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