jd1111 Posted November 30, 2015 Share Posted November 30, 2015 84 y/o female with 2 hours of vomiting. No significant pmhx, only med was crestor. Was initially slated for the main ED, and the doc was backed up so put in orders for labs, ekg and zofran. Vitals all stable, don't remember them off the top of my head but no abnormalities to note. Zofran was given before EKG was reviewed. Review of EKG showed somewhat elevated qt interval. within 2-3 minutes of giving zofran pt started vomiting again. each time she felt nauseous, pulse dropped to 28, 32, 36 bpm. I'm sure it was these pauses that were causing her to feel nauseous and vomit in the first place, but my question is do you think the zofran made it worse by further prolonging the qt? of note on the rhythm strip she did start dropping beats within a few minutes. had a pacemaker implanted and good outcome. Link to comment Share on other sites More sharing options...
andersenpa Posted November 30, 2015 Share Posted November 30, 2015 The typical arrhythmia in QT prolongation is torsades; block is less common. She's 84 and likely has underlying conduction disease, exacerbated by nausea/vagal tone. Prolonged refractoriness in LQT can sometimes look like 2dAVB Link to comment Share on other sites More sharing options...
Disciple3 Posted November 30, 2015 Share Posted November 30, 2015 Never heard of nor ever seen it have any effect on an EKG Link to comment Share on other sites More sharing options...
andersenpa Posted November 30, 2015 Share Posted November 30, 2015 The "4 A's" of QT prolongation: Antibiotics Antispsychotics Antiemetics Antiarrhythmics Link to comment Share on other sites More sharing options...
Disciple3 Posted November 30, 2015 Share Posted November 30, 2015 Isn't that dose dependent? How much would it take? Maybe in a chemo patient taking a ton for persistent nausea? Link to comment Share on other sites More sharing options...
fishbum Posted December 1, 2015 Share Posted December 1, 2015 Isn't that dose dependent? How much would it take? Maybe in a chemo patient taking a ton for persistent nausea? http://www.fda.gov/Drugs/DrugSafety/ucm310190.htm Good discussion there...looks to me like it takes a whole lot more than the typical 4mg doses in the ED. I'd bet on vagal stimulation from vomiting as the culprit for the bradycardia too...seen that many, many times before. Link to comment Share on other sites More sharing options...
Moderator EMEDPA Posted December 1, 2015 Moderator Share Posted December 1, 2015 we lost inapsine to a black box warning for the same reason. we would write doses like 1.25 mg and the studies all showed it took huge doses to prolong the qt. Link to comment Share on other sites More sharing options...
Reality Check 2 Posted December 2, 2015 Share Posted December 2, 2015 I just had a patient who complained of some ectopy and I heard it on auscultation. Thought PVC and did EKG to confirm. Yes, PVCs but also her QT came out over 485 at a pulse of 60. She is 63, healthy, nonsmoker, no HTN, just has IBS and hypothyroid. We are a small family practice and I referred her to cardiology for further evaluation and confirmation that they believe the QT is prolonged so she can have proper warnings about meds. How often are any of you seeing prolonged QT - known or unknown in any patient? I know this is off the zofran discussion but I am wondering if it is more recognized now with computers measuring the QT for you or if something is changing physiologically due to meds etc. Curious..... Link to comment Share on other sites More sharing options...
winterallsummer Posted December 3, 2015 Share Posted December 3, 2015 Do not think zofran was any issue in presented case. As stated above, meds in QT prolong could cause torsades, not bradycardia. Significant prolonged QTc not caused by meds warrants cards referral as prolonged QT syndrome needs specialist work up. That being said, in reality, many of our patients do have slight QTc prolongation and we rarely make much issue out of it. Link to comment Share on other sites More sharing options...
Moderator True Anomaly Posted December 6, 2015 Moderator Share Posted December 6, 2015 I just had a patient who complained of some ectopy and I heard it on auscultation. Thought PVC and did EKG to confirm. Yes, PVCs but also her QT came out over 485 at a pulse of 60. She is 63, healthy, nonsmoker, no HTN, just has IBS and hypothyroid. We are a small family practice and I referred her to cardiology for further evaluation and confirmation that they believe the QT is prolonged so she can have proper warnings about meds. How often are any of you seeing prolonged QT - known or unknown in any patient? I know this is off the zofran discussion but I am wondering if it is more recognized now with computers measuring the QT for you or if something is changing physiologically due to meds etc. Curious..... QTc of more than 480? All the time Link to comment Share on other sites More sharing options...
UGoLong Posted December 6, 2015 Share Posted December 6, 2015 We don't get too excited (in the absence of a new block) as long as the QTc is 500 or less. Torsades.org has a good list of medications that can cause QT prolongation. The risk is not just Torsades, but R-on-T. Link to comment Share on other sites More sharing options...
RetNavyPAC Posted December 13, 2015 Share Posted December 13, 2015 QT, you're the biggest pussy on the EKG! Dammit if I look sideways at you you prolong!! Grow a pair and stand up for yourself!! Link to comment Share on other sites More sharing options...
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