Determine the following:
Rhythm: _______________________________________
Rate: ___________________________________________
P waves: _______________________________________
PR interval: ____________________________________
QRS complex: __________________________________
What's your interpretation?
(Answers on next page)
Name that strip: Answers
Rhythm: Regular
Rate: 79 beats/minute
P waves: Sinus
PR interval: 0.16 to 0.18 second
QRS complex: 0.06 to 0.08 second
Interpretation: Normal sinus rhythm
Normal sinus rhythm (NSR) reflects the heart's normal electrical activity. The sinoatrial (SA) node normally initiates impulses at a rate of 60 to 100 beats/minute. Because this rate is faster than other pacemaker sites in the conduction system, the SA node retains control as the primary pacemaker of the heart. NSR originates in the SA node, and the impulse follows the normal conduction pathway through the atria, the atrioventricular node, the bundle branches, and the ventricles, resulting in normal atrial and ventricular depolarization.
NSR is regular with a heart rate between 60 and 100 beats/minute. The P waves are normal in size, shape, and direction and positive in lead II (a positive lead), with one P wave preceding each QRS complex. The duration of the PR interval and the QRS complex is within normal limits. Because NSR is the normal rhythm of the heart, no treatment is indicated.
Normal Sinus Rhythm: Identifying ECG Features
Rhythm: Regular
Rate: 60 to 100 beats/minute
P waves: Normal in size, shape, and direction; positive in lead II; one P wave precedes each QRS complex
PR interval: Normal (0.12 to 0.20 second)
QRS complex: Normal (0.10 second or less)