Stress Echocardiography

Conventional indications for stress echocardiography (SE) are similar to those for a nuclear scan. This modality permits the assessment of ischaemia (the development of a new wall motion abnormality or worsening of an existing one at high doses of stress) and viability (low dose augmentation of function at a low dose in a previously impaired segment of myocardium). 

The main stressors used in echocardiography are exercise (treadmill) and intravenous dobutamine. The former avoids the need for a cannula or drug infusion and is preferred in patients able to exercise. Acoustic windows must be identified shortly after the patient transfers from treadmill to couch since the effects of exercise wane within minutes.

For those that can't exercise, IV dobutamine is given in a stepwise protocol with additional atropine for patients who do not reach target heart rate. Stored loops are evaluated in a side-by-side quad screen layout showing images at baselines, low dose, high dose and peak stress. Image interpretation has been facilitated by scanner developments and the introduction of trans-pulmonary contrast, which opacifies the left ventricular cavity and improves endocardial border definition. Three-dimensional echocardiography offers the possibility of a single heart-beat entire volume acquisition during stress which may be most useful for patients with atrial fibrillation.

Page last edited: 24 November 2010