Cardiovascular System Lecture Notes

Cardiac Anatomy

Mediastinum

• Connective tissue-lined compartment bordered by lungs, sternum, thoracic vertebral bodies.
• Contains heart, aorta, PA, SVC, IVC, trachea, esophagus, thoracic duct, and lymph nodes.
• RV is the most anterior structure.

Pericardium

• Composed of fibrous outer layer and inner serous layer.
  • Fibrous layer: Affixes heart to mediastinum.
  • Serous layer: Parietal and visceral.

Epicardium

• Outermost layer.
• Coronary arteries lie on epicardial surface.

Myocardium

• Middle layer composed of heart muscle.

Endocardium

• Innermost layer lining the heart.

Cardiac Base and Apex

• Base: Posterior surface, superior aspect, where great vessels enter.
• Apex: Formed by the tip of LV; location of PMI.

Heart Chambers

Right Atrium

• Receives deoxygenated blood from SVC, IVC, and coronary sinus.

Right Ventricle

• Comprises the majority of inferior and anterior heart.

Left Atrium

• Receives oxygenated blood from lungs.

Left Ventricle

• Pumps blood to aorta.

Heart Valves

Atrioventricular Valves

• Located between atria and ventricles (mitral and tricuspid).

Semilunar Valves

• Aortic (left) and pulmonic (right).

Coronary Circulation

• Right & Left Coronary arteries supply O2 & nutrients.
• Right dominance: RCA supplies RA, most of RV.
• Left dominance: PDA is a branch of LCA.

Cardiac Hemodynamics

Systemic Vascular Resistance (SVR)

• Reflects resistance in the vascular system.
• SVR = (MAP-CVP) x 80 / CO

Laws Related to Cardiovascular System

• Fick's Principle: Relates to CO.
• LaPlace's Law: Wall tension, pressure, radius relationship.
• Poiseuille’s Law: Flow relationship with pressure and viscosity.
• Ohm’s Law: Proportionality of flow and pressure.

Cardiac Conduction System

• Consists of SA node, AV node, Bundle of His, L & R Bundle Branches, Purkinje fibers.

Common Cardiovascular Diseases

Hypertension

• Persistently high pressure in the blood vessels.

Coronary Artery Disease (CAD)

• Atherosclerotic heart disease, narrowing of coronary vessels.

Ischemic Heart Disease

• Risk factors include advanced age, smoking, DM, HTN.

Atherosclerosis & Angina

• Myocardial ischemia causes chest pressure, SOB.

Stable and Unstable Angina

• Stable: Predictable, relieved by rest.
• Unstable: New/worsening symptoms, requires immediate attention.

Acute Coronary Syndromes

• NSTEMI and STEMI.

Cardiomyopathy

• Diseases of heart muscle (dilated, hypertrophic, restrictive).

Heart Failure

• Heart's inability to pump enough blood.

Valvular Heart Disease

• Includes stenosis and regurgitation of heart valves.

Peripheral Artery Disease

• Affects adults over 55; risk factors include smoking, diabetes.

Arrhythmias

• Includes ventricular arrhythmias and their management.

Congenital Heart Disease

• Heart defects present at birth (e.g., ASD, VSD).

Preoperative Assessment & Cardiac Risk Factors

Importance of Preoperative Cardiac Assessment

• Identifies potential for perioperative complications.

Focused Cardiovascular Physical Exam

• Includes auscultation, pulse assessment, jugular venous pressure measurement.

Cardiac Tamponade

• Increased intrapericardial pressure; symptoms include Beck’s Triad.

Lab Results

• Important markers include Troponin, BNP, Creatine Kinase.

Anesthetic Goals

• Maintain myocardial oxygen supply.
• Ensure organ perfusion and manage anesthesia depth.

These notes cover the structural and functional aspects of the cardiovascular system, common diseases, diagnostics, and considerations for surgery and anesthesia, providing a comprehensive overview of the lecture content.