Heart & Cardiology/Borderline QTc
28 year old female 5'8" 178 lb and blood pressure 101/74 (suffer from orthostatic hypotension a, so Bp varies).
Medications: Flonase, zoloft 12.5 mg (just starting), and lorazepam .5 mg x3 daily.
I have a question in regards to EKG reading. I have a history of SVT, PVCs and have had 3 ablations for SVT.
I recently had two EKGs done at my doctors before starting Zoloft. For my first EKG my qtc was 470. The following week my qtc was 444 with pulse rate of 85. I asked the dr about the 470 qtc reading because I know that is prolonged and he wasn't sure why it was high. He said my heartrate was elevated during the EKG so the machine may have misread it. The following week my EKG was done and the qtc was 444. My dr said its fine to take the Zoloft, because I have has two prior qtc readings of 440 and 444. The 470 qtc seems to be a one time thing.
Here are my questions:
What is your opinion? Is it possible the machine over corrected my qtc at one point? I thought that during elevated heartrate a the qtc decreases..? Should the zoloft be fine to take? I can't find any info. About how much of a qt prolongation zoloft may cause. Is the qt prolongation dependant upon dose?
Thank you for your assistance.
The EKG probably read your QT correctly, but the formula for calculating QTC isn't very accurate for fast heart rates. 470 is the upper limit of normal for QTC, and is probably okay with a fast heart rate. Zoloft doesn't affect QT. I think it's safe for you to take Zoloft.
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