Simultaneous quantification of myocardial perfusion,oxidative metabolism,cardiac efficiency and pump function at rest and during supine bicycle exercise using 1‐11C‐acetate PET – a pilot study |
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Authors: | Jens Sörensen Sven Valind Lars G Andersson |
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Institution: | 1. Department of Nuclear Medicine, University Hospital, Uppsala;2. Department of Clinical Physiology, Malm? University Hospital, Malm?, Sweden |
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Abstract: | Background: PET using 1‐11C‐acetate (ACE‐PET) applied at rest is used for measuring absolute myocardial blood flow (MBF) and oxidative metabolic rate (kmono). We evaluated the feasibility of quantitative ACE‐PET during exercise. Methods: Five endurance athletes underwent dynamic PET scanning at rest and during supine bicycle stress. Exercise was maintained at a workload of 120 Watt for 17 min. The rate‐pressure product (RPP) was recorded repeatedly. MBF, kmono in left (LV) and right (RV) ventricular wall, cardiac output (CO), cardiac efficiency and a lung uptake value reflecting left heart diastolic pressures were calculated from the PET data using previously validated models. Results: MBF increased from 0·71 ± 0·17 to 2·48 ± 0·25 ml min?1 per ml, LV‐kmono from 0·050 ± 0·005 to 0·146 ± 0·021 min?1, RV‐kmono from 0·023 + 0·006 to 0·087 + 0·014 min‐1, RPP from 4·7 ± 0·8 to 13·2 ± 1·4 mmHg × min?1 × 103 and Cardiac Output from 5·2 ± 1·1 to 12·3 ± 1·2 l min ?1 (all P < 0·001). Cardiac efficiency was unchanged (P = 0·99). Lung uptake decreased from 1·1 ± 0·2 to 0·6 ± 0·1 ml g?1 (P < 0·001). Discussion: A number of important parameters related to cardiac function can be quantified non‐invasively and simultaneously with a short scanning protocol during steady state supine bicycling. This might open up new opportunities for studies of the integrated cardiac physiology in health and early asymptomatic disease. |
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Keywords: | cardiac physiology exercise testing myocardial blood flow oxidative metabolism positron emission tomography |
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