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352 Cardio Diabetes Medicine 2017

of volume by myocardial density of 1.05 g/mL and to identify subclinical LV dysfunction. GLS is calculat-
is normalized for the Body surface Area as LV Mass ed using a variety of proprietary software (EchoPAC,
Index. Left ventricular Hypertrophy is defined as Left GE Medical Systems, Milwaukee, Wisconsin, USA;
ventricular Mass Index of >115g/m and >95g/m for Syngo velocity vector imaging, Siemens, Mountain
2
2
women . 3D Echocardiographic quantification of LV View, California, USA; LV analysis, TomTec GmbH,
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Mass correlates better with CMR measurements 15.16 . Unterschlessheim, Germany). GLS is well validated
as a marker for the measurement of LV longitudinal
Evaluation of Left Atrium: deformation, which has emerged as a sensitive and
specificmarker to detect early and subtle myocardial
Left atrial size is a powerful marker of prognosis in
Diabetes under a variety of clinical situations and is dysfunction. In one of the recent meta-analysis, Ka-
a strong predictor of mortality and morbidity . Be- lam et al, have shown the independent prognostic
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cause, 3D volume calculation of left atrium is devoid significance of GLS in patients with mild LV global
of geometrical assumptions, it correlates better with impairment. The prognostic value of this information
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Cardiac Magnetic Resonance Imaging . Normal Left seems likely to be superior to that provided by LVEF.
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Atrial maximal volume and Total emptying fraction
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have been published . Regional assessment of left LV Torsional deformation and 3-Dimensional
atrial function by Speckle tracking Echocardiography Speckle Tracking Echocardiography:
has also evolved to be a novel Echocardiographic Shortening and lengthening which are the basic
technique . functions of the myocardial fibres result in a systol-
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ic twist followedby a diastolic untwisting of the left
Echocardiographic assessment of systolic ventricle due to helical orientation of the fibres.In
dysfunction LV Ejection fraction: systole, the LV apex undergoes a counterclockwise-
rotation about its longitudinal axis as viewed from
The cornerstone of the prognostication and treat-
ment schedule for Echocardiographic evaluation of the apex.Rotation of the LV base in systole is oppo-
Diabetic cardiomyopathy starts with evaluation of site in directioncompared to apical rotation. Thismo-
left ventricular ejection fraction. The evidence base tion has been compared with that used tosqueeze
for modern cardiology is so heavily based on this water out of a wet towel. The main determinant of
simple measurement that it is unlikely to disap- the LV twist is the apical rotation. Three-dimension-
pear.The problems in calculating EF as the ratio be- al speckle tracking echocardiographyhas emerged
tween stroke volume and end-diastolic volume are as an alternative non-invasivetechnique to assess
geometry dependence, load dependence, the effect LV rotation.The problems with 2D Speckle Tracking
of high and low heart rate due to heart blocks, Tachy- Echocardiography are the lower valuesfor apical ro-
cardias(especially Atrial Fibrillation) and insensitivity tation and LV twist, due to difficulties in selection of
to minor change when close to 50% . 3D imaging is optimal imaging planes for computation,as the im-
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now available with echocardiography and its results ages are acquired separately from entirely different
are comparable to Cardiac MRI . The main attraction cardiac cycles and rotation at each level peaks at a
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and advantage of 3D imaging is to avoid geometric different time in the cardiac cycle. A recent study by
assumptions when calculations of LV volumes, and Muhammad Ashraf et al., to compute left ventricular
reduction of errors created by cutting a 3D structure (LV) twist from 3-dimensional (3D) echocardiography
in two dimensions. The current software for 3D eval- concluded despite lower spatiotemporal resolution of
uation of LVEF is much easier and can be performed 3D echocardiography, LV twist and torsion can be
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within minutes in the setting of emergency room. The computed accurately LV twist is reduced in Dilated
sphericity index derived from 3D echocardiography cardiomyopathy due to cardiac fibrosis resulting in
(LVEDV divided by the volume of a sphere whose di- alteration of myocardial fibre orientation. Fig 2 shows
ameter is the LV end-diastolic long axis) is an added abnormally reduced twist and torsion in a normal in-
by product and is the best predictor for LV dilatation dividual, a patient with early diabetes without LVH,
in a patient with severe LVH and finally in a patient
with diabetic cardiomyopathy and LV dysfunction. A
Strain Imaging in decision making in decreased and delayed systolic LV torsion as well as
Diabetic Cardiomyopathy depressed, delayed and disorganised LV untwisting
have been previously reported in patients with dilat-
Global Longitudinal strain (GLS): ed cardiomyopathy (DCM). Moreover, paradoxical re-
Global longitudinal strain (GLS) has evolved as one of versal of LV rotation, with the base rotating counter
the most robust parameter, and this has been shown clockwise and the apex clockwise, with subsequent

GCDC 2017