L14 Heart Sounds PDF

Heart sounds Dr. Ghada Elgarawany Assistant professor of Medical Physiology * www.gmu.ac.ae COLLEGE OF MEDICINE Rules before lectures * www.gmu.ac.ae COLLEGE OF MEDICINE 1. 2. 3. 4. 5. Define volume pressure loop List types of heart sounds Describe 1st heart sound, causes, characters and area for au...

Heart sounds Dr. Ghada Elgarawany Assistant professor of Medical Physiology * www.gmu.ac.ae COLLEGE OF MEDICINE Rules before lectures * www.gmu.ac.ae COLLEGE OF MEDICINE 1. 2. 3. 4. 5. Define volume pressure loop List types of heart sounds Describe 1st heart sound, causes, characters and area for auscultation. Describe 2nd heart sound, causes, characters and area for auscultation. Define the S3 and S4 heart sounds and describe their timing, physiology, and clinical significance. * www.gmu.ac.ae COLLEGE OF MEDICINE Volume pressure loop Definition: It is the relation between left ventricular volume and left ventricular pressure... Isometric relaxation phase Ejection phases www.gmu.ac.ae Isometric contraction phase Filling phases * COLLEGE OF MEDICINE Heart Sounds  The heart sounds are produced by 1- Vibrations caused by the sudden closure of valves 2- Myocardial contraction 3- vibration caused by rushing of blood into the chambers of the heart.  Four heart sounds can be recorded via phonocardiography, but normally only two, the first and the second heart sounds, are audible through a stethoscope. * www.gmu.ac.ae COLLEGE OF MEDICINE First Heart Sound Cause: the sudden closure of AV valves (Mitral and tricuspid valve). It occurs at the beginning of ventricular systole (Isovolumetric contraction phase). Characters:  Low pitched (25 – 45 Hz)  Longer duration (0.14 Sec)  Give the sound of Lub Site:  Mitral area: (Apex of heart 5th intercostal space mid clavicular line)  Tricuspid area : between 4th and 5th space close to lower left quadrant of sternum * www.gmu.ac.ae COLLEGE OF MEDICINE Second Heart Sound Cause: closure of Semilunar valves (Aortic and pulmonary valves). It occurs at the end of ventricular systole( isovolumetric relaxation phase). Characters: High pitched( 50 Hz) Shorter duration( 0.11 sec) Give the sound of Dub Site: Auscultated in aortic and pulmonary areas.(Rt and Lt 2nd intercostal space) * https://exchange.scholarrx.com/brick/heart-sounds www.gmu.ac.ae COLLEGE OF MEDICINE Third Heart Sound Causes: caused by rushing of blood from atria into ventricle during rapid filling phase S3 is called gallop Physiological causes: Normally heard in most children, athletes and pregnant female. Pathological causes: congestive heart failure, aortic regurge and dilated cardiomyopathy https://exchange.scholarrx.com/brick/heart-sounds * www.gmu.ac.ae COLLEGE OF MEDICINE Fourth Heart Sound Causes: the atrial contraction (atrial systole) → vibration of ventricular wall causing S4.  which occurs at the end of ventricular diastole (During atrial systole)  Normally inaudible  Occurs in concentric ventricular hypertrophy (Stiff ventricular wall)  https://exchange.scholarrx.com/brick/heart-sounds * www.gmu.ac.ae COLLEGE OF MEDICINE Relation of heart sounds to the cardiac cycle * www.gmu.ac.ae COLLEGE OF MEDICINE Relation of heart sounds to the cardiac cycle  S1 presents in isovolumetric contraction phase.  S2 presents in isovolumetric relaxation phase.  S3 presents in rapid filling phase.  S4 presents in atrial systole. * www.gmu.ac.ae COLLEGE OF MEDICINE Review Questions First heart sound is produced by A. Closure of semilunar valves B. Closure of AV valves C. Opening of AV valves D. Atrial contraction * www.gmu.ac.ae COLLEGE OF MEDICINE Summary 1. 2. 3. 4. 5. Define volume pressure loop List types of heart sounds Describe 1st heart sound, causes, characters and area for auscultation. Describe 2nd heart sound, causes, characters and area for auscultation. Define the S3 and S4 heart sounds and describe their timing, physiology, and clinical significance. * www.gmu.ac.ae COLLEGE OF MEDICINE