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+--- Thread: You need more than step 3 knowledge for step3 exam - ravianka (/showthread.php?tid=577325)
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You need more than step 3 knowledge for step3 exam - ravianka - ArchivalUser - 03-30-2011
A 69-year-old woman with a history of severe coronary artery disease and a permanent pacemaker for tachybrady syndrome is admitted for dyspnea secondary to congestive heart failure. Her medications include digoxin, amiodarone, metoprolol, and furosemide. While in the telemetry unit, she develops torsades de pointes. She is initially treated with magnesium, atropine, and potassium. Her resting heart rate now is in the 40s. However, she continues having intermittent runs of torsade. The QT interval is 610 milliseconds. What is the next step in treating this dysrhythmia?
(A) Increase the atrial rate of the pacemaker
(B) Isoproterenol
© Procainamide
(D) Change oral amiodarone to intravenous
(E) Defibrillation at 200 Joules (J)
0 - ArchivalUser - 03-30-2011
A) Increase the atrial rate of the pacemaker
0 - ArchivalUser - 03-30-2011
If you could explain...
Please
0 - ArchivalUser - 03-30-2011
increase the heart rate with a pacemaker will shortens the QT interval and effectively reverse the torsade.
0 - ArchivalUser - 03-30-2011
Overdrive pacing
http://www.theheart.org/article/243261.do
Hope this helps
If you need further explanation please write here
0 - ArchivalUser - 03-30-2011
bumba..article talks about a fib... his patient has torsade with brady..what is th right answer
0 - ArchivalUser - 04-01-2011
may be sami is right. if this pacing fails cardioversion. check emedicine explanation.
Based on the fact that the QT interval shortens with a faster heart rate, pacing can be effective in terminating torsade. It is effective in both forms of the long QT syndrome because it facilitates the repolarizing potassium currents and prevents long pauses, suppressing EADs and decreasing the QT interval.
Atrial pacing is the preferred mode because it preserves the atrial contribution to ventricular filling and also results in a narrower QRS complex and hence a shorter QT. In patients with AV block, ventricular pacing can be used to suppress torsade.
Pacing should be instituted at a rate of 90-110 bpm until the QT interval is normalized. Overdrive pacing may be necessary at a rate of up to 140 bpm to control the rhythm.
The patient with torsade who is in extremis should be treated with electrical cardioversion or defibrillation. Anecdotal reports cite successful conversion with phenytoin (Dilantin) and lidocaine. A few cases of successful conversion using phenytoin and overdrive pacing have been reported.
If patient is unresponsive to conversion with phenytoin and overdrive pacing, attempt electrical cardioversion.
0 - ArchivalUser - 04-01-2011
Nice discussion here. I have read the above info, thanks for sharing.
Here similar topic from UW.
A 70-year-old Caucasian man is admitted to the hospital because of a change in mental status, fever, productive cough and shortness of breath. He has diabetes mellitus type 2, hypertension, atrial fibrillation, peripheral vascular disease and chronic renal failure. His current medications are warfarin, sotalol, insulin, and lisinopril. His chest x-ray shows an alveolar infiltrate in the left base. He is admitted and given azithromycin, ceftriaxone and oxygen therapy. He becomes agitated during the night, and he receives a dose of parenteral haloperidol. Two hours after the administration of haloperidol, he suddenly becomes unresponsive.
EKG..Torsades
Options
1. Intravenous magnesium sulfate
2. Defibrillation
3. Synchronized cardioversion
4. Temporal transvenous overdrive pacing
5. Intravenous amiodarone
Q doesnot mention about vitals, only say that pt is unresponsive.
So, answer is ...2, Defrib
next step is mgso4 when stable.
If refractory to Mgso4 , do overdrive pacemaker.
Thus from UW.
I am a bit confused, i guess.
UW explanation...
Magnesium sulfate is the drug of choice in stable patients.
(Choice D) Temporary overdrive pacing is indicated in patients who are refractory to intravenous magnesium administration.
(Choice C) Synchronized cardioversion is indicated for patients with stable ventricular tachycardia, atrial fibrillation, atrial flutter or supra ventricular tachycardia. It is not useful for patients with torsade de pointes.
(Choice E) Amiodarone is one of the drugs that can potentially cause torsade de pointes. Its use is contraindicated in this case; however, certain antiarrhythmics such as lidocaine or isoproterenol can be used.
Can some one please explain more ?
0 - ArchivalUser - 04-01-2011
Sami,
I guess, you are also talking about override pacing, right?
Mksap Q ...patient is refractory to Mg , so ,next step is override pacing. (UW said)
rate is minium 90 to maximum 140.
Thanks
0 - ArchivalUser - 07-03-2011
thanks forever for uploading this..so what is the answer for this...
defibrillation or over ride pacing?