Unit Four: The Circulation Chapter 23: Heart Valves and Heart Sounds: Valvular and Congenital Heart Defects Guyton and Hall, Textbook of Medical Physiology, 12 edition

Causes of the First and Second Heart Sounds Duration and Pitch of the First and Second Sounds Fig. 23.1 Amplitude of different frequency vibrations in the heart sounds and murmurs

Fourth Heart Sound (Atrial Heart Sound Heart Sounds Third Heart Sound Fourth Heart Sound (Atrial Heart Sound Chest Areas of Auscultation of Normal Heart Sounds Fig. 23.2 Chest areas from which sound from each valve is best heart

Heart Sounds Phonocardiogram Fig. 23.3 Phonocardiogram from normal and abnormal hearts

Heart Sounds Valvular Lesions—resulting from rheumatic fever Scarring of the Valves Congenital Defects Heart Murmurs Systolic murmur of aortic stenosis Diastolic murmur of aortic regurgiatation Systolic murmur of mitral regurgitation Diastolic murmur of mitral stenosis

Abnormal Circulatory Dynamics in Valvular Disease Aortic Stenosis and Aortic Regurgitation--the net stroke volume is reduced (stenosis: ventricle fails to empty and in regurgitation: blood flows backward into the ventricle Compensation by: Hypertrophy of the left ventricle Increase in blood volume Eventual failure of the left ventricle and development of pulmonary edema

Abnormal Circulatory Dynamics in Valvular Disease Mitral Stenosis and Mitral Pulmonary edema in mitral valvular disease Enlarged left atrium and atrial fibrillation Compensation in early mitral valvular disease Diminished excretion of water and salt by the kidneys Increase in blood volume Increased venous return to the heart

Abnormal Circulatory Dynamics in Congenital Heart Defects Three Major Congenital Anomalies: Stenosis of the channel of blood flow at some point in the heart or in a closely allied major blood vessel An anomaly that allows blood to flow backward from the left side of the heart or aorta to the right side or pulmonary artery (left-to-right-shunt) An anomaly that allows blood to flow directly from the right side of the heart into the left side of the heart (right-to-left-shunt)