ECG & Blood Pressure Physiology

equation for mean arterial pressure (MAP)

MAP = diastolic pressure + 1/3 pulse pressure

how do the changes in duration of systole compare with the changes in the duration of diastole?

as heart rate increases, the duration of BOTH systole and diastole shorten, but DIASTOLE experiences a GREATER DECREASE because the heart is at rest for an even shorter amount of time

at what point would you expect to see END-SYSTOLIC VOLUME?

at the end of t wave after ventricular systole

which electrical event immediately precedes ATRIAL SYSTOLE?

atrial depolarization - p wave

which electrical event immediately precedes ATRIAL DIASTOLE?

atrial repolarization - QRS complex

Why is mean arterial pressure not equal to (systolic pressure - diastolic pressure)/2?

because the ventricles spend more time in diastole

what occurs in the duration of systole and diastole post-exercise?

both SHORTENED

how does the duration of cardiac cycle change during the respiratory cycle?

bpm is HIGHER at start of INHALE bpm is LOWER at start of EXHALE

the first sound is known as individuals ______ pressure

systolic

equation for pulse pressure

systolic pressure - diastolic pressure

which electrical event immediately precedes VENTRICULAR SYSTOLE?

ventricular depolarization - QRS complex

which electrical event immediately precedes VENTRICULAR DIASTOLE?

ventricular repolarization - t wave

in a sphygmomanometer, where is the deflated bag and cuff placed on the arm?

1 inch above the antecubital space

how many electrical leads will be placed on the subject during a ECG?

3 leads

describe the physiological feedback cycle associated with the changes in heart rate and blood pressure when EXERCISING

when one exercises, there is a... 1. increases in venous return due to the skeletal muscle pump 2. stretch in atria stimulates cardiovascular center in the medulla = SA node stimulated to depolarize FASTER (INCREASING heart rate) 3. baroreceptors send information to CV to decrease parasympathetic NS and increase sympathetic NS to increase cardiac output and vasoconstriction (INCREASING blood pressure)

explain the physiologic feedback cycle associated with INHALE RESPIRATORY SINUS ARRYTHMIA

when one inhales, there is a... 1. decrease in intrathroacic pressure 2. increase in venous return 3. increase in blood volume 4. stretch in atria stimulates cardiovascular center in the medulla = SA node stimulated to depolarize FASTER

describe the physiological feedback cycle associated with the change in heart rate and blood pressure when MOVING FROM SUPINE TO SEAT POSITION

when one moves from supine to seated, there is a... 1. change in gravitational force detected by baroreceptors 2. info is sent to CV center in medulla 3. medulla instructs sympathetic/parasympathetic nervous system to control the heart and vasoconstriction of blood vessels

what is the isoelectric line of the ECG?

when zero activity is IDENTIFIED in the heart

explain the relationship between heart rate (BPM) and the length of a single cardiac cycle?

INCREASE heart rate = SHORTENED cardiac cycle

why is your blood pressure the lowest in supine position?

your heart does not have to pump blood against gravity

bpm is _________ when breathing in

faster

Name an artery other than the brachial that could be used for an indirect measurement of blood pressure.

femoral artery, radial artery, popliteal artery

pulse pressure

force the heart has to work to go from relaxation to contraction

diastolic pressure

pressure in arteries when ventricle is in diastole

systolic pressure

pressure in arteries when ventricle is in systole

where is the ground electrode placed?

right ankle (BLACK)

where is the negative electrode placed?

right forearm (WHITE)

bpm is _________ when breathing out

slower

normal blood pressure

120/80

when do you stop pumping the bulb?

150-160 mmHg

at what point would you expect to see END-DIASTOLE VOLUME?

QRS complex after atrial systole

oscillometric method

converting vibrations caused by the movement of blood through the brachial artery to a digital reading

as heart rate decreases, systolic blood pressure ______________

decreases

as heart rate increases, duration of ventricular diastole ______________

decreases

as heart rate increases, duration of ventricular systole ______________

decreases

as heart rate decreases, diastolic blood pressure ______________

decreases (minimally)

the last sound is known as individuals ______ pressure

diastolic

how is diastolic pressure used as an estimate of heart health?

diastolic pressure is the minimum value when the heart is at REST, so it should not be high or else that signifies some type of issue

is increased heart rate associated with increased or decreased duration of individual ECG components?

increased heart rate = decreased duration of ECG

as heart rate decreases, duration of ventricular diastole ______________

increases

as heart rate decreases, duration of ventricular systole ______________

increases

as heart rate increases, systolic blood pressure ______________

increases

as heart rate increases, diastolic blood pressure ______________

increases (minimally)

pulse pressure _________ as heart rate ___________

increases; increases

where is the positive electrode placed?

left ankle (RED)