Detection of occult right ventricular dysfunction in young Egyptians with type 1 diabetes mellitus by two-dimensional speckle tracking echocardiography

Abstract

Background: Type 1 diabetes mellitus (T1DM) is a common chronic disorder of childhood and adolescence. T1DM induced cardiomyopathy has a different entity than T2DM as it relies on different pathophysiological mechanisms, and rarely coexists with hypertension and obesity. Evaluation of right ventricular (RV) function in diabetic patients has been neglected despite the important contribution of RV to the overall cardiac function that affects the course and prognosis of diabetic cardiomyopathy (DCM).

Objective: To assess RV myocardial performance in asymptomatic T1DM using speckle tracking and standard echo parameters and correlate it with functional capacity using treadmill stress test.

Patients and methods: Thirty-nine patients with TIDM (Group 1, mean age 18.2±1.7y, BMI=26.2±3.9kg/m²), without cardiac problems and 15 apparently healthy matched subjects as a control group (Group 2, mean age 18.8±2.3 y, BMI=22.8±3.3kg/m²) were enrolled. RV function was evaluated using conventional, tissue Doppler and 2D speckle tracking echocardiography (2D-STE). The peak RV global longitudinal strain (RV-GLS) was obtained. Functional capacity was assessed by treadmill exercise test and estimated in metabolic equivalent (METs).

Results: In this study; the diabetic group showed statistically highly significant decrease in the average RV-GLS (-14.0±6.9 in group 1 vs. -22.7±2.5 in group 2, P<0.001), significant decrease in RV S velocity (9.5±2.2 in group 1 vs. 11.5±1.8 in group 2, P<0.05), significantly reduced E/A ratio (1.0±0.2 in group 1 vs. 1.1±0.1 in group 2, P<0.05), and highly significant increased E/Em ratio (7.9±3.2 in group 1 vs. 5.2±0.7 in group 2, P<0.001). We did not found any significant differences between the two groups regarding the other echocardiographic or functional capacity parameters.

Conclusion: In asymptomatic patients with T1DM, in addition to RV diastolic dysfunction, early (subclinical) RV systolic dysfunction is preferentially observed with normal RV and left ventricular (LV) ejection fraction (EF). 2D-STE has the ability to detect subclinical RV systolic dysfunction.

Keywords: 2D speckle tracking; Diabetes type I; Right ventricle assessment; Tissue Doppler.