Download Unit One: Introduction to Physiology: The Cell and General Physiology

Chapter 23: Heart Valves and Heart Sounds:
Valvular and Congenital Heart Defects
Guyton and Hall, Textbook of Medical Physiology, 12 edition
Heart Sounds
• 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
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
a.
b.
c.
d.
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
a. Compensation by:
1. Hypertrophy of the left ventricle
2. Increase in blood volume
b. Eventual failure of the left ventricle and development
of pulmonary edema
Abnormal Circulatory Dynamics in Valvular Disease
• Mitral Stenosis and Mitral
a. Pulmonary edema in mitral valvular disease
b. Enlarged left atrium and atrial fibrillation
c. Compensation in early mitral valvular disease
1. Diminished excretion of water and salt by the kidneys
2. Increase in blood volume
3. Increased venous return to the heart
Abnormal Circulatory Dynamics in Congenital Heart Defects
• Three Major Congenital Anomalies:
a. Stenosis of the channel of blood flow at some point in
the heart or in a closely allied major blood vessel
b. 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)
c. 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)