Abnormal response to inotropic stimulation in young asymptomatic type I diabetic patients demonstrated by serial gated myocardial perfusion SPECT imaging.
OBJECTIVE
In subjects without underlying cardiac disease dobutamine is known to enhance systolic LV function and LV relaxation. As end-systolic (ES) and end-diastolic (ED) volumes (V) can be derived from gated SPECT we intent to study these volumes and their response to dobutamine in order to have a better understanding of the mechanism by which stroke volume (SV) increases during dobutamine infusion. We intent to do this in normal controls and in young diabetic subjects.


METHODS
After injection of sestamibi, serial gated SPECT were obtained at baseline, and during low doses of dobutamine infusion in 12 asymptomatic type I diabetic patients, and in 12 age matched controls. LV EDV, ESV, SV and EF were calculated with the QGS program.


RESULTS
Gated SPECT showed comparable LV EF and SV in both groups at rest. There was a significant increase in LVEF and SV during dobutamine infusion but in the diabetic patients the increase in SV was due to a decrease in ESV from 25+/-5 to 20+/-6 ml/m2 (p=0.002) and no change in EDV. In normal controls, the increase in EF was due to an increase in EDV from 69+/-10 to 73+/-12 ml/m2 (p=0.002) with no significant change in ESV.


CONCLUSIONS
These data confirm the presence of subclinical abnormalities of diastolic function in asymptomatic type I diabetic patients and show differences in adaptation to inotropic stimulation in order to preserve the increase in stroke volume and LV ejection fraction.
Weytjens
C
C
Department of Cardiology, Free University of Brussels (VUB), Laarbeeklaan 101, 1090 Brussels, Belgium. igwsc@az.vub.ac.be
Cosyns
B
B
Van Camp
G
G
Daniels
C
C
Spincemaille
K
K
Dupont
A
A
Franken
P R
PR
D000328:Adult; D002316:Cardiotonic Agents / Q000008:administration & dosage; D003922:Diabetes Mellitus, Type 1 / Q000150:complications / Q000000981:diagnostic imaging* / Q000188:drug therapy; D004280:Dobutamine / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D015637:Gated Blood-Pool Imaging / Q000379:methods*; D006801:Humans; D008297:Male; D013318:Stroke Volume / Q000187:drug effects*; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000209:etiology
D002316:Cardiotonic Agents; D004280:Dobutamine