Background
Cor triatriatum (or triatrial heart) is a congenital heart defect where the left atrium(cor triatriatum sinistrum) or right atrium (cor triatriatum dextrum) is subdivided by a thin membrane, resulting in three atrial chambers. Cor triatriatum is a rare congenital anomaly with a ratio of men to women of 1.5:1 [1]
Cor triatriatum represents 0.1% -0,4% of all congenital cardiac malformations and usually refers to the left atrium. [2-3]In cor triatriatum sinister the left atrium is divided by a fibromuscular membrane into two distinct chambers: a posterior – superior chamber receiving the four pulmonary veins and an anterior – inferior chamber ( true left atrium ) which communicates with left ventricle LV through mitral valve [4]. In the majority of cases it is diagnosed in neonatal period or early infancy, whereas adult cases are very rare. [5]
In the pediatric population, this anomaly may be associated with major congenital cardiac lesions such as tetralogy of Fallot, double outlet right ventricle, coarctation of the aorta, partial anomalous pulmonary venous connection, persistent left superior vena cava with unroofed coronary sinus, ventricular septal defect, atrioventricular septal (endocardial cushion) defect, and common atrioventricular canal. [6] In the adult, cor triatriatum is frequently an isolated finding.
Case presentation
55- years old woman admitted to hospital because of the congenital heart disease, particularly atrial septal defect (ASD). Since childhood she presented with signs and symptoms of a heart failure, which have deteriorated to NYHA class III during last 2 years. Previously she was treated for hypertension and asthma. On physical examination central and peripheral cyanosis, clubbed fingers, and a systolic heart murmur in 4th intercostal septum were found.
Full blood count showed increased hematocrit (58%), with increased number of erytrocytes and hemoglobin level. NT- pro BNP was normal; in arterial blood gas oxygen saturation was decresed to 79,2%, with features of partial respiratory failure.
On ECG normal sinus rhythm, incomplete right bundle branch block were found, with signs of right and left atria, and right ventricle overload. In 6 minutes walk test she made 295 meters with blood oxygen desaturation form 76% to 66%.A transthoracic and transesophageal echocardiography revealed dilated right heart, moderate tricuspid regurgitation and signs of
pulmonary hypertension with RVSP 85mmHg. In the middle of a intraatrial septum 26mm defect was found, with right-to-left shunt. Normal systolic function of left ventricle was documented, with EF estimated >60%.
During cardiac catheterization mean pressure in right pulmonary artery was 53 mmHg, mean pressure in right atrium was 4 mmHg, and 10mmHg in left atrium. After Iloprost administration PA mean pressure decreased to 38 mmHg. Saturations in heart cavities suggested presence of left-to-right shunt (RA 83%,RV 86%,PA 87%) and a communication between right atrium and left ventricle. Saturation in aorta was the lowest and it was 75%
Coronary angiography showed normal coronary arteries.
In a CT threeatrial heart was seen, with a thin- walled membrane across the LA dividing it into two compartments, one receiving the pulmonary venous flow and a true left atrium that connects to the left ventricle through mitral valve. In addition, between right atrium and inflowing part of a left atrium, defect in intraatrial septum was seen, and there was no septum between right atrium and outflowing part of a left atrium. Confluens of coronary veins in the inflowing part of the LA was seen.
With these findings the patient was scheduled to the Bosentan therapy in a dose 62,5mg. After 4 months of ambulatory treatment patient was readmitted to cardiology ward for detailed follow-up examination and assessment of therapy results.
Patient made significant improvement and good tolerance of therapy. In 6 minutest walk test she made 400m without shortness of breath. In TTE reduction of right ventricle dimensions was seen, with decreased RVSP to 73mmHg. With these findings Bosentan monotherapy was continued with a dose titrated to 125mg BD.
References
1. Chieh-Shou Su, Tsai I-Chen, Wei-Wen Lin, Tain Lee, Ting Chih-Tai, Kae-Woei Liang: Usefulness of multidetector-row computed tomography in evaluating adult cor triatriatum. Tex Heart Inst J 2008
2. Niwayama G. Cor triatriatum. Am Heart J 1960
3. Jorgensen CR, Ferlic RM, Varco RL, Lillehei CW, Eliot RS. Cor triatriatum. Review of the surgical aspects with a followup report on the first patient successfully treated with surgery.
Circulation 1967
4. Rorie M, Xie GY, Miles H, Smith MD: Diagnosis and surgical correction of cor triatriatum in an adult: combined use of transesophageal echocardiography and cathetirazation. Cathet Cardiovasc Interv 2000
5. Tanaka F, Itoh M, Esaki H, Isobe J, Inoue R. Asymptomatic cor triatriatum incidentally revealed by computed tomography. Chest 1991;100:272-4.
6.Kirklin JW, Barratt-Boyes BG, editors. Cardiac surgery:morphology, diagnostic criteria, natural history, techniques,results, and indications. 2nd ed. New York: Churchill
Livingstone 1993:
Expert’s comments:(Written authorization required from each expert)
1. Prof. Pająk
Prof. Pająk suspected the presence of left superior vena cava, which drained into left atrium. Low saturation in aorta may suggest such conclusion.
2. Prof. Szydłowski
Prof. Szydłowski said that the case may remind a hemodynamic view of mitral stenosis, but he was concerned about low PCWP.
3. Prof. Podolec
Prof. Podolec said that the view of this malformation is unclear. If a presence of left superior vena cava draining into LA is taken into account, he suggested contrast echocardiophy should be considered (with saline given to both radial arteries). This view also can remind an enlarged coronary sinus. Nonetheless, pulmonary hypertension treatment is necessary.
4.Prof B. Kapelak
Prof B. Kapelak was of an opinion that radiological reconstruction should be made, with consideration of surgical treatment afterwards.
Expert’s conclusions:
After broadening of a diagnostic imaging- especially angioCT recontruction and contrast echocariography, cardiosurgical treatment of this malformation should be taken into account.
Authors:
Joanna Stanisz-Kempa1, Daniel Jakubowski1, Maria Kasztelan- Masłowska1, Barbara Monastyrska-Cup1, Romuald Twardowski1 , Mariusz Skowerski1, Zbigniew Gąsior1
Experts:
Prof. Pająk, Prof. Szydłowski, Prof. Podolec, Prof B. Kapelak
1 II Katedra i Klinika Kardiologii SUM Górnośląskie Centrum Medyczne Katowice- Ochojec
