Introduction:
Unroofed coronary sinus syndrome (URCSS) is a rare cardiovascular anomaly. The left atrium and coronary sinus are the two critical vascular components of the human heart. The coronary sinus and left atrium are not divided by the wall, or the wall between them is absent. The condition needs increasing attention due to its cardiovascular complications. The wall between the coronary sinus and left atrium is defective, leading to the direct blood flow between them. The coronary sinus comprises oxygen-poor blood; the left atrium has oxygen-rich blood. The defective wall between these two components leads mixing of oxygenated and deoxygenated blood. The patient may feel a wide variety of symptoms. Timely closure of the wall can prevent the occurrence of symptoms. The article discusses unroofed coronary sinus syndrome, its types, causes, symptoms, diagnosis, and treatment.
What Is Unroofed Coronary Sinus Syndrome?
Unroofed coronary sinus syndrome is a rare hereditary condition. The wall which divides the coronary sinus and the left atrium is defective. The left atrium is the heart's upper left chamber, and the coronary sinus is the vein that takes oxygen-poor blood from the heart muscle. Due to the defective wall, there is a direct link between the coronary sinus and the left atrium, leading to the mixing of oxygen-rich and oxygen-poor blood. The impure blood can cause a decrease in the oxygen saturation in the systemic circulation.
What Are the Types of Unroofed Coronary Sinus Syndrome?
Unroofed coronary artery syndrome consists of four types. The classification is done based on anomaly location and structures associated with it. The types are described below:
- Type 1 URCSS: The common type occurs due to the deficiency of the ceiling of the coronary sinus. The deficiency can cause a direct link between the coronary sinus and the left atrium. The condition can be treated with surgical intervention.
- Type 2 URCSS: The wall between the coronary sinus and the left atrium is incorrectly connected. The partial connection between them is due to an atrial septal defect. The defect in the ceiling of the coronary sinus may or may not be present. The condition can be repaired by surgical intervention.
- Type 3 URCSS: The atrial septal defect is present between the coronary sinus and left atrium. The defect in the ceiling is in the mid-portion. This can cause mixing in the left and right sides of the heart.
- Type 4 URCSS: A partial connection exists between the coronary sinus and the left atrium at the terminal portion. This partial connection is due to the atrial septal defect at the wall.
What Are the Causes of Unroofed Coronary Sinus Syndrome?
The potential causes of unroofed coronary sinus syndrome are as follows:
- Genetic Factors: Genetic factors can cause congenital heart anomalies, such as unroofed coronary sinus syndrome. These defects can be passed from the parents to the offspring.
- Environmental Factors: During fetal development, when the environmental factors are exposed to the pregnant woman can cause the condition.
- Congenital Heart Defect: The wrong development during fetal growth can cause an abnormal link between the coronary sinus and the left atrium.
- Atrial Septal Defects: The other reason is atrial septal defects. The presence of a puncture between the left atrium and left ventricle allows the blood to mix between them. This can make a pathway for the blood to move from the coronary sinus to the left atrium.
- Abnormal Venous Return: In case of abnormal venous return, the blood comes from the systemic venous circulation and goes to the heart, mixing mixed blood with oxygen-poor blood.
What Are the Signs and Symptoms of Unroofed Coronary Sinus Syndrome?
The signs and symptoms of unroofed coronary sinus syndrome are described below:
- Shortness of Breath: People with the condition may experience difficulty breathing during exercise because of the abnormal flow of mixed blood.
- Fatigue: The symptom of fatigue is due to the improper oxygen supply to the body.
- Cyanosis: Patients with the condition may have bluish lips, nail beds, and skin discoloration. The reason for cyanosis is the mixing of oxygen-rich and oxygen-poor blood.
- Heart Murmurs: The sound can be heard due to the turbulent blood flow.
- Recurrent Infections: The patient is more prone to develop respiratory infections.
- Clubbing of Fingers: This can be due to the chronic oxygen deficiency in the blood.
- Delayed Growth: Infants with the condition may show delayed growth.
- Heart Failure: This can be due to the strain on the heart, which can cause symptoms like swelling in the legs and fluid accumulation.
How Is Unroofed Coronary Sinus Syndrome Diagnosed?
The diagnosis process of unroofed coronary artery syndrome is described below:
- Detailed Medical History: The healthcare provider will take a detailed medical history to know any previous congenital heart anomalies and assess the signs and symptoms.
- Echocardiography: The diagnostic tool is used to see the blood flow pattern.
- Cardiac Catheterization: The catheter calculates the oxygen levels and pressure in the heart chambers and blood vessels.
- Pulse Oximetry: It is used to calculate the oxygen saturation level in the blood.
How Is Unroofed Coronary Sinus Syndrome Treated?
The condition can be treated with medical and surgical interventions. The overview of the treatment interventions is as follows:
- Medical Management: The healthcare provider may prescribe diuretics and heart failure medications. In addition, blood thinning medications can be taken to decrease the risk of formation of blood clots.
- Surgical Management: The condition can be managed by surgical repair. The surgeon will use the patch to close the abnormal connection between the coronary sinus and the left atrium. Sometimes, they may advise open heart surgery to repair the defect.
What Are the Complications of Unroofed Coronary Sinus Syndrome?
The complications of unroofed coronary sinus syndrome are as follows:
- Heart failure.
- Pulmonary hypertension.
- Irregular heartbeat.
- Stroke.
- Blood clot formation.
- Infection of the heart lining.
- Bluish skin discoloration (cyanosis).
- Delayed growth and development.
- Exercise intolerance.
- Cardiac enlargement.
- Atrial arrhythmias.
Conclusion:
In conclusion, unroofed coronary sinus syndrome is a genetic cardiac defect affecting infants from birth. The condition occurs due to an open link between the coronary sinus and the left atrium. The open link can cause a mixing of oxygen-rich and oxygen-poor blood, leading to clinical features such as bluish discoloration, fatigue, and shortness of breath. Various imaging techniques help in diagnosing the condition. Timely surgical intervention can decrease the threat of complications.
