Vasoactive response of different parts of human internal thoracic artery to isosorbide-dinitrate and nitroglycerin: an in-vitro study

Citation
Y. Paz et al., Vasoactive response of different parts of human internal thoracic artery to isosorbide-dinitrate and nitroglycerin: an in-vitro study, EUR J CAR-T, 19(3), 2001, pp. 254-259
Citations number
25
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Cardiovascular & Respiratory Systems
Journal title
EUROPEAN JOURNAL OF CARDIO-THORACIC SURGERY
ISSN journal
1010-7940 → ACNP
Volume
19
Issue
3
Year of publication
2001
Pages
254 - 259
Database
ISI
SICI code
1010-7940(200103)19:3<254:VRODPO>2.0.ZU;2-W
Abstract
Objective: The left internal thoracic artery (LITA) is the most important g raft for coronary artery bypass grafting (CABG). its distal region is, howe ver, prone to vasospasm. The effect of nitroglycerin (NTG) and isosorbide-d initrate (ISDN) on different segments of this region was studied. Methods: Rings of three segments of the LITA were studied: 6-9 mm proximal to the bi furcation (part A); 1-3 mm proximal to the bifurcation (part B); and 3-6 mm distal to the bifurcation (part C). After baseline, maximal contraction of the rings was achieved using 60 mmol/l of KCl, they were exposed to increa sing doses of ISDN and NTG (10-100 mug/ml), and dose-response curves were r ecorded. Results: The contractile response of part A to KCl was significant ly lower than that of parts B and C (1.87 +/- 0.25 versus 4.05 +/- 0.39 and 7.64 +/- 0.54 g, respectively; P < 0.001). Both nitrates inhibited the con tractile response in a concentration-dependent manner. The relaxing effects of both nitrates on part A was most pronounced (P < 0.01), with the effect of ISDN being higher than that of NTG (P < 0.01). Conclusions: The region 6-9 mm proximal to the LITA bifurcation is less prone to vasospasm, and has greater relaxation responses to ISDN and NTG than the more vasospastic dis tal parts of the LITA. We recommend avoiding the use of the very distal par t of this artery during CABG, and to use high doses of ISDN rather than NTG as an anti-spastic measure. <(c)> 2001 Elsevier Science B.V. All rights re served.