Discussion
The Discovery of dilated coronary sinus on echocardiography may further
lead to the exclusion of PLSVC. Non-invasive transthoracic
echocardiography study by agitated saline contrast can be easily
performed to confirm the related venous anomaly. Sub-aortic membrane
with PLSVC is usually presented with mild symptoms or asymptomatic in
younger age or in previously healthy adults [10]. In our case, the
patient with both persistence SVCs and subaortic membrane was presented
with mild symptoms. The coexistence of subaortic membrane and
persistence of both superior vena cava (SVCs) is a very rare condition
and only few cases are reported in the literature. A prevalence study by
Oliver et al. demonstrated that mild aortic regurgitation is common in
adult and non-progressive over time [11]. Some comprehensive study
evaluated that progression of subaortic stenosis in adults did not
coexistence with any case of an associated isolated PLSVC. Most patients
with subaortic membrane are at risk for faster progression and should be
monitored cautiously [10]. Therefore, most adult patients with PLSVC
and subaortic membrane should be reassured by symptomatic management.