Early diastolic impairment of diabetic heart: the significance of right ventricle.

BACKGROUND: Left ventricular diastolic dysfunction represents the earliest preclinical manifestation of diabetic cardiomyopathy. Right ventricular function has not been studied in depth yet in diabetic patients, although the right ventricle has an important contribution to the overall cardiac function. This study was designed to assess diastolic and systolic ventricular function in both ventricles, in patients with type 1 diabetes, free from coronary artery disease and hypertension. METHODS: We studied 66 type 1 diabetic patients and 66 age- and sex-matched normal subjects by conventional and tissue Doppler echocardiography. A possible correlation was examined for age, diabetes duration and echocardiographic measurements of left ventricular and right ventricular functions with univariate analysis. RESULTS: Type 1 diabetic patients were found to have impaired diastolic function in both ventricles with either conventional or tissue Doppler echocardiography. On the contrary, systolic function in both ventricles was preserved in our diabetic population. The measured indexes showed an expected correlation with age and diabetes duration except from systolic velocity in tricuspid annulus determined by color tissue Doppler. Moreover, significant correlations were found among parameters of left and right ventricular function. CONCLUSIONS: Patients with type 1 diabetes mellitus have impaired diastolic function, and particularly relaxation, in both ventricles before the development of myocardial systolic dysfunction. These alterations in myocardial function may be attributed to ventricular interdependence as well as to the uniform effect of diabetes to cardiac function

Usefulness of colour tissue Doppler imaging in assessing aortic elastic properties in Type 1 diabetic patients.

AIMS: Diabetes mellitus (DM) is associated with macrovascular disease and impaired aortic function. We hypothesized that the change in aortic elastic properties could be investigated with colour tissue Doppler imaging (CTDI) in Type 1 diabetic patients and that these findings could be related to the aortic stiffness index. METHODS: We examined by echocardiography 66 patients with Type 1 DM (mean age 35 +/- 10 years, mean duration of disease 20 +/- 9 years) without a history of arterial hypertension or coronary artery disease (negative thallium-201 stress test) and 66 age- and sex-matched normal subjects. Arterial pressure was measured before echocardiography was performed. Internal aortic systolic and diastolic diameters by M-mode echocardiography and aortic systolic upper wall tissue velocity (Sao, cm/s) by CTDI were measured 3 cm above the aortic valve. Aortic distensibility and aortic stiffness index were calculated using accepted formulae. RESULTS: Aortic stiffness, distensibility and Sao velocity differed significantly between the studied groups. In the diabetic group, duration of diabetes correlated with aortic stiffness (r = 0.53, P < 0.001), distensibility (r = -0.61, P < 0.001) and Sao velocity (r = -0.48, P < 0.001). There was a negative correlation between aortic stiffness and Sao velocity (r = -0.49, P < 0.001). Multiple stepwise linear regression analysis in the diabetic group revealed that aortic S velocity (beta = 0.30, P = 0.005) and duration of diabetes (beta = -0.49, P = 0.001) were the main predictors of aortic distensibility (overall R(2) = 0.48). CONCLUSIONS: Aortic elastic properties can be directly assessed by measuring the movements in the upper aortic wall. Reduced aortic S velocity is associated with increased aortic stiffness in Type 1 diabetic patients

Improved papillary muscle function attenuates functional mitral regurgitation in patients with dilated cardiomyopathy after cardiac resynchronization therapy.

BACKGROUND: Functional mitral valve regurgitation attenuation after cardiac resynchronization therapy (CRT) in patients with severe heart failure has been attributed to both the increased rate of left ventricular systolic pressure increase and to papillary muscle (PM) recoordinated contraction. We hypothesized that an increase in systolic deformation of the PMs or the adjacent myocardial wall may in part account for this effect, by preventing their outward displacement during systole. METHODS: We studied by echocardiography 22 patients with moderate/severe functional mitral valve regurgitation and a mean ejection fraction of 18 +/- 4% at baseline and after implantation of a CRT system. RESULTS: CRT induced a significant reduction of the effective regurgitant orifice area (0.18 +/- 0.11 vs 0.35 +/- 0.17 mm2, P < .001). Strain improved in both PMs and their adjacent walls, although this improvement was significant only in anterolateral PM (-16 +/- 4.7 vs -11 +/- 4.3%, P = .02) and posteromedial PM adjacent wall (-16 +/- 10 vs -8 +/- 4.6%, P = .01). CONCLUSIONS: CRT acutely reduces the severity of functional mitral valve regurgitation in patients with heart failure and this effect may be in part attributed to improved strain of PM or adjacent wall

Aortic elastic properties are related to left ventricular diastolic function in patients with type 1 diabetes mellitus.

OBJECTIVE: The aim of the study was to evaluate left ventricular diastolic function and its relation to aortic wall stiffness in patients with type 1 diabetes mellitus without coronary artery disease or hypertension. PATIENTS: Sixty-six patients with type 1 diabetes mellitus were examined by echocardiography and divided into two groups according to the diastolic filling pattern determined by mitral annulus tissue Doppler velocities. Group A patients (n = 21) presented diastolic dysfunction with a peak early diastolic mitral annular velocity (Em)/peak late diastolic mitral annular velocity (Am) ratio <1 whereas in group B patients (n = 45) the Em/Am ratio was >1. Coronary artery disease was excluded based on normal thallium scintigraphy. Aortic stiffness index was calculated from aortic diameters measured by echocardiography, using accepted criteria. RESULTS: Aortic stiffness index differed significantly among the two groups. Significant correlations were found between parameters of left ventricular diastolic function (Em/Am, isovolumic relaxation time, deceleration time) and aortic stiffness index. Multiple stepwise linear regression analysis revealed aortic stiffness index (beta = -0.39, p = 0.001) and isovolumic relaxation time (beta = -0.46, p < 0.001) as the main predictors of Em/Am ratio. CONCLUSIONS: Aortic stiffness is increased in type 1 diabetic patients with left ventricular diastolic dysfunction. This impairment in aortic elastic properties seems to be related to parameters of diastolic function