The normal heart sounds. Volume-pressure diagrams. Work output of the heart Flashcards
sound 1
location = apex
timing = start of ventricular contraction/ systole
cause = mitral valve closes + tricuspid valve closes
result = lub sound
sound 2
location = base
timing = start of ventricular diastole/ relaxation
cause = aortic valve closes before pulmonary valve due to higher pressure in aorta compared to pulmonary artery
result = dub sound
sound 3
location = left lateral decubitus apex of heart
timing = after s2
cause = blood enters rapidly from atria into a stiff ventricle
result = normal in children/ pathological in adults
s4
location = apex, left lateral decubitus position
timing = before s1
cause = short atrial contraction against a stiff ventricle
result = pathological -> hypertension/ ischemia/ aortic stenosis
auscultation point 1
AORTIC valve
intercostal space 2
RHS sternal border
base of heart
auscultation point 2
PULMONIC VALVE
intercostal space 2
LHS sternal border
base of heart
ausculation point 3
ERBS POINT
intercostal space 3
LHS sternal border
auscultation point 4
TRICUSPID VALVE
intercostal space 5
RHS sternal border
auscultation point 5
MITRAL VALVE
intercostal space 5
medial from mid clavicular line
auscultation points definition
points on chest to place stethoscope to hear auscultatio
other
MURMURS
= turbulent flow across heart valves
Work output of the heart - 1
CARDIAC OUTPUT
= volume of blood pumped by heart per min
CO = SV X HR (500l/min)
Work output of the heart - 2
STROKE VOLUME
amount of blood pumped by the left ventricle after 1 contraction
depends on
- preload
- afterload
- contractility
Work output of the heart - 3
BLOOD PRESSURE
pressure exerted by the fluid on vessel walls as it passes through vascular system
BP = CO x SVR
Work output of the heart - 4
HEART RATE
beats per minute
- 60-100bpm = normal
Work output of the heart - 5
ejection fraction
- % of blood ejected by the left ventricle during contraction
normal = 55-70%
