In adult patients, DCLV is most often detected incidentally during cardiac imaging rather than suspected clinically. In our case, the patient’s intermittent chest pain was assessed as noncardiac and is unlikely to have been caused by the DCLV. Therefore, the diagnosis was incidental rather than symptom-driven. Generally, the primary challenge lies in accurate interpretation of intracavitary left ventricular structures and differentiation from conditions such as left ventricular noncompaction, midventricular hypertrophic cardiomyopathy, ventricular diverticulum or aneurysm, and intracavitary thrombus [1,2,3]. Misclassification based solely on echocardiography has been reported and may lead to unnecessary anticoagulation or invasive procedures.

Echocardiography remains the first-line modality for detection of DCLV, allowing dynamic assessment of intracavitary structures and evaluation for features suggestive of significant obstruction. In the present case, no echocardiographic features suggestive of hemodynamically significant obstruction were identified. CMR imaging plays a key complementary role by providing precise anatomical definition, confirmation of myocardial continuity, synchronized contractility of both chambers, and tissue characterization to exclude fibrosis or thrombus, as well as definitive exclusion of interventricular shunting [4]. Three-dimensional transthoracic echocardiography (3D TTE) has the potential to provide more precise delineation of intracavitary structures and may reduce dependence on CMR for diagnosis. However, in this case, 3D TTE images were not available, and conventional multiplanar 2D imaging, together with CMR, provided sufficient diagnostic clarity.

Most reported adult cases are characterized by preserved global systolic function, absence of relevant intraventricular pressure gradients, and a benign clinical course [5]. Although DCLV is often isolated, it may occasionally coexist with small VSD, reflecting common embryologic pathways or developmental variations of the interventricular septum [5, 6]. Isolated reports of arrhythmias, intracavitary thrombus, or progressive obstruction suggest that the clinical spectrum may be broader. In asymptomatic patients without hemodynamic significance, a conservative approach with periodic clinical and echocardiographic follow-up appears appropriate, with repeat CMR reserved for evolving symptoms or changes on echocardiography.