The effects of load on systolic mitral annulus movements by tissue Doppler imaging in cardiac surgery patients.
OBJECTIVE
The main indexes of ventricular function used in clinical practice are strongly influenced by the ventricular load conditions. Tissue Doppler imaging (TDI) has been reported to be a powerful modality that enables assessment of ventricular wall motion with a high temporal and spatial resolution. The study of the systolic movements of the mitral annulus has been proposed as a valid index of myocardial contractility. The aim of this study was to verify if the systolic movements of the mitral annulus by TDI are load-dependent in patients undergoing coronary artery bypass grafting. We evaluated the effect of load changes on systolic (S(M)) and isovolumic (S(IVC)) velocity waves, and on isovolumic acceleration (S(IVA)).


METHODS
Twenty-three patients undergoing coronary artery bypass grafting were evaluate. Load was changed with a rapid infusion of 7 cc/kg of a gelatin solution. The sample volume of TDI was placed at the lateral side of the mitral annulus in the mid-esophageal 4-chamber view.


RESULTS
The increase preload resulted in a statistically significant increase of S(M) (8.7+/-1.04 cm/s vs. 9.99+/-0.88 cm/s P=0.01), and a statistically significant increase of S(IVC) (5.65+/-1.95 cm/s vs. 6.75+/-1.53 cm/s P=0.03). S(IVA) does not appear to be changed after the increase of preload (203.45+/-45.69 cm/s(2) vs. 211.41+/-71.28 p=0.81).


CONCLUSIONS
Only S(IVA) seems to be an independent index of cardiac functionality in cardiac surgery patients and appears to be an optimum index in the clinical evaluation of these patients.
Meco
M
M
Thoracic Surgery and Anesthesia and Intensive Care Department, Sant'Ambrogio Clinical Institute, Milan, Italy. massimo.meco@virgilio.it
Cirri
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D000368:Aged; D003102:Colloids / Q000008:administration & dosage; D001026:Coronary Artery Bypass; D015150:Echocardiography, Doppler; D017548:Echocardiography, Transesophageal; D005260:Female; D005780:Gelatin / Q000008:administration & dosage; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000000981:diagnostic imaging* / Q000503:physiopathology; D009200:Myocardial Contraction; D011237:Predictive Value of Tests; D013599:Systole; D016277:Ventricular Function, Left; D017725:Ventricular Pressure
D003102:Colloids; D005780:Gelatin