Coronary Sinus Rhythm in the Polysplenia Syndrome

¹ Department of Cardiology, The Children's Hospital Medical Center and the Department of Pediatrics, Harvard Medical School, Boston

A leftward and superior P wave axis, the so-called coronary sinus rhythm, was found in nine of 12 patients with the typical polysplenia syndrome. These nine patients had the usual developmental abnormalities of the sinus venosus, including absence of the renal to hepatic portion of the inferior vena cava, other associated cardiovascular lesions, visceral heterotaxia, and multiple spleens. The absence of the superior portion of the inferior vena cava complicated cardiac catheterization in all patients, making it impossible to perform from the inguinal approach in four. The finding of coronary sinus rhythm in a patient with congenital heart disease and visceral heterotaxia should alert the clinician to consider the diagnosis of polysplenia and the attendant constellation of anomalies. In contrast, the asplenia syndrome, which has many similar developmental defects, except that absence of the superior portion of the inferior vena cava is very rare, has a very low incidence of this atrial arrhythmia. In a critically ill infant who has coronary sinus rhythm, with congenital heart disease and heterotaxia, it might be expedient to approach cardiac catheterization from the upper extremity.