Diagnosis of an isolated persistent left side superior vena cava by contrast echocardiography compared with invasive angiographic study.

Background: The prevalence of left side superior vena cava (LSVC) is low and usually invasive angiography is necessary to validate its presence. Non-invasive echocardiographic study is important for the diagnosis and definition of associated lesions. The aim of this study is to demonstrate the clinical feasibility and accuracy of diagnosing LSVC by contrast echocardiography.

Methods: Four cases were included in this study. They were aged from 41 to 75 years old, 1 male and 3 female, all in sinus rhythm, with mean heart rate 83 +/- 14 beat per minute. They all received transthoracic echocardiography and transesophageal echocardiography. Contrast material was rapidly infused from both left arm vein and right arm vein to evaluate the diagnostic value of contrast enhancement for LSVC. They also received invasive angiographic study as the diagnostic golden standard. An isolated persistent left side superior vena cava with drainage into the right atrium was considered to be present, supposing the following diagnostic criteria were met: (1) the presence of a dilated coronary sinus in parasternal long axis view of two-dimensional echocardiography; (2) earlier enhancement of the dilated coronary sinus than the right cardiac chambers after contrast material infusion into a left arm vein; (3) right cardiac chambers were enhanced earlier than the dilated coronary sinus after contrast material infusion into a right arm vein.

Results: All 4 patients received the complete studies without any complications during the study procedures. Correct diagnostic yields could be obtained even with or without other associated cardiac lesions.

Conclusions: According to the experiences obtained from this study, contrast echocardiography is safe and highly informative for the definite diagnosis of left superior vena cava with drainage into coronary sinus. Correct diagnosis could be obtained by contrast echocardiography in all four cases within this study. The accuracy was 100%, if the above three echocardiographic diagnostic criteria were adopted.