Untwisting contributes to left ventricular filling through suction generation. We sought to investigate diastolic function and untwisting dynamics in different forms of left ventricular hypertrophy: in athlete`s heart and hypertrophic cardiomyopathy. Elite athletes in kayaking, canoeing and rowing (n=28), patients with hypertrophic cardiomyopathy (HCM, n=15) and healthy sedentary volunteers (n=13) were compared. Left ventricular volumes, wall thickness-to-volume ratio were assessed by cardiac MRI. Following conventional and tissue Doppler measurements, untwist and untwist rate were determined by speckle tracking echocardiography. Wall thickness-to-volume ratio describing remodelling was significantly higher in HCM, but similar in athletes and controls (athlete vs. HCM vs. control: 0.107±0.019 vs. 0.271±0.091 vs. 0.104±0.012 mm×m²/ml, mean±SD, p<0.001). Mitral lateral annulus e` velocity referred to diastolic dysfunction in HCM (15.3±3.6 vs. 7.9±3.3 vs. 15.0±3.0 cm/s, p<0.01). At time point of mitral valve opening, untwist and untwist rate were significantly different: the highest values were measured in athletes, while the lowest were found in HCM (untwist: 51.3±19.1 vs. 11.6±10.4 vs. 35.9±16.3%; untwist rate: -32.5±13.0 vs. -10.6±10.8 vs. -23.0±7.7°/s, p<0.05). Untwisting correlated with E/A, e` and E/e`. Athlete`s heart is characterized by increased untwist and untwist rate, which can aid diastolic function. Evaluation of untwisting dynamics may help to distinguish pathological hypertrophy.
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