1. Cardiovascular PhysiologyECG

2. What is systole and diastole? Systole- a period of contraction in the heart Diastole- a period of relaxation in the heart 3. What causes the sounds of the heart beat? The closing of valves! Not the contraction ofthe muscles 4. Creation of Heart SoundsLubb-Dubb Ventricular Contraction (Systole) Lub AV valves closing Cont. Vent. Contraction (Systole 62% ofcardiac cycle) Finish Vent. Contraction Dub Semilunar valves closing Slight split due to pressure diff. L/Rduring INSPIRATION Vent. Relaxation(Diastole 38% of cardiac cycle) AV valves open blood fills vent. Atrial contraction 5. Blood Pressure Systolic BP First sound when releasing air in cuff Normal = 120 mmHg Diastolic BP Last sound heard Normal = 80 mmHg Hypertension Systolic >140 mmHg Diastolic >90 mmHg 6. Blood Pressure Pulse Pressure Systolic diastolic Mean ArterialPressure (MAP) Diastolic pressure + 1/3 pulse pressure 120/80 80+1/3(40)=93.3mmH g 7. Electrical Activity of the HeartSequence of Excitation1. SA node (pacemaker)-Location: R atrium near opening SVC-Spontaneously generates depolarizing action potentials-Determines heart rate2. AV node-Location: Base of R atrium-Delay for complete atrial contraction3. AV bundle (bundle of His)-Location: Interventricular septum4. Bundle branches (R and L branches)-Location: Interventricular septum5. Purkinje fibers-Location: Ventricles-rapidly distributes impulse throughout ventricles-leading to ventricular contraction 8. Electrocardiogram (ECG)ECG primary tool for evaluating electrical events of the heart;records voltage differences generated by the heartStandard Limb LeadsLead I: RA LALead II: RA LL(most similar to normal fxn)Lead III: LA LL*RL = ground Einthoven Triangle 9. Electrocardiogram (ECG) Waves P Wave depolarization of atria QRS complex depolarization of ventricles/repolarization of atria T Wave repolarization of ventricles Intervals PR AV conduction time QT electromechanical events of ventricles (dep & rep) 10. PulsePulse number ofheartbeats per minute Normal values forresting heart rate (bpm): newborn infants:100 to 160 children 1 to 10 years: 70 to 120 children >10 & adults: 60 to 100 well-trained athletes: 40 to 60