In:
Circulation, Ovid Technologies (Wolters Kluwer Health), Vol. 99, No. 4 ( 1999-02-02), p. 482-490
Abstract:
Background —AMI reperfusion by thrombolysis does not improve TIMI flow and LV function. The role of infarct-related artery (IRA) stenosis and superimposed changes in coronary vasomotor tone in maintaining LV dysfunction must be elucidated. Methods and Results —Forty patients underwent diagnostic angiography 24 hours after thrombolysis. Seventy-two hours after thrombolysis, the culprit lesion was dilated with coronary stenting. During angioplasty, LV function was monitored by transesophageal echocardiography. Percent regional systolic thickening was quantitatively assessed before PTCA, soon after stenting, 15 minutes after stenting, and after phentolamine 12 μg/kg IC (n=10), the α 1 -blocker urapidil 600 μg/kg IV (n=10), or saline (n=10). Ten patients pretreated with β-blockers received urapidil 10 mg IC. Coronary stenting significantly improved thickening in IRA-dependent and in non–IRA-dependent myocardium (from 27±15% to 38±16% and from 40±15% to 45±15%, respectively). Simultaneously, TIMI frame count decreased from 39±11 and 40±11 in the IRA and non-IRA, respectively, to 23±10 and 25±7 ( P 〈 0.05). Fifteen minutes after stenting, thickening worsened in both IRA- and non–IRA-dependent myocardium (to 19±14% and 28±14%, P 〈 0.05), and TIMI frame count returned, in both the IRA and non-IRA, to the values obtained before stenting. Phentolamine and urapidil increased thickening to 36±17% and 41±14% in IRA and to 48±11% and 49±17% in non-IRA myocardium respectively, and TIMI frame count decreased to 16±6 and to 17±5, respectively. Changes were attenuated with β-blocker pretreatment. Conclusions —Our finding that α-adrenergic blockade attenuates vasoconstriction and postischemic LV dysfunction supports the hypothesis of an important role of neural mechanisms in this phenomenon.
Type of Medium:
Online Resource
ISSN:
0009-7322
,
1524-4539
DOI:
10.1161/01.CIR.99.4.482
Language:
English
Publisher:
Ovid Technologies (Wolters Kluwer Health)
Publication Date:
1999
detail.hit.zdb_id:
1466401-X
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