Exercise tolerance testing

Question 1

ETT sensitivity and specificity

Answer 1

Sens 78%, Specificity 70%

[ For example, in a low risk population, such as men aged under 30 years and women aged under 40, a positive test result is more likely to be a false positive than true.

In a high risk population, such as those aged over 50 with typical angina symptoms, a negative result cannot rule out ischaemic heart disease]

Question 2

How many stages in bruce protocol?
How is assessment of workload measured in ETTS ?

Answer 2

The protocol has seven stages, each lasting three minutes, resulting in 21 minutes’ exercise for a complete test. In stage 1 the patient walks at 1.7 mph (2.7 km) up a 10% incline.
Energy expenditure is estimated to be 4.8 METs (metabolic equivalents) during this stage.

metabolic equivalents (METs)

Question 3

How much O2 do you need for 1 MET?
How many mets for ADLS

Answer 3

1 MET is 3.5 ml oxygen/kg per minute

activities of daily living require an exercise intensity of at least 5 METs is require

Question 4

What drugs need to be withheld for ETTS

Answer 4

B blockers - on day of test
Digoxin - 1 week (ST segment abnormalities)

Question 5

What is maximum predicted heart rate? What is satisfactory for ETT

Answer 5

220 (210 for women) minus the patient’s age

Satisfactory = reaching 85% max predicted

Question 6

What ECGs are taken before ETT

Answer 6

sitting and standing, are recorded as electrocardiographic changes, particularly T wave inversion, may occur as the patient stands up

Question 7

Contraindications for ETT

Answer 7

Acute myocardial infarction (within 4-6 days)
Unstable angina (rest pain in previous 48 hours)
Uncontrolled heart failure
Acute myocarditis or pericarditis
Acute systemic infection
Deep vein thrombosis
Uncontrolled hypertension (systolic blood pressure >220 mm Hg, diastolic >120 mm Hg)
Severe aortic stenosis
Severe hypertrophic obstructive cardiomyopathy
Untreated life threatening arrhythmia
Dissecting aneurysm
Recent aortic surgery

Question 8

What are the normal ECG changes with exercise

Answer 8

The J point becomes depressed

[P wave increases in height
R wave decreases in height
J point becomes depressed
ST segment becomes sharply upsloping
Q-T interval shortens
T wave decreases in height]

Normal changes from rest (A), after three minutes’ exercise (B), and after six minutes’ exercise (C). Note the upsloping ST segments

Question 9

What is the key abnormal ECG change during exercise?

Answer 9

ST segment response is horizontal (planar) or downsloping depression of >1 mm

Horizontal ST segment depression of ⩽ 2 mm
Downsloping ST segment depression
Early positive response within six minutes
Persistence of ST depression for more than six minutes into recovery
ST segment depression in five or more leads
Exertional hypotension

[bottom image during exercise]

Question 10

ETT shows this on exercise - normal or not?

Answer 10

Pathological ST segment depression as measured 80 ms from J point

Question 11

ETT shows this on exercise - normal or not?

Answer 11

Normal - Note the upsloping ST segments

Question 12

ETT shows this on exercise - normal or not?

Answer 12

Abnormal - downsloping ST segment depression

Question 13

ECG shows this - normal or not?

Answer 13

Abnormal - Persistence of ST depression for more than six minutes into recovery