Lecture 5: Exercise Electrocardiography

Question 1

How would you recognise Atrial Fibrilation (AF) on the ECG trace?

Answer 1

Individuals who suffer from the condition Atrial Fibrilation (AF) would show clear signs on an ECG. These are as follows:
The trace would be irregularly irregular meaning there is no clear pattern.
There would be an absence of P waves, instead there would just be a fibrillating baseline/iso-electric, also known as the ‘F-wave’.
The RR intervals would be irregular and erratic.
The risk of AF increases with athletes who participate in >2,000 hours of vigorous exercise.

Question 2

Describe the normal ECG changes during exercise? (Hill and Timmis, 2002)

Answer 2

The normal ECG changes we expect to see during exercise are as follows:
P wave increases in height
R and T wave decrease in height
J point becomes slightly depressed
QT segment is shortened
ST segment becomes sharply up-sloping

Question 3

Describe the electrocardiographic criteria for myocardial ischaemia during an exercise test?

Answer 3

ST segment depression measured at 80m/s-1 post J point. If depression is >1mm this is indicative of a positive test.
Down-sloping ST
ST depression in more than 5 leads
Persistence of ST depression 6min in to recovery
T-wave inversion must also be present to diagnose ischaemia, however only if it’s seen in conjunction with other factors not just on its own. Finally premature ventricular contractions must also occur which may give evidence there is a case to diagnose ischaemia.

Question 4

ECG - Ischaemia?

Answer 4

Ischaemia would be suggested if:
Horizontal ST segment depression of >2mm
Downsloping ST segment depression
Early positive response within the first 6 minutes - indicating low functional capacity.
ST segment depression in >5 ECG leads
Exertional hypotension