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.