Keywords
single atrium - common atrium - miscarriages - preterm births - heart defect - pregnancy
Introduction
Single atrium is a rare heart condition comprising under 1% of all congenital heart
disease, in which inter atrial septum is missing, without atrioventricular valve pathology.
The patient we are going to present is an adult woman, who underwent successful surgical
correction of the defect after three preterm births. Premature birth is a first course
of death of babies in many countries and second course of death worldwide. Premature
birth and miscarriages have many causes, heart defects is one of them.
Case Presentation
A 27-year-old female patient presented to the outpatient clinic with history of rhythm
disturbances, cyanosis, and weight loss. She was seen previously by a gynecologist
for other reasons and finally visited by a cardiologist who noticed on echocardiography
a single atrium. She went through three early births.
During her life, she avoided sport and other physical activities. To avoid exercise,
she started working as a hairdresser.
After her marriage, she had two preterm births and one miscarriage[1] (her first pregnancy was a preterm birth and terminated on 29th week, her baby was
only 810 g in weight and died few hours later. Her second pregnancy was a miscarriage
at 23rd week. Baby weight 360 g, died couple of hours later. Her third and last pregnancy
again was a preterm birth and ended at 30th week of gestation (baby died couple of
hours later) that made her to seek medical advice. After her third baby loss, her
gynecologist noticed that she had supraventricular extra systoles and referred her
to a cardiologist, who on echocardiography noticed a single atrium and referred her
to us for surgical treatment. She was not diagnosed with heterotaxy syndrome, Ellis-van
Creveld or trisomy 21.
In our clinic, she presented with mild cyanosis of her fingers and lips. She told
us that her feet and hands have been cold since childhood and on exercise she had
difficulty in breathing.
Saturations on room air 91%, on arterial gasses partial pressure of oxygen (pO2) 69 mm Hg, SaO2 89%.
Preoperative echocardiography and TEE described a single atrium, diameter 9.97 cm
with 6.18 cm. Left ventricular ejection fraction (LVEF) 60%. Mitral and tricuspid
valve insufficiency grades I to II, same level offset, and pulmonary arterial pressure
(PAP) 40 to 45 mm Hg. Dilated right ventricle (33 mm), and tricuspid annular plane
systolic excursion (TAPSE) 22 mm. Systemic blood flow/pulmonary blood flow (Qp/Qs)
is 4.1 ([Figs. 1B], [2A1], [2A2]).
Fig. 1 Preoperative Imaging. (A) Chest X-ray: demonstrating cardiomegaly, right atrial and right ventricular enlargement
and a prominent pulmonary trunk (B) Echocardiography: four chamber view, single atrium with a diameter 9.9 cm × 6.1 cm.
IVS, interventricular septum; LV, left ventricel; MV, mitral valve; RV, right Ventricel;
SA, single atrium; TV, tricuspid valve.
Fig. 2 Preoperative Imaging. (A) TEE: A1, tricuspid Valve with a short septal leaflet and mild insufficiency; A2,
mitral valve with mild insufficiency and light myxomatous leaflets. (B) CT angiography: B1 is the transversal view; single atrium with normal drainage of
pulomonary veins to the left side. B2 is the frontal view; hugh single atrium with
contrast from superior vena cava drained to right side of the atrium and promiment
pulmonary artery trunk. A, aorta; CT, computed tomography; LPV, left pulmonal veins;
LV, left ventricel; RPV, right pulmonal veins; RV, right ventricle; SA, single atrium;
TP, truncus pulmonalis; VCS, vena cava superior.
TEE showed a left shift of the interventricular septum, aortic valve with three normal
leaflets, mitral valve with myxomatous leaflets, and mild insufficiency, mild tricuspid
valve insufficiency.
Computed tomography (CT) angiography showed a single atrium with normal drainage of
pulmonary veins to the left side of atrium and with the superior and inferior vena
cava drained to the right side of atrium. Truncus pulmonalis was prominent ([Fig. 2B1], [2B2], [Video 2])
Video 1
Echocardiography follow-up after 2 years.
Surgical Procedure
Surgical procedure for this study was standard midline sternotomy and aortic and bicaval
cannulation. After opening of the right atrium, we noticed complete absence of the
interatrial septum ([Fig. 3A, B]). Superior and inferior pulmonary veins from the right and left lung drained into
what supposed to be left atrium. Mitral and tricuspid valves had normal morphology.
The coronary sinus opened normally into right atrium. After careful inspection of
the entire atrium, we started to create an interatrial septum, with double pericardial
patch. As described by Jing et al (second technique[2]), we started sutures (4–0 Prolen) from the middle of the ventricular septal crest
downward to the borderline between the tricuspid septal valve annulus to the left
inner side of the coronary sinus to the remaining border of the atrial septum. The
patch was sutured with running sutures and extra fixating mattress suture without
pledgets were taken every 2 to 3 cm.
Fig. 3 Intraopeartive imaging and TTE at follow-up after 2 years. (A) TV and MV with the patch in the middle and the suture line where the patch was sutured
at the posterior border of CS. (B) Right atrium, view of tricuspid valve and artifical septum with patch. (C) Echocardiography, follow up after 2 years. Mild insufficency of mitral valve. Vena
contracta 0.2. CS, coronary sinus; LA, left atrium; LV, left ventricel; MV, mitral
valve; RA, right atrium; RPV, right pulmonal veins; RV, right ventricle; TTE, transthorakal
echokardiografy; TV, tricuspid valve; VCI, vena cava inferior.
Results
Intraoperative and postoperative echocardiography showed that there was a mild mitral
and tricuspid valve insufficiency. There was no interatrial defect remained. Right
atrium with normal size, however, mildly enlarged left atrium.
Postoperatively, there was no atrial fibrillation or AV block diagnosed; however,
saturations dropped to a range of 84 to 85%. Mitral valve had mild insufficiency,
v.contracta 0.2 cm on echocardiography postoperative and in follow up after 2 years
([Fig. 3C], [Video 1]). The pulmonary systolic arterial pressure (PSAP) postoperatively was 29 mm Hg and
the right ventricular systolic pressure (RVSP) was 23 mm Hg. Anticoagulation with
cumarine (international normalized ratio [INR]:2.5-3.0) was given for a period of
6 months. Follow-up was performed after first and second year, the patient was in
very good condition result.
Video 2
CT angio-thorax. CT, computed tomography.
In the initial recovery period, we noticed a reduction of saturation in room air (SaO2), from 93% preoperatively to 84 to 85% during the first 30 days postoperatively.
The SaO2 values stabilized within 1 year from surgery. At present, her SaO2 values are maintained at 97%, with partial pressure of oxygen (pO2) 66 mm Hg, partial pressure of dioxidecarbon (pCO2) 28.4 mm Hg and on follow-up echocardiography PASP reduced to 29 mm Hg from 45 mm
Hg, without medical therapy. She keeps very active and for the first time she does
not complain of tiredness and there is no cyanosis present.
Discussion and Conclusion
Discussion and Conclusion
There are few case reported involving common atrium also known as single atrium.[1]
Rastelli and associates[3] reported few cases were the absence of the atrial septum was accompanied by presence
of the cleft into the anterior leaflet of the mitral valve and the absence of interventricular
communication. On the other hand, Levy and associates[4] reported a case where the complete absence of the atrial septum was not accompanied
by other defects as described by Rastelli et al, suggesting that this condition can
exist alone as a specific entity. Our case supports the recommendation by Levy and
associates; the term “single atrium” is used in this report.
The term miscarriage is defined as pregnancy that ended spontaneously with the loss
of a non-registerable fetus under <24 weeks of gestation. Preterm birth is defined
as a birth before 37 weeks of gestation.[5] In March of Dimes, the miscarriage is defined as early pregnancy loss before 20
weeks of pregnancy.
The clinical picture of our patient, cyanosis, rhythm disturbances, weight loss, and
reduced exercise tolerance started years back. This clinical presentation did not
differ from patients diagnosed with a large atrial defect at the fossa ovalis.[4]
In single atrium, the blood (arterial and venous) is mixed, which explains mild cyanosis,
shortness of breath, increased fatigue,[6] and reduced exercise tolerance early in life.[7]
Surgical correction should be done early in life to prevent later complications. Our
patient unfortunately was diagnosed very late and only after going through three preterm
births.[5] Surgical repair consists in creating two atria, using a patch, which could be a
Dacron or an autologous pericardial patch. For reconstruction of the atrium, an artificial
patch, as we could not obtain a fixating solution for native pericardium. The suture
method was as described by Jing et al (second technique).[1]
We cannot explain the drop in oxygen saturations in the initial postoperative period.
There was no postoperative shunt present and the blood was not mixed in the atria.
Maybe, this was as a result of postoperative pain, impeding patient to take deep breaths
and perform respiratory exercises resulting in mild atelectasis or maybe that was
triggered by pulmonary hypertensive attack. In these situations, use of sildenafil
would be recommended. We are open to discussion about this problem and maybe some
other authors have encountered this in their cases.
Prematurity is a health priority in many countries. Howson et al[8] described as a second leading cause of death in children under 5 years. The Organization
March of Dimes reports that premature birth is a first cause of death of babies in
the United States.[5]
World Health Organization (WHO) in the Global Action Report “Born Too Soon”[9] want to support all families who have been touched by preterm births and said that
over three quarters of premature babies could be saved.
Congenital Heart Disease Guidelines from 2018 recommended a pregnancy heart team:
include pediatric cardiologist, gynecologist–obstetrician, anesthetist, and cardiothoracic
surgeon should discuss and follow prepregnancy patients who can have complications
during pregnancy and offer adequate treatment.
Our patient presented with a heart defect which was undiagnosed for years and costs
our patient three preterm births and lately divorce. This history makes us push forward
the need for guidelines to be followed and implemented in every institution which
treat pregnant women. Patients like ours will not only bear the consequences of losing
three pregnancies, but losing her family too, which will have psychological implications.
We can conclude that presence of single atrium in child bearing women, increases the
risk of early births and endangering a woman's life. After successful surgical repair,
long-term survival is very good and quality of life improves enormously.
