Prominent Crista Terminalis in the Neonatal Period

The prominent crista terminalis (PCT) is an anatomical variant of the heart sometimes observed in older patients.

We present a female newborn of a healthy mother with no relevant medical history. During pregnancy, a right intraatrial malformation was detected by ultrasound, establishing the suspected diagnosis of prominent Eustachian valve or tumour. At birth, echocardiogram showed an atrial septal aneurysm, a Chiari network inside the right atrium and an echogenic image located at the top and posterior surface of the right atrium ([Fig. 1] [2]) of 6 mm, that not modified blood flow and did not change with time and was labeled as PCT. Normal Eustachian valve was checked ([Fig. 3]).

Fig. 1 2D echocardiogram showing an echogenic mass at the top and posterior region of the right atrium (arrow).

Fig. 2 2D echocardiogram showing Chiari network a and interatrial septal aneurysm b.

Fig. 3 2D echocardiogram showing long axis view of the right atrium with normal Eustachian valve a near the prominent crista terminalis b.

Crista terminalis is a normal fibromuscular ridge at the posterolateral region of the right atrium and has a close relationship with the sinus node (Salustri A et al. Prominent crista terminalis mimicking a right atrial mass: case report. Cardiovasc Ultrasound 2010; 8: 47). Occasionally, it can be prominent which can mimic other findings as a mass, thrombus (Gaudio C et al. Prominent crista terminalis mimicking a right atrial mixoma: cardiac magnetic resonance aspects. Eur Rev Med Pharmacol Sci 2004; 8: 165–168), or variants of normal structures as Chiari network or Thebesian and Eustachian valves (Akcay M et al. Prominent crista terminalis: An anatomic structure leading to atrial arrhythmias and mimicking right atrial mass. J Am Soc Echocardiogr 2007; 20: 197). Its diagnosis in adult patients can be performed by transesophageal echocardiography. However, the good transthoracic window in newborn babies could come close to a diagnosis by non-invasively echocardiogram.

Although not frequently, it may be associated with other phenomena such as atrial septal aneurysm. These 2 structures can act as arrhythmogenic focus (Bolognesi M et al. A prominent crista terminalis associated with atrial septal aneurysm that mimics right atrial mass leading to arrhythmias: a case report. J Med Case Rep 2012; 6: 403) (Zhao QY et al. Relationship between autonomic innervation in crista terminalis and atrial arrhythmia. J Cardiovasc Electrophysiol 2009; 20: 551–557). Our baby did not show arrhythmias or other symptoms.

Although PCT has not been previously described in the medical literature in newborns, it must be included as a differential diagnosis of the right atrium mass at this age. Atrium’s anatomy must be known to avoid unnecessary additional tests.