Heart Concept Map

Heart Concept Map

1. Anatomy

   • Chambers
     • Left Atrium
       • Interatrial Septum
       • Vessels that enter
         • Right Pulmonary Vein
         • Left Pulmonary Vein
     • Right Atrium
       • Vessels that enter
         • Superior Vena Cava
         • Inferior Vena Cava
         • Coronary Sinus (collects blood)
     • Left Ventricle
       • Interventricular Septum
       • Thicker because contracts blood out of aorta to rest of body and receives most of coronary blood supply
       • Vessels that exit
         • Aorta
     • Right Ventricle
       • Vessels that exit
         • Pulmonary trunk of left pulmonary artery
   • Valves
     • Ensure unidirectional flow through heart
       • Atrioventricular (AV) Valve
         • Bicuspid (Mitral)
           • Bicuspid closes before Tricuspid
         • Tricuspid
         • Lub Sound: closing of AV valves
           • During start of ventricular systole
         • Chordae Tendineae anchor cusps to papillary muscles
         • Open when atrial pressure greater than ventricular
       • Semilunar (SV) Valve
         • Aortic Semilunar
           • Aortic closes before Pulmonary
             • Differences allow auscultation of each valve when stethoscope is placed in four different regions
         • Pulmonary Semilunar
         • Open due to increase in ventricular pressure
         • Inter-ventricular pressure falls, blood flows back from arteries, fills cusps of valves
           • Dup Sound: closing of SL valves
             • During start of ventricular diastole
   • Coronary Circulation
     • Coronary Arteries
       • Left Coronary Artery
         • Supplies blood to inter-ventricular septum, left atrium, & left ventricle
         • Divides
           • Anterior inter-ventricular artery
           • Circumflex artery
       • Right Coronary Artery
         • Coronary Capillaries
           • Coronary Veins
             • Divides
               • Anterior Cardiac Veins
               • Great Cardiac Vein
               • Anterior Cardiac Vein
               • Small Cardiac Vein
         • Encircle heart in coronary sulcus
         • Supplies blood to right atrium & right ventricle
         • Divides
           • Posterior inter-ventricular artery
           • Marginal artery
     • Supplies oxygen to heart tissues
     • Functional blood supply to heart muscle
     • Shortest circulation in body
     • Delivered when heart relaxed

2. Physiology

   • ECG
     • P-Wave
       • SA node travels to atria
         • Depolarization of SA node & atria occurs
       • 1. Atrial depolarization initiated by SA node causes P wave
         • 2. With atrial depolarization complete implies delayed at AV node
           • 3. Ventricular depolarization begins at apex causing QRS complex (atrial repolarization occurs)
             • 4. Ventricular depolarization complete
               • 5. Ventricular repolarization begins at apex causing T-wave
                 • 6. Ventricular repolarization is complete
     • QRS Complex
       • Ventricular depolarization & Atrial repolarization
     • T-Wave
       • Ventricular repolarization instantly prior to diastole
     • P-R interval
       • Start of atrial excitation to start of ventricular excitation
     • Q-T interval
       • Start of ventricular depolarization through ventricular repolarization
     • S-T segment
       • Entire ventricular myocardium depolarized
     • Graphic recording of electrical activity
     • Composed of all action potentials (AP)
     • Electrodes on body measure voltage differences
   • CAD
     • Definition
       • Develops when major blood vessels that supply heart with blood, oxygen & nutrients (coronary arteries) become damaged or diseased
         • Cholesterol-containing deposits (plaque) in your arteries and inflammation
           • Plaque builds up, they narrow your coronary arteries, decreasing blood flow to your heart.
     • Symptoms
       • 1. Chest Pain (Angina)
       • 2. SOB
       • 3. Heart Attack
     • Treatment
       • Drugs
         • 1. Aspirin
           • Blood thinner that reduces risk of blood clots
             • Prevents obstruction of coronary arteries
         • 2. Beta-Blockers
           • Slow HR, Decrease BP
             • Decreases hearts demand for O2
               • Reduces risk of future attacks
         • 3. Nitroglycerin
           • Forms: tablets, sprays, patches
             • Temporary dilate coronary arteries
               • Reduces hearts demand for blood
       • Surgical Technique
         • 1. Coronary Artery Bypass
           • Open heart surgery
             • Graft created to bypass blocked coronary arteries using vessel from another part of your body
               • Allows blood flow around blocked coronary arteries to reach heart
         • 2. Angioplasty & Stent Replacement
           • Insertion of catheter into narrowed part of artery
             • Wire with deflated balloon is passed through catheter into narrowed area of artery
               • Balloon inflated pressing plaque deposits against artery wall
                 • Stent left in artery to keep it open
                   • Some stents slowly release medication to keep artery open
       • Lifestyle Changes
         • Quit smoking, Eat Healthy, Exercise Regularly, Lose Excess Weight, Reduce Stress
     • Causes
       • Smoking, High BP, High cholesterol, Diabetes or insulin resistance, sedentary lifestyle
   • Electrocardiograph
     • Detects electrical currents generated by heart
   • Blood Pressure
     • Systole
       • Maximum pressure felt on artery during left ventricular contraction
         • Normal: 120mmHg
     • Diastole
       • Resting pressure exerted by blood constantly between contractions
         • Normal: 80mmHg
       • Pulse Pressure
         • Difference between systolic and diastolic pressure reflects stroke volume
           • Average Stroke Volume: 70ml
     • Force of blood pushing against the side of a vessel wall
     • Cardiac Cycle
       • Blood flow through heart during one complete heart beat
         • Mechanical Events
           • 1. Ventricular Filling
             • Pressure low, 80% of blood passively flows from atria through open AV valves into ventricles (SL valves closed)
               • Atrial depolarization triggers atrial systole (P wave), atria contracts, pushes 20% of blood into ventricle
                 • End Diastolic Volume (EDV): volume of blood in each ventricle at end of ventricular diastole
                 • Depolarization spreads to ventricles (QRS wave)
                   • 2. Ventricular Systole
                     • Ventricles contract, rising ventricular pressure causes AV valves to close
                       • Two phases
                         • A. Isovolumetric Contraction
                           • all valves are closed
                         • B. Ejection
                           • ventricular pressure exceeds pressure in large arteries, forcing SL valves open
                       • End Systolic Volume (ESV): volume of blood remaining in each ventricle after systole
                         • 3. Isovolumetric Relaxation
                           • Following ventricular repolarization (T wave), ventricles relaxed, atria relaxed and filling
                             • Back flow of blood in aorta and pulmonary trunk closes SL valves
                               • Dicrotic Notch: brief rise in aortic pressure as blood rebounds off closed valves
                               • Ventricles are totally closed chambers (isovolumetric)
                               • Atrial pressure exceeds ventricular pressure
               • AV valves open
   • Autorythmic (pacemaker) cell
     • Types
       • 1. Sino-atrial (SA node)
       • 2. Atrio-ventricular (AV node)
       • 3.Bundle of HIS (purkinjee fibers)
     • Set pace & rhythm of heart
     • Potential: -60 to -40