Signs and Symptoms of ACS

Signs and Symptoms of Acute Coronary Syndrome (ACS)

• Pain Characteristics: Substernal pain with radiation to jaw, neck, shoulder, arm, and back.
• Abnormal Heartbeat: Pounding sensation (palpitations) and chest tightness are common.
• Tachycardia: Increased heart rate perceived as "indigestion".
• Levine's Sign: Patient may clutch chest, indicating chest pain.
• Angina Pectoris: Pain lasts less than 15 minutes, relieved by rest and nitrates.
• Myocardial Infarction (MI): Pain persists longer than 15 minutes, unrelieved by rest or nitrates; treated with morphine.

Diagnostic Tests

• Electrocardiogram (ECG): Displays cardiac electrical activity; used to diagnose ischemia, injury, and infarction.

  • QRS Complex: Indicative of ventricular contraction.
  • T-wave inversion suggests ischemia.
  • ST segment elevation indicates injury.
  • Large or pathologic Q waves show infarction.

• Serum Cardiac Biomarkers: Indicators of myocardial tissue death; namely:

  • Myoglobin: Elevates after 1 hour.
  • Troponin: Elevates within 2-4 hours, considered gold standard.
  • CK-MB: Elevates 4-6 hours post-event.
  • AST: Elevates after 8 hours.
  • LDH: Elevates after 24 hours.

Heart Status Monitoring

• Monitored through vital signs, telemetry for continuous ECG, and serum biomarkers.
• Oxygen Therapy: Priority in enhancing myocardial tissue oxygenation, position patient in high Fowler's for lung expansion.
• Acute MI Complications: Monitor for cardiac arrhythmias such as PVC, which can lead to VTach and V-fibrillation.

Anatomy and Physiology of the Heart

• Location: Heart located in the mediastinum, deviating to the left, average weight is 300 grams.
• Function: Pumps blood throughout the body; emotion regulation comes from the hypothalamus.
• Contraction: Heart muscles contract using energy from ATP produced via aerobic metabolism.
• Key Components for ATP: Oxygen, glucose, phosphorus, and potassium is the essential electrolyte.

Heart Wall Structure

• Layers:
  • Endocardium: Inner layer, inflammation causes endocarditis.
  • Myocardium: Muscular middle layer, inflammation leads to myocarditis.
  • Epicardium: Outermost layer.

Pericardium

• Thin fibrous sac encasing the heart, potentially leading to pericarditis if swollen.
• Pericardial Effusion: Fluid accumulation can compress the heart, causing cardiac tamponade, which compromises circulation leading to cardiogenic shock.

Pulse and Survival

• Pulse indicates left ventricular contraction; delay in treatment leads to cardiac arrest risk.
• Recommendations: Complete bed rest in the first 24 hours, passive range of motion exercises, low-sodium/quinoa diet, recommend avoiding smoking.

Medication Treatment for ACS

• Nitrates: Used as vasodilators in MI management; key types include:
  • Nitroglycerin, Isosorbide Dinitrate, Isosorbide Mononitrate.
• Administration: Transdermal application recommended; avoid shaving at application site to prevent rapid absorption.
• Mechanism of Action: Decreases myocardial demand, cardiac workload, vascular resistance, and pain perception; IV form available for rapid effect.
• Adverse Effects: CNS and respiratory depression possible; monitor respiratory rate before administration.

Emergency Considerations

• Respiratory Monitoring: Check rates carefully, particularly with low rates; report significantly low rates (e.g., 10 bpm) immediately.
• Antidotes: Naloxone (Narcan) for overdose; Methadone for withdrawal.