Download Sinus Rhythms

Originate at the Sinus Node
 Normal Sinus Rhythm (NSR)
 Sinus Bradycardia
 Sinus Tachycardia
 Sinus Arrhythmia
NSR
 Technically, it is not an arrhythmia because it is a
normal , rhythmic pattern.
 Arrhythmia, dysrhythmia, or rhythm all used
interchangeably
Since the SA node inherently fires
at a rate of 60-100bpm…
 If the EKG rhythm is slower or faster, it is not
considered a normal sinus rhythm.
If ANY measurements fall outside
of the normal limits…
 It is not a NSR.
Rules for NSR
 Rate: 60-100 bpm
 P wave: uniform shape: one P wave in front of every
QRS complex
 PRI: .12-.20 seconds and constant
 QRS: less than .12 seconds
Sinus Bradycardia
 When a rhythm originates in the sinus node, but the
rate is slower than 60 bpm.
Rules for Sinus Bradycardia
 Regularity: regular
 Rate: The atrial and ventricular rates are equal;heart
rate is less than 60 bpm
 P wave: there is a uniform P wave in front of every QRS
complex.
 PRI: The PR interval measures between .12 and .20
seconds; the PRI measurement is constant across the
strip.
 QRS: The QRS complex measures less than .12
seconds.
Sinus Tachycardia
 When the rate is more than 100 bpm.
 Rules are the same, except rate is usually between 100-
160 bpm.
Sinus Arrhythmia
 The rate changes with the patient’s respirations.
 When breathing in, the rate increases; when breathing
out, the rate decreases.
 Causes an irregular R-R interval.