Changes in the response of hibernated myocardium to inotropic stimulation after angioplasty: a Doppler myocardial imaging study.
BACKGROUND
Angioplasty of an infarct related artery (IRA) performed several weeks or months after myocardial infarction (MI) may improve myocardial function.


OBJECTIVE
We hypothesized that, as Doppler myocardial imaging (DMI) allows for the quantitative assessment of the systolic movement of myocardial segments, it may be a sensitive method for assessing changes in regional myocardial contraction and contractile reserve pre and post angioplasty of the IRA.


METHODS
In all, 39 patients (30 men, mean age 53.4 +/- 8.3 years), 1 to 6 months after MI, who qualified for IRA angioplasty on the basis of myocardial viability in the infarcted zone as demonstrated by dobutamine stress echocardiography, were included in the study. Peak regional myocardial systolic velocities (S wave) of the infarcted segments were measured at rest and during low-dose dobutamine infusion (15 microg/kg/min) 1 day before angioplasty (Exam 1), 2 to 5 days (Exam 2), and 30 days (Exam 3) after successful angioplasty. The long-axis movement of the mitral annulus and of the basal and medial segments of the posterior (20 patients), anterior (17 patients), and lateral walls (2 patients) was evaluated.


RESULTS
At rest, S-wave velocity of the infarcted segments increased between Exams 1 and 2, without further improvement between Exams 2 and 3 (4.9 +/- 1.2 vs. 5.6 +/- 1.3 cm/s, p < 0.05 and 5.6 +/- 1.3 vs. 5.5 +/- 1.3 cm/s, NS, respectively). However, S-wave velocities measured during low-dose dobutamine infusion differed significantly both between Exams 1 and 2, and 2 and 3 (7.0 +/- 1.5 vs. 7.8 +/- 1.8 cm/s; p < 0.01; 7.8 +/- 1.8 vs. 8.5 +/- 1.6 cm/s; p < 0.05).


CONCLUSIONS
Resting contractility at an infarct zone demonstrated rapid initial improvement after angioplasty of the IRA with no further change, whereas contractile reserve improved not only immediately after angioplasty but also during the next month.
Klisiewicz
Anna
A
Department of Non-Invasive Cardiology, National Institute of Cardiology, Warsaw, Poland. aklis@ikard.waw.pl
Michałek
Piotr
P
Szymański
Piotr
P
Hoffman
Piotr
P
D015906:Angioplasty, Balloon, Coronary; D002316:Cardiotonic Agents / Q000494:pharmacology; D004280:Dobutamine / Q000494:pharmacology; D025401:Echocardiography, Stress; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000187:drug effects; D017682:Myocardial Stunning / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000628:therapy*; D013997:Time Factors; D018608:Ultrasonography, Doppler; D016276:Ventricular Function / Q000187:drug effects*
D002316:Cardiotonic Agents; D004280:Dobutamine