Friday, 24 September 2010

MRCP revision battle 19.7: Exercise tolerance tests

Exercise tolerance tests are starting to go out of fashion but are still currently a mainstay of assessment of angina. 

I'd recommend this BMJ article for a comprehensive discussion; what follows below are just a few salient MRCP points.

ETTs are carried out according to the Bruce protocol, which is 7 sections each 3 minutes long so a maximum of 21 minutes of exercise.  A modified bruce can be used in higher risk/frailer patients.

Beta blockers must be stopped the day before an ETT
Digoxin should be stopped a week before.

The test is deemed to be positive if:
  • anginal symptoms
  • BP decreases by 15mmHg or fails to increase on exercise
  • arrhythmia
  • ST depression
  • failure to achieve target heartrate (220-age in men, 210-age in women)
  • ST elevation

Now for the last battle of the day, lead poisoning