Cardiac, Pharmacology, and Cardiovascular Medication Notes

Cardiac and Vascular Prescription and Pharmacology medications

• Nursing roles and responsibilities, emphasizing patient education, medication administration, and continuous monitoring.

• Review of Anatomy and Physiology (AP), focusing on the cardiovascular system and its functions.

• Note: This particular PowerPoint may not be uploaded due to the AP review and potential copyright issues.

• Active participation is encouraged to facilitate a more effective learning process; questions are highly welcome.

Brief Review

• Preload: Volume of blood in ventricles at the end of diastole (end diastolic pressure). It is the initial stretching of the cardiac myocytes prior to contraction. Related to venous return to the heart.

• Afterload: Resistance the left ventricle must overcome to circulate blood. Increased in hypertension and vasoconstriction.

• Blood flow throughout the heart includes deoxygenated blood being oxygenated in the lungs.

• The left ventricle pumps oxygenated blood out of the heart into the aorta and then to the rest of the body.

• Veins carry deoxygenated blood back to the heart under low pressure; valves prevent backflow.

Heart as a Pump

• Comparing the heart’s function to a pump that pushes fluid out to a system.

• The sinus node, or sinoatrial (SA) node, is the heart's natural pacemaker. It generates electrical impulses, setting the rhythm and rate of the heart.

Heart as an Engine

• The heart's function can be analogized to a car engine, where each component has a specific function to ensure the car runs smoothly.

• Oil (Blood): Lubricates and cleans engine parts, preventing friction and overheating, similar to how blood provides oxygen and nutrients while removing waste.

• Kidneys: Act as oil filters, removing waste products and excess fluids from the blood.

• Spark Plug (Sinus Node): Creates the electrical current to start the engine, initiating the combustion process, which is analogous to the sinus node initiating the heart's contraction.

• When the engine stops, pumping stops, leading to system failure and death, reflecting the critical interdependence of the heart and other organ systems.

Cardiac Output

• Cardiac output (CO) is the volume of blood pumped by the heart per minute, measured in liters per minute (L/min).

• The body increases cardiac output by increasing stroke volume (the amount of blood ejected per beat) and heart rate. Blood pressure also affects cardiac output.

• Cardiac output is crucial for transporting oxygen, nutrients, and hormones to cells and removing metabolic waste products from tissues.

Blood Pressure

• Blood pressure (BP) is the force exerted by circulating blood on the walls of blood vessels.

• Normal blood pressure: 120/80 mmHg

• Systolic: The top number represents the pressure during ventricular contraction (systole), when blood is ejected into the arteries.

• Diastolic: The bottom number represents the pressure when the heart muscle relaxes between beats (diastole), allowing the heart to fill with blood.

Balance (Homeostasis)

• The brain, heart, and kidneys must be balanced to maintain physiological equilibrium.

• If there is an imbalance, the brain initiates corrective actions, possibly including medication, lifestyle changes, or other interventions.

• The goal is to maintain internal stability and optimal function through multiple regulatory mechanisms.

Heart and Kidney Connection

• If the heart fails, the kidney experiences poor perfusion and reduced filtration, leading to waste retention, fluid overload, and electrolyte imbalances.

• If the kidneys fail, toxins accumulate, increasing blood pressure, causing strain on the heart, and exacerbating cardiovascular problems.

• The kidneys receive 25% of cardiac output to filter waste, control blood pressure, and maintain fluid and electrolyte balance.

Factors Affecting Heart Function and Electrical Activity

• Electrolytes (K, Na, Ca, Mg), habits (smoking, alcohol), hormones (thyroid), and stress significantly impact heart function. Lifestyle choices strongly influence heart health.

• Assess patients holistically without judgment, considering the totality of their lifestyle, genetic predispositions, and environmental factors.

• Poor lifestyle choices (e.g., obesity, smoking) can lead to hypertension, tachycardia, arrhythmias, and diabetes, significantly raising the risk of heart disease.

Medications Affecting the Kidneys

• ACE inhibitors and ARBs lower blood pressure and decrease kidney resistance but can reduce kidney filtration rate; monitor renal function.

• If pressure drops too low, potassium can accumulate, resulting in hyperkalemia; monitor potassium levels.

Tricks to remember medications

• Acronym for cardiac meds: A Dark Pink Ball Beat To The Coach And Dove Into The Dark Thick Mud.

  • ACE inhibitors typically end with "-pril". (e.g., Lisinopril)

  • Beta blockers typically end in "-lol". (e.g., Metoprolol)

  • Calcium channel blockers typically end in "-pine". (e.g., Amlodipine)

  • Digoxin is digoxin.

  • Diuretics are either a thiazide or end in "-mide". (e.g., Furosemide, Hydrochlorothiazide)

Heart Failure

• Heart failure (HF) is a chronic condition where the heart cannot pump enough blood to meet the body’s demands for oxygen and nutrients.

• There is no cure, but symptoms and disease progression can be managed with medications, lifestyle modifications, and, in some cases, medical devices or surgery.

• Common Symptoms: shortness of breath, fatigue, poor memory, persistent cough, swollen ankles, and consistently cold feet.

• Poor memory occurs because the brain does not receive enough oxygenated blood; cold feet result from poor peripheral circulation.

Hypertension

• Hypertension is defined as high blood pressure, typically a reading of 130/80 mmHg or higher.

• Normal blood pressure is ideally around 120/80 mmHg.

• Untreated hypertension can lead to severe complications, including heart failure, kidney damage, stroke, and heart attack.

• Common medications for managing hypertension include diuretics, ACE inhibitors (""), beta blockers (""), and calcium channel blockers ("").

ACE Inhibitors

• Examples: Lisinopril, Enalapril.

• Mechanism of action: ACE inhibitors block the angiotensin-converting enzyme, preventing the formation of angiotensin II, which reduces sodium and water retention, leading to decreased blood pressure.

• Monitor: sodium (Na) and potassium (K) levels, and renal function (BUN, creatinine) regularly.

• Used to treat: hypertension, CHF, and diabetic nephropathy.

• Adverse reactions/side effects: angioedema (swollen tongue), hyperkalemia, persistent dry cough, and bronchospasms.

Angiotensin Receptor Blockers (ARBs)

• Mechanism of action: ARBs selectively block angiotensin II receptors, leading to vasodilation and increased sodium and water excretion.

• Key takeaway: ARBs reduce blood pressure without significantly affecting heart rate.

• Monitor: potassium levels (risk of hyperkalemia) and renal function.

• Adverse reactions: hyperkalemia, hypotension, and dizziness.

Beta Blockers

• Mechanism of action: Beta blockers block beta-1 adrenergic receptors in the heart, reducing heart rate and blood pressure, which decreases cardiac output and myocardial oxygen demand.

• Monitor: heart rate (risk of bradycardia and arrhythmias) and renal function.

• Adverse reactions: hypotension, bradycardia (heart rate 60), bronchospasm, fatigue, and dizziness.

Nursing Considerations when using Beta Blockers

• Check heart rate and blood pressure before administering beta blockers.

• Hold the medication and notify the physician if the heart rate is below 60 bpm or if systolic blood pressure is less than 100 mmHg.

Calcium Channel Blockers

• Suffix: "-pine" (e.g., Amlodipine).

• Mechanism of action: Calcium channel blockers slow down electrical conduction in the heart, vasodilate blood vessels, and relax smooth muscle, reducing the heart’s workload and lowering blood pressure.

• Monitor: blood pressure, pulse rate, and level of consciousness (LOC).

• Side effects: hypotension, dizziness, headache, and chest pain.

Nursing considerations when using Calcium Channel Blockers

• Monitor apical heart rate and peripheral pulses regularly.

• Do not give to patients with acute MI, second/third-degree heart block, or severe hypotension.

• Calcium channel blockers calm the heart (CDC).

Digoxin

• Action: Digoxin increases myocardial contractility, slows heart rate, and improves cardiac efficiency without necessarily prolonging survival in CHF patients; it primarily manages symptoms.

• Narrow therapeutic range: 0.5 to 2.0 ng/mL; levels above this increase the risk of toxicity.

• Used to treat heart failure and atrial fibrillation.

Nursing Considerations when using Digoxin

• Apical pulse rate should be assessed for a full minute before administering digoxin.

• Monitor serum digoxin and potassium levels (normal K: 3.5-5.0 mEq/L); hypokalemia increases the risk of digoxin toxicity.

• Do not administer if pulse rate is less than 60 bpm.

• Signs of digoxin toxicity: nausea, vomiting, seeing halos around lights, altered mental status, and arrhythmias.

Edema

• Edema is the accumulation of excessive fluid in body tissues, typically caused by imbalances in fluid regulation.

Diuretics

• Medications of choice for managing fluid overload and edema by increasing urine production and eliminating excess fluid from the body.

• Lasix (furosemide): loop diuretic, depletes potassium; used to treat pulmonary edema. Monitor potassium levels and watch for signs of hypokalemia.

• Spironolactone: potassium-sparing diuretic; risk for hyperkalemia. Avoid potassium supplements and monitor potassium levels closely.

• Hydrochlorothiazide: thiazide diuretic; risk for sodium, potassium, and magnesium depletion. Monitor electrolytes.

• Mannitol: osmotic diuretic, used cautiously for reducing intracranial pressure and promoting diuresis in acute renal failure.

Monitoring Diuretics

• Kidney function (creatinine, BUN), monitor for dehydration (dry mouth, thirst, headache), and monitor electrolyte balance (K, Na). Report any abnormalities to the healthcare provider.

Nursing Considerations when using Diuretics

• Administer diuretics in the morning to prevent nocturia and sleep disruption.

• Use cautiously in geriatric populations due to increased risk of renal impairment and electrolyte imbalances.

• Watch for electrolyte depletion; Canada Dry Can Make Change (K, Na, Ca, Mg). Encourage a balanced diet and electrolyte supplementation as needed.

• Change positions carefully to avoid orthostatic hypotension and dizziness.

Hyperlipidemia

• Hyperlipidemia is a condition characterized by elevated levels of lipids (fats), especially cholesterol and triglycerides, in the blood, increasing the risk of atherosclerosis and cardiovascular disease.

Statins

• Examples: Atorvastatin, Simvastatin.

• Mechanism of action: Statins inhibit HMG-CoA reductase, an enzyme essential for cholesterol synthesis in the liver, reducing LDL cholesterol and increasing HDL cholesterol.

• Monitor: liver function tests (LFTs) and blood glucose (risk of hyperglycemia). Regular monitoring is essential to detect liver damage or elevated blood sugar levels.

• Adverse effects: rhabdomyolysis (muscle breakdown leading to tea-colored urine), myalgia, and liver damage.

Nursing Considerations when using statins

• Use cautiously in the elderly due to increased risk of falls and adverse effects.

• Do not use in patients with active hepatic disease or unexplained elevated liver enzymes.

• Contraindicated in pregnancy or breastfeeding due to potential harm to the fetus or infant.

• Avoid grapefruit juice, as it can increase statin levels and the risk of side effects.

• Monitor for muscle pain, tenderness, and weakness; report promptly to the healthcare provider.

Mnemonics for Lipids

• LDL: lousy cholesterol (increases risk of heart disease).

• HDL: helpful cholesterol (helps remove LDL from arteries).

• Triglycerides: too much tacos these days are the use calories and fats (excess calories converted to triglycerides).

Antiplatelets

• Examples: Aspirin, Clopidogrel. Antiplatelets prevent platelets from sticking together, reducing the risk of clot formation but increasing bleeding risk.

• Assess for bleeding risk (nosebleeds, GI bleeds, bruising). Monitor for signs of bleeding.

• Inspect stool for dark, tarry stool, which may indicate gastrointestinal bleeding.

Nursing Considerations when using antiplatelets

• Use a soft toothbrush and electric razor to minimize the risk of bleeding.

• Avoid contact sports and activities that could cause injury.

• Report falls or injuries immediately due to the increased risk of bleeding.

Anticoagulants

• Aspirin: prevents platelet clumping and reduces risk of heart attack, stroke, and other clots.

• Enoxaparin (Lovenox): a low-molecular-weight heparin, administered subcutaneously (SQ) in the abdomen; alternate injection sites to prevent skin irritation.

Heparin

• Heparin Flush: used to maintain the patency of intravenous (IV) lines by preventing blood from clotting inside the catheter.

• Subcutaneous Heparin: used for the treatment and prevention of deep vein thrombosis (DVT) and pulmonary embolism (PE).

• Heparin Bolus: an initial, higher dose of heparin administered intravenously (IV) before starting a continuous heparin infusion to achieve therapeutic anticoagulation rapidly.

• Key takeaway: the reversal agent for heparin is protamine sulfate.

• Monitor: activated partial thromboplastin time (aPTT).

  • The aPTT should be $1.5$ to $2.5$ times the normal value while on heparin.

    • Too low = clot risks

    • Too high = bleeding risks

Warfarin (Coumadin)

• Oral tablet.

• Advantage: less frequent lab monitoring compared to heparin, but regular monitoring is still required to ensure therapeutic levels.

• Key takeaway: monitor Prothrombin Time (PT) and International Normalized Ratio (INR), with a target range of $2.0$ to $3.5$ for most indications. The reversal agent is Vitamin K.

Extra Points Question

• A nurse is reviewing medication instructions with a client newly prescribed Eliquis for atrial fibrillation. Which of the following client statements indicates a need for further teaching?

• Answer: C. Herbal supplements may interfere with my bleeding. (Some herbal supplements can increase the risk of bleeding when taken with anticoagulants.)

Nurse Care Question

• A nurse is caring for a client who is prescribed digoxin for heart failure. Which of the following findings should the nurse report immediately?

• Answer: A. Heart rate, 58 bpm. (Bradycardia is a significant side effect of digoxin and can be a sign of toxicity.)