Identification of contractility abnormalities in intensive care unit patients with sepsis using tissue Doppler imaging

Introduction

Tissue Doppler imaging (TDI), as a more recent ultrasound technique, is a precious diagnostic tool revealing earlier left ventricular (LV) contractility abnormalities as compared with the conventional echocardiography. This study aimed at assessing the contribution of TDI to the early diagnosis of LV systolic dysfunction in ICU septic patients maintaining a normal ejection fraction (EF).

Methods

Twenty-two ICU patients of average age 57.6 ± 7.3 years (13 males) (Group A) and 20 seemingly healthy individuals (Group B) were studied. The ICU patients met the sepsis criteria (infection by Gram-negative bacterium and, at least, two of the SIRS criteria). The APACHE II score mean value was 21.2 ± 4.9. All the patients of the study were subjected to the same session in a 2D echocardiogram. The EF of the left ventricle was calculated according to Simpson's method. The systolic velocities on the long axis were measured by TDI, placing the sample volume 0.5 cm distance from the mitral annular in the basic posterior interventricular septum (Sm) and on the lateral wall (Sl). Patients with ischemic, dilated, hypertrophic cardiomyopathy, severe valvular disease, uncontrolled blood pressure and chronic atrial fibrillation were excluded.

Results

No differences were observed in the LV systolic performance by use of the conventional 2D echocardiography between the two groups (EF: 63.8 ± 3.7% in Group A as compared with 64 ± 4.8% in Group B, P = not significant). Nevertheless, differences were ascertained in the maximum systolic velocities on the long axis using TDI. Sm: 8.2 ± 1.1 m/s in Group A, 9.7 ± 1 m/s in Group B (P = 0.04), Sl: 10.6 ± 1.3 m/s in Group A, 13.6 ± 1.4 m/s in Group B (P = 0.02).

Conclusion

TDI echocardiography identifies LV contractility abnormalities in ICU septic patients that appear to have a normal EF in the conventional echocardiogram, so it provides earlier recognition and treatment of LV dysfunction related to sepsis.