supraventricular tachycardia
"I started taking 50mg and it worked well for about 6 months. Then my flutters started again from my SVT and rapid heart rate. I was switched to 100mg once a day. This med caused me to be quite tired/fatigued. In the beginning I was also dizzy but that eventually went away almost completely. The sleepiness has not gone away but it's manageable. The good it does for my heart outweighs the side effects for me."