[CRT-FORUM] 18P. Right bundle branch block and CRT. Dr. Perez Riera

[CRT-INFO]

Dear and admired Dr. Levine,
The work by Pachon was in fact published in December 1999 in our journal
called Arquivos Brasileiros de Cardiologia. (Pachón Mateos JC, Albornoz RN,
Pachón Mateos EI, Gimenez VM, Pachón MZ, Santos Filho ER, Medeiros P, Silva
MA, Paulista PP, Sousa JE, Jatene AD. Right ventricular bifocal stimulation
in the treatment of dilated cardiomyopathy with heart failure. Arq Bras
Cardiol. 1999 Dec;73(6):485-498.) Pachon is an honour for our national
cardiology, an extremely creative and talented person. The summary of this
paper is included in the attachment (Portuguese) It will be available in 
the next five days:

http://www.grupoakros.com.ar/upload/files/3097403820/Estimulação.doc

Best regards,
Andrés Ricardo Pérez Riera MD, chief of electrovectorcardiology sector ABC
Faculty of Medicine (FMABC), Discipline of Cardiology, Foundation of ABC
(FUABC), Santo André, São Paulo, Brazil.
> Dr. Perez makes some excellent points.  I would like to cite a 
> reference with respect to VERBS - Ventricular Endocardial Right 
> Bifocal Stimulation.  Dr. Jose Pachon and colleagues have a superb 
> article reviewing this topic published in 2001.
> Pachon J C, et al, Ventricular Endocardial Right Bifocal Stimulation 
> in the treatment of severe dilated cardiomyopathy heart failure with 
> wide QRS, PACE 2001; 24: 1369-1376
>
> If either Dr. Juan, Enrique or Jose Pachon are participating in this 
> symposium, perhaps they might offer some additional comments with 
> respect to VERBS and its potential role in the treatment of Chagasic 
> cardiomyopathy.
>
> With respect to RBBB, over the years, I have treated a number of 
> patients for sick sinus syndrome who have concomitant RBBB and have 
> normalized the QRS complex by careful programming of the paced and 
> sensed AV delays to force intentional fusion.   This has not been 
> subjected to formal clinical study and in the patients in whom I have 
> used this technique, their ventricular function was basically normal.   
> The concept of using fusion to improve hemodynamics was first reported 
> (that I am aware of) at the VIIth World Symposium on Cardiac Pacing in 
> 1983 in Vienna by de Teresa and colleagues.  They studied 4 patients 
> with chronic LBBB who had undergone aortic valve surgery.  They were 
> doing poorly in the post-operative period and taking advantage of 
> temporary LV epicardial pacing lead and insertion of a temporary 
> endocardial right atrial lead, they carefully timed ventricular pacing 
> (LV lead pacing) with the P wave and intrinsic conduction to result in 
> fusion with normalization of the QRS and improvement in hemodynamics.   
>
>
> Paul A. Levine MD, FHRS, FACC, CCDS
> Vice President, Medical Services
> St, Jude Medical CRMD
> Tel: 1-818-493-2900 Fax: 1-818-362-2242
> plevine at sjm.com
> Clinical Professor of Medicine - Loma Linda University School of Medicine
> Clinical Associate Professor of Medicine -UCLA
>
>> Dear colleague Marcos Souza From Belo Horizonte Minas Gerais  Brazil: 
>> It is unclear whether benefits of CRT extend to patients with right 
>> branch bundle block (RBBB) or a paced QRS at baseline despite QRS>120 
>> ms. Very recently, O'Connor et al (1) in a preliminary report 
>> suggests that similar reverse remodeling can be observed in Complete 
>> RBBB (CRBBB) patients as patients with LBBB after CRT. The authors 
>> studied 4 consecutive patients with CRBBB advanced ischemic HF, EF 
>> ≤35%) and intraventricular asynchrony ≥50 ms scheduled for CRT. 
>> Dobutamine stress echocardiography  was performed within the week 
>> before CRT. Viability was defined as increased wall thickening during 
>> dobutamine stress echocardiography. Viability in the region of LV 
>> pacing lead was defined as the presence of viability in 2 contiguous 
>> segments. Response was defined by LV reverse remodeling (i.e. ≥15% 
>> reduction in LV end-systolic volume) 3-6 months after CRT.
>> Three patients demonstrated LV reverse remodeling at follow-up. 
>> Responders showed LV end-systolic volume decrease of -31+/-16% from 
>> baseline to follow-up whereas no change was observed in the non 
>> responder patient. Similar LV asynchronism was found in all patients. 
>> All responders had viability in ≥2 segments in the region of LV 
>> pacing. Intraventricular asynchrony and CRBBB, viability in the 
>> region of pacing lead may help to predict response to CRT in patients 
>> with HF.
>>
>> In patients with CRBBB (N= 62 patients: 10% of all universe) 
>> undergoing CRT had low rates of symptomatic and echocardiographic 
>> response, and their survival free from orthotopic heart 
>> transplantation or ventricular assist device placement was 
>> significantly worse than in patients with LBBB (N=412; 65%),. 
>> Patients with conventionally paced QRS (N=412; 65%), experienced an 
>> intermediate response(2).
>> From 29 patients (mean age 61.5) with predominant  chagasic 
>> cardiomyopathy cardiac resynchronization therapy was effective for 
>> patients with conventional pacemakers and advanced HF as it yields a 
>> high rate of response (86.2%), significantly improves LVEF and 
>> reduces QRS duration(3).
>> Finally, Studies have demonstrated a beneficial effect of right 
>> ventricular  bifocal pacing, using two leads at different positions, 
>> in Chagas disease patients who developed both severe dilated 
>> cardiomiopathy and chronic AF.
>>
>> References
>>
>> 1)    O'Connor K, Sénéchal M, Lancellotti P, Dubois M, Magne J, 
>> Champagne J, Philippon F, Pierard L, O'Hara G. Usefulness of cardiac 
>> resynchronisation therapy in patients with right bundle branch block: 
>> Is viability an important piece of the puzzle? Int J Cardiol. 2009 
>> Jan 23. [Epub ahead of print]
>> 2)    Adelstein EC, Saba S. Usefulness of baseline 
>> electrocardiographic QRS complex pattern to predict response to 
>> cardiac resynchronization. Am J Cardiol. 2009 Jan 15;103(2):238-42.
>> 3)    Silva RT, Martinelli Filho M, Lima CE, Martins DG, Nishióka SA, 
>> Pedrosa AA, Crevelari ES, Costa R, Sosa EA, Ramires JA. Functional 
>> behavior of patients with conventional pacemakers undergoing cardiac 
>> resynchronization. Arq Bras Cardiol. 2008 Feb;90:138-143.
>>
>> All the best
>> Andrés Ricardo Pérez Riera MD, chief of electrovectorcardiology sector
>> ABC Faculty of Medicine (FMABC), Discipline of Cardiology, Foundation 
>> of ABC (FUABC), Santo André, São Paulo, Brazil.
>>
>>> Dear colleagues,
>>>
>>> congratulations to all participants and specially to organizers!
>>>
>>> I would like a review or a discussion about ressyncronization 
>>> therapy in patients with right bundle branch block, specially in 
>>> Chagas disease,
>>>
>>> thank you,
>>>
>>> Marcos Sousa - Mater Dei hospital and Federal University of Minas 
>>> Gerais
>>>
>>> Belo Horizonte, Minas Gerais,  Brazil
>>>
>>
>>
>
>


-- 
Dr. Sergio Dubner
President of Scientific Committee

Dr. Edgardo Schapachnik
President of Steering Committee