Symptoms. Heart murmurs don’t have symptoms unless they are accompanied by another condition or disease. These murmurs are discovered by the doctor during a routine check up or during a well baby exam. If the person does have a condition that involves a heart murmur, their extremities may be blue, they may suddenly gain weight, be short of breath, have a chronic cough and suffer chest pain and dizziness. Their liver and the veins in their neck may be abnormally large. Babies may fail to thrive.