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CARDIOVASCULAR ANESTHESIOLOGY

Coronary Sinus Atrial Septal Defect

From the Department of Anesthesiology, University of Washington Medical Center, Seattle, Washington.

Address correspondence and reprint requests to Denise C. Joffe, MD, Department of Anesthesiology, Children’s Hospital and Regional Medical Center, 4800 Sand Point Way NE, Seattle, WA 98105. Address e-mail to denise.joffe{at}seattlechildrens.org.

A 69-yr-old previously healthy man with a history of atrial fibrillation and an atrial septal defect (ASD) presented for ASD closure and a Maze procedure.

On transthoracic echocardiogram (TTE) the patient had a 13 mm defect in the inferoposterior part of the interatrial septum just above the tricuspid annulus with predominantly left-to-right shunting. An inferior sinus venosus ASD or a coronary sinus ASD was suspected. Because the coronary sinus was enlarged, the presence of a left superior vena cava (LSVC) was considered. There was biatrial enlargement and moderate right ventricular (RV) dilation. RV function was normal. The pulmonary veins were not well seen. Calculation of his pulmonary to systemic blood flow ratio was estimated at 1.8:1. On angiography, the defect was described as an inferior sinus venosus type.

Intraoperative transesophageal echocardiography (TEE) was performed with the transducer positioned at the midesophageal long axis and aortic valve long axis views. A 13 mm defect at the level of the coronary sinus was demonstrated (Fig. 1A and Video 1; please see video clip available at www.anesthesia-analgesia.org). With the probe turned counterclockwise, rotated to 102 degrees and with color Doppler applied, predominantly left-to-right shunting into the coronary sinus and then the right atrium (RA) was seen (Fig. 1B and Video 2). The coronary sinus was normal in caliber (<1 cm) in the midesophageal long axis view before its opening into the left atrium (LA). It then enlarged as it opened into the LA, demonstrating an unroofed coronary sinus (Video 1). All pulmonary veins emptied into the LA. There was biatrial, RV, and pulmonary artery enlargement. A contrast study performed by injecting agitated saline into the left arm was negative for a LSVC. All bubbles entered directly into the RA. The remainder of the septum was intact.

View larger version (36K): [in this window] [in a new window]   Figure 1. (A) Midesophageal aortic valve long axis view shows the coronary sinus unroofed (*) into the LA. (B) From above, the probe is rotated counterclockwise and the angle is changed to 102 degrees. Color Doppler demonstrates left-to-right shunting from the LA, through the unroofed coronary sinus, and into the RA. LA = left atrium; RA = right atrium.

A bilateral Maze procedure was performed, then the ASD was repaired. A defect from the coronary sinus into the LA was identified which measured 1 cm in diameter. This was repaired by patching or "putting a roof" on the coronary sinus using a piece of pericardium and allowing the coronary sinus effluent to drain normally into the RA. The patient was easily weaned off bypass. On TEE, no flow was seen across the atrial septum and the coronary sinus no longer opened into the LA.

ASDs exist in several morphologic varieties that must be characterized, since they are often associated with co-existing congenital abnormalities (Table 1).1 In addition, the location and associated defects may affect the technique of repair.

Isolated coronary sinus ASDs are exceedingly rare congenital cardiac defects.1,2 They make up <1% of ASDs. The defect is characterized by a deficiency in the tissue separating the coronary sinus from the LA. This results in partial or complete unroofing of the coronary sinus leading to a predominantly left-to-right shunt through the coronary sinus (LA to coronary sinus to RA). The orifice of the ostium is frequently large because of the increased flow. From the RA side, the defect is located at the level of the coronary sinus ostium and may also include some deficiency in atrial tissue around the ostium. From the LA side, the size can be variable depending on the degree of unroofing of the coronary sinus. In the RA, the location of an inferior sinus venosus defect and a coronary sinus ASD are in close proximity (near the inferior vena cava); however, the defects can be distinguished by the unroofed coronary sinus and additional associated lesions (Table 1).

The coronary sinus is best visualized by TEE by starting from the high four chamber view and turning the image plane towards the right heart. The probe is then advanced until the coronary sinus is seen entering the RA adjacent to the tricuspid annulus. Rotation of the probe from 90 to 120 degrees provides a second view of the coronary sinus entering the RA. When unroofed, the midesophageal long axis view demonstrates the coronary sinus opening into LA.

The technique of closure of isolated coronary sinus defects depends on the presence or absence of an LSVC.3,4 Without an associated LSVC, the coronary sinus ostium is patched closed from the RA and the coronary sinus is left to drain into the LA. This results in a clinically insignificant right to left shunt. The presence of a sizeable LSVC requires that other techniques be used since simple patch closure would allow coronary sinus blood and venous return from the LSVC to enter the LA, resulting in an unacceptable degree of cyanosis. Most commonly, the roof of the defect (in the LA) is covered with pericardium and the coronary sinus is allowed to drain normally into the RA. This is often referred to as a baffle.3,4 In this patient, although there was no LSVC, the surgeon felt that he was less likely to cause heart block by performing the closure with a "baffle technique."

It is important to distinguish this defect from other ASDs so that a careful search for an unroofed coronary sinus and LSVC are not missed. LSVCs may be present with other ASDs, but they usually drain to a normal coronary sinus. This results in all venous return entering the RA, in contrast to the pattern on return with an unroofed coronary sinus.

The post-bypass TEE should verify that the interatrial shunt no longer exists. In addition, if the coronary sinus was "baffled" it should no longer be seen to open into the LA.

In summary, this patient presented with what was described on multiple TTEs and a cardiac catheterization as an ASD in the posterior inferior atrial septum. A description of coronary sinus ASDs and the techniques used to repair the defect describe why it is important to identify their location for an optimal surgical repair. In this case, TEE images clearly demonstrated the anatomy in contrast to TTE or angiography.

Footnotes

This article has supplementary material on the Web site: www.anesthesia-analgesia.org.

Accepted for publication May 7, 2008.

REFERENCES

1. Russell IA, Rouine-Rapp K, Stratmann G, Miller-Hance WC. Congenital heart disease in the adult: a review with internet accessible transesophageal echocardiographic images. Anesth Analg 2006;102:692–723
2. Keane JF, Geva T, Fyler DC. Atrial septal defects. In: Keane JF, Lock JE, Fyler DC, eds. Nada’s Pediatric Cardiology. Philadelphia, PA: Saunders, 2006
3. Quaegebeur J, Kirklin JW, Pacifico AD, Bargeron LM Jr. Surgical experience with unroofed coronary sinus. Ann Thorac Surg 1979;27:418–25[Abstract]
4. Ootaki Y, Yamaguchi M, Yoshimura N, Oka S, Yoshida M, Hasegawa T. Unroofed coronary sinus syndrome: diagnosis, classification, and surgical treatment. J Thorac Cardiovasc Surg 2003;126:1655–6[Free Full Text]

This Article Full Text (PDF) Echo Loops Alert me when this article is cited Alert me if a correction is posted Services Email this article to a colleague Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Joffe, D. C. Articles by Oxorn, D. C. Search for Related Content PubMed PubMed Citation Articles by Joffe, D. C. Articles by Oxorn, D. C. Related Collections Cardiovascular Heart Echo Rounds Video Clip