QUESTIONS AND ANSWERS EXPERT
REVIEWED GRADED A+
●● PR interval.
Answer: measured from the beginning of the P wave to the beginning of
the Q wave. should be < 200ms, result of delay in conduction at AV node
●● QRS Complex.
Answer: Ventricular depolarization, should be <120ms
●● ST Segment.
Answer: Measured from the end of the S wave to the beginning of the T
wave. M.I., muscle injury or pericarditis will elevate. Myocardial
ischemia will depress.
●● T wave.
Answer: Ventricular repolarization. < 5mm high in limb leads and
<10mm high in precordial leads. tall or spiked = hyperkalemia. short or
flat = hypokalemia.
●● Rate.
Answer: -Normal adult rate: 60-99bpm
, -Bradycardia < 60bpm
-Tachycardia:100-250bpm
-Flutter:250-350bpm
-Fibrillation:350-450bpm
●● Rate.
Answer: -SA node: 60-100bpm
-Atria:60-80bpm
-AV node: 40-60bpm
-Bundle branches: 40-60bpm
-Ventricles<40bpm
●● Sinus Rhythm.
Answer: Electrical impulse originates from the SA node. Will always
produce an upright P wave in lead II.
●● Normal Sinus Rhythm.
Answer: Equal spacing between each beat and the rate is anywhere from
60-99bpm.
●● Sinus Bradycardia.
Answer: The rhythm is sinus, the rate is <60bpm