Impaired left ventricular synchronicity in patients with metabolic syndrome, regardless of hypertension

Abstract

To assess the left ventricular (LV) diastolic and systolic synchronicity in patients with metabolic syndrome. Tissue Doppler echocardiography was performed in 235 individuals (135 with metabolic syndrome and 100 controls). Diastolic and systolic synchronicity was determined by measuring the SD of time to peak myocardial early diastolic relaxation and systolic contraction and the maximal difference in time to peak myocardial early diastolic relaxation and systolic contraction with six basal and six middle LV segments. Compared with controls, patients with metabolic syndrome showed significantly prolonged SD of time to peak myocardial early diastolic relaxation (20.79 +/- 11.29 vs. 16.33 +/- 5.67 ms, P < 0.001) and SD of time to peak myocardial early systolic contraction (24.50 +/- 15.27 vs. 17.27 +/- 5.46 ms, P < 0.001) and prolonged maximal difference in time to peak myocardial early diastolic relaxation (66.76 +/- 40.81 vs. 45.59 +/- 17.78 ms, P < 0.001) and maximal difference in time to peak myocardial early systolic contraction (71.47 +/- 49.19 vs. 47.64 +/- 17.25 ms, P < 0.001) among all the 12 left ventricular segments. Multiple regression analysis revealed waist-to-hip ratio, fasting blood glucose, age and LV mass for height to the power 2.7 as independent predictors of impaired diastolic synchronicity in metabolic syndrome, with age and LV mass for height to the power 2.7 as independent predictors of impaired systolic synchronicity. Subgroup analyses indicated that there was no difference of LV synchronicity between nonhypertensive and hypertensive subgroups in metabolic syndrome patients. Patients with metabolic syndrome have impaired LV diastolic and systolic synchronicity. Obesity, hyperglycemia and age play important roles in it, whereas hypertension is not the key factor to cause the impaired synchronicity.