarization (lidocaine, mexiletine) 1C: prolonged conduction with little/no effect on repolarization (flecainide, propafenone) Copyright © 2015, 2012, 2009, 2006, 2003, 2000, 1997, 1993 by Saunders, an imprint of Elsevier Inc.

Antidysrhythmic Drugs (Cont.) Class II Beta-adrenergic blockers Reduce calcium entry, decrease conduction velocity, automaticity, and recovery time Propranolol (Inderal) Acebutolol (Sectral) Esmolol (Brevibloc) Sotalol (Betapace) Copyright © 2015, 2012, 2009, 2006, 2003, 2000, 1997, 1993 by Saunders, an imprint of Elsevier Inc.

Antidysrhythmic Drugs (Cont.) Class III Prolong repolarization Amiodarone (Cordarone) Class IV Block calcium influx (calcium channel blockers) Verapamil (Calan, Isoptin) Diltiazem (Cardizem) Copyright © 2015, 2012, 2009, 2006, 2003, 2000, 1997, 1993 by Saunders, an imprint of Elsevier Inc.

Nursing Process: Antidysrhythmics Assessment Nursing diagnoses Planning Nursing interventions Patient teaching Evaluation Copyright © 2015, 2012, 2009, 2006, 2003, 2000, 1997, 1993 by Saunders, an imprint of Elsevier Inc.

Practice Question #1 A patient has angina pectoris. The patient’s BP is 100/60 mm Hg. The nurse administers nitroglycerin 0.4 mg sublingual (SL). It is most important for the nurse to assess the patient for the development of bradycardia. hypotension. bradypenia. hypokalemia. Answer: B Rationale: A side effect of nitroglycerin is hypotension owing to the vasodilation of blood vessels. Copyright © 2015, 2012, 2009, 2006, 2003, 2000, 1997, 1993 by Saunders, an imprint of Elsevier Inc.

Practice Question #2 A nurse is administering digoxin, 0.125 mg, to a patient. Which nursing interventions will the nurse implement? (Select all that apply.) Checking the apical pulse rate before administration Monitoring the patient’s serum digoxin level Instructing patient to report pulse rate less than 60 Advising patient to avoid foods high in potassium Always giving an antacid with digoxin to reduce GI distress Answer: A, B, C Rationale: The apical pulse should be taken before digoxin administration and the drug withheld if the heart rate is less than 60. The patient’s serum digoxin level should be monitored and withheld if in toxic range. Therapeutic level is 0.5 to 2 ng/mL. Patient should be advised to eat foods high in potassium. Patient should be advised to avoid taking antacids with digoxin because they decrease absorption. Copyright © 2015, 2012, 2009, 2006, 2003, 2000, 1997, 1993 by Saunders, an imprint of Elsevier Inc.

Practice Question #3 A patient is ordered to receive digoxin (Lanoxin) to treat congestive heart failure. The nurse is most concerned about which assessment finding? Heart rate 56 beats/min BP 138/90 mm Hg RR 18 breaths/min 1+ pitting edema of the lower extremities Answer: A Rationale: A baseline pulse rate for the patient should be obtained for future comparisons. Apical pulse should be taken for a full minute and should be greater than 60 beats/min. The prescriber should be notified if the patient’s pulse is less than 60 beats per minute. Copyright © 2015, 2012, 2009, 2006, 2003, 2000, 1997, 1993 by Saunders, an imprint of Elsevier Inc.

Practice Question #4 A nurse is preparing to administer digoxin (Digitalis) to a patient. Which laboratory result is the nurse most concerned about? Sodium 138 mEq/L Potassium 3.0 mEq/L Digitalis level 1.8 ng/mL BNP 200 pg/mL Answer: B Rationale: A low serum potassium level enhances the action of digoxin and can cause digitalis toxicity. Copyright © 2015, 2012, 2009, 2006, 2003, 2000, 1997, 1993 by Saunders, an imprint of Elsevier Inc.

Practice Question #5 When administering antianginal drugs, the nurses identifies which as the most common response? Tachycardia Bradypnea Hypotension Dry mouth Answer: C Rationale: The most common side effect of antianginal drugs is hypotension. Copyright © 2015, 2012, 2009, 2006, 2003, 2000, 1997, 1993 by Saunders, an imprint of Elsevier Inc.

Practice Question #6 Which drug group is most effective for the treatment of variant (vasospastic) angina? Calcium channel blockers Beta blockers Cardiac glycosides Phosphodiesterase inhibitors Answer: A Rationale: Nitrates and calcium channel blockers are effective in treating variant (vasospastic) angina pectoris. Copyright © 2015, 2012, 2009, 2006, 2003, 2000, 1997, 1993 by Saunders, an imprint of Elsevier Inc.

Practice Question #7 The nurse should teach the patient to report which of the following to the health care provider immediately if experienced after taking nitroglycerin? Dizziness Faintness Headache Persistent pain Answer: D Rationale: Dizziness, faintness, and headache can occur when taking nitroglycerin. It is important to teach the patient about avoiding complications related to orthostatic hypotension. Persistent pain indicates the possibility of acute coronary syndrome. Copyright © 2015, 2012, 2009, 2006, 2003, 2000, 1997, 1993 by Saunders, an imprint of Elsevier Inc.

Practice Question #8 The nurse identifies which drug as a calcium channel blocker used for the treatment of dysrhythmias? Diltiazem (Cardizem) Esmolol (Brevibloc) Flecainide (Tambocor) Sotalol HCl (Betapace) Answer: A Rationale: Diltiazem (Cardizem) is a calcium channel blocker used to treat dysrhythmias. Esmolol (Brevibloc) is a beta blocker. Flecainide (Tambocor) is a sodium channel blocker. Sotalol HCl (Betapace) is a beta blocker. Copyright © 2015, 2012, 2009, 2006, 2003, 2000, 1997, 1993 by Saunders, an imprint of Elsevier Inc.

Practice Question #9 A patient with angina and a long history of severe chronic obstructive pulmonary disease is ordered beta blocker therapy. Which beta blocker would be most effective for this patient? Propranolol (Inderal) Nadolol (Corgard) Pindolol (Visken) Atenolol (Tenormin) Answer: D Rationale: Cardioselective beta blockers act more strongly on the beta1 receptor, which decreases the heart rate but avoids bronchoconstriction. Examples of selective beta blockers are atenolol (Tenormin) and metoprolol (Lopressor, Toprol-XL). Examples of nonselective beta blockers are propranolol (Inderal), nadolol (Corgard), and pindolol (Visken). These drugs decrease the heart rate and can cause bronchoconstriction. Copyright © 2015, 2012, 2009, 2006, 2003, 2000, 1997, 1993 by Saunders, an imprint of Elsevier Inc.