Wednesday, July 18, 2012

Incidence of cardiac rhythms as determined by Paramedics on an ALS ambulance

The following are the incidence of various cardiac rhythms as determined by the treating Paramedic for an ALS ambulance from October 2007 to June 2012. Outlier data were examined for correctness, including all interpretations of rhythms with less than 2% incidence. Incomplete data for each record was added if available, otherwise the record was ignored. AV Nodal Blocks and Bundle Branch Blocks were not recorded in this data set.

  • Patients: 3528 (47% male)
  • Age: 8 hours - 110 years (avg 56 yr, median 60 yr)

  • First Contact Heart Rate (>0): 22-260 bpm (avg 91 bpm, median 90 bpm, stdev 29.5)


  • First Contact Rhythm:
Count Rhythm
184152.18%Normal Sinus Rhythm
99528.20%Sinus Tachycardia
1454.11%Paced Rhythm
1393.94%Sinus Bradycardia
1143.23%Atrial Fibrillation
882.49%Asystole
681.93%Sinus Arrhythmia
671.90%Atrial Fibrillation w/ RVR
190.54%Pulseless Electrical Activity
180.51%Supraventricular Tachycardia
110.31%Ventricular Fibrillation
100.28%Atrial Flutter
50.14%Ventricular Tachycardia
40.11%Junctional Rhythm
20.06%Idioventricular Rhythm
10.03%Ectopic Atrial Tachycardia
10.03%Junctional Tachycardia

2 comments:

Jarvik 7 said...

Incidence of paced rhythm > SB and AF! That is surprising to me and very interesting; what is particularly thought provoking is how this incidence data would compare to that of other geographical regions with different demographics (eg. economic, access to insurance, access to care, proximity to university med. cen., ethnic, educational, etc.).

Also, how does the incidence based on paramedic/ prehospital dx reflect the incidence in the general population as determined by MD dx (excluding morbid rhythms), or how does pre-hospital dx reflect ED dx? Where are the disparities, and why?

Thanks for making me think about this stuff!

Christopher said...

Our population is older (2 nursing homes introduce bias) and less insured (low median income).

If you include AF w/ RVR then atrial fibrillation has a higher incidence than paced rhythms.

I did find it interesting that sinus brady was lower in incidence, but perhaps that is due to sampling bias: patients that paramedics decide to place on the cardiac monitor.

My favorite was the median heart rate! Ambulatory holter monitoring usually shows a rate in the mid 70's or mid 60's depending on the age group.

I just wanted to see how prevalent dysrhythmias were for a single ambulance, and I enjoyed it!