dobutamine stress echocardiogram or persantin nuclear stress test), noting that a stress ECG cannot be done on its own using pharmacological stress. It is important to ensure that the appropriate stress modality is ordered: if patients cannot walk at a reasonable workload, order an imaging pharmacological stress test (eg. 3 In the presence of a relative contraindication the test may still proceed if the benefit of identifying ischaemia outweighs the risk of performing the test. Relative contraindications include left main coronary stenosis, severe arterial hypertension, electrolyte abnormalities, hypertrophic obstructive cardiomyopathy and uncontrolled arrhythmia. Functional effect of stenosis not routinely assessedĪre there any contra-indications to testing?Ībsolute contraindications to cardiac stress testing include acute myocardial infarction (including the presence of new left bundle branch block ), high risk unstable angina, symptomatic severe aortic stenosis, uncontrolled arrhythmia causing symptoms or haemodynamic instability, unstable heart failure, acute pulmonary embolus and acute aortic dissection.Functional effect of stenosis not usually assessed, nor exercise capacity.High negative predictive value (especially in low to intermediate risk subjects).(Requires referral from specialist or consultant physician) False positives due to higher sensitivity/ diaphragmatic attenuation.False negatives in single vessel/circumflex territory ischaemia (increased sensitivity with cycle ergometry).Assessment of exercise capacity, cardiac structure/function.Lowest sensitivity of all stress tests: risk of false negative test.First line test in absence of contraindications.Cardiac stress test cost, performance, advantages and disadvantages 1,3,5,6 There are advantages and limitations to each of the different testing modalities for the evaluation of myocardial ischaemia ( Table 1). chronotropic incompetence), as well as risk assessment in the postinfarct, preoperative or high risk patient populations. Other indications include work-up for potential cardiac causes of dyspnoea (noting dyspnoea can be a cardiac equivalent symptom of CAD), and evaluation of the effects of exercise on valvular dysfunction, pulmonary pressures or arrhythmia (eg. The annual risk of cardiovascular mortality can be quantified from stress test results by measures such as the Duke treadmill score (low risk equating to 5% per year cardiovascular mortality). The main reason for cardiac stress testing is the risk stratification of known or possible CAD. When should cardiac stress testing be ordered? A detailed discussion of other tests for the noninvasive assessment of CAD, such as nuclear stress testing or computerised tomography (CT) coronary angiography, is beyond the scope of this article. 1,2Ĭardiac stress testing includes stress electrocardiography (ECG) – also known as exercise stress test (EST) – and stress echocardiography. Cardiac stress testing is useful in the risk stratification of chest pain noting that 15–39% of angiograms performed are normal. Coronary angiography is the gold standard for identifying CAD, although it is invasive and not without risk of complication. Coronary artery disease (CAD) affects over 600 000 Australians and is implicated in approximately one in 5 deaths.
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