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.
Department of Academic Cardiology, University of Hull, Castle Hill Hospital, Cottingham, East Yorkshire, UK. simonthackray@hotmail.com
Simon D R
SD
Thackray
Graham A
GA
Wright
Klaus K A
KK
Witte
Nikolay P
NP
Nikitin
Ann C
AC
Tweddel
Andrew L
AL
Clark
John G F
JG
Cleland
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