Layer-specific myocardial strain analysis: investigation of regional deformation in a rabbit model of diabetes mellitus during different stages.

Abstract

Aim: The purpose of the present study was to determine the characteristics of myocardial damage at different stages of diabetes mellitus (DM) using layer-specific myocardial strain. Material and methods: Thirty six New Zealand white rabbits were randomly divided into either the control group (n =18) or the DM group (induced with alloxan) (n=18). For the myocardial deformation studies echocardiography and layer-specific strain were performed at baseline and after 3, 6, and 9 months in all of the rabbits. Three-layer longitudinal strain (LS) was calculated in the apical 4-chamber view, and three-layer circumferential strain (CS) in the short-axis view at the level of mitral valve. Layer-specific longitudinal and circumferential strains were assessed from endocardium, mid-myocardium and epicardium. For histomorphological study of the heart structure, the rabbits were sacrificed at 3, 6 and 9 months. Routine hematoxylin and eosin staining was performed. Results: The highest absolute values of left ventricular longitudinal strain (LS) and circumferential strain (CS) were registered in the endocardium and the lowest in the epicardium in both groups. At 3 months, there was no significant difference in three-layer LS and CS (p>0.05), but at 6 months the LS of endocardium (LSendo) and CS of endocardium (CSendo) were lower in the DM group compared with the control group; at 9 months, the rest of the parameters were also decreased (p<0.05). Moreover, in ROC analysis at 6 months LSendo yielded better sensitivity and specificity in the detection of diabetic cardiomyopathy (AUC of LSendo was 0.897 and AUC of CSendo was 0.617). With the progression of untreated diabetes, the histopathological abnormalities intensified gradually beginning at 6 months. Conclusion: The progressive impairments in LV myocardial deformation and structure occurs early in diabetic rabbits, the myocardial damage may be nontransmural, and endocardial function is more susceptible to be affected by DM. Layer-specific myocardial strain echocardiography may identify subtle myocardial dysfunction in the early stages of DM.

In-Depth Insight Into the Mechanisms of Cardiac Dysfunction in Patients With Childhood Cancer After Anthracycline Treatment Using Layer-Specific Strain Analysis

“…30 In patients with ischemia, not only the endocardial CS but also epicardial CS decreases as the disease progresses. 19, 27 Furthermore, we previously reported on the time course of LV dysfunction in patients with repaired tetralogy of Fallot: impaired myocardial deformation increases with age, extending from the endocardium to the epicardium.…”

Mechanisms of Left Ventricular Dysfunction Assessed by Layer-Specific Strain Analysis in Patients With Repaired Tetralogy of Fallot

“…16 Yu et al showed that in anthracycline-treated survivors of childhood cancers, subendocardial circumferential deformation is sensitive to anthracycline. 17 In a rabbit model of DM, 25 and in patients with ischemia 15 or hypertension, 26 the vulnerability of the endocardial layers has been proposed. Although vulnerability of the endocardial layers in patients with rTOF has not been clarified physiologically or pathologically, the present study's findings demonstrated that potential myocardial damage occurs in the endocardial layers before the midmyocardial and epicardial layers in patients with rTOF when measured with layer-specific strain analysis, which is concordant with findings in reports on other diseases.…”

In-Depth Insight Into the Mechanisms of Cardiac Dysfunction in Patients With Type 1 Diabetes Mellitus Using Layer-Specific Strain Analysis

“…15,16 Studies of animal models of T1DM have also demonstrated LV dysfunction. [6][7][8] Some studies indicated that cardiac dysfunction begins during childhood or adolescence, 9,17,18 but the long-term changes of DCM in patients with T1DM, especially between childhood and adulthood, remain unknown.…”

“…4 Although ischemic heart disease has been the most researched form of CVD in patients with T1DM, 4 diabetic cardiomyopathy (DCM) has recently attracted a great deal of attention. [5][6][7][8][9] DCM is defined as myocardial dysfunction independent of coronary artery disease and hypertension. 10 The development of DCM is associated with structural and functional alterations in cardiomyocytes, coronary microangiopathy, Layer-Specific Strain Analysis in T1DM Patients…”