The effect of ventricular pacing on measurements of left ventricular function: a comparison between echocardiographic methods and with radionuclide ventriculography.
OBJECTIVE
Different methods exist for measuring left ventricular function echocardiographically; each may be error prone due to the abnormal pattern of ventricular activation during pacing.


RESULTS
Echocardiography was undertaken on 307 patients with permanent pacemakers; a subset of 57 underwent radionuclide ventriculography. Intrinsic and paced beats were analysed for left ventricular function by: Simpson's bi-plane, Teicholz M-mode, wall-motion scoring and 'eyeball' assessment. Agreement between techniques and with radionuclide ventriculography were compared according to intrinsic or paced beats. Echocardiographic measures of ejection fraction give mean values 5% higher than radionuclide ventriculography (Simpson's 30+/-9%, vs. Teicholz 30+/-13% vs. radionuclide ventriculography 25+/-9%, p=0.03). Agreement between Simpson's, Teicholz and radionuclide ventriculography by Bland-Altman analysis showed poor agreement (Simpson's vs. Teicholz range (4xSD)=57%, Simpson's vs. radionuclide ventriculography=36%, Teicholz vs. radionuclide ventriculography=46%, p=0.02), the level of agreement deteriorates with ventricular pacing (Simpson's vs. Teicholz range=61%, Simpson's vs. radionuclide ventriculography=34%, Teicholz vs. radionuclide ventriculography=47%, p=0.02). The correlation between wall motion analysis and radionuclide ventriculography is moderately poor (all subjects r=0.58, ventricular pacing r=0.52, not pacing r=0.66).


CONCLUSIONS
Echocardiography and radionuclide ventriculography are the only non-invasive techniques to assess left ventricular function in the paced population. Results are poorly interchangeable and the accuracy of any comparison dependent on the underlying rhythm.
Thackray
Simon D R
SD
Department of Academic Cardiology, University of Hull, Castle Hill Hospital, Cottingham, East Yorkshire, UK. simonthackray@hotmail.com
Wright
Graham A
GA
Witte
Klaus K A
KK
Nikitin
Nikolay P
NP
Tweddel
Ann C
AC
Clark
Andrew L
AL
Cleland
John G F
JG
D004452:Echocardiography / Q000379:methods*; D006801:Humans; D010138:Pacemaker, Artificial; D015635:Radionuclide Ventriculography; D013318:Stroke Volume / Q000502:physiology; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis; D016277:Ventricular Function, Left