Effect of Diabetes Mellitus on Left Atrial Volumes and Functions Using 3D Echocardiography in Patients Without Symptomatic Cardiovascular Disease

Abstract

SUMMARY I ndividuals with diabetes mellitus carry an increased risk of vascular and myocardial disease, these complications contribute significantly to morbidity and mortality among diabetics. Patients with diabetes mellitus are more likely to develop congestive heart failure compared with non-diabetic individuals. The aim of the study was the evaluation the effect of diabetes mellitus on left atrial volumes and functions by using real-time three dimensional echocardiography in a population of patients free of symptomatic cardiovascular disease as compared to normal subjects. The study included 110 individuals; 50 healthy controls who were recruited from echo lab of Ain Shams university hospital and 60 patients with diabetes mellitus; 30 patients with type 1 and 30 patients with type 2 diabetes mellitus who were consecutively recruited from diabetic clinic in Ain Shams university hospital. All individuals were subjected to adequate history taking, proper physical examinations, ECG, 2D echocardiography and 3D echocardiography study. LA assessed by 2D and 3D echocardiography, two dimensional echocardiography LA maximum volume was measured using simpson s biplane method of discs. LA phasic volumes (Vmax , Vmin , VpreA ) and LA maximum volume indexed to body surface area were measured by 3D echocardiography using Q Lab offline analysis. LA functions (LA total stroke volume, LA active stroke volume and LA active emptying fraction) were obtained from RT3D volumetric analysis. The results of the analysis were then compared and the data statistically analyzed which revealed that type 2 diabetes mellitus showed enlarged Vmax, Vmin and LAVI with increased LA total stroke volume and decreased active emptying fraction, while type 1 diabetics showed only decreased in active emptying fraction. 2DE and 3DE LA maximum volume was correlated well. LA total stroke volume was positively correlated with increased LA area, increased LA diameter, increased LA length, increased LA maximum volume, higher (A) velocity and those with older age while LA active stroke volume was positively correlated with increased LA area and increased LA maximum volume. But LA minimum volume was observed to be increased in those patients with higher (A) velocity and those with increased BMI. Antero-posterior diameter of LA was measured using 2D guided M-mode from parasternal long axis view, showed no correlation with LAVi. Study concluded patients with type 2 diabetes mellitus have increased LA volume and impaired compliance and contractility, while patients with type 1 diabetes mellitus have impaired contractility.

CONCLUSION AND RECOMMENDATIONS 1. Evaluation of asymptomatic diabetic patients by using RT3DE atrial volume analysis may facilitate recognition of subtle alterations related with type 1 & type 2 diabetes. 2. Patients with type 2 diabetes mellitus have increased left atrial volume and impaired left atrial compliance and contractility in relation to normal healthy subjects. 3. Patients with type 1 diabetes mellitus have impaired left atrial contractility in relation to normal healthy subjects. 4. Presence of diabetes mellitus, type of diabetes mellitus and age were independent predictors of Vmin while only type of diabetes mellitus was independent predictor of Vmax. 5. Presence of diabetes mellitus and type of diabetes mellitus were independent predictors of LAVi and only type of diabetes mellitus was independent predictors of LA total stroke volume while non of them were independent predictors of LA active emptying fraction. 6. Intrinsic alterations in atrial myocardial activity seem to be responsible for left atrial dysfunction in addition to impairment in left ventricular diastolic function which is known to be common in diabetic patients. 7. Further large scale prospective studies are needed to explain mechanisms and examine the prognostic significance of these findings and confirm value of 3D echo in relation to other modalities (CT, MRI).