Determinants of kinetic energy of blood flow in the four-chambered heart in athletes and sedentary controls.
The kinetic energy (KE) of intracardiac blood may play an important role in cardiac function. The aims of the present study were to 1) quantify and investigate the determinants of KE, 2) compare the KE expenditure of intracardiac blood between athletes and control subjects, and 3) quantify the amount of KE inside and outside the diastolic vortex. Fourteen athletes and fourteen volunteers underwent cardiac MRI, including four-dimensional phase-contrast sequences. KE was quantified in four chambers, and energy expenditure was calculated by determining the mean KE/cardiac index. Left ventricular (LV) mass was an independent predictor of diastolic LVKE (R(2) = 0.66, P < 0.001), whereas right ventricular (RV) end-diastolic volume was important for diastolic RVKE (R(2) = 0.76, P < 0.001). The mean KE/cardiac index did not differ between groups (control subjects: 0.53 ± 0.14 mJ·l(-1)·min·m(2) and athletes: 0.56 ± 0.21 mJ·l(-1)·min·m(2), P = 0.98). Mean LV diastolic vortex KE made up 70 ± 1% and 73 ± 2% of total LV diastolic KE in athletes and control subjects (P = 0.18). In conclusion, the characteristics of the LV as a pressure pump and the RV as a volume pump are demonstrated as an association between LVKE and LV mass and between RVKE and end-diastolic volume. This also suggests different filling mechanisms where the LV is dependent on diastolic suction, whereas the RV fills with a basal movement of the atrioventricular plane over "stationary" blood. Both groups had similar energy expenditure for intracardiac blood flow, indicating similar pumping efficiency, likely explained by the lower heart rate that cancels the higher KE per heart beat in athletes. The majority of LVKE is found within the LV diastolic vortex, in contrast to earlier findings.
Department of Clinical Physiology, Lund University, Lund University Hospital Lund, Lund, Sweden katarina.ehrenborg@med.lu.se.
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http://orcid.org/0000-0002-7250-6508
K
Steding-Ehrenborg
Department of Clinical Physiology, Lund University, Lund University Hospital Lund, Lund, Sweden.
P M
PM
Arvidsson
Department of Clinical Physiology, Lund University, Lund University Hospital Lund, Lund, Sweden.
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J
Töger
Department of Clinical Physiology, Lund University, Lund University Hospital Lund, Lund, Sweden.
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M
Rydberg
Department of Clinical Physiology, Lund University, Lund University Hospital Lund, Lund, Sweden.
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E
Heiberg
Department of Clinical Physiology, Lund University, Lund University Hospital Lund, Lund, Sweden.
M
M
Carlsson
Department of Clinical Physiology, Lund University, Lund University Hospital Lund, Lund, Sweden.
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H
Arheden
D000328:Adult; D056352:Athletes; D016279:Atrial Function, Left; D016280:Atrial Function, Right; D001696:Biomechanical Phenomena; D001783:Blood Flow Velocity; D016022:Case-Control Studies; D003326:Coronary Circulation; D005260:Female; D006321:Heart / Q000502:physiology*; D006439:Hemodynamics; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007700:Kinetics; D008279:Magnetic Resonance Imaging; D008297:Male; D055414:Myocardial Perfusion Imaging / Q000379:methods; D057185:Sedentary Behavior; D013318:Stroke Volume; D016277:Ventricular Function, Left; D016278:Ventricular Function, Right; D017725:Ventricular Pressure; D055815:Young Adult
atrium; diastolic function; ventricle; vortex formation