ABSTRACT
Impairment of cardiac function in patients with type 1 DM represents one of the serious complications and, if present, may affect the quality of life and prognosis of the disease. Conventional and tissue Doppler echocardiographic imaging can predict early stage and progression of diabetic cardiomyopathic changes. The aim of this study is to assess the effect of type 1 diabetes on cardiac systolic and diastolic functions in both ventricles in patients without evidence of coronary artery disease or hypertension. The study included 30 patients with type 1 DM [18 females and 12 males] and 10 healthy individuals, their age 14.2 +/- 2.4 years, and diabetes duration of 5 years or more. Cardiac functions were assessed by conventional echocardiography, and tissue Doppler imaging studies. The study showed that there is statistically significant difference as regard end diastolic volume [EDV], right ventricular wall thickness [RVWT], Peak systolic myocardial velocity [Sm] velocity of inferior and septal segments of LV, Peak late diastolic myocardial [Am] velocity and Em/Am ratio of lateral segment of RV, between diabetic and non diabetic population. Also, there is significant negative correlation of diabetes duration to Peak early diastolic myocardial velocity [Em] of anterior segment [r = -0.492, p<0.006], Am of anterior segment [r = -0.355, p<0.048] and Em of septal segment of the left ventricle in patient group [r = -0.448, p<0.013]. No significant correlation between diabetes duration and all other echo-cardiographic parameters, age or HgAlc level. Ventricular interaction was also demonstrated since significant relations were found between right and left ventricular, diastolic and systolic, functional indices, as regards [1] positive correlation between the mitral and tricuspid [E,A] velocities in diabetic patients [r=0.371, p<0.044], [r=0.438, p<0.015] respectively, [2] positive correlation of Em/Am ratio of the lateral segment of the RV to Em/Am ratio of the septal segment of LV [r =0.465, p< 0.010], [3]positive correlation of right ventricular end-diastolic diameter [RVEDd] to interventricular septum systolic diameter [IVSs], [r = 0.401, p<0.028], posterior wall thickness at end systole [LVPWTs], [r=0.443, p<0.014] and [EDV] of LV [r=0.366, p<0.047]. There were no significant correlation between age and HgAlc blood level with Doppler [E/A ratios] and pulsed tissue Doppler [Em/Am ratios] of both ventricles in diabetic population studied. Patients with type 1 DM have impaired diastolic function, in both ventricles before the development of myocardial systolic dysfunction when assessed with either conventional or tissue Doppler imaging. These alterations in myocardial function were related to the duration of DM and may be attributed to ventricular interdependence as well as the uniform effect of diabetes on cardiac function. Serial echocardiographic assessment, and particularly tissue Doppler imaging, are warranted in patients with type 1 DM to follow the progression from ventricular subclinical involvement to the development of symptomatic ventricular dysfunction