The value of three-dimensional echocardiography in the evaluation of cor triatrium sinister

Abstract

Introduction Cor triatrium sinister is a very rare congenital heart disease in which the pulmonary veins enter a proximal accessory left atrial chamber that is separated from a distal true left atrial chamber by a fibromuscular membrane presenting one or more ostia. Its incidence in the adulthood is extremely rare. Adult patients are symptomatic in case the orifice across the membrane becomes obstructive mimicking a mitral stenosis. It has been reported that severe obstruction is present if maximum doppler velocity across the orifice is more than 2 m/s.1 However, in a review of case series no correlation could be found between the pressure gradient across the fenestration and the clinical symptoms.2 We report the case of a symptomatic adult female with obstructive cor triatrium in whom the intraoperative three-dimensional transesophageal echocardiography (3D TEE) revealed the severity of obstruction in contrast to the mild intraoperative pressure gradients. Methods A 34-year-old female was scheduled for surgical repair of a cor triatrium sinister. The symptoms of dyspnea had increased during the last months (NYHA III) which resulted in the echocardiographic diagnosis. The mean pressure gradient across the orifice was estimated 6 mmHg at rest and 18 mmHg at effort using modified Bernoulli equation. There were no associated cardiac abnormalities and no signs of pulmonary hypertension. The patient gave written consent to present her case. Results The induction of anesthesia was performed with the aim to keep hemodynamic stability. The intraoperative TEE confirmed the diagnosis. Color flow across the orifice showed an aspect of rather laminar flow. The mean pressure gradient across the sole orifice was 2 mmHg.Three-dimensional en face view of the membrane permitted offline analysis of the lesion in several orthogonal planes and measurement of the effective opening area of the orifice which was 1.45 cm2 (Fig 1). Discussion This case illustrates that pressure gradient across an obstructive cor triatrium may underestimate the true severity of the lesion as the blood flow may be low through the channel. Therefore, 3D echocardiography should be routinely performed in patients with cor triatrium in order to measure the exact maximal fenestration orifice area.