Second Most Common Heart Attack Symptom Is Considered 'Atypical,' May Cause More Deaths KEY POINTS Heart attack patients with atypical symptoms are less likely to receive emergency help, a study finds The study also said patients with atypical symptoms are more likely to die within 30 days compared to those with chest pain Atypical symptoms include breathing difficulties, extreme exhaustion and abdominal pain, with the first being the most common Breathing problems and other "atypical" symptoms of heart attacks are often overlooked, resulting in a higher risk of death among patients with these symptoms compared to those who experience chest pain, according to a recent study.