Left ventricular function at rest and during bicycle exercise in normal subjects: assessment by ECG-gated myocardial perfusion SPET with 99Tcm-tetrofosmin.
99Tcm-labelled myocardial perfusion tracers allow simultaneous assessment of myocardial perfusion and left ventricular function using ECG-gated SPET. The aim of this study was to evaluate left ventricular performance during exercise by means of ECG-gated myocardial perfusion SPET. After the administration of 99Tcm-tetrofosmin (555-740 MBq), eight healthy volunteers aged 27-49 years underwent ECG-gated myocardial perfusion SPET at rest and during supine submaximal exercise (75 and 125 W), for 3 min each. Using ECG-gated SPET data, left ventricular end-diastolic volume (LVEDV) demonstrated a biphasic response during exercise (from 106.4 +/- 17.5 to 119.9 +/- 19.9 to 108.1 +/- 19.2 ml). In contrast, left ventricular end-systolic volume decreased gradually and significantly during exercise (from 47.1 +/- 11.9 to 41.5 +/- 8.9 to 36.1 +/- 10.1 ml; P < 0.05), and left ventricular ejection fraction continued to increase at higher workloads (from 56.1 +/- 6.0 to 63.0 +/- 2.7 to 67.0 +/- 4.3; P < 0.01) despite a fall in LVEDV. There was a progressive increase in cardiac output during exercise, which reached a peak of 7.2 +/- 0.9 l.min-1. We conclude that ECG-gated myocardial perfusion SPET can assess left ventricular function during exercise and may provide useful information for the evaluation of patients with ischaemic heart disease.
Kumita
S
S
Department of Radiology, Nippon Medical School, Tokyo, Japan.
Cho
K
K
Mizumura
S
S
Kijima
T
T
Nakajo
H
H
Takahama
K
K
Furukawa
K
K
Kumazaki
T
T
Sano
J
J
Munakata
K
K
D000328:Adult; D002302:Cardiac Output; D004562:Electrocardiography; D005080:Exercise Test; D015637:Gated Blood-Pool Imaging; D006339:Heart Rate; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D009943:Organophosphorus Compounds / Q000493:pharmacokinetics; D015609:Organotechnetium Compounds / Q000493:pharmacokinetics; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D012016:Reference Values; D012146:Rest; D013599:Systole; D014055:Tomography, Emission-Computed; D016277:Ventricular Function, Left / Q000502:physiology*
D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; C078700:technetium tc-99m tetrofosmin