Cardiovascular Pathology Quiz

Cardiovascular Pathology: Ischemic Conditions

• Evaluation & Treatment Objectives: Students should be able to perform a brief subjective history of a mock patient with a primary cardiac disorder, reflect on their performance, state signs/symptoms, pathophysiology, and interventions for common cardiovascular conditions.
• Risk Factors Identification: Students must identify risk factors for cardiovascular disease from mock or real cases for PT treatment, including exercise.
• PT Interventions: How physical therapy improves patient/client cardiovascular risk profile, including prevention and secondary intervention.
• Medical Chart Information: Synthesize information from a medical chart to determine if PT is indicated or if referrals are needed.

Ischemic Cardiovascular Conditions

• Atherosclerosis: Diseases causing progressive hardening and narrowing of coronary, cerebral, and peripheral arteries.
• Coronary Artery Disease (CAD): Presence of an obstruction limiting blood flow without significantly impacting myocardial function.
• Coronary Heart Disease (CHD): Presence of an obstruction causing permanent damage to heart muscle function.

Clinical Presentation of CHD

• Sudden Cardiac Death (SCD): First presenting symptoms in 40-50% of patients; death within 1 hour of symptom onset; usually caused by a rhythm disturbance.
• Chronic Stable Angina: Known level of "work" or activity brings on symptoms. Supply of oxygen to myocardium doesn't meet demands. Symptoms relieved by rest, reduction in intensity of work, or nitroglycerin.
• Acute Coronary Syndrome (ACS): Includes unstable angina, STEMI, and Non-STEMI.
  • Unstable Angina: Angina symptoms change from stable angina to an increase in frequency or occur at rest/more severe/lasts > 20 minutes.
  • ST-Elevation Myocardial Infarction (STEMI): ST segment elevation. Prolonged blockage = "typical MI".
  • Non-ST-Elevation Myocardial Infarction (NSTEMI): Blood tests indicate ischemia/infarction, but the ST segment does not elevate. May see ST depression or T-wave inversion. Blockage is partial or temporary; less damage than STEMI.
• Cardiac Muscle Dysfunction (Heart Failure): A separate category of CHD presentation.

Coronary Artery Anatomy & Physiology

• Coronary Artery Perfusion: Coronary arteries are perfused during diastole (relaxation phase of heart).
• Blood Flow Determinants: Diastolic blood pressure, vasomotor tone (vasoconstriction/dilation), resistance to flow, and left ventricular end-diastolic volume.

Plaque Formation

• Fatty Streak: The first sign of plaque.
• Stable Plaque: Plaques that calcify and are rich in lipids.
• Unstable Plaque: Plaques are rich in lipids and inflammatory cells without calcification. They have a thin fibrous cap more likely to rupture.

Atherosclerosis Mechanisms

• Nitric Oxide (NO) Dysfunction: NO in endothelium is affected causing endothelial dysfunction and an immune response.
• Lipid Macrophage Response: Lipid-filled macrophages cause endothelium stretching and separation.
• Platelet Aggregation & Collagen Levels: Platelets aggregate, and collagen levels increase, destroying the elastic layer of the media (responsible for dilation).
• Fibrous Cap Formation: A fibrous cap of thrombi forms over the plaque.

McGraw Hill Video: Anatomy and Physiology

• Roles:
  • Damaged endothelium
  • LDL
  • Monocytes/macrophages
  • Foam cells
  • Rupture
  • Ischemia vs. Infarction

Angina Pectoris

• Angina Meaning: "Strangling" and indicates ischemia.
• Ischemia Mechanism: Sensory impulses travel on unmyelinated sympathetic nerves to upper thoracic ganglia, dorsal horn, spinothalamic tract, and land in the cortex. The brain also receives input from cutaneous nerves, but the location of the pain is unclear.

PT to Treat or Not to Treat

• Enzyme Stabilization: Look for enzyme stabilisation or decline.
• Hemodynamic Stability: Consider hemodynamic stability.
• Monitoring: Monitor, monitor, monitor.

Lab Values - Cardiac Focus

• Complete Blood Count (CBC): WBC (infection) , RBC (hydration), HgB (oxygen carrying capacity-impacts exercise tolerance), Plt (bleeding risk).
• Electrolytes: Rhythm disturbances, especially potassium.
• Cardiac Enzymes (Diagnosis & MI): Troponin I is specific and sensitive for MI (Levels rise within 3-12 hours, peak 24-48 hrs, return to baseline 5-14 days). Creatinine Phosphokinase (CPK - MB) may be elevated in muscle disease, DM, muscle trauma, PE, alcohol toxicity.

Case Study (68-Year-Old Male)

• Lab Values: Hgb 13 g/dL, WBC 5 k, Plt 200k, Troponin 1.8 ng/ml, CK-MB/CK 3.5.
• Interpretation: These values indicate myocardial damage.

Echocardiography ("Echo")

• Non-Invasive Technique: Gives information about heart structure (chamber size, wall thickness), and function (e.g., valve function and estimation of ejection fraction).
• Ejection Fraction (EF): 55-70% is normal. Poorly correlated with exercise tolerance.
• Clinical Considerations: Look for ejection fraction, comments on valve function (increased myocardial workload), and wall effects.

Cardiac Catheterization/Angiogram

• Procedure: A hollow tube is inserted in an artery (femoral or another) and threaded to coronary arteries. Dye is injected, and coronaries are illuminated.
• Most Common Use: To identify the extent and location of coronary plaque.

Case Study: 54-Year-Old Male with Stable Angina

• 80% RCA Occlusion: PT should expect decreased cardiac output due to potential transient hypoxia of the left ventricle secondary to the RCA occlusion.