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CCD is a very rare malformation. Exact prevalence and incidence data are not available. About 0.4% or 1 of 250 cardiac necropsy cases showed this malformation. In the literature, the combined number of aneurysm/diverticle reports is 418 cases. Incidence of 1/2700 on echocardiographic studies (0.04% of the population) has been reported. A very slightly higher incidence has been reported in males compared to females (1.05:1.0).

Congenital cardiac diverticulum is often associated with other cardiac abnormalities (midline defects) but is mostly an isolated anomaly. It is mostly found in infants and children and occasionally as an incidental finding in adults. The left ventricular apex is the most common location, but right ventricular diverticula are also reported. Two types of CCD are described: fibrous CCD which may be asymptomatic or associated with thromboembolic events, and muscular CCD with normal myocardial contraction which is frequently associated with other congenital anomalies and may cause rupture, aortic insufficiency, endocarditis, heart failure and tachyarrhythmia. Other clinical manifestations may include dyspnea, palpitation, and chest pain. Fetal death has also been described because of intrauterine diverticulum rupture. Congenital aneurysms are composed of collagenous or connective tissue and are associated with akinesis or dyskinesis. Acquired forms of cardiac diverticulum/aneurysm are common, particularly after myocardial infarction.

The etiology of congenital cardiac diverticulum is not known. Hemodynamic factors may play a role. In the 4th embryonic life there are outpouchings in the early wall of the left ventricle which later enlarge ventriclular cavity volume. Failure during this process could be responsible for the development of aneurysms.