cardiovascular assessment Flashcards
cardiovascular assessments
- blood pressure
- hydrostatic pressure
- ## ECG
blood pressure
- systolic is less than 160 mmHg and diastolic is less than 90 mmHg, it is good
- if both are greater than, physician clearance is recommended
what is blood pressure influenced by
- blood volume (contracted vs expanded)
- vascular resistance (dilation vs. constriction)
- cardiac output ( exercise increases CO)
afterload
- the pressure the heart needs to work against to eject blood during systole
- higher afterload = increased work
- elevated BP increases the afterload on the heart
- stroke work = sv x mean arterial pressure
- cardiac work = sw x hr
- elevated bp can also damage small vessels/ capillaries in end-organs = leakage
auscultation method
- listening to bodily sounds using a stethoscope
- krotokop sounds
- pumping cuff –> 0 blood flow, reducing pressure to allow blood flow to get back in.
- vibration is the blood flow through the arteries (bracial)
- highest pressure = systolic
- no more sound = diastole
Korotkoff sounds
phase 1: clear “tapping” (systolic pressure)
phase 2: softer tapping
phase 3: clear tapping ( mean arterial pressure)
phase 4: muffled tapping
phase 5: tapping disappears (diastole)
mercury monometer
- used for calibration
- measures using mmHg
bp machine (fancy computer)
- continuous measure of bp
- 5 minute intervals
- picks up bp every single heart beat
- $$$
automated cuffs
- sensors that pick up vibrations in brachial artery
- searches for peak MAP
- doesn’t actually measure systolic and diastolic pressures
intravenous catheter
- hooks up to pressure catheter
- measures pressure inside artery
- calibrated first
- complicated and invasive
- have to be trained to use
BP considerations
- individuals should be seated and relaxed, legs not crossed, not talking
- as soon as the lower limbs are engaged, it increased cardiac output, impeded venous return
- normally taken from the brachial artery, if no arm taken from lower leg
- cuff size should be appropriate
- inflated to 30mmHg above systolic pressure
- deflated at a rate of 2-3 mmHg/s (gives time to pick up sounds)
- systolic bp tends to be underestimated b/c you are waiting for a sound on beat
diastolic is usually overestimated - repeated measures should be separated by 1+ min, back-back could cause stress and blood clots
hydrostatic gradient
- relation to the heart
- amount of pressure exerted by a fluid column
- relationship to position of the heart
- because the artery is closer to the heart, hydrostatic gradient is decreased
hydrostatic pressure
- pressure = p (density of blood liquid) x gravity(9.81) x height
- +-0.8mmHg for every cm
- above arm = lower than actual by +-0.8mmHg
- below arm = higher than actual for ever cm
- important for arm amputees
heart rate cutoffs
- if bpm is 99 or less at rest, proceed with appraisal
- if bpm is greater than 99bpm after second reading, physician clearance is recommended
electrocardiography
- ECG=EKG
- the machine
- electrocardiogram is the tracing
- measures the electrical activity of the heart along different vectors
- uses to assess basic abnormalities in the heart
Scope of practice with ECGs
- a CSEP-CPT is not sanctioned by CSEP to use an ECG for any purpose ( not part of training )
- can not diagnose pathology based on assessment or observation
- can only find the HR and the normal range
- CANNOT see if the rhythm is regular, if the waves are in their proper form
what CAN the CSEP-CEP do under scope of practice
- measure and monitor HR
- monitor electrical activity of the heart using ECG
- measure BP at rest , during exercise, and post-exercise
- can identify irregularities during rest, sub-maximal, and maximal exercise .
lead
- consists of two terminals (pair of electrodes) that form an axis to provide a different view or tracing of the heart’s electrical activity
- is directional and aligned with a particular vector from the (-) electrode TOWARDS the (+) electrode
- the orientation of the lead (vector) in relation to the electrical current of the heart is what produces the ECG waveform
- leads can change, electrodes directions DO NOT
12-lead ECG
- also called precordial leads
- provides spatial information about the heart’s electrical activity in 3 orthogonal plans
- goes around the heart in a horizontal plane
- right –> left
- superior –> inferior
- anterior –> posterior
- leads are unipolar
- measure the change in electrical potential along a vector from the heart towards the electrode
3 limb lead ECG
- creates 6 vectors derived from the “limb” electrodes
- creates an ECG limb pattern through the atrium of the heart down through the ventricle
- geta finer look on different depolarizations in the heart
- different angles allow for this (aVF, aVR, aVL)
- purpose is to pick up different functions of the heart
- different for re and de polarization
bipolar leads
- 2 electrodes creating the leads
- the usual standard
- leads 1-3 on a 3 limb lead are considered bipolar
augmented (unipolar) limb leads
- use two electrodes to create a “null point” which is halfway compared to the third electrode
aVR
- augmented vector right
- pattern travels from the left atrium and leg lead as the initial , to meet in the middle/halfway to go to the right atrium
aVL
- augmented vector left
- pattern travels from the right atrium and the leg lead as the initial, to meet half way to reach the left atrium
aVF
- augmented vector foot
- pattern travels from the right atrium and the left atrium as the initial, to meet halfway to reach the leg lead
waves of the electrocardiography
- P = atria depolarization
- ORS = ventricle depolarization
- T = ventricle repolarization
- U = repolarization of purkinje cells and or/ papillary muscle of valves (hard to differentiate to pick up)
- R-R = 1 heart beat
extra waves if an electrocardiograph
- J point = transition point between the QRS complex and the ST segment
- PR interval = 0.12 - 0.20 sec, <2.5 mm in size
- QRS interval = 0.07 - 0.11 sec, 6-25-30mm in size
- ST segment= ventricular refractory period which should be smooth and gradual before repolarization , can be elevated ad depressed depending on what lead you are looking at
- QT interval = should be <1/2 the distance of RR interval, the ECG part that shortens during exercise
how to see measure the time of a HR
- gird divided into large and small squares where 1 large square = 5 small squares
- standard chart recorder speed : 25mm/sec
- one large square = 0.20s (one row)
- one small square = 0.04s
OR - count the number of boxes between a full cycle (RR)
equations for measuring HR
RR interval = (number of big boxes x 0.2) + (2 x 0.04) = s/beat
Method 2: 1500/ number of small boxes btw RR
tachycardia
- type of arrythmia
- rapid beating greater than 100 bpm at rest in an untrained adult
bradycardia
- beating less than 60 bpm at rest in an untrained adult
- symptomatic is less than 50 bpm
arrythmia
- abnormal rate, rhythm or conduction of electrical impulse in the heart
- multiple causes
- related to fever, dehydration, shock, hormonal imbalance, stress, cardiac abnormalities, and heart failure
premature ventricular contraction
- caused by the depolarization of the ventricle before atria can contract
- absence of P wave before another QRS complex
- extra beats occur under the influence of autorhythmic cells other than the SA node
- QRS and T waves look abnormal
- need to be treated when they occur as greater than 6 per/min
sinus pause
- failure of SA node firing
- no P wave
- usually fire because AV node picks up
third degree heart block
- no P wave
- AV node is off
- SA + AV node not coordinating
- ## usually signs of stress
S-T depressions
- unsloping, horizontal, and downsloping depressions
- depression/elevation of greater than 1.0mm 0.08s after J point
- can tell you about the arteries in the heart
- possible heart attack ( myocardial ischemia )
fibrillation
- uncoordinated atria or ventricle contractions caused by re-entry of electrical impulses and requires defibrillation
- EMERGENCY
- no RQRS waves
- some or no coordination/contraction
when to use ECG
- with untrained, older, or diseased individuals
- establishes a resting ECG looking for abnormalities
- record a tracing every workload during exercise for stress tests
- difficult however to obtain clear traces during high intensity exercise
- breathing may even cause oscillation in heart
normal EGC response in healthy individuals
- slight increase in P wave amplitude
- shortening of P-R interval
- shift to the right of QRS axis
- S-T segment depression of less than 1.0mm
- decreased T wave amplitude
- single or rare PVCs during exercise and recovery
- single or rare PVCs or PACs
abnormal ECG response with CHD
- appearance of bundle branch block at a critical HR
- recurrent of multifocal PVCs during exercise and recovery
- ventricular tachycardia
- appearance of bradyarrhythmias, tachyarrhythmias
- S-T segment depression/elevation of greater than 0.1mm 0.08s after J point
- exercise bradycardia
- submaximal exercise tachycardia
- increase in frequency of severity of any of above