Congenital Left Ventricular Diverticulum Diagnosed by<br />
64-Detector CT Imaging<br />
<br />

Congenital left ventricular (LV) aneurysms are rare, and the term “congenital ventricular aneurysm” can be used to describe an isolated aneurysm when no known causes of acquired aneurysms (i.e., coronary disease, post cardiac surgery, trauma to the chest) are discovered. Generally, patients are asymptomatic, but may present with congestive heart failure, ventricular arrhythmias, thrombo-embolic phenomena, or rarely with ventricular rupture.¹
Standard radiologic methods such as chest roentgenography and echocardiography may not reveal the presence of such an aneurysm. The cardiac silhouette may be normal on chest X-ray and echocardiography. Magnetic resonance imaging or left ventriculography has usually been performed to confirm suspected aneurysms and to delineate the anatomy. We report a case where 64-detector computed tomographic (CT) imaging accurately detected the aneurysm and allowed adequate functional assessment with cine CT multiphase imaging at end-systole and end-diastole.

Case Summary. A 28-year-old male with no past medical history presented for 64-detector CT (64-CT) to assess atypical chest pain. Notably, the patient had a significant family history of coronary artery disease, with his father suffering a myocardial infarction at the age of 48 years. On 64-CT, a left ventricular aneurysm was identified in the inferoposterior wall of the LV. The base of this diverticulum was very thin. During systole, the diverticulum cavity was obliterated (Figure 1). The coronary arteries showed no stenosis. There was, however, a long-segment myocardial bridge identified in the left anterior descending artery (Figure 2). Cine display revealed normal LV contractile function.

Discussion. Congenital ventricular diverticulum is a rare malformation with an incidence of about 0.4% in an autopsy series of patients with cardiac death, and in about 0.26% in nonselected patients undergoing cardiac catheterization. A typical congenital cardiac diverticulum is characterized by a finger-like projection emerging from the wall of the left ventricle, contracting in synchrony with the corresponding chamber. The communication to the ventricular cavity is narrow. The development of a congenital diverticulum can be explained by a partial stop in the development of the embryonic ventricle. Congenital left ventricular diverticula are frequently associated with numerous other congenital anomalies, including ventricular septal defect, atrial septal defect and patent foramen ovale, tricuspid atresia, tetralogy of Fallot or cardiac malposition (e.g., dextrorotation).²
Although echocardiography and ventriculography can image LV diverticula, cardiac 64-CT provides optimal visualization in oblique views. The natural history of isolated, asymptomatic LV diverticulum is unknown. Some authors have suggested that surgical therapy has to be advocated in all cases due to the presence or development of thrombus leading to embolism and/or the development of cardiac dyssrhythmias, but no firm consensus has been reached with respect to the optimal management of these patients due to the lack of larger trials with longer observation periods.³ With respect to follow up, again no firm consensus is agreed upon, however, careful attention to symptoms of LV dysfunction such as chest pain, palpitations, and/or dyspnea, or the development of hypertension should be monitored. Follow up is most easily performed employing transthoracic echocardiography.^2,3 In our case, the patient did not undergo echocardiography because it was felt that the 64-CT provided adequate imaging of the diverticulum. Our patient was managed conservatively and will be followed up with close attention to symptom development or any signs of hypertension with treatment as he gets older.

References

1. Hamaoka K, Onaka M, Tanaka T, et al. Congenital ventricular aneurysm and diverticulum in children. Pediatr Cardiol 1987;8:169–175.
   
2. Ohlow, MA. Congenital left ventricular Aneurysms and diverticula: Definition, pathophysiology, clinical relevance and treatment. Cardiology 2006;106:63–72.
   
3. Mady C. Left ventricular diverticulum: Analysis of two operated cases and review of the literature. Angiology 1982;33:280–286.