I've been taking desvenlafaxine (Pristiq) 25 mg per day for just over 4 weeks. Persistent side effects include slightly increased heart rate with a more pronounced beat. I wouldn't call it pounding, but I'm aware of it. Last night It sped up extremely fast for about 6 to 8 beats and then slowed. I checked in with a nurse today and she offered to change medication but also said it was okay to continue taking it. I had an EKG and stress test before going on this drug and things were normal. I have a history of heart palpitations and tightness in my chest when stressed, but this feels different. Has anyone else experienced changes in heart rate or intensity in beating? There are other side effects, but this is the one that's most concerning to me. Thanks for any feedback in advance