Cardiac CycleThe 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 patients cardiac output.

Wave InterpretationP Wave = contraction of atriaPQ Wave = signal arrives at AV node slowing down a bit to allow ventricles to fill with bloodQ Wave = signal moves to Bundle of His and divides into the bundles and Purkinje fibersR Wave = contraction of left ventricleS Wave = contraction of right ventricleT Wave = ventricles relaxing

Rule of 300Take 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 fast, this method only works for regular rhythms.(300 / 6) = 50 bpm

What is the heart rate?(300 / 1.5) = 200 bpm

10 Second RuleAs 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

PulseHeart RatePulsePressure wave of bloodMonitored at pressure points in arteries where pulse is easily foundPulse averages 7080 beats per minute at rest

Blood PressureMeasurements by health professionals are made on the pressure in large arteriesSystolicpressure at the peak of ventricular contraction Diastolicpressure when ventricles relaxWrite 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