Background
A double-chambered left ventricle (DCLV) constitutes a rare congenital malformation. It is usually diagnosed at a neonatal or pediatric age, and often exhibits mixed criteria for diverticulae and aneurysms. This anomaly is characterized by the subdivision of the left ventricle into two chambers by an abnormal septum or muscle band. In this article, we present the case of 30-year-old asymptomatic patient, in whom DCLV was diagnosed by routine echocardiographic study.
Case presentation
We present the case report of a 30-year-old patient who was admitted to our outpatients’ clinic in order to perform a routine echocardiographic study that was necessary for his employment health check. He was asymptomatic, had no history of cardiac diseases, or any other chronic diseases. He reported no symptoms of heart failure, dyspnea, or chest pain. His physical examination was normal. Sinus rhythm was observed on the ECG, and no rhythm disturbances were seen.
Transthoracic echocardiography revealed normal left ventricle (LV) function (image 1). No valvular dysfunction or hypertrophy was observed. However, an additional cavity lying within the left ventricle was visualized in the 2-chamber (image 2) and 3-chamber (image 3) apical long axis views. The additional cavity of the LV was located in the postero-inferior LV wall. The cavity was not very visible in the traditional parasternal long-axis in 2D, and images in the 4 chamber apical view (image 1) were not very obvious for the pathology. The global LV systolic function was normal. The muscle of additional LV cavity thickened during systole, however, the myocardium was nonhomogenous with small lacunae. The ratio of spongy / compacted layers was about 1. No thrombus was seen. There was a septum dividing both cavities, which was rich in fenestrations and lacunae that enabled free flow between the two of them (image 3). Turbulent systolic inflow and diastolic outflow with high velocities was present in the pulse and color Doppler imaging (image 4). The final diagnosis was a double-chambered left ventricle (DCLV).
The patient was evaluated by a heart team and the decision was made for conservative treatment. He was advised to take anticoagulants to prevent potential, though relatively low, thrombotic complications of the pathology. He was also advised to get regular echocardiographic check- ups and is currently waiting for an MRI evaluation.
Current guidelines
In the literature, only a few case reports of a double-chambered LV have been described to date. When the Pub MED database was searched for “Double-chambered left ventricle” (DCLV), only 19 citations were found. The majority concentrated on single case reports. The DCLV etiology is not well known, but the anomaly is generally thought to be congenital if diagnosed late and is non-progressive. Gerlis et al. reported the largest number (3 cases), which consisted of patients who had endomyocardial fibroelastosis and cardiomyopathy. There were double-chambered ventricles in all three cases. All of those patients died in the first year of life from the cardiomyopathy1. A double-chambered ventricle occurring along with Tetralogy of Fallot is also described in the literature1. An extremely important point in defining the pathology is the differential diagnosis. It is reasonable to assume that echocardiography and computed tomography can aid in the detection of double-chambered ventricles. An MRI will characterize the condition better because of its higher spatial resolution and the ability for tissue characterization, especially with the differentiation between fibrosis and normal myocardium 2-4.
Detection of an accessory chamber in communication with the LV cavity needs special consideration, because an LV aneurysm or diverticulum can sometimes mimic a double-chambered LV. Therefore, a precise evaluation of their wall motion during systole and diastole as well as the width of their communication with the main LV cavity would help to differentiate between these entities 3-5. Even more important is that the treatment modalities are quite different for each of those pathologies. The diagnosis with the worst prognosis is an LV pseudo aneurysm which is a contained rupture of LV free wall. However, this is a disease that is the result of chest trauma, MI or endocarditis. An aneurysm of the LV is described as a wall that is thinner than the adjacent myocardial segments, while a diverticulum is an outpouching containing the endocardium, myocardium and pericardium. Both an aneurysm and a diverticulum, need to be resectioned when symptomatic 4-6.
Another diagnosis that should be taken into consideration is LV non-compaction. In our patient, the ratio between spongy and compact layer (about 1 in the systole) did not fulfill criteria of this cardiomyopathy.
Accessory cavities sequestrated by aberrant muscular ridges are not well recognized. Surgically, they may be resolved by a resection of the aberrant tissue (IV). Indications for surgery must be made for each individual case as there have only been few reports on this pathology. We decided on a conservative treatment for the patient. Our decision was made based on the fact that the patient was totally asymptomatic, had no history of thromboembolism and that there seemed to be a low probability of developing thrombus in the additional LV cavity. Moreover, it did not affect the proper global functioning of LV – which seemed essential point for us.
References
1. Gerlis LM, Partridge JB, Fiddler GI et al. . Two chambered left ventricle. Three new varieties. Br Heart J. 1981 Sep;46(3):278-84.
2. Nacif MS, Mello RA, Lacerda Junior OO, et al. Double-chambered left ventricle in an adult: diagnosis by CMRI. Clinics (SaoPaulo). 2010;65(12):1393-5
3. Amirghofran AA, Peiravian F, Karimi A, et al. .Triple-cavity left ventricle with an abnormal mitral valve apparatus. Ann Thorac Surg. 2010 Aug;90(2):e20-2
4. Makkuni P, Kotler MN, Figueredo VM. Diverticular and aneurysmal structures of the left ventricle in adults: report of a case within the context of a literature review. Tex Heart Inst J. 2010;37(6):699-705. Review.
