Lab Quiz 4 - Blood Pressure and Electrical Conduction Flashcards
autorhythmic cells
- also known as the pacemaker
- depolarizes at a rate of 80-100 times per minute and sets the resting heart rate of aobut 75bpm
sinoatrial (SA) node)
true or false: not every depolarization of the SA node leads to a heart beat
true
components of the intrinsic conduction system
- sinoatrial (SA) nnode
- atrioventricular (AV) node
- AV bundle (Bundle of HIS)
- Punkinje fibers
splits into left and right bundle branches
AV bundle (bundle of HIS)
steps to intrinsic conduction
- sinoatrial (SA) node (pacemaker) generates impulses
- impulses pause (0.1s) at the atrioventricular (AV) node
- atrioventricular (AV) bundle connects atria to ventricles
- bundle branches conduct the impuleses through the interventricular septum
- the purkinje fibers depolarize the contractile cells of both ventricles
in order to see if the valves and pumps of the heart are working correctly, you need to
auscultate
indicates depolarization of atria immediately before atrial contraction
p wave
precedes ventricular contraction, signals ventricular depolarization
QRS complex
signifies repolarization of ventricles
T wave
- represents the time between atrial and ventricular depolarization
- 0.12-0.2s
PR interval
what might a PR interval that is too long indicate
AV node damage
when the atria and ventricles beat independently of one another
total heart block
- represents the period between ventricular depolarization to ventricular repolarization
- 0.28-0.4s
QT interval
what happens to the QT interval if heart rate increases
QT interval becomes shorter
what happens to the QT interval when heart rate decreases
QT inteval becomes longer
- the time it takes for one complete cycle
- 0.8s
RR interval
when the atria are contracting, should be isoelectric
PQ segment
when the ventricles are contracting, should be isoelectric
ST segment
- HR >100bpm
- can lead to fibrillation if sustained over long periods
tachycardia
chambers contracting
systole
chambers relaxing
diastole
- HR < 60 bpm
- good in conditioned athletes, otherwise can lead to O2 deprivation of the brain
bradycardia
uncoordinated contraction of the chambers of the heart
fibrillation
no contraction of the chambers of the heart
asystole
what area are we auscultating when we are auscultating the 2nd right intercostal space
aortic area
what area are we auscultating when we are auscultating the 2nd left intercostal space
pulmonic area
what area are we auscultating when we are auscultating the lower left sternal border
tricuspid valve area
what area are we auscultating when we are auscultating the apex of the heart
mitral (bicuspid) valve area
the pressure exerted by blood against any unit area of the blood vessel wall and is usually measured in the arteries
blood pressure
- one beat of the heart
- takes ~0.8s
cardiac cycle
phases of the cardiac cycle
- ventricle filling / atrial systole
- ventricle systole (isometric and ejection phases)
- ventricular diastole
what is a normal cardiac output
4,000-6,000 mL/min
- = SV (stroke volume) x HR (heart rate)
- a measure of flow rate (mL/min)
cardiac output
= systolic BP - diastolic BP
pulse pressure (PP)
= pulse pressure x 1.7
stroke volume
- sound of mitral valve closing at the beginning of systole
- soft/absent because the mitral valve doesn’t completely close
S1 heart sound
- beginning of diastole when aortic and pulmonary valves close
S2 heart sound
normal heart sounds consist of which heart sounds
S1 and S2
- early diastole when ventricle is dilated and filling
- can be normal in children or a sign of ventricular dysfunction in adults
S3 heart sound
- end of diastole
- caused by ventricular filling and atrial contraction
- absent in atrial fibrillation [AFib]
S4 heart sound
- ventricular contraction
- top number
systolic bp
- ventricular relaxation
- bottom number
diastolic bp
superficial pulse points
- superficial temporal artery
- facial artery
- common carotid artery
- brachial artery
- radial artery
- femoral artery
- popliteal artery
- posterior tibial artery
- dorsalis pedis artery
systolic bp < 120
diastolic bp < 80
normal blood pressure
systolic bp: 120-129
diastolic bp: < 80
elevated blood pressure
systolic bp: 130-139
or
diastolic bp: 80-89
stage 1 of hypertension
systolic bp: 140 or HIGHER
or
diastolic bp: 90 or HIGHER
stage 2 of hypertension
systolic bp: > 180
and/or
diastolic bp: > 120
hypertensive crisis
- the RR interval of the pause is equal to the two preceding RR intervals
- almost always located in the AV node, meaning QRS duration is usually narrow
1st degree heart block
- typically occurs in individuals with structural heart disease, w/ or w/o heart failure, and ischemic coronary artery disease
- a type of arrythmia that occurs when the electrical signal that controls the heartbeat starts from an unusual location in the upper chambers (atria) adn rapidly repeats, causing the atria to beat too quickly
atrial tachycardia (AT or ATach)
- ventricles are rapidly generating their own abnormal beats
- patient iwll need to be shocked if they are unresponsive
- occurs when ventricles beat too fast to pump well and the body doesn’t receive enough oxygenated blood
- 170+ bpm
ventricular tachycardia (VT or VTach)
sounds created by the release of blood as the blood pressure cuff loosens
sounds of Korotkoff
- systolic bp
- tapping sound when cuff pressure is 110-120 mmHg
1st korotkoff sound
- when the sound of the pulse disappears
- diastolic bp
5th korotkoff sound
- a type of irregular heart beat in which the heart chambers contract in a very rapid and uncoordinated manner
- the heart doesn’t pump blood to the rest of the body
- 300bpm
- very disorganized
- no P or QRS waves
- patient needs to be defibrillated immediately
ventricular fibrillation (VFib)
- 0 bpm
- CPR asap
- heart’s electrical system fails entirely, which causes your heart to stop pumping
- “flat lining”
- NOT SHOCKABLE
asystole
- elevated ST segment (that should be isoelectric)
- normal heart rate
- a type of severe heart attack caused by a complete blockage of a coronary artery
- extremely serious and can be life threatening
(STEMI) myocardial infarction
usually results from severe coronary artery narrowing, transient occlusion, or microembolization of thrombus and/or artheromatoous material
NSTEMI myocardial infarction
sound made when AV valves close
LUB
sound made when semilunar valves close
DUP
heard as swishing or screeching sounds
murmurs