Single coronary artery: a fatal R-I type.

Coronary artery anomalies are found in approximately 1.3 % of symptomatic adult patients undergoing coronary arteriography and encompass a wide variety of anatomic patterns. Single coronary arteries are found in 0.024-0.066 % of this group. The particular type of a single coronary artery with an anatomically correct course of either artery (so-called L/R-I type according to the Lipton and Yamanaka/Hobbs classification) is an especially rare phenomenon and has been described for the left coronary artery and for the right coronary artery in adults. In these anomalies an isolated coronary artery ensuring the blood supply of the entire heart displayed a compensatory widening of the lumen. The case of a 6-year-old boy who collapsed during exercise and died subsequently of acute cardiac death is presented. At autopsy a single right coronary artery with an anatomically correct course (R-I type) arising from the right sinus of Valsalva was found. On microscopic examination myocardial calcifications and scars were found in the papillary muscles of the mitral valve. Common ion channel disorders were excluded by DNA analysis. Sudden cardiac death on the basis of chronic ischemic heart disease was ascertained as the cause of death. Autopsy and microscopic findings, as well as aspects of the underlying pathophysiology, are presented and discussed.