[Usefulness of dobutamine stress echocardiography in qualification of patients to angioplasty of infarct related artery].
Late angioplasty of an infarct-related artery (IRA) performed weeks or months after myocardial infarction (MI) may restore blood flow in IRA and would result in improvement of regional wall motion. This study was designed to assess dobutamine stress echocardiography (DSE) in predicting the improvement of regional left ventricular (LV) function in patients after late PTCA of IRA.


METHODS
44 patients (36 M 8 F, mean age 54 +/- 7 year) who had a MI 15 +/- +/- 8 weeks earlier, were qualified to angioplasty of IRA when DSE showed the change in wall motion at the infarct zone--improved during low dose infusion (5-10 micrograms/kg/min) and/or worsened during a high dose dobutamine (up to 40 micrograms/kg/min). Regional wall motion was assessed by DSE performed at 2-7 days and 6-month after successful angioplasty. Wall motion score index (WMSI) decreased from 1.51 +/- 0.29 at rest to 1.31 +/- 0.28 at low-dose dobutamine infusion (p > 0.001) before angioplasty. Early after PTCA regional wall motion improves and baseline, exercise and rest values of WMSI decreased, compared with values before angioplasty. At baseline echocardiography 248 of segments were dyssynergic (112 hypokinetic, 125 akinetic and 10 dyskinetic). Viability during DSE was more frequent in segments with biphasic reaction during DSE than in segments showed monophasic reaction. In 34 patients control angiography (CA) was performed 6 month after successful PTCA. In this selected group CA showed significant restenosis of IRA in 12 pts (35% =, 9 of them showed positive DSE. Their base WMSI increased from 1.36 +/- 0.28 to 1.47 +/- 0.30 and peak stress WMSI from 1.32 +/- 0.29 to 1.60 +/- 0.30 (p < 0.001), respectively, between the exam just after PTCA comparing with the exam which detected restenosis.


CONCLUSIONS
In some patients with infarction and a narrowed or occluded IRA the myocardium remains viable for a prolonged period. Improvement of wall motion during low-dose DSE and/or worsened during high dose DSE at infarct zone is a very useful tool in predicting of viable myocardium at infarct zone. DSE is an excellent method to demonstrate an immediate improvement in regional LV dysfunction after angioplasty of IRA. At 6 months' follow-up restenosis of IRA is often seen.
Michałek
P
P
Zakład Diagnostyki Nieinwazyjnej Instytutu Kardiologii w Aninie.
Klisiewicz
A
A
Witkowski
A
A
Ruzyłło
W
W
Rydlewska-Sadowska
W
W
D015906:Angioplasty, Balloon, Coronary / Q000379:methods*; D002316:Cardiotonic Agents / Q000008:administration & dosage; D003326:Coronary Circulation / Q000187:drug effects*; D004280:Dobutamine / Q000008:administration & dosage; D004334:Drug Administration Schedule; D004452:Echocardiography; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000601:surgery
D002316:Cardiotonic Agents; D004280:Dobutamine