Problem: Summarize and paraphrase this A heart murmur is a whooshing or swishing sound heard through a stethoscope when blood flows abnormally over your heart valves. - A murmur is caused by turbulent or abnormal blood flow across your heart valves. - If blood is flowing more rapidly than normal, it can cause an innocent heart murmur (also called normal or physiologic). This type of murmur is common during: - Childhood. Want Online Tutoring?