title: Vulnerability of Coronary Circulation After Norwood Operation.
abstract: BACKGROUND
  We hypothesized that the myocardial oxygen supply-demand balance is impaired in patients after a Norwood procedure and that an abnormal oxygen supply-demand balance is associated with pronounced activation of the renin-angiotensin-aldosterone system and worse clinical outcome after this procedure.
  
  
  METHODS
  To investigate the myocardial oxygen supply-demand balance, the subendocardial viability ratio (SEVR) was measured in 29 hypoplastic left heart syndrome patients after the Norwood procedure, in 27 patients with pulmonary atresia whose pulmonary blood flow was supplied from the aortopulmonary (AP) shunt, and in 30 control patients who were considered to have normal biventricular circulation. The SEVR in Norwood (0.57 ± 0.18) and AP shunt (0.66 ± 0.10) patients was significantly reduced compared with that in controls (0.94 ± 0.25, p < 0.001 vs Norwood and AP shunt).
  
  
  RESULTS
  After controlling for heart rate, the SEVR was significantly lower in Norwood than in AP shunt patients (p < 0.001). Importantly, the SEVR was significantly lower in Norwood patients with poor clinical outcomes (cardiac arrest before second-stage operation, progressive tricuspid regurgitation, or reduction of ejection fraction <0.35) than in the remaining Norwood patients (0.51 ± 0.12 vs 0.69 ± 0.22, p < 0.01). An SEVR of less than 0.52 had a more than 76% probability of having a poor outcome (p < 0.05). Furthermore, a lower SEVR was significantly correlated with more pronounced renin-angiotensin-aldosterone system activation and elevated natriuretic peptides in serum. Multiple regression analysis revealed that increased aortic stiffness and a smaller neoaorta relative to the native descending aorta were independent determinants of reduced SEVR.
  
  
  CONCLUSIONS
  Myocardial oxygen supply-demand imbalance is intrinsic to Norwood circulation but may be improved by technical refinement of aortic reconstruction or afterload-reducing medication with renin-angiotensin-aldosterone system blockade.
authors: Department of Pediatric Cardiology, Saitama Medical Center, Saitama Medical University, Saitama, Japan.
authors: Hirofumi
authors: H
authors: Saiki
authors: Department of Pediatric Cardiology, Saitama Medical Center, Saitama Medical University, Saitama, Japan.
authors: Seiko
authors: S
authors: Kuwata
authors: Department of Pediatric Cardiology, Saitama Medical Center, Saitama Medical University, Saitama, Japan.
authors: Clara
authors: C
authors: Kurishima
authors: Department of Pediatric Cardiology, Saitama Medical Center, Saitama Medical University, Saitama, Japan.
authors: Satoshi
authors: S
authors: Masutani
authors: Department of Pediatric Cardiology, Saitama Medical Center, Saitama Medical University, Saitama, Japan. Electronic address: hsenzaki@saitama-med.ac.jp.
authors: Hideaki
authors: H
authors: Senzaki
mesh_terms: D000367:Age Factors; D000704:Analysis of Variance; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D016001:Confidence Intervals; D003326:Coronary Circulation / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D018636:Hypoplastic Left Heart Syndrome / Q000175:diagnosis / Q000601:surgery*; D007564:Japan; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D015999:Multivariate Analysis; D017202:Myocardial Ischemia / Q000209:etiology* / Q000503:physiopathology; D058327:Norwood Procedures / Q000009:adverse effects / Q000379:methods*; D010101:Oxygen Consumption / Q000502:physiology*; D012189:Retrospective Studies; D018570:Risk Assessment; D012737:Sex Factors; D016896:Treatment Outcome; D035862:Vulnerable Populations