Assessment of Atrial Electromechanical Delay, Diastolic Functions, and Left Atrial Mechanical Functions in Patients with Type 1 Diabetes Mellitus

Objective

The aim of this study was to evaluate atrial electromechanical coupling obtained by tissue Doppler imaging (TDI), left and right ventricular diastolic functions, and left atrial (LA) mechanical functions in patients with type 1 diabetes mellitus (DM-1).

Methods

A total of 43 patients with DM-1 (age 19.6 ± 6.8 years) and 42 age- and gender-matched controls (age 19.5 ± 6.4 years) were included. Atrial electromechanical coupling was measured with TDI and corrected for heart rate. P-wave dispersion (Pd) was calculated from the 12-lead electrocardiograms. Systolic and diastolic functions in both ventricles were assessed using conventional echocardiography and TDI. Myocardial performance index was calculated with TDI. LA maximal, minimal, and pre-systolic volumes were measured according to the biplane area-length method. LA mechanical function parameters were calculated.

Results

Intra- and interatrial electromechanical delays and Pd were significantly higher in patients with DM-1 compared with controls (P = .02, P < .0001, and P = 0.005, respectively). A-wave velocity and isovolumic relaxation time were higher and E/A ratio was lower in patients with DM-1 (P = .03, P = .03, and P = .003, respectively). According to TDI, systolic velocities and myocardial performance index values of both ventricles were comparable. Diastolic filling velocities of the left ventricle, including E_m global, A_m global, E_m/A_m ratio, and right ventricular A_m, were different between groups (P = .03, P = .02, P < .001, and P = .02, respectively). LA passive emptying fraction was decreased, and LA active emptying volume and LA active emptying fraction were increased in patients with DM-1 (P = .02, P = .001, and P < .0001, respectively). Interatrial electromechanical delay was positively correlated with the presence of DM-1, age, LA active emptying fraction, and Pd (P < .001, P = .007, P < .001, and P = .002, respectively), and was negatively correlated with E_m/A_m ratio and LA passive emptying fraction (P < .001 and P = .001, respectively). In multivariate analyses, age and DM-1 were independent predictors of interatrial electromechanical delay (P = .001 and P < .001, respectively).

Conclusion

This study shows that intra- and interatrial electromechanical delays are prolonged diastolic functions of both ventricles and that LA mechanical functions are impaired in patients with DM-1. Age and the presence of DM-1 were independent factors of the interatrial electromechanical delay.

Keywords: Atrial electromechanical delay, Diastolic function, Left atrial mechanical function, Type 1 diabetes mellitus