OBJECTIVES: To assess whether quantification of myocardial systolic
velocities by pulsed wave tissue Doppler imaging can differentiate between
stunned, hibernating, and scarred myocardium. DESIGN: Observational study.
SETTING: Tertiary referral centre. PATIENTS: 70 patients with reduced left
ventricular function caused by chronic coronary artery disease. METHODS:
Pulsed wave tissue Doppler imaging was done close to the mitral annulus at
rest and during low dose dobutamine; systolic ejection velocity (Vs) and
the difference in Vs between low dose dobutamine and the resting value
(DeltaVs) were assessed using a six segment model. Assessment of perfusion
(with Tc-99m-tetrofosmin SPECT) and glucose utilisation (by
18F-fluorodeoxyglucose SPECT) was used to classify dysfunctional regions
(by resting cross sectional echocardiography) as stunned, hibernating, or
scarred. RESULTS: 253 of 420 regions (60%) were dysfunctional. Of these,
132 (52%) were classified as stunned, 25 (10%) as hibernating, and 96
(38%) as scarred. At rest, Vs in stunned, hibernating, and scar tissue
was, respectively, 6.3 (1.8), 6.6 (2.2), and 5.5 (1.5) cm/s (p = 0.001 by
ANOVA). There was a gradual decline in Vs during low dose dobutamine
infusion between stunned, hibernating, and scar tissue (8.3 (2.6) v 7.8
(1.5) v 6.8 (1.9) cm/s, p < 0.001 by ANOVA). DeltaVs was higher in stunned
(2.1 (1.9) cm/s) than in hibernating (1.2 (1.4) cm/s, p < 0.05) or scarred
regions (1.3 (1.2) cm/s, p = 0.001). CONCLUSIONS: Quantitative tissue
Doppler imaging showed a gradual reduction in regional velocities between
stunned, hibernating, and scarred myocardium. Dobutamine induced
contractile reserve was higher in stunned regions than in hibernating and
scarred myocardium, reflecting different severities of myocardial damag