A case of giant diverticulum at the apex of the left ventricle
Introduction
Background
Congenital ventricular diverticulum is a rare congenital cardiac malformation, accounting for 0.05% of all congenital heart defects (1). Left ventricular diverticulum is relatively common, but its cause remains unclear. It has been speculated that this condition is related to congenital factors or potentially caused by myocardial ischemia resulting from viral infection or coronary artery abnormalities (2). Histologically, ventricular diverticula can be classified into two types: muscular and fibrous (3). This disease is usually diagnosed in childhood and often coexists with other congenital heart diseases (4), but most cases are asymptomatic and are usually discovered incidentally. The associated complications include myocardial infarction, arrhythmia, and heart failure, among others, with the most serious being diverticulum rupture, which can even lead to patient death. Echocardiography is the preferred examination method for cardiac diverticulum, and techniques such as computed tomography (CT), single-photon emission CT (SPECT), myocardial perfusion imaging, and ventriculography can also provide imaging evidence for diagnosis. Magnetic resonance imaging (MRI) can distinguish the characteristics of the surrounding tissue of the cyst wall. However, there is currently no unified treatment guideline for left ventricular diverticulum, and the treatment plan depends on the patient’s clinical manifestations, individual characteristics, and complications.
Rationale and knowledge gap
The exact pathogenesis of congenital ventricular diverticulum remains incompletely understood, representing a significant deficit in knowledge for this subject. Although it is commonly thought to be associated with congenital factors, the specific genetic or developmental mechanisms require further investigation. Additionally, the natural history and prognosis of left ventricular diverticulum, particularly in asymptomatic patients, are relatively poorly understood. In terms of diagnosis, although various imaging modalities are available, the accuracy and applicability of each method need to be further evaluated and compared. Regarding treatment, a unified treatment guideline is lacking, and the optimal treatment approach for different types and severities of left ventricular diverticulum remains unclear.
Objective
The aim of this report was to improve the understanding of congenital ventricular diverticulum by means of describing a patient with a giant diverticulum at the left ventricular apex and to investigate its diagnostic approaches and treatment strategies.
Case presentation
A 9-year-old male patient complained of a 2-week history of dizziness after exercise. Two weeks previously, he had experienced dizziness following physical activity, and an electrocardiogram at another hospital revealed frequent ventricular premature beats. Our 24-hour Holter monitor corroborated this finding, with a total of 3,813 beats, accounting for 4.3% of the total heart rate. Echocardiography indicated that the diameters of all chambers and the ventricular cavity were within the normal range. The left ventricular apex protruded locally outward, measuring approximately 60 mm × 40 mm in size. The internal trabeculae were abundant, and the wall at the apex was thinner, with the thinnest part being about 2–3 mm. The range of motion was slightly reduced (Figure 1 and Video 1). The ultrasound findings were as follows: (I) local protrusion of the left ventricular apex with abundant internal trabeculae, which suggested a giant diverticulum and indicated examination via cardiac magnetic resonance (CMR); and (II) mild regurgitation of the mitral, tricuspid, and pulmonary valves. Further CMR plain scan showed a significant irregular sac-like protrusion at the left ventricular apex, with an abundance of trabeculae structures within it. The amplitude of contraction and relaxation movements was reduced (Figure 2), and the left ventricular inflow and outflow tracts were unobstructed. CMR plain scan and cardiac function tests indicated decreased left heart function and an obvious irregular cystic protrusion at the left ventricular apex, suggesting the possibility of a congenital diverticulum. To rule out the possibility of congenital coronary artery disease in the patient, coronary CT angiography (CTA) was performed, which showed the following: (I) there was an abnormal course of the left anterior descending artery (LAD) running in the distal segment of the myocardium, a myocardial embedding range of about 1.0 cm and an embedding depth of about 0.26 cm, and slightly slender vessels at the embedding site; (II) the heart was enlarged, and a cystic protrusion was visible locally at the left ventricular apex, measuring approximately 4.5 cm × 2.8 cm and connected to the left ventricle. The myocardium was weak, with the thinnest point being about 1 mm. The lesion was closely related to the adjacent pericardium, and the continuity of the pericardium was not interrupted (Figure 3). The diagnosis of a giant left ventricular diverticulum in the patient was further confirmed.
All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Declaration of Helsinki and its subsequent amendments. Written informed consent was obtained from the patient’s parents for publication of this article and accompanying images. A copy of the written consent is available for review by the editorial office of this journal.
Discussion
Key findings
We treated a 9-year-old male with a giant diverticulum at the apex of the left ventricle. At the age of 3 years, a chest X-ray examination due to pneumonia revealed a slightly bulging left ventricular apex (Figure 4), but no systematic diagnosis or treatment was carried out. Six years later, he complained of dizziness after exercise, and the diverticulum was detected. Examinations, including echocardiography, CMR, and CTA, clearly defined the size, shape, location, and relationship with surrounding tissues of the diverticulum. Given the child’s condition, active surgical treatment was clinically considered.
Strengths and limitations
The clinical data of this rare case, including the results of multiple imaging examinations, have been described in detail, providing abundant information for further research. However, this is a report of a single case, and further studies with more substantial sample sizes are needed to confirm the findings.
Comparison with the literature
Compared with a similar report (5), this case differs in patient age, diverticulum size, and certain clinical manifestations, further enriching the understanding of left ventricular diverticulum.
Explanations of findings
The child had a slightly bulging left ventricular apex since childhood. Considering the symptoms and examination results at the time, we considered it to be a congenital diverticulum.
The existence of the diverticulum may affect the myocardial contraction and relaxation functions, leading to complications such as arrhythmia. In our case, the patient’s 24-hour Holter electrocardiogram demonstrated frequent ventricular premature beats (Figure 5). It was thus determined that the apex wall was significantly thinner, with surgical treatment being the preferred option; however, the surgical risk and prognosis remain to be comprehensively evaluated.
Implications and actions needed
In pediatric patients, even in the absence of obvious early symptoms, close follow-up and observation should be implemented if cardiac structural abnormalities are detected. The combination of multiple imaging examination methods is conducive to enhancing the diagnostic accuracy of left ventricular diverticula.
Clinicians should enhance their awareness and vigilance regarding left ventricular diverticula when encountering similar cases. The relevant examination procedures should be further optimized to ensure accurate diagnosis. For diagnosed patients, a rational treatment plan should be formulated promptly in accordance with the condition.
Conclusions
This report describes a case of a 9-year-old boy with a giant left ventricular apex diverticulum. The disease is rare, usually diagnosed in childhood, and often asymptomatic, but may lead to serious complications. Early detection and risk assessment are crucial for treatment. There is currently no unified treatment guideline, and individualized treatment based on the patient’s condition is recommended.
Acknowledgments
None.
Footnote
Funding: This study was supported by
Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://qims.amegroups.com/article/view/10.21037/qims-2024-2550/coif). The authors have no conflicts of interest to declare.
Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Declaration of Helsinki and its subsequent amendments. Written informed consent was obtained from the patient’s parents for publication of this article and accompanying images. A copy of the written consent is available for review by the editorial office of this journal.
Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.
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