Myocardial perfusion and perfusion reserve in endurance-trained men.
OBJECTIVE
This study was undertaken to determine whether endurance training is associated with changes in myocardial perfusion in humans.


METHODS
Myocardial perfusion was measured in eleven trained and nine sedentary men at rest and during adenosine-stimulated hyperemia using positron emission tomography (PET). Left ventricular (LV) dimensions and mass were measured using echocardiography. Myocardial work per gram of tissue was calculated as (cardiac output. mean arterial blood pressure)/LV mass.


RESULTS
LV mass was significantly higher and myocardial work per gram of tissue lower in the trained than in the untrained subjects. Basal (0.78 +/- 0.10 and 0.76 +/- 0.15 mL. min-1. g-1, P = NS) and adenosine-stimulated perfusion (3.46 +/- 0.91 and 3.14 +/- 0.70 mL. min-1. g-1, P = NS) were similar between trained and untrained men, respectively. Consequently, myocardial perfusion reserve was similar in both groups (4.4 +/- 1.2 and 4.1 +/- 0.7, P = NS). In addition, coronary resistance at baseline (115 +/- 17 vs 119 +/- 22, mm Hg. mL. min-1. g-1, P = NS) and during adenosine infusion (28 +/- 8 vs 30 +/- 8, mm Hg. mL. min-1. g-1, P = NS) were similar in both groups. Resting myocardial work correlated with resting myocardial perfusion in both groups, but the relationship between perfusion and work was different between the groups so that perfusion for a given myocardial work was significantly higher in trained subjects (0.56 +/- 0.04 and 0.34 +/- 0.05 mL. (mm Hg. L)-1, P < 0.001).


CONCLUSIONS
These findings suggest that endurance trained subjects do not have different resting or adenosine-stimulated myocardial perfusion. However, the relationship between myocardial perfusion and work appears altered in the athletes.
Kalliokoski
Kari K
KK
Turku PET Centre, Turku, Finland. Kari.Kalliokoski@pet.tyks.fi
Nuutila
Pirjo
P
Laine
Hanna
H
Luotolahti
Matti
M
Janatuinen
Tuula
T
Raitakari
Olli T
OT
Takala
Teemu O
TO
Knuuti
Juhani
J
D000241:Adenosine / Q000008:administration & dosage; D000328:Adult; D003326:Coronary Circulation / Q000502:physiology*; D004452:Echocardiography; D015444:Exercise / Q000502:physiology*; D006801:Humans; D008019:Life Style; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D010806:Physical Education and Training / Q000379:methods; D010807:Physical Endurance / Q000502:physiology*; D012146:Rest / Q000502:physiology; D014055:Tomography, Emission-Computed; D016277:Ventricular Function, Left / Q000502:physiology
D000241:Adenosine