Ann Thorac Surg 1999;68:1069-1071
© 1999 The Society of Thoracic Surgeons
Case Reports
Effect of CABG on coronary flow reserve in atresia of the left coronary ostium
Kenji Hamaoka, MDa,
Kentaro Toiyama, MDa,
Hisashi Satoh, MDa,
Zenshiro Onouchi, MDa,
Kazuhiro Kitaura, MDb
a Division of Pediatrics, Children’s Research Hospital, Kyoto Prefectural University of Medicine, Kyoto, Japan
b Second Department of Surgery, Kyoto Prefectural University of Medicine, Kyoto, Japan
Address reprint requests to Dr Hamaoka, Division of Pediatrics, Children’s Research Hospital, Kyoto Prefectural University of Medicine, 465 Kajiicho, Kamikyou-ku, Kyoto 602-8566, Japan
e-mail: khamaoka{at}koto.kpu-m.ac.jp
 |
Abstract
|
|---|
We evaluated the change of coronary flow reserve using a Doppler guidewire before and after coronary artery bypass grafting to assess the coronary hemodynamic effect of surgical revascularization in a 13-year-old boy with congenital atresia of the left coronary ostium, which is one of the rarest of the congenital coronary anomalies. Coronary flow reserve in the right coronary artery and left anterior descending artery increased significantly after coronary revascularization, and a microvascular bed developed in the left anterior descending artery.
|
Introduction
|
|---|
Atresia of the left coronary ostium is one of the rarest of the congenital coronary anomalies [1]. The proximal left main trunk ends blindly, and coronary blood flows from the right coronary artery to the left coronary via small-sized collateral arteries and in a retrograde fashion in at least one of the left-sided arteries. Although there have been reports of successful coronary artery bypass grafting (CABG) [1, 2] with the saphenous vein or
the internal mammary artery, coronary hemodynamic effects of the coronary revascularization have not been clarified in patients with atresia of left coronary ostium. We evaluated the change of coronary flow reserve [3, 4] in the right coronary artery (RCA) and the left anterior descending coronary artery (LAD) before and after CABG to assess the coronary hemodynamic effect of surgical revascularization.
A 13-year-old boy was referred to our hospital for evaluation of an abnormal electrocardiogram and a syncopal episode. On physical examination, he appeared healthy, and weighed 56 kg. His blood pressure was 122/82 mm Hg, his heart rate was 70 beats/min, and his respiratory rate was 24 breaths/min. A soft systolic murmur was heard at Erb’s area. An electrocardiogram showed regular sinus rhythm and mildly high QRS voltage with flattened T waves in leads V5 and V6. Treadmill-loading exercise testing showed significant ST segment depression (1.5 to 2.0 mV) in leads II, III, aVF, and V5-6. A chest radiograph showed a normal cardiac silhouette and size (cardio-thoracic ratio [CTR] = 47%). Two-dimensional echocardiography showed normal left ventricular wall motion with mild hypertrophy of the left ventricular postero-inferior wall. Exercise stress 201-thallium myocardial scintigraphy showed a significant reversible decrease in myocardial perfusion in the apical and anterior walls. Coronary angiography demonstrated atresia of the left coronary ostium with well-developed collateral circulation from the RCA to the LAD (Fig 1A). Left ventriculography showed normal left ventricular wall motion. Because of his syncopal episode, a CABG was performed on segment 7 of the LAD with his left internal mammary artery. The left circumflex coronary artery (LCX) received blood supply via the LAD from the bypass graft. Collateral arteries have almost disappeared on coronary angiogram 1 and 6 months (Fig 1B) after CABG. Significant improvement has been observed in the treadmill testing and exercise stress 201-thallium myocardial scintigraphy. Patency of the bypass graft has been maintained. Coronary flow reserve (CFR), assessed by calculating the quotient of the hyperemic average peak velocity (APV) after intracoronary administration of adenosine triphosphate [5] and the baseline APV using a Doppler guidewire [6–8], was significantly improved in both the RCA and LAD (proximal to segment 8) (Fig 2). CFR in the RCA increased from 2.0 before CABG to 3.0–3.9 after CABG in segment 2, and from 1.6 before CABG to 2.7–2.9 after CABG in the regions distal to segment 3. Postoperatively, coronary flow reserve in the LAD and bypass graft also increased from 2.0 to 2.7 in segment 8, and from 1.3 to 2.0 proximal to the anastomosis of the graft and the LAD. The postoperative course was uneventful.
View larger version (71K):
[in this window]
[in a new window]
|
Fig 1. Coronary angiographs before (A) and 6 months after coronary artery bypass grafting. Left (B) and right (C) coronary system. The left coronary artery with atresia of the ostium receives blood supply via the small-sized collateral vessels from the right coronary artery to the left anterior descending artery. Collateral vessels almost disappeared on coronary angiogram 6 months after coronary artery bypass grafting.
|
|
View larger version (27K):
[in this window]
[in a new window]
|
Fig 2. Changes in coronary flow reserve before and after coronary artery bypass grafting. Coronary flow reserve significantly increased in both the right coronary artery and the left anterior descending artery after coronary revascularization.
|
|
|
Comment
|
|---|
In this patient, CFR increased significantly postoperatively. Intracoronary adenosine triphosphate is a potent vasodilator in the microvascular bed but does not dilate the epicardial coronary vessels [5, 8]. Therefore, it is possible that the increased CFR in the RCA was due to resetting the dilatory potential of the small coronary arteries in the RCA after the cessation of collateral flow from the RCA to the LCA, as well as the development of the microvascular bed in the LAD. Thus, this case report indicates that a CABG with an internal mammary artery in congenital atresia of the left coronary ostium can induce development of a microvascular bed of the hypoplastic left coronary artery, resulting in a good long-term prognosis.
|
References
|
|---|
-
Hoffman J.I.E. Congenital anomalies of the coronary vessels and the aortic root. In: Emmanouilides G.C., Riemenschneider T.A., Allen H.D., Gutgesell H.P., eds. Moss and Adams heart disease in infants, children, and adolescents. Baltimore: Williams & Wilkins, 1995:769-791.
-
Musiani A., Gernigliaro C., Sansa M., Maselli D., Gasperi C.D. Left main coronary artery atresia. Eur J Cardiothorac Surg 1997;11:505-514.[Abstract]
-
Gould K.L., Lipscomb K., Hamilton G.W. Physiologic basis for assessing critical coronary stenosis. Am J Cardiol 1974;33:87-94.[Medline]
-
Kern M.J., Tatineni S., Gudipati C., et al. Regional coronary blood flow velocity and vasodilator reserve in patients with angiographically normal coronary arteries. Coronary Artery Dis 1990;1:579-589.
-
Hamaoka K., Onouchi Z. Effects of intracoronary adenosine triphosphate on coronary flow velocity dynamics in children. Jpn Heart J 1997;38:39-52.[Medline]
-
Doucette J.W., Corl P.O., Payne H.M., et al. Validation of a Doppler guide wire for intravascular measurement of coronary artery flow velocity. Circulation 1992;85:1899-1911.[Abstract/Free Full Text]
-
Ofili E.O., Labovitz A.J., Kern M.J., et al. Coronary flow velocity dynamics in normal and diseased arteries. Am J Cardiol 1993;71:3-9.
-
Hamaoka K., Onouchi Z., Ohmochi Y., Sakata K. Coronary arterial flow-velocity dynamics in children with angiographically normal coronary arteries. Circulation 1995;92:2457-2462.[Abstract/Free Full Text]
Accepted for publication February 2, 1999.
Top
Abstract
Introduction
