Cardiology In Critical Care

Arrhythmia Recognition

Sinus Bradycardia (SB)

Sinus Bradycardia

Similar to normal sinus rhythm except that the rate is less than 60/min in adults and older children or less than 80 in younger children.  The PR interval may be slightly prolonged and/or P wave abnormally wide.  Physiological bradycardia occurs in healthy individuals (usually athletes) with increased vagal tone.  Exercise or atropine always increase the rate to normal.  Pathological bradycardia occurs in subjects with acute myocardial infarction (especially inferior) or other heart disease involving the SA node, in subjects taking drugs such as digitalis or beta blockers and in elderly subjects.  Exercise or atropine often fail to increase the rate to normal.

Rhythm P Wave PR Interval
(in seconds)
(in seconds)
< 60 bpm Regular Before each QRS, identical .12 to .20 < .12

There have been Visitors to this website.

Return to Nurse Bob's™ Page