Mobitz 1, To Pace or not to pace?
Smith Rhoade
deal with Mobitz 1 av block.
I've also read at least one manuscript stating that pacing was appropriate
for anyone over 45 years, with Mobitz 1 atriovetnricular block, and this
single manuscript showed a distinct benefit in terms of longevity.
What criteria would (should be) used to make a rational decision on whether
or not to pace in a patient as follows: 63 y.o. female; Mobitz 1; Medtronic
Hall mitral prosthesis, in place 13 years; otherwise healthy except for
trashed inner ear--which makes it very difficult to discern the source of
complaints of lightheadedness--are they vertigo or symptomatic av block.
In responding, please assume no bundle involvement. No ischemia. No
syncope. Normal electrolytes. On 5mg Norvasc daily.
I want a specific answer---scientific criteria to be used in making a
rational decision.
In other words, how would or should a cardiologist proceed to reach a
decision.
Thanks.
(Not a homework problem.)
Andrew B. Chung, MD/PhD
> I've read manuscripts that state unambiguously that pacing isn't needed to
> deal with Mobitz 1 av block.
This is also written in all the cardiology textbooks.
> I've also read at least one manuscript stating that pacing was appropriate
> for anyone over 45 years, with Mobitz 1 atriovetnricular block, and this
> single manuscript showed a distinct benefit in terms of longevity.
Not familiar with the study that you are referring to.
> What criteria would (should be) used to make a rational decision on whether
> or not to pace in a patient as follows: 63 y.o. female; Mobitz 1; Medtronic
> Hall mitral prosthesis, in place 13 years; otherwise healthy except for
> trashed inner ear--which makes it very difficult to discern the source of
> complaints of lightheadedness--are they vertigo or symptomatic av block.
>
> In responding, please assume no bundle involvement. No ischemia. No
> syncope. Normal electrolytes. On 5mg Norvasc daily.
If the assumption is no syncope, then this woman is assumed to be
asymptomatic.
> I want a specific answer---scientific criteria to be used in making a
> rational decision.
> In other words, how would or should a cardiologist proceed to reach a
> decision.
Primum non nocere.
> Thanks.
You are welcome.
All thanks and praises belong to GOD Whom I love with all my heart,
soul, mind, and strength.
> (Not a homework problem.)
Wouldn't bother me if it were.
May GOD help you with your needs, dear neighbor Smith whom I love
unconditionally.
Prayerfully in Christ's amazing love,
Andrew <><
--
Andrew B. Chung
Cardiologist, Atlanta, Georgia, USA
http://HeartMDPhD.com/HolySpirit
As for knowing who are the very elect, these you will know by the
unconditional love they have for everyone including their enemies
(Matthew 5:44-45, 1 Corinthians 13:3, James 2:14-17).
http://groups.google.com/group/sci.med.cardiology/msg/f4dad7fe68478acf?
Smith Rhoade
>> I've also read at least one manuscript stating that pacing was
>> appropriate
>> for anyone over 45 years, with Mobitz 1 atriovetnricular block, and this
>> single manuscript showed a distinct benefit in terms of longevity.
>
> Not familiar with the study that you are referring to.
>
© 2004 by BMJ Publishing Group & British Cardiac Society
--------------------------------------------------------------------------
CARDIOVASCULAR MEDICINE
Is Mobitz type I atrioventricular block benign in adults?
D B Shaw, J I Gowers, C A Kekwick, K H J New and A W T Whistance
Andrew B. Chung, MD/PhD
Thanks.
Here's a link to the full text of the article:
http://heart.bmjjournals.com/cgi/content/full/90/2/169#SEC1
**** Begin article excerpt from its methods ****
Patients: 147 subjects aged 20 years (age cohorts 20-44, 45-64,
65-79, and 80) with chronic Mobitz I without second degree Mobitz II
or third degree (higher degree) block on entry, seen from 1968 to 1993
and followed up to 30 June 1997. Sixty four had organic heart disease.
The presence of symptomatic bradycardia was defined as highly likely in
47 patients (class 1); probable in 14 (class 2); and absent in 86
(class 3).
Interventions: Pacemakers were implanted in 90 patients for the
following indications: symptoms in 74 and prophylaxis in 16.
Main outcome measures: The main outcome measure was death, with
conduction deterioration to higher degree block or symptomatic
bradycardia the alternative measure.
**** End article methods excerpt ****
Comments:
This was a non-randomized non-blinded prospective study.
Without blinded randomization of treatment (pacemaker) and control
group assignments, one can never be certain that the differences in
outcome are truly due to differences in treatment (pacemaker presence
or absence) or due to something spurious like differences in group
characteristics (such as frailer patients being more likely to be
passed over for invasive pacemaker implantation) or differences in
group survelliance (such as those with pacemakers getting more frequent
visits with the cardiologist for pacemaker checks and consequently
getting overall better cardiovascular care. One example would be that
atrial fibrillation would likely be detected sooner in the pacemaker
group potentially saving lives by earlier warfarin anticoagulation).
The mean age for the 147 subjects is reported to be 69.3, with only 15
in the youngest age cohort (20-44), 25 in the second age cohort
(45-64), 70 in the third (65-79), and 37 in the fourth (older than
80). With 107 out of 147 older than 65 years only and 64 out of the
same 147 with documented organic heart disease, these subjects were at
high risk for death from cardiovascular causes other than bradycardia
from deterioration of Mobitz I to higher grade AV block or even
complete AV block. The older age cohorts would most certainly benefit
from the closer cardiovascular survelliance (more frequent visits with
a cardiologist) associated with having a pacemaker and this may be all
that is behind the outcome difference because it is hard to explain how
an extra heart beat here and there will prolong life because even if
this prevented progression to complete heart block, the latter is not a
cause of death.
May these comments prove helpful.