Common Rhythm strips:

    • Rate: 60-99 bpm `

    • Rhythm: regular

    • QRS Duration: normal <0.12s

    • P Wave: visible before each QRS complex

    • P-R Interval: normal <0.2s

    • Fast rate >100 beats per minute

    • Rhythm: regular

    • QRS Complex: narrow

    • P Wave: present

    • Each P wave is followed by a QRS complex

    • Possible causes: infection, fever, hypovolemia, pain, exercise etc.

    • Slow rate < 60 bpm

    • Rhythm: regular

    • Can be normal physiological variant in very fit individuals

    • Possible pathological causes: Disease of the sino-atrial node, problems with conduction through the atrioventricular node, medication, electrolyte disturbance, raised intracranial pressure, infection etc.

    • Rate: usually 100-160 bpm but slower if on medication – can have AF but be rate controlled.

    • Rhythm: irregularly irregular

    • QRS Duration: usually normal

    • P Wave: not distinguishable as the atria are firing randomly

    • P-R Interval: not measurable

    • The atria fire electrical impulses in an irregular fashion causing irregular heart rhythm

    • Causes: heart failure, hypertension, cardiac ischaemia, mitral valve disease, pneumonia, alcohol etc

    • Broad complex tachycardia originating in the ventricles

    • Rate: very fast > 100 bpm

    • QRS duration: wide >120ms

    • No P waves

    • Can be sustained (duration >30 seconds) or non-sustained 3 or more consecutive ventricular complexes.

    • Causes: MI or myocardial ischaemia, medications that prolong QT interval, electrolyte imbalance. 

    • Signs and symptoms: angina, syncope, dizziness, palpitation, hypotension 

    • Treatment = if no pulse CPR = shockable rhythm.

Look at the following rhythms and try to identify them:

  • Sinus tachycardia

  • Sinus bradycardia

  • Sinus rhythm

  • Ventricular Tachycardia (VT)

  • Atrial Fibrilation