In the presence of a grade III/VI murmur found during examination of an infant, what is suggested when seeking to establish a diagnosis of a ventricular septal defect?

For diagnosing a ventricular septal defect (VSD), conducting an echocardiogram is the preferred method. An echocardiogram allows for direct visualization of the heart's structure and can effectively identify the presence of a ventricular septal defect, as well as assess its size, location, and the hemodynamic impact it may have on the infant.

The echocardiogram is non-invasive, does not require sedation, and provides real-time images of the heart, making it an ideal first-line diagnostic tool in this situation. The information obtained from an echocardiogram is crucial for forming an accurate diagnosis and determining the appropriate course of management or intervention.

Other modalities such as a CT angiogram involve exposure to radiation and contrast, which is typically unnecessary for the initial evaluation of VSD in an infant. While an electrocardiogram can provide indirect information about heart function and potential complications associated with VSD, it does not offer the anatomical specifics required to establish the diagnosis. Cardiac catheterization, although a useful tool in some cases, is more invasive and usually reserved for cases where non-invasive imaging does not provide sufficient information or when intervention is directly needed. Therefore, conduct an echocardiogram is the most logical and appropriate first step