[Doppler echocardiography and double chamber pacing].
Doppler-echocardiography is playing an increasing role in cardiac pacing: 1) Before implantation, to determine any cardiac disease possibly accompanying the conduction disturbance, and the quality of atrial function in order to identify the appropriate indications for the type of pacing which will restore normal AV synchronism. Alongside morphometric data (size of atria, etc.), this analysis is based above all on the evaluation of LV filling flows and ejection, if necessary during provisional pacing in DRV mode. It is important to be aware of and prevent certain problems: 1st degree AV block with very long PR, high degree interatrial conduction disturbances, etc. 2) To evaluate the possible benefits of pacing in certain new indications, e.g. obstructive hypertrophic cardiomyopathy (measurement of intra-LV gradient in sinus rhythm and with DRV pacing with total ventricular capture). 3) After implantation, to optimise the programming of double-chamber pacemakers and in particular AV intervals (base-line AV interval with paced atrial cycle, AV interval with detected atrial cycle, hysteresis of AV interval corresponding to the difference between the two previous values, slope of automatic variation in AV interval during exercise, etc.). Individual programming of these parameters based upon analysis of transmitral and ejection flow rates, at rest and, if necessary, during exercise, enables the optimisation of cardiac function (which is above all useful in the presence of concomitant organic heart disease) while at the same time improving the electrophysiological behaviour of the pacemaker at high frequencies.
Mabo
P
P
Hôtel-Dieu, CHR, Rennes.
Varin
C
C
De Place
C
C
Kermarrec
A
A
Berder
V
V
Daubert
C
C
D002304:Cardiac Pacing, Artificial / Q000379:methods; D015150:Echocardiography, Doppler; D006321:Heart / Q000502:physiology / Q000503:physiopathology; D006439:Hemodynamics; D006801:Humans
Echo-Doppler cardiaque et stimulation double-chambre.