Heart

• Normal heart: 0.4-0.5% of body weight
• Sinoatrial (SA) node

  • pacemaker at the junction or right atrial appendage and superior vena cave
• Gate keeper function, located in the right atrium — Atrioventricular (AV) node
• Connecting right atrium to ventricular septum — Bundle of His (AV bundle)
• Right and left bundle branch division stimulates their respective ventricles via further arborization into the Purkinje network
• 3 major Epicardial Coronary Arteries

  1. Left anterior descending (LAD)
  2. Left circumflex (LCX) - lateral wall of LV
  3. Right Coronary artery
• Inability of heart to pump blood in relation to metabolic demands — heart failure
• End stage of many forms of chronic heart disease — heart failure
• Most common heart failure — left-sided
• Disorders affecting the lungs — Cor Pulmonale
• Pleural effusion, if large — atelectasis
• Peritoneal effusion (ascites) — impair
• Diaphragmatic movement — dyspnea
• Ischemic heart disease

  • imbalance between myocardial supply and cardiac demand of oxygenated blood
• Stenosed coronary arteries w/o plaque disruption — stable angina
• Plaque disruption leading thrombosis — unstable angina
• Acute plaque change— myocardial infraction
• Transmural

  • full thickness of ventricular wall, most common
• Myocardial irritability and or conduction disturbances — arrhythmias
• Weakening of necrotic muscle — chamber dilation
• Aschoff bodies — foci of t lymphocytes, occasional plasma cells and activated macrophages
• Verrucae — vegatations within valve cusps
• Osler nodes — subcutaneous nodules in the pulp of the digits
• Roth spots— retinal hemorrhages in the eyes
• Libman-sacks disease

  • valvular scarring and leaflet fusion