Increased Left Ventricular Torsion in Uncomplicated Type 1 Diabetic Patients: The role of coronary microvascular function

OBJECTIVE

We used speckle tracking echocardiography to study the early changes in left ventricular (LV) torsion in young patients with uncomplicated type 1 diabetes and stress magnetic resonance imaging (MRI) to assess its interrelationships with coronary microangiopathy.

RESEARCH DESIGN AND METHODS

We recruited 33 asymptomatic subjects with type 1 diabetes and 32 age-matched healthy control subjects. All subjects underwent echocardiograms. Stress MRIs were performed in 30 subjects (8 healthy control subjects) to compute myocardial perfusion reserve index (MPRI).

RESULTS

A significant increase in LV torsion (2 ± 0.7 vs. 1.4 ± 0.7°/cm, P < 0.05) was identified in longer-term and retinopathy-positive type 1 diabetic subjects (1.9 ± 0.7 vs. 1.4 ± 0.7°/cm, P < 0.05) as compared with the healthy control subjects. The MPRI was independently associated with increased LV torsion.

CONCLUSIONS

We demonstrate that LV torsion is increased in young patients with uncomplicated type 1 diabetes and that coronary microvascular disease may play a key pathophysiological role in the development of increased LV torsion.There is increasing evidence for the presence of diabetic cardiomyopathy as a separate entity. However, detection of early changes in the myocardium is challenging in patients with diabetes. Speckle tracking echocardiography is a novel method of measuring left ventricular (LV) strain and rotation (1,2). Previous studies with tagged magnetic resonance imaging (MRI) have shown increased torsion in both patients with type 1 and type 2 diabetes (3,4). The main aim of this study was to confirm and extend these findings by exploring the potential pathophysiological mechanisms involved. We utilized speckle tracking to measure LV torsion and stress MRI to compute myocardial perfusion reserve index (MPRI), which is a measure of coronary microvascular function.