[Effects of GLP-1 Agonist Exenatide on Cardiac Diastolic Function and Vascular Endothelial Function in Diabetic Patients].

OBJECTIVE: To study the protective effect of glucagon-like peptide-1 (GLP-1) on the left ventricular diastolic function and endothelial function in patients with type 2 diabetes. METHODS: 27 patients with type 2 diabetes were randomly divided into two groups: GLP-1 treated group and insulin treated group. Patients in the GLP-1 group were given GLP-1 analogue and metformin hydrochloride. Patients in the insulin group were given insulin and metformin hydrochloride. The outcomes of treatments were measured by fasting plasma glucose (FBG) fasting lipid profile, glycosylated hemoglobin (HbA1c), blood pressure and general clinical features. High resolution Doppler ultrasound was performed to detect mitral early diastolic rapid filling (E-wave), atrial contraction late filling (A-wave), E/A ratio, early diastolic mitral annular velocity (e), late diastolic mitral annular velocity (a), e/a ratio, endothelium-dependent vasodilatation (EDV) mediated by brachial arterial blood flow, and endothelium-independent vasodilatation (EIV) mediated by nitroglycerin. RESULTS: The levels of FBG and HbA1c decreased significantly in both groups after treatments (P < 0.05). Patients in the GLP-1 group showed improved e, e/a ratio, and E/e ratio after treatments (P < 0.05), but no significant changed in E, A, and E/A ratio (P > 0.05). By contrast, patients in the insulin group showed no significant changes in e, a, E, A, E/A ratio, e/a ratio and E/e ratio after treatments (P > 0.05). EDV increased significantly after treatments in both groups (P < 0.05). A higher level of post-treatment EDV was found in patients in the GLP-1 group compared with those in the insulin group. No significant changes in EIV were found in both groups. CONCLUSION: GLP-1 may be able to mitigate the left ventricular diastolic dysfunction and improve endothelial function of patients with type 2 diabetes. Our findings suggest that GLP-1 has the potential to prevent or delay cardiovascular complications in patients with type 2 diabetes. Further studies are needed.

Early Impairment of Cardiac Function and Asynchronization of Systemic Amyloidosis with Preserved Ejection Fraction Using Two-Dimensional Speckle Tracking Echocardiography.

AIMS: To observe the ventricular global and regional function of the patients with systemic amyloidosis using two-dimensional speckle tracking echocardiography. METHODS: The study enrolled 31 consecutive biopsy-proved patients with systemic amyloidosis who underwent echocardiographic examination and EF ≥ 55% and 37 age- and gender-matched healthy controls. We compared systolic strain and strain rate, diastolic strain rate, time to peak strain, peak delay time in longitudinal, radial, circumferential directions in 16 left ventricular segments. The global peak systolic longitudinal and radial strain of left ventricle, peak systolic longitudinal strain and strain rate, diastolic strain rate of right ventricular free wall were also compared. RESULTS: (1) Global peak systolic longitudinal strain (GPSLS), peak systolic longitudinal strain (PSLS) and strain rate (PSLSR), peak early diastolic longitudinal strain rate (PELSR) in 16 segments were decreased in case (P < 0.05). (2) Peak systolic radial strain and strain rate of inferoseptum and inferolateral at the level of papillary muscle were lower (P < 0.05), and peak early diastolic radial strain rate (PERSR) was reduced (P < 0.05). (3) Peak early diastolic circumferential strain rate was lower (P < 0.05). (4) Time to peak systolic longitudinal, radial, circumferential strain was longer, and peak delay time at the same level retarded (P < 0.05). (5) Into right ventricular wall, PSLS and PSLSR at mid-segment, and PSLSR, PELSR, peak atrial systolic longitudinal strain rate (PALSR) at basal were reduced (P < 0.05). (6) Inverse correlation between interventricular septum (IVS) thickness and GPSLS and GPSRS was found (P < 0.05). CONCLUSION: Systolic and diastolic dysfunction existed in systemic amyloidosis with preserved EF. Mechanical contraction disorder may be one reason for systolic dysfunction. GPLSR and GPRSR were negatively related to IVS thickness.

[Left ventricular diastolic function of patients with newly diagnosed hyperthyroidism].

OBJECTIVE: To evaluate the left ventricular diastolic function of patients with newly diagnosed hyperthyroidism. METHODS: 43 patients with newly diagnosed hyperthyroidism and 45 healthy participants were recruited to have their left ventricular diastolic function assessed with conventional echocardiography (Mitral inflow) and by indicators such as valsalva maneuver, pulmonary venous flow, Tissue Doppler imaging and Left atrial volume index (LAVI). RESULTS: 1. Hyperthyroidism patients had higher heart rate and left ventricular ejection fraction than the controls (P < 0.05). 2. There was no significant difference in LAVI (P > 0.05) between the two groups. Both groups had E/A>1. E'/A'<1 during Valsalva maneuver were found in both groups, but with significant difference (P < 0.05). The hyperthyroidism patients had significantly longer A duration than the controls (P < 0.05). 3. The hyperthyroidism patients had greater peak anterograde diastolic velocity (D), peak velociey in late diastole (Ar), duration of the Ar (Ar duration) in pulmonary venous waveforms and time difference between Ar and mitral A-wave duration (Ar -A duration) than the controls(P < 0.05). Significant difference in S/D was found between the two groups (P < 0.05). 4. Em/Am<1 and E/Em>8 was found in the patients while Em/Am>l and E/Em<8 was found in the controls (P < 0.05). CONCLUSION: 1. Hyperthyroidism patients have impaired Left ventricular diastolic function. 2. Combined use of pulmonary venous flow, Tissue doppler imaging and mitral inflow during Valsalva maneuver is more sensitive than conventional Doppler echocardiography for assessing diastolic dysfunction.