Left Ventricular Diastolic Dysfunction in Asymptomatic Type 2 Diabetic Patients: Detection and Evaluation by Tissue Doppler Imaging

Abstract

Bedri faik zahiti, daut rashit gorani, fitim Bejtullah gashi, sami Bajram gjoka, lorita Bedri zahiti, Bekim sylë Haxhiu, lulzim selim kamberi university clinical centre of kosova, prishtina, kosovo corresponding author: daut rashit gorani, md. e-mail: daut_g@yahoo.com introductionAbnormalities in diastolic function are considered to be an early sign of diabetic cardiomyopathy, and are identified in type 2 diabetic patients without systolic ventricular dysfunction as assessed by conventional methods, and also by tissue Doppler imaging (TDI) (1,2,3,4,5,6,7,8). The close association of diabetes with high cardiovascular morbidity and mortality is primarily due to an increased rate of ischemic heart disease. Some authors have reported a direct effect of diabetes on the myocardium (diabetic cardiomyopathy) that can lead to congestive heart failure in the absence of coronary atherosclerosis (9, 10, 11). Prevalence of CVD especially of ischemic heart disease in diabetics is more increased when associated with: arterial hypertension, overweight, increased levels of serum lipoproteins etc. (12, 13). Therefore, tissue Doppler imaging, as a new echocardiography tool, based on measurement of wall motion velocities (1,14,15,16,17,18), seems better suited for evaluating diastolic function, and is expected to improve the identification of diabetic patients with diastolic dysfunction and early impairment of cardiac performance (1,19). Recent studies have reported that the addition of TDI to CE increases the ability to identify diastolic dysfunction among diabetic patients (6). In the early stage, diabetic cardiomyopathy is characterized by left ventricular diastolic dysfunction (LVDD), while left ventricular (LV) systolic function impairs later on in the clinical course of diabetes (20).The aim of the study was to evaluate whether TDI is able to detect abnormalities of diastolic function by using exercise stress test in type 2 diabetic subjects even in the presence of a normal cardiac function with CE and symptom free in rest. material and metHods subjectsThree hundred subjects of both genders were studied; the study population was selected from two groups of subjects: 150 non-obese, normotensive, uncomplicated type 2 diabetic patients of average age of 50,5±10, in five years duration of disease and the control group which consisted of 150 non-diabetic subjects, of average age of 47,50±8,5, recruited from healthy volunteers. From the study were excluded patients with HTA, obesity, acute ischemic disease, heart failure, heart defects and pulmonary obstructive disease. The diagnosis of original paper ABSTRACT the aim of the study was detection of diastolic dysfunction of myocardium with Tissue Doppler Imaging (TDI) in asymptomatic type 2 diabetic patients, in five years duration of disease, and normal cardiac function on conventional echocardiography (CE), according to the performance showed on exercise stress test. material and methods: We studied 300 patients, of them 150 patients with nonobese, normotensive, uncomplicated type ...

Type 2 diabetes and reduced exercise tolerance: a review of the literature through an integrated physiology approach

“…a Vasogenic determinants: impaired modulation of peripheral vascular resistances reduces muscle blood flow and oxygen diffusion, thus negatively affecting skeletal muscle performance, peripheral oxygen extraction and cardiac output through enhanced baroreflex and muscle metaboreflex activation. b Neurogenic determinants: altered autonomic tone and hyperactive muscle metaboreflex and cardiac sympathetic efferent reflex might account for impaired cardiac output, suboptimal vascular and pulmonary adjustments during exercise, eventually leading to reduced muscle perfusion and oxygen extraction (see main text for full description) values, S' (peak systolic annular) and E' (early left ventricular filling phase) velocities of the mitral annulus measured through tissue Doppler were significantly reduced in patients with T2DM during exercise compared to controls, thus unmasking reduced systo-diastolic reserve [41][42][43]. Importantly, reduced VO 2peak was associated with S' and E' and also to cardiac magnetic resonance assessed myocardial fibrosis [44].…”

A Study of cardiac functions in type-2 diabetic patients

“…Our study shows that the diastolic dysfunction is common in type 2 diabetes mellitus patients. Increase in collagen deposition and myocyte fibrosis can develop the diastolic dysfunction in diabetic models, which was shown by different histopathological studies [20]. High concentration of glucose causes formation of Advanced Glycation End-products (AGEs) that cause change in collagen structure [21].…”

“…Diabetes also has adverse effects on myocardium, causing glucotoxicity, lipotoxicity, mitochondrial dysfunction, impaired calcium homeostasis, increased oxidative stress [22,23]. These alteration leads to necrosis of cardiomyocyte and apoptosis which is associated with myocardial fibrosis and subsequent myocardial dysfunction, called diabetic cardiomyopathy [20,24].…”

Methods for Ultrasound Screening of Cardiovascular Diseases in Type 2 Diabetic Patients

“…Boyer et al [9] found LVDD with the help of TDI in 63% of asymptomatic type 2 diabetes patients, while with the conventional Doppler only 46% of the individuals were determined to have dysfunction. Zahiti et al [10] studied 300 patients, of them 150 patients non-obese with normotensive, uncomplicated T2D and 150 healthy control subjects. The conventional echocardiography showed no substantial differences in the systolic and diastolic function between the two groups.…”

“…Except for LVDD, other echocardiographic changes that can be found in type 2 diabetes patients [10,17] are left ventricle remodeling and hypertrophy [18], reduced EF [19], dilated left atrium [19], and valvular impairment [20]. These disorders could be diagnosed early in the course of the diabetes progression and often remain asymptomatic [19].…”