When teaching a patient with stable angina who is about to be discharged from the hospital, it's crucial to ensure they understand the signs of worsening condition and when to seek medical help. Among the provided options, the most vital information to convey is:
Get medical help if one dose of nitroglycerine does not stop the pain.
This is because stable angina is characterized by predictable patterns of chest pain that typically resolve with rest and/or nitroglycerin. If the angina pain does not respond to nitroglycerin, which is intended to alleviate this pain, it may indicate that the angina has progressed to unstable angina, which is a medical emergency requiring prompt evaluation and treatment.
While the other options contain important information, this particular point about the ineffectiveness of nitroglycerin is a critical sign that should not be overlooked.