Download EKG and blood pressure

Cardiac Cycle
► The
two atria contract at the same time,
then they relax while the two ventricles
simultaneously contract.
► The contraction phase of the ventricle
chambers is called systole.
► The relaxation phase is called diastole.
► At a normal heart rate, one cardiac cycle
last for 0.8 seconds!
Electrocardiogram?
The electrocardiogram (EKG
or ECG) is a graphic display
of the electrical events of
the cardiac cycle.
Each event has a
distinctive waveform, the
study of which can lead to
greater insight into a
patient’s cardiac output.
Wave Interpretation
►P
Wave = contraction of atria
► PQ Wave = signal arrives at AV node slowing
down a bit to allow ventricles to fill with blood
► Q Wave = signal moves to Bundle of His and
divides into the bundles and Purkinje fibers
► R Wave = contraction of left ventricle
► S Wave = contraction of right ventricle
► T Wave = ventricles relaxing
Rule of 300
(300 / 6) = 50 bpm
►Take
the number of “big boxes” between
neighboring QRS complexes, and divide this into
300. The result will be approximately equal to the
heart rate
►Although
rhythms.
fast, this method only works for regular
What is the heart rate?
(300 / 1.5) = 200 bpm
10 Second Rule
►As
most EKGs record 10 seconds of
rhythm per page, one can simply count the
number of beats present on the EKG and
multiply by 6 to get the number of beats per
60 seconds.
►This
method works well for irregular
rhythms.
What is the heart rate?
33 x 6 = 198 bpm
Pulse
“Heart Rate”
►Pulse
 Pressure wave of blood
►Monitored
at “pressure
points” in arteries
where pulse is easily
found
►Pulse averages 70–80
beats per minute at
rest
Blood Pressure
►Measurements
by health professionals are
made on the pressure in large arteries
 Systolic—pressure at the peak of ventricular
contraction
 Diastolic—pressure when ventricles relax
 Write systolic pressure first and diastolic last
(120/80 mm Hg)
►Pressure
in blood vessels decreases as
distance from the heart increases
Measuring Arterial Blood Pressure
Measuring Arterial Blood Pressure