Tissue Doppler imaging for the detection and quantitation of myocardial dysfunction in patients with type 2 diabetes mellitus

Abstract

The prevalence of type 2 diabetes mellitus is rapidly increasing. Myocardial dysfunction may be a consequence of diabetic cardiomyopathy and it contributes to the poor prognosis of diabetic patients. Aims This study was designed to test whether tissue Doppler imaging might be a suitable tool for early detection of myocardial dysfunction in diabetic patients. Methods Forty-three diabetic patients and 33 non-diabetic controls, including age-matched subgroups without evidence of coronary artery disease (n=12), were recruited if they had normal LV-function by standard 2-D echocardiography and no clinical signs of heart failure. They were investigated with tissue Doppler imaging at rest and during pharmacological stress with dipyridamole and/or dobutamine. Myocardial function was calculated as the mean value from six basal myocardial segments for peak velocity at systole (Vs), early diastole (Ve) and atrial contraction (Va). Results Compared to controls, diabetic patients had compromised Ve at rest (8.5. ± 1.7 vs. 9.6 ± 1.9 cm/sec, p<0.02), as did the subgroups without coronary artery disease (9.3 ± 1.7 vs. 10.7 ± 1.5 cm/sec, p<0.05). Dobutamine stress resulted in lower Vs (10.7 ± 2.7 vs. 13.6 ± 3.4 cm/sec, p<0.05) and Ve (10.0 ± 2.1 vs. 13.1 ± 3.8 cm/sec, p<0.05) in the diabetic patients, demonstrating an impaired increase of Vs, Vd and Va (p<0.05, p<0.0003 and p<0.03, respectively). An inverse correlation was observed between Ve and age in both control and diabetic individuals. Thus, abnormal values were defined in relation to age. Conclusions Diastolic and systolic myocardial dysfunction in patients with type 2 diabetes may be identified by quantitative tissue Doppler imaging before the onset of clinical signs of heart failure and before the appearance of traditional echocardiographic indices of systolic myocardial dysfunction.