Week 1 - Ischemic Heart Disease & Embryology

Week 1- Ischemic Heart Disease

• Ischemic heart disease is a condition where the heart muscle doesn't receive enough blood.

Basic Embryology of the Heart and Fetal Circulation

• Heart formation begins around day 18, from mesoderm.
• Two heart fields—primary and secondary—develop into the atria, left ventricles, and right ventricles.
• Day 21: Heart tube formation.
• Specific sections: truncus arteriosus (aorta and pulmonary artery), bulbus cordis (right ventricle), primitive ventricle (left ventricle), and primitive atrium.
• The single heart tube folds and loops to form the heart's final shape.
• Heart chamber formation occurs during week 4.

Fetal Circulation

• Umbilical vein (80% oxygenated blood) carries blood from the placenta.
• Half of blood goes to fetal liver, other half goes to inferior vena cava via the ductus venosus.
• Blood empties into right atrium (RA).
• RA-LA (foramen ovale): directs oxygenated blood into the left side of the heart.
• LV-systemic circulation.
• Other portion of blood: pulmonary artery (PA) via ductus arteriosus.
• Blood returns to the fetus via umbilical arteries.
• After birth:
  • Ductus venosus → ligamentum venosum
  • Ductus arteriosus → ligamentum arteriosus
  • Foramen ovale → fossa ovalis

Heart Structure & Characteristics

• Right atrium has a smooth wall and a crista terminalis.
• The sinus venosus is an embryonic remnant.
• The sinoatrial (SA) node is located near the superior vena cava (SVC).
• The atrioventricular (AV) node is located near the tricuspid valve and is part of the heart's conduction system.

Week 2 - Ischemic Heart Disease

• Ischemic heart disease is a condition where the heart muscle doesn't receive enough blood causing angina. This is due to reduced oxygen supply to the myocardium.
• Angina can lead to myocardial infarction (MI) if blood flow and oxygen are severely restricted, leading to heart attack and cell death.
• Stable angina occurs in response to increased oxygen demand in the myocardium, often induced by physical exertion or stress.
• Unstable angina occurs unexpectedly, even at rest, and often signals a critical blockage requiring prompt medical intervention.
• Heart anatomy (right and left atria, ventricles, valves etc).

Week 3 - Hypertension and Vascular System

• Blood vessels consist of three layers: tunica intima (innermost layer), tunica media (middle layer), tunica externa/adventitia (outermost layer).
• Factors affecting blood flow and blood pressure include cardiac output (heart rate x stroke volume) and total peripheral resistance (TPR).
• Regulation of blood pressure is tightly controlled through the sympathetic nervous system, renin-angiotensin-aldosterone system (RAAS), and antidiuretic hormone (ADH).
• Edema occurs due to increased hydrostatic pressure in the capillaries, forcing fluid into the tissues, or decreased oncotic pressure, preventing fluid reabsorption.

Week 4- Valvular Function

• Intra-cardiac pressures, normal vs abnormal.
• Heart sounds (S1 and S2) and murmurs (abnormal) indicate valve function.
• Valve defects: stenosis (narrowing) and regurgitation (leakage).
• Symptoms and diagnosis of valve defects, including murmurs.

Other Topics

• Coronary Artery Disease, Atherogenic process, coronary thrombosis, acute coronary syndromes.
• Pathophysiology of stable and unstable angina, symptoms and treatment of angina, diagnostic tests.
• Congenital heart defects, including atrial septal defect (ASD), ventricular septal defect (VSD), and tetralogy of Fallot.
• Pathophysiology of mitral valve prolapse, bicuspid aortic valve.
• Treatment of valvular diseases, including medication and surgical intervention.
• Other Cardiovascular diseases: Rheumatic fever, echocardiography, etc.