Panic attacks and myocardial infarction share very similar symptoms and can be difficult to distinguish. If it is your first attack or the episode presents differently from usual — such as pain radiating to the left arm or jaw, cold sweats, nausea, or chest pain lasting more than 30 minutes — call 119 (emergency services) immediately or go to the ER for an ECG and cardiac enzyme test. Suicidal ideation or thoughts of self-harm accompanying the attack also require immediate emergency response. If you have already been diagnosed with panic disorder and your attack pattern is consistent, you can first try breathing techniques and acupressure to stabilize before deciding on an ER visit.