Week 6: Heart Health and Cardiac Conditions

Overview of Class Structure

  • Examinations:

    • Exam 2 scheduled for Thursday, Week 7.

    • Similar format to Exam 1 with 40 multiple-choice questions; emphasis on case studies.

    • Worth 200 points, contributing 20% to the overall grade.

    • Available time: 70 minutes.

  • Current Topic Coverage:

    • Finished Topic 3, starting Topic 4A.

    • Plan to complete Topic 4A by Thursday and begin Topic 4B.

    • Any unfinished topics will be completed the following Tuesday.

  • Homework:

    • Topic 4 study guide and amplification modules due Sunday before the exam.

    • Focus during class on discussing case studies for review.

Review Session Plans

  • In-class Activities:

    • Conduct in-class review using case studies.

    • Plans for a Zoom review session on the Monday prior to the exam.

Chest Pain Causes

  • Types of Chest Pain:

    • Two main categories:

    • Musculoskeletal Pain:

      • Causes include inflammation around the ribs or abnormalities in the spine.

      • Example: Costochondritis (inflammation of rib cartilage).

      • Most common non-cardiac cause, accounting for 30% of ER visits for chest pain.

    • Visceral Pain:

      • Related to internal organ inflammation (e.g., heart).

  • Gastroesophageal reflux disorder (GERD)

    • Commonly causes retrosternal pain due to stomach acid irritating the esophagus.

    • Acute episodes can mimic heart attacks, causing panic in patients.

Costochondritis

  • Definition and Symptoms:

    • Inflammation of costal cartilage leading to sharp chest pain, increasing with chest movement.

    • Symptoms may worsen with coughing or deep breathing.

    • Pain is typically reproducible on touch of the inflamed area.

  • Treatment:

    • Involves NSAIDs to treat inflammation. Recovery time can be several weeks to months.

Myocardial Ischemia and Infarction

  • Differences between Myocardial Ischemia and Myocardial Infarction:

    • Ischemia: A temporary reduction in blood flow, leading to chest pain but no permanent tissue damage.

    • Infarction: Prolonged ischemia leading to cell death and irreversible injury.

  • Cardiac Muscle Physiology:

    • Cardiac muscle cells (cardiomyocytes) rich in mitochondria for energy production.

    • Susceptible to damage when blood flow is interrupted, leading to anaerobic metabolism and lactic acid build-up.

  • Coronary Artery Anatomy:

    • Blood supply from the right and left coronary arteries; the left coronary artery is particularly critical.

    • Myocardial infarctions involving the left coronary artery can be fatal (known as “widowmaker” infarctions).

Atherosclerosis

  • Definition:

    • Thickening and hardening of artery walls due to plaque buildup (lipid accumulation).

  • Causes and Contributing Factors:

    • Major cause of coronary artery disease; risk factors include age, diabetes, high cholesterol (LDL), smoking, and hypertension.

  • Inflammation Process:

    • Endothelial cell damage leads to recruitment of white blood cells and plaque formation.

    • Progresses from fatty streak to calcified plaque within arterial walls over a decade.

Angina Types

  • Stable Angina (Angina Pectoris):

    • Caused by reversible myocardial ischemia, typically tied to exertion.

    • Symptoms last usually under 20 minutes and subside with rest.

    • No necrosis; labs show no cardiac enzymes present.

  • Unstable Angina:

    • Symptoms occur unpredictably and may last between 10-20 minutes.

    • Triggered by plaque rupture and thrombus formation.

    • No cell necrosis; cardiac enzymes remain normal.

  • Prinzmetal's Angina:

    • Caused by vasospasm, independent of atheroma; rare and occurs at rest.

Myocardial Infarction Types

  • Subendocardial Infarction (NSTEMI):

    • Occurs when a thrombus breaks down before full-thickness necrosis occurs.

    • Symptoms and ST segment depression on EKG; presence of cardiac enzymes indicates necrosis.

  • Transmural Infarction (STEMI):

    • Characterized by a complete blockage of coronary artery leading to necrosis through the full heart wall.

    • ST elevation seen on EKG; significant cardiac enzyme elevation.

Risk Factor Considerations

  • Modifiable Risk Factors:

    • Lifestyle modifications can help; smoking cessation, dietary improvements, weight management, exercise, and blood pressure control are effective strategies.

  • Nonmodifiable Risk Factors:

    • Family history, genetics, age, and gender.

Treatment Approaches

  • Emergency Management of Cardiac Events:

    • Initial treatment may include morphine, oxygen, nitroglycerin, and aspirin.

    • For myocardial infarctions, options include coronary artery bypass grafting (CABG) or percutaneous coronary intervention (PCI).

  • Pharmacological Treatments:

    • Use of ACE inhibitors to lower blood pressure and decrease cardiac workload post-MI.

Hypertension Overview

  • Classification of Blood Pressure:

    • Normal: Systolic <120 mmHg and Diastolic <80 mmHg.

    • Hypertension Stage 1: Systolic 130-139 or Diastolic 80-89.

    • Hypertension Stage 2: Systolic ≥140 or Diastolic ≥90.

  • Types of Hypertension:

    • Essential hypertension: No known cause, accounts for >90% of cases.

    • Secondary hypertension: Secondary to another condition, e.g., kidney disease.

  • Complications and Symptoms:

    • Often asymptomatic but can lead to headaches, visual disturbances, or arrhythmias.

Conclusion

  • Final Remarks:

    • Importance of comprehensive understanding for distinguishing cardiac-related chest pain and implications for effective management strategies and patient education.