What medications, such as beta-blockers (e.g. metoprolol, atenolol), nitrates (e.g. nitroglycerin), and anti-arrhythmic medications, should be held before an exercise stress test?

Medications to Hold Before an Exercise Stress Test

Beta-blockers should be held for 24-48 hours before an exercise stress test when the test is performed for diagnostic purposes to detect ischemia, as they can significantly attenuate heart rate and blood pressure responses, limiting the diagnostic value of the test. 1

Beta-Blockers

Beta-blockers are the primary medications that should be considered for discontinuation before an exercise stress test:

• Common beta-blockers to hold:

  • Metoprolol (hold for 24-48 hours)
  • Atenolol (hold for 24-48 hours)
  • Bisoprolol (hold for 24-48 hours)
  • Propranolol (hold for 24-48 hours)

• Rationale: Beta-blockers attenuate heart rate and blood pressure responses to exercise, which can mask ischemic changes and reduce the sensitivity of the test for detecting coronary artery disease 1.

• Discontinuation method: When discontinuing beta-blockers, consider using half the prescribed dose on the morning of the test rather than abrupt discontinuation to avoid rebound phenomena, which could include tachycardia, increased blood pressure, or worsening angina 2.

Other Cardiovascular Medications to Consider Holding

Nitrates

• Long-acting nitrates (e.g., isosorbide mononitrate, isosorbide dinitrate) should be held for 12-24 hours before the test 1.
• Short-acting nitroglycerin can be used as needed for symptoms but should be noted if used before testing.

Calcium Channel Blockers

• Non-dihydropyridine calcium channel blockers (diltiazem, verapamil) should be considered for holding as they can have negative chronotropic effects similar to beta-blockers 1.
• These medications may need to be held for 24 hours before the test.

Anti-arrhythmic Medications

• Class I and III anti-arrhythmic agents may need to be held as they can affect ECG interpretation and heart rate response 1.
• Amiodarone typically does not need to be discontinued due to its long half-life.

When to Continue Medications

• If the purpose of the test is to evaluate the effectiveness of the current medication regimen or to assess functional capacity rather than diagnose ischemia, medications should be continued 1.
• For patients with high cardiovascular risk or unstable symptoms, the decision to hold medications should be made on a case-by-case basis, weighing the diagnostic benefits against safety concerns.

Practical Recommendations

1. For diagnostic tests: Hold beta-blockers, calcium channel blockers, and nitrates for 24-48 hours if the primary purpose is to detect ischemia.

2. For functional capacity assessment: Continue all medications if the purpose is to evaluate exercise tolerance on current therapy.

3. Documentation: Always record which medications were taken or held before the test, as this information is crucial for proper interpretation of results.

4. Communication: Clear instructions should be provided to patients regarding which medications to hold and when to hold them before the test.

Potential Pitfalls

• Rebound phenomena: Abrupt discontinuation of beta-blockers can lead to rebound tachycardia, hypertension, or angina. Consider tapering or using half-dose on the test day 2.

• False negative results: Failure to hold beta-blockers may result in false negative stress tests due to limited heart rate response 3, 4.

• Safety concerns: In high-risk patients, the benefits of continuing protective medications may outweigh the diagnostic advantages of holding them.