What causes Prinzmetal angina?

Unlike typical exertional angina, a coronary spasm may occur while resting, often at night or in the early morning. The artery narrows briefly, limiting oxygen delivery and causing pressure, tightness or pain in the chest. Cold exposure, emotional stress, smoking and some medicines or recreational drugs can provoke spasm in susceptible people. High blood pressure and other vessel problems may coexist, but a spasm can occur without a major fixed blockage. Symptoms may come and go, so an episode that settles still deserves medical assessment.

Stop activity, sit upright and use any prescribed reliever exactly as directed. Arrange a medical review for recurring episodes. Assessment may include an ECG, blood tests and a review of cardiovascular risks and medicines. Treatment can involve medicines that relax coronary arteries; the choice depends on the diagnosis and your wider health. Do not start, stop or share heart medicines. Avoid smoking and tell the clinician about supplements, migraine medicines and recreational substances.

Call emergency services for chest pain that is severe, prolonged, new, or associated with sweating, nausea, faintness, breathlessness or pain spreading to the arm, jaw or back. Do not drive yourself. A new episode should be treated as potentially urgent because spasm and a heart attack can feel similar. If symptoms have stopped, seek prompt clinical advice rather than waiting for another episode.

Could my symptoms be caused by coronary spasm or another form of angina? Which tests are appropriate? What should I do during an episode, and could any medicine or substance be triggering it?