The Evaluation of Type 2 Diabetes Mellitus Related Changes in Diastolic Dysfunction During Exercise Using Conventional and Tissue Doppler Echocardiography

Abstract

Background: The aim of this study was to evaluate the relationship between changes in diastolic functions during exercise and the exercising capacity in diabetic patients with diastolic dysfunction and to compare them with healthy individuals and diabetic patients without diastolic dysfunction.

Methods: Totally 70 patients prospectively were included in the study and three groups were formed. Forty-six diabetic patients were divided into two groups: those with (group 1) and without (group 2) diastolic dysfunction. The control group (group 3) consisted of 24 patients. All patients were subjected to treadmill exercising test. Echocardiographical assessment was made before exercise and immediately after peak exercise.

Results: Exercising time was dramatically decreased in group 1 compared to the other groups (group 1: 396 125 second, group 2: 487 66 second and group 3: 519 102 second). In group 1, the diastolic mitral flow pattern at rest was transformed into pseudo-normal pattern at peak exercise from abnormal relaxation pattern (E/A ratio 0.70 0.11 during rest, 1.02 0.16; P < 0.0001 during peak exercise). Deceleration time (DT) and iso-volumetric relaxation time (IVRT) turned to normal values (DT 238.86 39.48 millisecond during rest and 199.5 23.57 millisecond during peak exercise; P = 0.001, IVRT 102.83 16.22 millisecond during rest and 74.36 8.67 millisecond during peak exercise; P = 0.001). In groups 2 and 3, the mitral flow pattern, DT and IVRT remained within normal limits during rest and exercise. E/Em ratio, which is one of the parameters of tissue Doppler, increased during peak exercise in the diabetic group with diastolic dysfunction (E/Em ratio 7.85 3.31 during rest and 11.14 3.40 after peak exercise; P < 0.0001).

Conclusions: Diabetic patients with diastolic dysfunction demonstrated a reduced exercise capacity, which may be due to aggravation of pre-existing left ventricular dysfunction.




Cardiol Res. 2015;6(6):346-351
doi: http://dx.doi.org/10.14740/cr439w