[CRT-FORUM] 56E Predictive value of the electrical axis. Dr. Perez Riera

[CRT-INFO]

Dear colleague Dr. Alfredo Cagnolatti from “the empire” (el
iiiiiiiiiiiiimperio en cordoooobé.

We group together LBBB according to electrical axis in the FP as following:
1) With SÂQRS not deviated: between -30 and +60 degree (65 to 70% of cases)

2) With SÂQRS with extreme left-axis deviation (LAD): beyond –30 degree
(25%)

3) With SÂQRS deviated to the right -axis deviation (RAD): between +60 and
+90 degree (3.5 a 5% of cases)

4) With SÂQRS with extreme right -axis deviation: beyond +90 (<1%). It is
named the "paradoxical of Lepeschkin" type.

Biventricular pacing has been proposed for treating patients with drug
refractory HF and intraventricular conduction delay. The purpose is to
restore ventricular relaxation and contraction sequences as homogeneously as
possible. Alonso et al (1) studied if some ECG factors could predict the
long-term clinical effectiveness of biventricular pacing. The study included
26 patients, aged 66 +/- 7 years, with drug refractory HF and wide LBBB QRS
complex. Patients were implanted with a biventricular pacemaker. The LV was
paced through a coronary sinus tributary. NYHA functional class, exercise
tolerance, and LVEF were collected at baseline and after pacemaker
implantation.
Patients were divided into 2 groups:
Group I = responders
Group II = non-responders
QRSd and QRS axis at baseline and during biventricular pacing,
interventricular conduction time, and LV and RV lead positions were compared
between the 2 groups. Group I patients (n = 19) had a mean reduction of 1.3
in functional class and an increase in peak oxygen consumption rate by a
mean of 50%. The only parameter that differed between the 2 groups was the
QRSd during biventricular pacing, with a significantly shorter value in
group I than in group II. Thus, a positive response to biventricular pacing
is correlated with the quality of electrical resynchronization. The optimal
positions of the right and LV leads would be those that could induce the
greatest shortening of QRSd.
Reference
1) Alonso C, Leclercq C, Victor F, Mansour H, de Place C, Pavin D,
Carré F, Mabo P, Daubert JC. Electrocardiographic predictive factors of
long-term clinical improvement with multisite biventricular pacing in
advanced heart failure Am J Cardiol. 1999 Dec 15; 84:1417-1421.

All the best for all
Andrés Ricardo Pérez Riera.MD
Chief of electrovectorcardiographic sector. ABC’s Medical School, ABC
Foundation, Santo André, São Paulo, Brazil Riera at uol.com.br
> Congratulations to the steering committee and the sponsors of this 
> forum. I
> seize this opportunity to ask the experts what is the predictive value 
> as to
> responders and non-responders, of the shift of the axis with left bundle
> branch block to the left, or left bundle branch block with normal axis in
> the location of the LV lead, whether to place it in the anterior or the
> postero-lateral region.
>
> Dr. Alfredo Cagnolatti
> Rio Cuarto
> Cordoba - Argentina
>


-- 
Dr. Sergio Dubner
President of Scientific Committee

Dr. Edgardo Schapachnik
President of Steering Committee