identifying heart sounds

atria

chamber of the heart with thin walls

atria

serves as collection chambers for blood returning from the lungs (left atrium) or body tissues (right atrium)

pumps blood to the entire body

the left ventricle is most muscular since it —

systole, diastole

the heart alternates between contraction (—) and relaxation (—)

cardiac cycle

cycle for one complete sequence of contraction and relaxation

cardiac output

amount of blood pumped by each ventricle per minute

heart rate and stroke volume

cardiac output is determined by

5L/min

average resting cardiac output is  —

fivefold 

during heavy exercise, cardiac output can increase up to —

four valves

ensure one-way blood flow and prevent backflow

av valves 

valve between atria and ventricles

• anchored by strong fibers to prevent inversion during contraction 

when ventricles contract 

when do av valves close 

semilunar valves

valve at exits of ventricles (pulmonary artery and aorta)

during ventricular contraction

when do semilunar valves open

during relaxation

when do semilunar valves close

systole

tricuspid and mitral valves close at the start of — producing the first heart sound (lub)

tricuspid, mitral

valves that close at the start of systole that produce the first heart sound

diastole

aortic and pulmonary valves close at the start of — produce the second heart sound (dub)

aortic, pulmonary

valves that close at the start of diastole that produce the second heart sound

aortic area

area located at the second right intercostal space at the right sternal border

pulmonic area

area located at the second left intercostal space at the left sternal border

tricuspid area

area located at the fourth left intercostal space at the lower left sternal border

mitral area

area located at the fifth left intercostal space, medial to the mid-clavicular line

heart murmurs 

extra or unusual sound heard during a heartbeat, often described as a whooshing or swishing 

abnormal valve function

heart murmurs are caused by — allowing blood to leak backward 

mechanical valve replacement

severe defects of heart murmurs can be corrected by —

harmful

NOT all murmurs are —

still’s murmur 

innocent (physiologic) murmurs

• vibratory or musical sound, low pitched 

• left lower sternal border

• children ages 2-7

• louder when lying down, quieter when standing 

pulmonary flow murmur 

innocent (physiologic) murmurs

• soft, blowing systolic murmur

• left upper sternal border

• adolescents or young adults, esp. during fever, anemia, pregnancy 

venous hum 

innocent (physiologic) murmurs

• continuous humming sound from blood flow in neck veins

• right supraclavicular area

• disappears when turning the head or lying down 

aortic sternosis 

pathologic murmurs

• harsh, crescendo-decrescendo systolic murmur

• right upper sternal border, radiates to carotids

• weak pulse, narrow pulse pressure 

mitral regurgitation

pathologic murmurs

• blowing, holosystolic murmur

• apex, radiates to axilla 

• S3 gallop, displaced apex beat 

ventricular septal defect 

pathologic murmurs

• loud, harsh holosystolic murmur

• lower left sternal border

• may have palpable thrill 

aortic regurgitation

pathologic murmurs

• blowing, decrescendo diastolic murmur

• left sternal border 

• boundning pulses, wide pulse pressure

mitral stenosis 

pathologic murmurs

• low-pitched rumbling diastolic murmur

• apex

• often seen after rheumatic fever

patent ductus arteriosus

pathologic murmurs

• continuous “machinery” murmur

• left infraclavicular area

• bounding pulses, widened pulse pressure

loudness

how strong the sound is

pitch

how high or low it sounds

timing

when it occurs in the cardiac cycle

diaphragm

using the stethoscope

• for high-pitched sounds (s1-s2 murmurs)

bell

using the stethoscope

• for low-pitched sounds (s3-s4)

light pressure

apply — with the bell; too much pressure can muffled low tones