Typical characteristics of angina symptoms should be assessed, including:
- How the patient senses their angina (chest, back, arm, shoulder, jaw)
- Type of activities/intensity of exercise that typically produces angina
- How the patient resolves the symptoms (rest, GTN)
- Severity of discomfort (scoring system out of 10)
TIP: When reviewing exercise tests, establish whether ischaemic ECG changes are accompanied by symptoms. A patient is at greater risk if ECG changes occur in the absence of overt symptoms.
The volume and territory of the possible ischaemia should be determined. A larger volume of affected myocardium implies a greater risk, as does anterior ischaemia compared with inferior wall ischaemia.
The following strategies can be considered to reduce physiological demand:
- Prescribe exercise using less volume of muscle mass – rowing ergometer > cycling > unilateral leg extension
- Prescribe small bouts of exercise with periods of rest – weight resistance or brief aerobic exercise
- Reduce the intensity of exercise
- Use prophylactic GTN
An important component of each exercise session is a warm-up and cool-down. Patients with exertional angina benefit from a very prolonged and gradual warm-up.
Prophylactic use of GTN
In consultation with the treating doctor, GTN can be used before or during exercise to prevent myocardial ischaemia.
Prophylactic GTN dilates the vasculature, increasing blood flow to the myocardium prior to the onset of symptoms. However, this systemic vasodilation may also reduce BP to the point of hypotensive symptoms. Therefore, BP should be recorded before and after GTN administration, both in a seated and standing position. Maximum dilation from GTN will occur within 5 minutes.