Cardiovascular Pharmacology Quiz

EHS 202 Pharmacology in EMS - Cardiac Drugs

• Course title: Pharmacology in EMS
• Course code: EHS 202
• Topic: Cardiac Drugs Part 1
• Date: 10/2/2024

Learning Objectives

• Students will be able to describe and understand the pharmacological management of patients with acute coronary syndromes.
• Students will be able to differentiate between antiplatelets, anticoagulants, and fibrinolytics.
• Students will be able to explain the pharmacological management of patients with cardiac arrhythmias.
• Students will be able to discuss and understand hypertension and associated complications, including those presenting with seizures.
• Students will be able to differentiate between percutaneous coronary intervention (PCI) and fibrinolytics.

Functional Components of the Heart

• Myocardium: Cardiac muscle fibers in four chambers (two atria and two ventricles).
• Conduction system: Specialized tissue conducting nerve impulses (SA node, AV node, bundle of His, bundle branches, and Purkinje fibers).
• Nerve supply: Branches from sympathetic and parasympathetic divisions regulating heart rate and contraction force.

Main Diseases of the Cardiovascular System

• Acute Coronary Syndrome (ACS)
• Congestive heart failure
• Cardiac arrhythmias
• Hypertension emergencies

Drug Review for Cardiac Emergencies

• Oxygen

• Nitroglycerin

• Aspirin

• Morphine sulfate

• Fentanyl

• Acetylsalicylic acid

• Clopidogrel

• Epinephrine

• Atropine

• Amiodarone

• Beta-blockers (not for paramedic use)

• ACE inhibitors (not for paramedic use)

• Tenecteplase (fibrinolytic)

• Heparin

• Nifedipine (not for paramedic use)

Acute Coronary Syndrome (ACS)

• ACS: A progression of ischemic heart disease from angina to acute myocardial infarction.
• Begins with early plaque formation in arteries.
• Inflammatory response triggers cholesterol buildup.
• Plaque rupture causing thrombus formation and obstructing blood flow.
• Stable angina: Chest pain from insufficient oxygen supply to heart tissue, relieved with rest.
• Unstable angina: More severe, longer-lasting pain, not relieved by rest.
• Unsable angina can lead to myocardial infarction (USA).
• Myocardial infarction: Partial or complete blockage of the arteries supplying the heart.
• UA: Occurs when partially occluding thrombus produces ischemia.
• UA pain: Longer duration, may not be relieved by rest or medication, requires immediate attention.
• Non-ST-segment elevation myocardial infarction (NSTEMI): Ischemia effects myocardium, no ST segment elevation on ECG. NSTEMI has elevated cardiac enzymes.
• Indicates necrosis of cardiac tissue.
• ST-segment elevation myocardial infarction (STEMI): Actual infarction of cardiac tissue secondary to oxygen deprivation. Causes cell death and ST segment elevation on ECG.

Unstable Angina and NSTEMI Management

• Aspirin
• Morphine sulfate
• Nitroglycerin (effective, safe, easily administered; sublingual nitroglycerin considered gold standard; before administering, determine if patient taking phosphodiesterase inhibitor medications; assess ECG for right ventricular infarction; patients dependent on adequate preload may decompensate.)

Glyceryl Trinitrate (Nitroglycerin)

• Produces vasodilation and dilates veins. Reduces cardiac preload and workload.
• Improves blood flow to ischemic myocardium.
• Decreases myocardial oxygen demand.

Morphine Sulfate

• Commonly used for pain relief.
• Relieves pulmonary congestion via vasodilation.
• Lowers myocardial oxygen demand and anxiety reduction.
• Respiratory depressant.

ST-Segment Myocardial Infarction (STEMI)

• Pathophysiology of STEMI: Complete blockage of an artery by a ruptured plaque and thrombus formation.
• Decreased blood flow can result from vasospasm.
• Cocaine abuse can cause STEMI.
• If not reversed, infarction will occur, leading to cell death.

STEMI Management

• Appropriate prehospital care includes: Starting oxygen, initiating IV, placing patient on cardiac monitor.
• Administering oxygen, aspirin, nitroglycerin (GTN), morphine sulfate.
• Remember MONA (Morphine, Oxygen, Nitrates, Aspirin).
• Reperfusion therapy is also indicated in STEMI treatment: Pharmacologic reperfusion (fibrinolytics like Tenecteplase), primary percutaneous coronary intervention (PPCI).

Antiplatelets, Anticoagulants, Fibrinolytics

• Antiplatelets: Prevent blood cell clumping (aspirin, clopidogrel).
• Anticoagulants: Slow clot formation (heparin, warfarin).
• Fibrinolytics: Break down clots (streptokinase, tenecteplase, alteplase).

Antiplatelets

• Aspirin: Antiplatelet medication. Prevents platelets from adhering to each other.
• Clopidogrel: Inhibits platelet aggregation. Used with aspirin to reduce ischemic events.

Anticoagulants

• Heparin: Prevents fibrin formation and platelet activation; administered with tenecteplase.

Fibrinolytics

• Used for acute STEMI within 6 hours of symptom onset when PCI is not readily available. Tenecteplase activates fibrinolytic system breaking up intravascular thrombi/emboli.
• Thrombolysis checklist needed prior to tenecteplase administration.

Congestive Heart Failure (CHF)

• A cardiovascular disorder.
• Prevalence increases with age.
• CHF patients often take multiple medications.
• Providers must be familiar with medications for long-term therapy and exacerbations, including pulmonary edema.
• Heart failure may result from: Ischemic heart disease, diabetes mellitus, hypertension, and heart valve disease.

CHF Management

• Follow international resuscitation guidelines (AHA or ERC).
• Patients take medications for long-term systolic/diastolic hypertension control, lipid disorders, and thyroid disorders. Angiotensin-converting enzyme (ACE) inhibitors.
• Oxygen: Supplemental oxygen for significant respiratory distress or low oxygen saturation.
• Non-invasive positive pressure ventilation: For patients with profound respiratory distress.
• Common medications: Nitroglycerin, furosemide, morphine sulfate.

Furosemide

• Increases urine output by decreasing water absorption in the kidneys.
• Increases urine production, decreasing intravascular volume.
• Loop diuretic, often more effective than other diuretics.
• Initial dose: 20-40 mg IV push.
• Takes approximately 20 minutes to be effective.

Some Other Medications Used for Long-Term Management of CHF

• Digoxin
• ACE inhibitors
• Beta-blockers

Cardiac Arrhythmias

• Loss or abnormality of cardiac rhythms.
• Types: Bradycardia, atrial arrhythmias (sinus tachycardia, supraventricular tachycardia (SVT), atrial fibrillation (AF), atrial flutter), ventricular arrhythmias (ventricular tachycardia (VT), premature ventricular contraction (PVC), ventricular fibrillation (VF), torsades de pointes), and cardiac arrest.

Bradycardia

• Heart rate < 60 bpm
• Treatment: Ensure airway, supplemental oxygen, cardiac monitoring, IV line.
• Medications: Atropine (600 mcg IV, repeating as necessary to 3mg total dose), epinephrine (2-10 mcg/min), dopamine (2-10 mcg/kg/min).
• Transcutaneous pacing might be required.

Atrial Arrhythmias

• Sinus tachycardia, supraventricular tachycardia (SVT), atrial fibrillation (AF), atrial flutter.

Atrial Arrhythmias Pharmacological Treatment

• Sinus tachycardia: Normally a physiologic response.
• SVT: Adenosine (6 mg, 12 mg, 12 mg). Calcium channel blockers, beta-blockers.
• Atrial fibrillation (AF): Amiodarone (IV; 150 mg/10 min → 1 mg/min infusion for 6 hours), Calcium channel blockers, beta-blockers.
• Atrial flutter: Amiodarone (IV; 150 mg/10 min → 1 mg/min infusion for 6 hours), Calcium channel blockers, beta-blockers.

Ventricular Arrhythmias

• Ventricular tachycardia, premature ventricular contractions, ventricular fibrillation, Torsades de Pointes.

Ventricular Arrhythmias Pharmacological Treatment

• Ventricular tachycardia (VT): Stable VT: Amiodarone (IV, 150 mg/10 min → 1 mg/min infusion for 6 hours), Lidocaine (0.5mg-1mg/kg → infusion 1-4mg/min).
• Unstable VT: Synchronized cardioversion.
• Ventricular fibrillation (VF): Epinephrine (1:10,000), amiodarone (IV, 300 mg then 150 mg IV, Lidocaine 1-1.5 mg/kg).

Cardiac Arrest

• Arrhythmias associated with cardiac arrest: Pulseless electrical activity (PEA), Asystole, Pulseless ventricular tachycardia (VT), Ventricular Fibrillation (VF)
• PEA/Asystole: Treat with epinephrine (1 mg IV/IO every 3-5 minutes)
• VF: Electrical therapy for most effective treatment.

Hypertension

• High blood pressure, the silent killer, often asymptomatic until organ damage.
• Types: Essential (no identifiable cause), systolic hypertension.
• Dangerous for older adults.
• Diagnosis categories: Normal, high-normal, grade 1, 2, 3 hypertension, isolated systolic hypertension, isolated systolic hypertension with widened pulse pressure.

Hypertension with Seizures

• Elevated blood pressure with seizure activity.
• May be caused by drugs (e.g., cocaine).
• Treatment differs from other hypertensive emergencies.

Hypertension with Seizure Management

• Diazepam: A benzodiazepine to induce sleep, relieve anxiety, and relax muscle spasm.
• Midazolam: A benzodiazepine that promotes relaxation.