Final answer:
Heart murmurs are typically present in patients with sinus venosus atrial septal defect, a congenital heart condition leading to abnormal openings in the heart's atrial septum and potentially causing significant symptoms if not treated.
Step-by-step explanation:
Heart murmurs are almost always present in patients with sinus venosus atrial septal defect, a condition characterized by an abnormal opening in the interatrial septum, specifically at the junction of the superior vena cava and the right atrium. The sinus venosus defect is a congenital heart defect that can lead to complications such as right atrial and ventricular enlargement due to the increased flow of blood through the lungs. Symptoms, which may be absent or mild in early life, can become more significant and lead to heart failure if left untreated; therefore, early diagnosis through physical examination and echocardiogram imaging is crucial for effective management.