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Examples of Ventricular Tachycardia Caused by Amiodarone – Part I

ResearchBlogging.org
 

How much worse could the patient get if we give amiodarone?

But amiodarone doesn’t cause V Tach (Ventricular Tachycardia). Amiodarone stops V Tach.

Right?

If amiodarone can cause V Tach, shouldn’t someone have told us?
 


Click on image to make it larger.
 

This is a wide complex tachycardia, which should be presumed to be V Tach. The diagnosis of the rhythm as V Tach is supported by the P-wave dissociation and by the history of a heart attack a couple of weeks before. 19 QRS complexes in 5 seconds (multiply by 12 to get the rate for 60 seconds) = 228.

According to ACLS (Advanced Cardiac Life Support) what drug would be indicated for the above rhythm?

For the old timers, let’s throw in a bit of information that is supposed to be important in deciding among the various antiarrhythmics –
 

Transthoracic echocardiography was performed, and the ejection fraction was 34% based on the modified Simpson method.[1]

 

Does the ejection fraction matter in treating wide-complex tachycardia?
 

Note that amiodarone becomes the antiarrhythmic of choice (after failure of adenosine) if the patient’s cardiac function is impaired and the ejection fraction is <40% or there are signs of congestive heart failure.[2]

 

That was only mentioned in the 2000 ACLS guidelines. The 2005 ACLS guidelines and the 2010 ACLS guidelines do not mention ejection fraction in the treatment of V Tach.
 

Do we have good evidence that amiodarone is effective for stable V Tach?
 

Amiodarone has not been studied specifically for the pharmacological termination of hemodynamically stable VT, but it is effective in treating hemodynamically unstable VT and VF.78 81 82 83 84 85 86 87 88 89 90 91 [2]

 

That was written in 2000 and the answer was NO.

Now we have evidence that amiodarone may be effective in about one out of four patients – if we are prepared to wait a half hour, or more. In other words, it is rare for amiodarone to work and rarer still for amiodarone to work before we can get the patient to the hospital.[3],[4],[5]

We do have evidence that amiodarone may be a part of the long-term treatment of unstable V Tach. On the other hand, maybe not.

I do mean long-term treatment, even though these are unstable patients.
 

Twenty-seven (58.5%) of the 46 patients responded to intravenous amiodarone, and an additional 6 patients (13%) showed a late response to amiodarone (Fig. I). Fifteen of the 27 responders (33% of all patients) responded immediately (0 to 2 h), and 26 responded within 72 h . The other patient responded within 84 h (Fig. 2).[6]

 
Up to 84 hours to take effect.

Not exactly an emergency drug.

I have worked some very long shifts. I have never worked an 84 hour shift.

If amiodarone can take 84 hours to work, and the patient is receiving a variety of other treatments during those 84 hours, is it really the amiodarone that is working?

Compared with 84 hours, a less than two hour time to response seems almost instantaneous, but it is not fast for EMS.
 

This patient was treated with oral amiodarone for sustained V Tach during his previous hospital admission for an acute anterior MI (Myocardial Infarction) treated with a stent in the LAD (Left Anterior Descending) coronary artery.

This time he was treated with IV (IntraVenous) amiodarone. The problems began on the first day of IV amiodarone treatment.
 

On the first day of hospitalization, the patients had 10 attacks of pulseless VT treated with successful DC shocks. Occasionally, VT attacks degenerated to ventricular fibrillation.[1]

 

And continued –
 

On the second day of hospitalization, the patient had 14 pulseless VT attacks with successful DC shocks.[1]

 

But the V Tach stopped after the amiodarone was stopped and antithyroid therapy was begun.
 

Thyroid gland toxicity is one of the most important adverse effects of amiodarone and is called amiodarone-induced thyrotoxicosis. Thyrotoxicosis may alter arrhythmia and lead to frequent ventricular tachycardia attacks.[1]

 

All things are poison, and nothing is without poison; only the dose permits something not to be poisonous. – Paracelsus (1493-1541)
 

We do not seem to explain that well in EMS, or even in emergency medicine.
 

All antiarrhythmic agents have some degree of proarrhythmic effects.[7]

 

Amiodarone is one of the most dangerous drugs we carry in EMS.

How much thought do we give to the problems we can cause for our patients with this drug?

How much do we understand about the problems we could be causing when we push medications, such as amiodarone?

Footnotes:

[1] Therapy-resistant ventricular tachycardia caused by amiodarone-induced thyrotoxicosis: a case report of electrical storm.
Erdogan HI, Gul EE, Gok H, Nikus KC.
Am J Emerg Med. 2012 Nov;30(9):2092.e5-7. doi: 10.1016/j.ajem.2011.12.035. Epub 2012 Mar 3.
PMID: 22386340 [PubMed – indexed for MEDLINE]

[2] Amiodarone
2000 ECC Guidelines
Part 6: Advanced Cardiovascular Life Support
Section 5: Pharmacology I: Agents for Arrhythmias
Arrhythmias and the Drugs Used to Treat Them
Hemodynamically Stable Wide-/Broad-Complex Tachycardias
Treatment of Wide-Complex Tachycardias
Free Full Text from Circulation.

[3] Amiodarone is poorly effective for the acute termination of ventricular tachycardia.
Marill KA, deSouza IS, Nishijima DK, Stair TO, Setnik GS, Ruskin JN.
Ann Emerg Med. 2006 Mar;47(3):217-24. Epub 2005 Nov 21.
PMID: 16492484 [PubMed – indexed for MEDLINE]

[4] Amiodarone or procainamide for the termination of sustained stable ventricular tachycardia: an historical multicenter comparison.
Marill KA, deSouza IS, Nishijima DK, Senecal EL, Setnik GS, Stair TO, Ruskin JN, Ellinor PT.
Acad Emerg Med. 2010 Mar;17(3):297-306. doi: 10.1111/j.1553-2712.2010.00680.x.
PMID: 20370763 [PubMed – indexed for MEDLINE]

Free Full Text from Academic Emergency Medicine.

[5] Intravenous amiodarone for the pharmacological termination of haemodynamically-tolerated sustained ventricular tachycardia: is bolus dose amiodarone an appropriate first-line treatment?
Tomlinson DR, Cherian P, Betts TR, Bashir Y.
Emerg Med J. 2008 Jan;25(1):15-8.
PMID: 18156531 [PubMed – indexed for MEDLINE]

[6] Use of intravenous amiodarone for emergency treatment of life-threatening ventricular arrhythmias.
Helmy I, Herre JM, Gee G, Sharkey H, Malone P, Sauve MJ, Griffin JC, Scheinman MM.
J Am Coll Cardiol. 1988 Oct;12(4):1015-22.
PMID: 3417974 [PubMed – indexed for MEDLINE]

Page with link to Free Full Text Download in PDF format from J Am Coll Cardiol.

This is footnote 84 from the second 2000 ACLS quote.

[7] New Concerns From the International Guidelines 2000 Conference: Impaired Hearts and “Proarrhythmic Antiarrhythmics”
2000 ECC Guidelines
Part 6: Advanced Cardiovascular Life Support
Section 5: Pharmacology I: Agents for Arrhythmias
Arrhythmias and the Drugs Used to Treat Them
Hemodynamically Stable Wide-/Broad-Complex Tachycardias
Free Full Text from Circulation.

Erdogan, H., Gul, E., Gok, H., & Nikus, K. (2012). Therapy-resistant ventricular tachycardia caused by amiodarone-induced thyrotoxicosis: a case report of electrical storm The American Journal of Emergency Medicine, 30 (9), 209200000-2147483647 DOI: 10.1016/j.ajem.2011.12.035

Marill, K., deSouza, I., Nishijima, D., Stair, T., Setnik, G., & Ruskin, J. (2006). Amiodarone Is Poorly Effective for the Acute Termination of Ventricular Tachycardia Annals of Emergency Medicine, 47 (3), 217-224 DOI: 10.1016/j.annemergmed.2005.08.022

Marill, K., deSouza, I., Nishijima, D., Senecal, E., Setnik, G., Stair, T., Ruskin, J., & Ellinor, P. (2010). Amiodarone or Procainamide for the Termination of Sustained Stable Ventricular Tachycardia: An Historical Multicenter Comparison Academic Emergency Medicine, 17 (3), 297-306 DOI: 10.1111/j.1553-2712.2010.00680.x

Tomlinson, D., Cherian, P., Betts, T., & Bashir, Y. (2008). Intravenous amiodarone for the pharmacological termination of haemodynamically-tolerated sustained ventricular tachycardia: is bolus dose amiodarone an appropriate first-line treatment? Emergency Medicine Journal, 25 (1), 15-18 DOI: 10.1136/emj.2007.051086

Helmy, I., Herre, J., Gee, G., Sharkey, H., Malone, P., Sauve, M., Griffin, J., & Scheinman, M. (1988). Use of intravenous amiodarone for emergency treatment of life-threatening ventricular arrhythmias Journal of the American College of Cardiology, 12 (4), 1015-1022 DOI: 10.1016/0735-1097(88)90470-6

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