Ms. H is a 34 year old female. She has no past medical history. She is presenting to your office for a physical prior to training for her yearly marathon. What are the findings on her EKG?
| Rate | 42. QRS complexes following each p wave. |
| Rhythm | Normal Sinus Rhythm |
| Axis | Normal |
| Conduction | QRS <0.12s |
| Hypertrophy | None |
| Infarction | No Q waves. No ST-T abnormalities |
The only abnormality on this EKG is sinus bradycardia.
The easiest method to calculate the rate with slow or irregular rhythms is to count all the complexes along the rhythm strip (which is 10s) and multiply by 6.
Before ascribing a diagnosis of sinus bradycardia, it is important rule out a second degree heart block by making sure that there are no hidden p waves . Sinus bradycardia, as in this case, can be a normal finding in athletic individuals, but can also be seen in sleep, hypothyroidism and states of increased parasympathetic activity. A Mobitz type II heart block, however, is an unstable rhythm and is an indication for pacemaker insertion.
Review the RVH tutorial .