Re: Risk of thrombosis, electrical vs chemical cardioversion

[Guest guest]

Based on published information, from American Heart Association Guidelines

http://circ.ahajournals.org/cgi/content/full/104/17/2118#SEC8

or

http://tinyurl.com/32ybp

risk of stroke does not differ between^ pharmacological and electrical

cardioversion so recommendations^ for anticoagulation are the same for

both methods.^

Bobby

[Guest guest]

> From: Bobby

> Date: 3/13/04, 9:34 AM -0500

>

> Based on published information, from American Heart

>Association Guidelines

> http://circ.ahajournals.org/cgi/content/full/104/17/2118#SEC8

> or

> http://tinyurl.com/32ybp

>

> risk of stroke does not differ between^ pharmacological and

>electrical

> cardioversion so recommendations^ for anticoagulation are the

>same for

> both methods.

Thanks for this URL, it is useful. Yes, indeed,

at VIII. Management, B. Cardioversion, 2. Methods

of Cardioversion, it says:

" The risk of thromboembolism or stroke

does not differ between pharmacological

and electrical cardioversion. Thus,

recommendations for anticoagulation are

the same for both methods. "

I disagree. I will explain why and, maybe, you will

agree with me. Don't reject my opinion before you

have read my argumentation - keep an open mind.

This publication (33 pages) is a review of the

literature; it lists 268 citations. Every detail

is documented, yet the statement that there is no

difference in risk between pharmacological and

electrical cardioversion is unsupported. This is

interesting. Considering the extensive review and

citation of the literature and the review process

of this publication (a joint publication of four

professional organisations, three dozens reviewers)

it is save to assume that there is no publication

and that there has been done no survey that support

that the " risk of stroke or thromboembolism does

not differ between pharmacological and electrical

cardioversion. " (But this does not explain why this

statement was made. Maybe the writer concluded there

is no difference when he didn't see anything to the

contrary.)

My argumentation that there is a differnce of risk

between these two methods requires an assumption:

clots (or at least some of them) that form in the

atria during fibrillation are not freely floating

in the atria but are in a state or place where they

are not washed out when the atria resume their normal

mechanical function.

I believe I have read that the clots are not freely

floating but somehow adhere to the wall. (See recent

message #26085, http://tinyurl.com/3ekfa " [the clot]

will attach itself to the heart muscle. " ) Also, if

they were freely floating they would be washed out

when the atria resume pumping and at that point

strokes would occur, but, considering the many

uneventful spontaneous conversions, it seems this

does not happen.

Why should there be a differnce of risk between the

pharmacological and electrical cardioversion method,

specifically, why should the pharmacological method

be saver with respect to thromboembolism or stroke?

Firstly, consider the pharmacological and the

spontaneous self-conversion from A-fib to NSR. In both

of these the transition from A-fib to NSR is smooth.

(In the pharmacological conversion the pumping action

of the heart may be reduced for a moment resulting in

insufficient blood flow to the brain, causing fainting.

But these hydrodynamic effects have nothing to do with

clots getting into the blood flow. Recently a list

member was mistaken about this - when this happened to

her she was terrified and thought she is going to die.)

Compare this with the electrical cardioversion. Here

the heart is jolted and violent movements occur,

involving all parts of the heart. In this event it is

much more likely that clots get thrown into the blood

stream.

From the foregoing it must be concluded that the risk

of thromboembolism or stroke in the pharmacological

and the spontaneous self-conversion is the same but

is higher in the electrical cardioversion.

Recommended Doses of Drugs Proven Effective for

Pharmacological Cardioversion of Atrial Fibrillation:

http://tinyurl.com/269lo

[Guest guest]

> From: Bobby

> Date: 3/13/04, 9:34 AM -0500

>

> Based on published information, from American Heart

>Association Guidelines

> http://circ.ahajournals.org/cgi/content/full/104/17/2118#SEC8

> or

> http://tinyurl.com/32ybp

>

> risk of stroke does not differ between^ pharmacological and

>electrical

> cardioversion so recommendations^ for anticoagulation are the

>same for

> both methods.

Thanks for this URL, it is useful. Yes, indeed,

at VIII. Management, B. Cardioversion, 2. Methods

of Cardioversion, it says:

" The risk of thromboembolism or stroke

does not differ between pharmacological

and electrical cardioversion. Thus,

recommendations for anticoagulation are

the same for both methods. "

I disagree. I will explain why and, maybe, you will

agree with me. Don't reject my opinion before you

have read my argumentation - keep an open mind.

This publication (33 pages) is a review of the

literature; it lists 268 citations. Every detail

is documented, yet the statement that there is no

difference in risk between pharmacological and

electrical cardioversion is unsupported. This is

interesting. Considering the extensive review and

citation of the literature and the review process

of this publication (a joint publication of four

professional organisations, three dozens reviewers)

it is save to assume that there is no publication

and that there has been done no survey that support

that the " risk of stroke or thromboembolism does

not differ between pharmacological and electrical

cardioversion. " (But this does not explain why this

statement was made. Maybe the writer concluded there

is no difference when he didn't see anything to the

contrary.)

My argumentation that there is a differnce of risk

between these two methods requires an assumption:

clots (or at least some of them) that form in the

atria during fibrillation are not freely floating

in the atria but are in a state or place where they

are not washed out when the atria resume their normal

mechanical function.

I believe I have read that the clots are not freely

floating but somehow adhere to the wall. (See recent

message #26085, http://tinyurl.com/3ekfa " [the clot]

will attach itself to the heart muscle. " ) Also, if

they were freely floating they would be washed out

when the atria resume pumping and at that point

strokes would occur, but, considering the many

uneventful spontaneous conversions, it seems this

does not happen.

Why should there be a differnce of risk between the

pharmacological and electrical cardioversion method,

specifically, why should the pharmacological method

be saver with respect to thromboembolism or stroke?

Firstly, consider the pharmacological and the

spontaneous self-conversion from A-fib to NSR. In both

of these the transition from A-fib to NSR is smooth.

(In the pharmacological conversion the pumping action

of the heart may be reduced for a moment resulting in

insufficient blood flow to the brain, causing fainting.

But these hydrodynamic effects have nothing to do with

clots getting into the blood flow. Recently a list

member was mistaken about this - when this happened to

her she was terrified and thought she is going to die.)

Compare this with the electrical cardioversion. Here

the heart is jolted and violent movements occur,

involving all parts of the heart. In this event it is

much more likely that clots get thrown into the blood

stream.

From the foregoing it must be concluded that the risk

of thromboembolism or stroke in the pharmacological

and the spontaneous self-conversion is the same but

is higher in the electrical cardioversion.

Recommended Doses of Drugs Proven Effective for

Pharmacological Cardioversion of Atrial Fibrillation:

http://tinyurl.com/269lo

[Guest guest]

In addition to fred's argument I'd like to put forward the idea that

electric cardioversion carries is it's own upfront risk for a clot

forming after the event (even if one isn't present at the time of

conversion) which may well different from chemical cardioversion.

see

Anticoagulation for cardioversion of atrial fibrillation.

http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve & db=pubmed & dopt=Abs\

tract & list_uids=11830718

(http://tinyurl.com/ysoxc)

--

D

[Guest guest]

In addition to fred's argument I'd like to put forward the idea that

electric cardioversion carries is it's own upfront risk for a clot

forming after the event (even if one isn't present at the time of

conversion) which may well different from chemical cardioversion.

see

Anticoagulation for cardioversion of atrial fibrillation.

http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve & db=pubmed & dopt=Abs\

tract & list_uids=11830718

(http://tinyurl.com/ysoxc)

--

D