Sinus Rhythms Originate at the Sinus Node Normal

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 -100 bpm… �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 100160 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.