Total Coronary Vein–Left Atrial Drainage
An asymptomatic 54-year-old man with severe mitral regurgitation caused by prolapse and pulmonary hypertension was referred for mitral valve surgery. The resting ECG (Figure 1) and chest radiograph (Figure 2) were unremarkable. A transesophageal echocardiogram showed a degenerated mitral valve with rupture of chordae tendineae and leaflet prolapse causing severe mitral regurgitation (Figure 3).
Preoperative computed tomographic coronary angiography demonstrated normal coronary arteries; however, all cardiac veins were found to drain into the left atrium (Figures 4 and 5⇓). The great cardiac vein and a small persistent left superior vena cava connected to a remnant of the coronary sinus (CS). Complete absence of the sinoatrial wall was noted, and this remnant CS drained directly into the left atrium. The posterior interventricular vein and the middle and small cardiac veins drained through a dilated common conduit into the posterior region of the left atrium. The posterior vein of the left ventricle had an independent ostium that entered the left atrium. The atrial situs was solitus, with normal morphology of both left and right appendages.
The patient underwent mitral valve repair (Figure 6). On the basis of the results of the computed tomographic coronary angiography, during the surgery, only anterograde cardioplegia was used, and the persistent left superior vena cava was not ligated. A postoperative transesophageal echocardiogram showed the blood flow from the remnant of the CS entering the left atrium (Figure 7) and a normal-functioning mitral valve (Figure 8). The postoperative course was uneventful, and the patient was discharged.
Four types of CS abnormalities have been described: Enlarged CS, absence of CS, hypoplasia of CS, and atresia of the right atrial CS ostium.1 Interatrial septal defects and persistent left superior vena cava are usually associated. The case reported here would correspond to the second type with an associated left superior vena cava. A similar case has been described previously with the hypothesis of a cardinal vein isomerism as the cause of the defect2; however, the drainage of all of the coronary veins into the left atrium and the absence of other congenital heart defects make this a unique case.
Sources of Funding
Dr Gonzalo Pizarro is supported by a fellowship from the Sociedad Española de Cardiología.
Mantini E, Grondin CM, Lillehei CW, Edward J. Congenital anomalies involving the coronary sinus. Circulation. 1966; 33: 317–327.
Miraldi F, di Gioia CR, Proietti P, De Santis M, d'Amati G, Gallo P. Cardinal vein isomerism: an embryological hypothesis to explain a persistent left superior vena cava draining into the roof of the left atrium in the absence of coronary sinus and atrial septal defect. Cardiovasc Pathol. 2002; 11: 149–152.