Michael Scharf MD, Presenter: Research Grant, Bayer AG

Axel Schmid MD, Abstract Co-Author: Nothing to Disclose

Michael Uder MD, Abstract Co-Author: Speakers Bureau, Bracco Group Speakers Bureau, Siemens AG Research Grant, Siemens AG

Michael Marcus Lell MD, Abstract Co-Author: Research Grant, Siemens AG Speakers Bureau, Siemens AG Research Grant, Bayer AG Speakers Bureau, Bayer AG Research Consultant, Bracco Group

To prospectively evaluate whether short term endurance high intensity training (HIT) induces detectable morphologic cardiac changes in previously untrained men, as assessed with magnetic resonance imaging (MRI), and to compare findings to inactive control subjects.

84 untrained volunteers were randomly assigned to a HIT-group (n=42; 44.1±4.7 years; range 33-51 years) or an inactive control group (n=42; 42.3±5.6 years; range 31-51 years). Before and after 4 months of HIT subjects underwent cardiac MRI (cine, late gadolinium enhancement, tagging) to assess myocardial morphology and function of the left and right ventricle. In addition, a stepwise progressive-intensity treadmill test with continuous assessment of ventilation parameters and determination of heart rate at the anaerobic threshold was performed. Ejection fraction, end-diastolic volume, end-sytolic-volume, stroke-volume, myocardial mass and cardiac index were measured for the left and right ventricle. LV and RV remodeling index (myocardial mass/end-diastolic volume) were calculated to determine the pattern of ventricular remodeling. Evaluation of LGE was performed according to the 17-segment model of the American Heart Association guidelines. We evaluated myocardial strain using Intag-Software.  

Indexed volume and mass for the left and right ventricle were significantly greater after HIT whereas values in control subjects remained unchanged. Changes in ventricular EDV and MM were significantly correlated with changes in indexed VO2max (Pearson correlation, 0.609 and 0.588: P<0.001). Mean left and right ventricular remodeling indexes of the HIT-group did not alter with training (0.76g/mL±0.09 and 0.24g/mL±0.10, respectively [P=0.97 and P=0.72]), indicating balanced cardiac adaptation. Detected pre-training late gadolinium enhancement in 3/84 participants as well as the pattern of myocardial strain in both groups did not alter with HIT.

A relatively short period of HIT in previously untrained men leads to significant changes in left and right ventricular morphologic characteristics and function. These findings are not associated with pathologic features predisposing for sudden cardiac death.

A short period of HIT leads to significant changes in cardiac morphologic characteristics and function which are not associated with pathologic features predisposing for sudden cardiac death.

Scharf, M, Schmid, A, Uder, M, Lell, M, Myocardial Adaption in Previously Untrained Men after Four Months of High-intensity Running Training (HIT): A Comprehensive Longitudinal Cardiac MR Imaging Study.  Radiological Society of North America 2013 Scientific Assembly and Annual Meeting, December 1 - December 6, 2013 ,Chicago IL. http://archive.rsna.org/2013/13019905.html