Download Heart Sounds/Disorders

Objectives
• 1. Discuss heart sounds
• 2. Describe the major types of cardiac
valve disorders
• 3. Explain how a myocardial infarction
might occur.
• 4. Describe the major types of cardiac
dysrhythmia.
• 5. List and describe possible causes of
heart failure.
Heart Sounds
• Two distinct sounds can be heard when
listening to the heart – “lub dup”
• “lub” – caused by vibration and abrupt
closure of the AV valves as the ventricle
contracts
• This sound is of a longer duration and
lower pitch than is the second sound.
• “dup” – closing of the semilunar valves
Valve Disorders
• Incompetent valves – leak
• Stenosed valves – narrower than normal
• Rheumatic heart disease – inflammation of
cardiac valves and other tissues
• Mitral valve prolapse (MVP) – bicuspid
valve flaps extend into left atrium causing
incompetence
Heart Attack
• A myocardial
infarction may result
from occlusion or
blockage of the left
coronary artery
Cardiac Dysrhythmia
• Heart block – AV node block
• Bradycardia – slow heart rhythm (below 60
beats per minute); slight bradycardia is
normal during sleep; abnormal caused
from improper autonomic nervous control
of the heart or a damaged SA node
• Tachycardia – rapid heart rhythm (over
100 beats per minute); normal during
exercise or stress response; abnormal
results from improper autonomic control of
the heart, blood loss or shock, action of
drugs and toxins, fever, et al
• Sinus dysrhythmia – variation in heart rate
during breathing cycle
Extrasystoles
• Frequent premature contractions
• Can lead to fibrillation – cardiac muscle
fibers contract out of step with each other
• Ventricular fibrillation – immediately lifethreatening
Heart Failure
• Cardiomyopathy – disease of the
myocardial tissue, reduces pumping
effectiveness
• Dysrhythmias can impair pumping
effectiveness
• Congestive heart failure – left heart failure;
decreases pumping pressure in the
systemic circulation (portions become
congested with fluids)