MI & Angina

Understanding Heart Attacks and Cardiac Monitoring

Heart Attack Overview

  • Importance of Left Coronary Artery:
      - Known as the Widowmaker because blockage leads to significant blood supply loss to the heart's left side.
      - Total blockage can result in complete heart loss if untreated.

  • Personal Anecdote:
      - The speaker shares their father’s heart health journey, including a CABG (Coronary Artery Bypass Grafting) at St. Joe's Hospital in 2016 due to dysrhythmias.
      - The father later passed away from cancer, impacting the speaker’s approach to cardiac care.

Cardiac Monitoring Basics

  • Heart Sounds: Key aspect of cardiac assessment.
      - Stethoscope Types:
        - Bell: Used for low-pitched sounds (e.g., heart murmurs).
        - Diaphragm: Used for higher-pitched sounds (e.g., lung and bowel sounds).
      - Technique: Flip the stethoscope to the appropriate side based on sound pitch.

  • Listening Techniques:
      - Assess heart valves by placing the stethoscope at different areas:
        - Aortic Area
        - Pulmonic Area
        - Erb's Point
        - Tricuspid Area
        - Mitral Valve/Apical Area (use side-lying position to enhance sound from the mitral area).

Types of Angina

  • Stable Angina:
      - Predictable pain pattern, typically relieved by rest.
      - No permanent heart damage; cardiac markers are negative.
      - Example: Speaker’s father experiencing pain while lifting blocks, relieved by sitting down (ischemia during exertion).

  • Unstable Angina:
      - Unpredictable pain, may occur at rest.
      - Pain unrelieved or relieved intermittently by nitroglycerin; potential ST depression on the EKG but still no permanent damage.
      - A crucial warning sign that should not be ignored.

  • NSTEMI (Non-ST Elevation Myocardial Infarction):
      - Partial thickness heart muscle injury, typically treated with Lovenox or PCI (Percutaneous Coronary Intervention).
      - Positive cardiac markers after three hours, indicating damage.

  • STEMI (ST Elevation Myocardial Infarction):
      - Full thickness heart muscle damage requiring TPA or PCI to restore blood flow.
      - Symptoms must be treated within six hours to prevent myocardium death.
      - Associated with significant ST elevations on EKG and permanent necrosis indicated by Q waves.

Clinical Assessment and EKG Interpretation

  • EKG Monitoring:
      - Essential to track heart status, looking for ST depression/elevation and rhythm abnormalities.
      - Cardiac Markers: Troponins and CK levels are keys in diagnosing myocardial injury.

  • Troponin Basics:
      - Traditional range: 0 to 0.04 ng/mL. New high sensitivity range is less than 14 pg/mL.
      - Drawn initially, then at 1 hour and 3 hours. Immediate results allow for early detection of myocardial injury.

  • Clinical Considerations for Women:
      - Women may present differently (e.g., fatigue instead of chest pain), increasing the chance of misdiagnosis.

Risk Factors for Heart Disease

  • Important factors to consider for heart disease include:
      - Diabetes
      - Metabolic syndrome
      - Smoking
      - Other lifestyle-related risks.

Treatments and Medications

  • Initial Treatment Protocols:
      - Aspirin: For platelet aggregation, often administered immediately.
      - Oxygen and IV Access: Serial monitoring of vitals and symptoms post myocardial infarction.
      - Beta Blockers: To reduce myocardial oxygen demand.
      - ACE Inhibitors: Reduce afterload by lowering blood pressure.
      - Post-Stent Medications: Patients discharged on Aspirin and Plavix to prevent clot formation on the stent.

Cardiac Catheterization Considerations

  • Monitoring Post-Procedure:
      - Digital pulses to ensure adequate circulation and monitor for possible occlusions.
      - Six P's of assessment: Pain, Paresthesia, Paralysis, Pulselessness, Power, Pallor (hypothermia).

Anatomical and Procedural Insights

  • Understanding the anatomy related to myocardial infarction is crucial:
      - Inferior Wall MI: May affect pacemaker function leading to bradycardia and AV blocks.
      - Anterior Wall MI: Affects left ventricle, risk of left heart failure signs (e.g., JVD, pulmonary congestion).
      - Lateral Wall MI: Impacts effective pumping to the body, leading to potential CHF signs.

Conclusion

  • Recognizing signs and symptoms of myocardial infarction in patients is critical for effective intervention and survival.

  • Continuous assessment, EKG interpretation, and understanding the pathophysiology of heart attacks are vital components of cardiac care.