Does the metabolic syndrome impact left-ventricular mechanics? A two-dimensional speckle tracking study

Objective: To evaluate left-ventricular mechanics estimated by two-dimensional echocardiography (2DE) speckle tracking analyses in patients with the metabolic syndrome. Methods: This cross-sectional study included 95 untreated patients with metabolic syndrome and 65 controls similar by sex and age. Metabolic syndrome was defined by the presence of at least three ATP-AHA-NHLB criteria. All the patients underwent adequate laboratory analyses and complete 2DE examination. Results: 2DE global longitudinal and circumferential strain was significantly decreased in the metabolic syndrome group, whereas 2DE global radial strain was similar between the observed groups. The left-ventricular torsion was similar between the metabolic syndrome participants and the controls; whereas the left-ventricular untwisting rate was significantly increased in the metabolic syndrome group. The increasing number of the metabolic syndrome criteria induces progressive reduction of the left-ventricular longitudinal strain from the individuals with no metabolic syndrome risk factors to the individuals with five metabolic syndrome criteria. The same pattern was not noticed for left-ventricular circumferential and radial strain. The combination of increased blood pressure, abdominal obesity and increased fasting glucose level was associated with the higher level of left-ventricular mechanical impairment comparing with other clusters of the metabolic syndrome components. The multivariate analysis of the metabolic syndrome criteria showed that 24-h mean blood pressure, waist circumference and fasting glucose level were independently associated with 2DE global longitudinal and circumferential myocardial strain, and left-ventricular untwisting rate. The interaction between sex and metabolic syndrome significantly impacts the left-ventricular longitudinal strain and untwisting rate. Conclusion: Left-ventricular mechanics assessed by 2DE strain is significantly impaired in the metabolic syndrome patients. Among all metabolic syndrome components, blood pressure, waist circumference and fasting glucose level are the most responsible for damage of left-ventricular deformation.