Myocardial Regional Function by Dobutamine Stress Echocardiography in the Metabolic Syndrome and Type 2 Diabetes
Condition: Diabetes-related Complications
MeSH terms: Metabolic Syndrome; Diabetes Complications
Study type: Interventional

Summary: 
      Summary.

      Theoretical Rationale:

      The left ventricular myocardial performance results from a complex interplay between linear
      deformations (longitudinal, circumferential and radial) and twist/ untwist mechanics. These
      components of myocardial mechanics can be assessed, at rest and during stress conditions, by
      high resolution echocardiography using the "2D-strain" technology and constitute good indexes
      of tissue intrinsic contractility / relaxation properties. Type 2 diabetes (T2DM) and
      metabolic syndrome (MS) are associated with an increased risk for cardiac diseases. While
      several clinical studies have reported, particularly in T2DM, a diastolic dysfunction
      (concept of "diabetic cardiomyopathy"), the existence of impaired regional myocardial
      function, with altered intrinsic contractility properties, remains largely unanswered,
      especially in the SM. Stress echocardiography is very interesting to reveal myocardial
      dysfunction, discrete or absent at rest. To the best of our knowledge, no scientific study
      is, however, today available on the kinetics of linear strains and twist/untwist dynamics in
      response to stress in T2DM as well as SM. The epicardial adipose tissue is the source of
      production of important pro-inflammatory cytokines that have the potential, through an
      exacerbation of oxidative stress, to impair coronary endothelial function, increase fibrosis,
      but also directly affect cardiomyocyte calcium homeostasis. An increase in epicardial adipose
      tissue is consensually reported in T2DM and SM and is clearly associated with coronary
      atherosclerosis. A link between cardiac adiposity and overall cardiac function, particularly
      diastolic, is now suggested but to our knowledge no study has challenged its association with
      myocardial dysfunction in T2DM as SM patients.

      Objectives and Methodology: - To investigate regional myocardial linear deformations and
      torsion, at rest and in response to a dobutamine stress, in asymptomatic T2DM and SM patients
      without clinical complications, - to study the links between expected regional myocardial
      abnormalities and inflammation, hyperglycemia and cardiac adiposity. A control group of
      healthy individuals matched for sex and age will also be included.

      All the subjects will benefit from a clinical, anthropometric and biological evaluation. In
      addition, conventional echocardiography (remodelling and global diastolic and systolic
      functions) complemented by a functional analysis by tissue Doppler imaging will be performed.
      Furthermore, 2D cine loops will be recorded in the apical 4, 3 and 2- chamber views for the
      objective assessment of myocardial longitudinal deformations as well as in the parasternal
      short axis (base and apex) for the evaluation of the circumferential deformations and basal
      and apical rotations and left ventricular torsion, at rest and under low dose of dobutamine
      (110 and 120 bpm).
    


Intervention name(s): dobutamine
Intervention type(s): Drug
Intervention description(s): In each participant, dobutamine will be administered via intravenous infusion in doses of 10, 20, 30 and 40 lg/kg/min during 3-min stages and 2D strain echocardiography will be performed at each stage.
Intervention MeSH terms: Dobutamine
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Diagnostic
Keywords: Metabolic syndrome; diabetes; myocardial function; dobutamine