The Study Of Cardiac Function In Growth Hormone-secreting Pituitary Adenoma

Pituitary adenoma is one of the common intracranial tumors, accounting for 10 to 15% of them, second only to meningeoma and glioma. The incidence of growth hormone (GH)-secreting pituitary adenoma is inferior to non-functional adenomas and prolactin adenomas. GH, secreted excessively by the tumor, has direct or indirect effects on mammal organs, leads to multiple organs and systems dysfunction. The high mortality of pituitary adenoma is mainly due to the injury of cardiovascular system. Earlier diagnosis, earlier treatment of cardiac dysfunction in pituitary patients would improve the prognosis. However, the data about left ventricular remodeling, myocardial systolic and diastolic function, and left atrial function in these patients remain inadequate, because of the absence of a useful tool in early detection the cardiac functional damage. Based on two dimensional image pixels, two-dimensional speckle tracking echocardiography (2D-STE) allows evaluating quantitatively the regional and global myocardial movement and deformation by tracking the trajectory of the pixels during the cardiac cycle. Without the angle-dependence,2D-STE has more sensitivity, repeatability and high accuracy in evaluating the myocardial function. In the present study, we measured the 2D strains and strain rates of LA and LV myocardium in pituitary patients using the 2D-STE, and evaluated the clinical value of 2D-STE in early detecting the myocardial dysfunction in patients with GH pituitary adenoma. The research mainly includes two parts:Part I Evaluation of left ventricular myocardial function in growth hormone-secreting pituitary adenomaPurpose:To detect the myocardial impairment in the patients with GH pituitary adenoma using 2D speckle tracking echocardiography (2D STE).Methods:We studied 53 patients with pituitary adenoma (35 males, mean age 42.9 ± 9.8 years) and 39 gender (20 males) and age (45.2 ± 10.6 years) matched normal controls. All participants underwent conventional echocardiography to assess the left ventricular (LV) function. The LV global and segmental circumferential, radial and longitudinal strains (CS, RS and LS) at the basal, middle and apical levels were measured by 2D STE.Results:Though the conventional echocardiography parameters, such as 2D-LV ejection fraction (2D-LVEF) and Tei index, were no different between the 2 study groups, the left cardiac chambers size of the pituitary group were significantly increased, accompanied with left ventricular hypertrophy and left ventricular diastolic dysfunction, which were found in 37 cases (69.8%) and in 27 cases (50.9%) respectively. The 3D LVEF, global and segmental CS, RS and LS strains were significantly decreased in pituitary tumors patients, especially the global strain (CS:-15.71±1.61 Vs.-21.38±1.55, RS:16.31+1.797 Vs.24.87±3.43, LS:-15.17±1.64 Vs.-20.84±2.28, all p value< 0.05).Conclusions:There were cardiac remodeling, and systolic and diastolic dysfunction in pituitary adenoma patients.2D-STE can effectively detect the subtle abnormalities of regional and global function, which usually ignored by conventional echocardiography.Part II Evaluation of left atrial function in growth hormone-secreting pituitary adenomaPurpose:To assess the change of left atrial structure and function in the patients with GH pituitary adenoma by echocardiography.Methods:Fifty-three patients with GH pituitary adenoma (35 males, mean age 42.9 ± 9.8 years) and thirty-nine gender (20 males) and age (45.2 ± 10.6 years) matched normal controls were included. LA volume measurements, including the maximum, the minimum, and the pre-atrial contraction LA volume; and LA function indices, including the total, the passive, and the active atrial ejection fraction (LAtEF, LApEF, LAaEF), were all measured and calculated with Biplane Simpson’s method. The patients were further divided into two groups according to LAVI(≥34ml/m2):dilated LA group(30 cases,21males, mean age 45.0 ± 9.8 years) and no-dilated LA group (23cases,14 males, mean age 39.6±9.4 years). The average LA longitudinal systolic, early diastolic and late diastolic strain(S-LAs, S-LAe, S-LAa) and strain rate(SR-LAs, SR-LAe, SR-LAa) were measured by 2D STE (Philips IE33, version 8.0), and the LA diastolic stiff index was calculated as the value of E/e’/S-LAs.Results:Compared with the controls, the values of strains (S-LAs, S-LAe, S-LAa) and strain rates (SR-LAs, SR-LAe, SR-LAa) in pituitary group were significantly decreased, and more predominantly in the pituitary patients with a dilated LA. The pituitary patients with a normal LA were younger than other two groups. In the dilated LA pituitary group, LAtEF and LAaEF significantly decreased while the LA diastolic stiff index increased (all p value<0.05). S-LAa was positively correlated to LAaEF while SR-LAa was negatively correlated to LAaEF (rs-LAa= 0.674, rsR-LAa= 0.630, P <0.05).Conclusions:There subtle damages of the reservoir, conduit and booster pump function of LA were found in the pituitary adenoma patients, even without LA dilation; the LA dysfunction was more significant in the patients with a dilated LA.2D-STE can provide unique data about LA function in the patients with GH pituitary adenoma.