Cardiac Drugs and Heart Failure Overview Unit 6.1

Cardiac Drugs

• Types: Cardiac Glycosides, Antianginals, Antidysrhythmics

Heart Failure

• Acute heart failure: Heart muscle weakens and enlarges, losing ability to pump blood adequately; compensatory mechanisms fail, leading to congested lungs and periphery.
• Right-sided: Blood backs up in the periphery
• Left-sided: Blood backs up in the lungs

Heart Failure - Nonpharmacological Treatment

• Limit salt and saturated fat intake
• Limit or avoid alcohol; stop smoking
• Perform mild exercise

Cardiac Glycosides - Digoxin

• Uses: Heart failure (CHF), atrial arrhythmias
• Actions: Inhibits sodium-potassium ATPase, positive inotropic (increases myocardial contractility, increases stroke volume and cardiac output, increases blood flow), decreases preload, negative chronotropic (decreases heart rate), negative dromotropic (decreases conduction of heart cells)
• Side effects: Dizziness, weakness, headache
• Adverse reactions: Digoxin toxicity (anorexia, nausea, vomiting, diarrhea, blurred vision, green or yellow halos, bradycardia, premature ventricular contractions, cardiac dysrhythmias)
• Drug interactions: Diuretics (hypokalemia), Cortisone (sodium retention, potassium release), Antacids (decrease digitalis absorption)
• Contraindications: Ventricular dysrhythmias, bradycardia, hypokalemia, renal disease

Nursing Process - Digoxin

• Assessment: Baseline pulse rate (apical pulse), medical/medication history, electrolytes, signs and symptoms of heart failure/atrial arrhythmia/edema/lung sounds, assess for digitalis toxicity.
• Nursing interventions: Monitor serum digoxin level (0.5-2 ng/mL, toxic over 2.2 ng/mL), monitor serum potassium level and report if hypokalemia, monitor edema/CHF signs and symptoms, obtain pulse.
• Teaching: Take drug same time daily, take pulse, notify HCP if pulse <60 or >100, report signs of digoxin toxicity, potassium supplements if taking diuretics

Angina

• Classic (stable): Predictable pain occurring with exertion or stress.
• Unstable (preinfarction): Unpredictable, progressive pain unrelated to activity.
• Variant (Prinzmetal, vasospastic): Occurs during rest.

Nitroglycerin

• Action: Promotes vasodilation, decreasing preload and afterload.
• Acute anginal pain: Sublingual (1-3 minutes, ~30 min duration), aerosol spray, IV.
• Prevention: Topical ointment, transdermal patch, oral extended-release capsule/tablet.
• Side effects: Headache, flushing, dizziness, weakness, syncope
• Adverse Reactions: Hypotension
• Contraindications: Increased intracranial pressure, severe hypotension
• Interactions: Other antihypertensive meds, other vasodilators, alcohol.
• Do not abruptly discontinue.

Beta Blockers

• Action: Blocks epinephrine and norepinephrine, decreasing workload of the heart and oxygen demands.
• Side effects: Dizziness, depression, fatigue, sexual dysfunction, peripheral edema.
• Adverse reactions: Bronchospasms, bradycardia, hypotension
• Caution: Do not abruptly discontinue.

Calcium Channel Blockers

• Action: Relax coronary arteries, decrease coronary artery spasm, reduce cardiac workload and oxygen demands.
• Side effects: Dizziness, flushing, headache, peripheral edema, fatigue.
• Adverse reactions: Hypotension, bradycardia

Nursing Process - Antianginal Drugs

• Assessment: Baseline vital signs, medication/medical history, pain level for acute episode, history of angina attacks.
• Nursing interventions: Monitor vital signs, position client sitting or lying down initially, use gloves for topical application, administer SL nitroglycerin for chest pain (every 5 minutes x 3), monitor effects of fast-acting nitro (SL & IV), avoid light.
• Teaching: Sit and rest during attacks, take nitro, call 911 if pain does not improve or worsens, demonstrate SL administration, medication storage, site rotation for topical application, acetaminophen for headache, do not stop beta blockers or calcium channel blockers abruptly, monitor heart rate and blood pressure, notify HCP with persistent dizziness or faintness.

Antidysrhythmic Drugs

• Beta-adrenergic blockers (beta-blockers): Block epinephrine and norepinephrine, reduce calcium entry, decrease conduction velocity, automaticity, and recovery time.
• Calcium channel blockers: Block calcium influx, decrease myocardial contractility, slow conduction velocity. Increase refraction in atrioventricular node
• K channel blockers (amiodarone): prolong repolarization, prolong action potential duration.
• Antidysrhythmic Drugs - Examples: Acebutolol, Diltiazem, Amiodarone

Nursing Process - Antidysrhythmic Drugs

• Assessment: Obtain baseline vital signs and ECG for comparison, medical/medication history, palpitations, apical pulse compared to radial pulse, cardiac enzymes (if ordered).
• Nursing interventions: Monitor vital signs, monitor lung sounds, IV administration should be slow, monitor ECG for abnormal patterns, monitor client on cardiac monitor.
• Teaching: Monitor blood pressure and pulse, take drugs as prescribed, do not stop medications abruptly, report side effects to healthcare provider, advise about avoiding alcohol, caffeine, and tobacco, and teach to get up slowly.

Practice Questions & Answers

• Multiple practice questions on various cardiac medications are provided, along with the correct answers, and explanations. (These questions cover Digoxin, Nitroglycerin, Beta Blockers, Calcium Channel blockers. and Antidysrhythmic drugs)