Echocardiographic and Impedance Cardiography Analysis of Left Ventricular Diastolic Function in Acromegaly Patients

BACKGROUND Due to the chronic effects of excess growth hormone (GH) and insulin-like growth factor-1 (IGF-1), patients with acromegaly (AC) may develop acromegalic cardiomyopathy with biventricular hypertrophy, systolic and diastolic dysfunction, resulting in congestive heart failure. This study aimed to evaluate the echocardiographic parameters of left ventricular (LV) diastolic function and impedance cardiography (ICG) parameters of cardiovascular hemodynamics in patients with AC. MATERIAL AND METHODS A total of 33 patients (male to female ratio: 1.2; mean age 47 years) newly diagnosed with AC based on the blood hormone levels and imaging study findings were included into this observational cohort study. The echocardiographic parameters of LV diastolic function included early diastolic velocity of the average mitral annulus (e'avg), ratio of early diastolic mitral inflow velocity to early diastolic mitral annular tissue velocity (E/e'ratio), mitral flow early (E) and late (A) phase ratio (E/A). The ICG parameters included stroke volume index (SI), cardiac index (CI), acceleration index (ACI), systemic vascular resistance index (SVRI), total arterial compliance index (TACI) and thoracic fluid content (TFC). RESULTS Poorer parameters of LV diastolic function corresponded to the parameters assessed via ICG: 1) lower ratio E/A was associated with lower SI (P<0.001), CI (P=0.007), VI (P=0.04), ACI (P=0.02), TACI (P=0.005) and higher SVRI (P<0.001), 2) lower E/e' ratio was associated with higher TFC (P=0.03); 3) lower e'avg was associated with lower SI (P=0.01) and CI (P=0.048) and higher SVRI (P=0.03), despite normal LV ejection fraction. CONCLUSIONS Impaired LV diastolic function in AC is associated with impaired pumping function of the heart and higher afterload as assessed on ICG.