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304 Diabetic Cardiomyopathy :
Mechanisms, Diagnosis and Treatment

crease was correlated with diabetes imbalance (gly- lar interaction mechanism, and the diabetes mellitus
cated hemoglobin) or microvascular complications per se. Interestingly, it has been demonstrated that in
(microalbuminuria). However, longitudinal alteration diabetic patients both the systolic and diastolic func-
is independently associated with diabetes mellitus, tion of the RV are affected. In addition, van den Brom
regardless of LV hypertrophy or other conventional et al have shown that in diabetic mice the changes
risk factors. On the other hand radial systolic func- caused by diabetes in the functionality of the RV
tion has been less investigated, and with conflicting are in line with those observed in the LV, but the
results. The initial studies suggested that radial func- changes in geometry and remodeling are not simi-
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tion was increased or preserved to compensate for lar. More specifically, LV changes are characterized
alterations in longitudinal function. However, most of by hypertrophy of myocardial cells without dilation,
these studies were based on TDI and its derived ve- while the opposite was observed in the RV. These
locity and strain rate measurements, which depend interesting findings have also been reported by other
on Doppler angle. STI as an angle-independent meth- investigators. 15
od could allow a more robust and extensive evalua- Clinical presentation and diagnostic approach
tion of radial function in diabetic as well as in non-di-
abetic patients. In the early stages of diabetic cardiomyopathy the pa-
tients are usually asymptomatic. In advanced stages
Left ventricular diastolic dysfunction in of diabetic cardiomyopathy overt heart failure occurs.
diabetic cardiomyopathy Patients develop symptoms due to forward heart
failure (weakness, fatigue, angina, syncope) and
LV diastolic dysfunction, as evaluated from the trans- backward heart failure (dyspnea, raised jugular vein
mitral LV filling pattern (i.e. abnormal relaxation and/ pressure, lower extremity edema, hepatomegaly).
or pseudo normal filling), was observed in 47-75% of Interstitial and perivascular fibrosis is a histological
asymptomatic normotensive patients with well-con- hallmark of diabetic cardiomyopathy, and the extent
trolled diabetes mellitus type 2.TDI, as a more sen- of fibrosis correlates with heart weight. In addition
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sitive technique for the detection of LV dysfunction, to the increase in collagen deposition, crosslinking
enables the measurement of myocardial tissue veloc- of collagen fibers may be increased by diabetes,
ities in the longitudinal direction, and the peak early contributing to a reduction in ventricular compliance.
diastolic myocardial velocity (é) reflects the global LV Interstitial fibrosis in diabetic hearts can be assessed
diastolic function. Studies by Kosmala and Di Bonito by integrated backscatter (myocardial ultrasound re-
reported that é was significantly lower in diabetic pa- flectivity) in two-dimensional echocardiography and
tients without hypertension than in normal subjects. by late gadolinium (Gd) enhancement in cardiac MRI.
Additionally, Boyer et al found that TDI revealed LV Diabetes (mostly diabetes mellitus type 2) is associ-
diastolic dysfunction in 63% of patients with asymp- ated with LV hypertrophy or concentric LV remodeling
tomatic diabetes mellitus type 2, while convention- (i.e. increased ratio of LV mass to LV end-diastolic
al Doppler echocardiography was abnormal in only volume). This finding was previously observed most-
46% of the subjects. Diastolic variables are related ly in females using transthoracic echocardiography.
to prognosis in diabetic patients without patent heart However MRI studies have demonstrated that it is not
disease. A study by From et al demonstrated that age- or sex specific. The most frequent echocardio-
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the E/é ratio was associated with an increase in glob- graphic finding in patients with asymptomatic diabe-
al mortality, after adjustment for age, sex, coronary tes mellitus is LV diastolic dysfunction with preserved
artery disease, hypertension, LV ejection fraction, LV ejection fraction. Diastolic dysfunction is also de-
and left atrial volume.
tectable in diabetic hearts without hypertrophy. There
is also evidence that diabetic patients are at increased
The right ventricle risk of arrhythmias, including sudden cardiac death.
It is known that dysfunction of the RV is associated The underlying arrhythmogenic mechanisms include
with a worse prognosis in a variety of cardiovascular imbalance in autonomic tone, silent ischemia, slowed
diseases, including acute myocardial infarction and conduction, heterogeneities in atrial and ventricular
heart failure. Although most investigators studied the repolarisation, and the extent of myocardial damage
effect of diabetes on the functionality and geometry and scar formation. Currently, the best approach to
of the LV, there are also scanty data indicating that the diagnosis of diabetic cardiomyopathy is detection
diabetes is equally detrimental for the RV. We can of functional, structural and metabolic changes in the
assume that in patients with diabetic cardiomyopathy LV and the exclusion of other heart diseases being
the RV is influenced by both the LV, via a biventricu- responsible for these changes in a diabetic patient:

GCDC 2017