Presentation on theme: "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."— Presentation transcript:
1 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!
2 Cardiac Cycle Continued…. Cardiac Cycle = “events of one complete heart beat”Mid-to-late diastole (relaxation) = blood flows into ventriclesVentricular systole (contraction) = blood pressure builds before ventricles contract pushing blood outEarly diastole = atria finish re-filling; ventricular pressure is low
5 What is an 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.
7 Wave Interpretation P Wave = contraction of atria PQ 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
9 Rule of 300Take the number of “big boxes” between neighboring QRS complexes, and divide this into The result will be approximately equal to the heart rateAlthough fast, this method only works for regular rhythms.
13 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.
15 Pulse “Heart Rate” Pulse Pressure wave of bloodMonitored at “pressure points” in arteries where pulse is easily palpatedPulse averages 70–76 beats per minute at rest
16 Blood PressureMeasurements by health professionals are made on the pressure in large arteriesSystolic—pressure at the peak of ventricular contractionDiastolic—pressure when ventricles relaxWrite systolic pressure first and diastolic last (120/80 mm Hg)Pressure in blood vessels decreases as distance from the heart increases