The stabbing pain is like a jolt, very quick, and only lasts for a second. It is followed by a chill that runs up my left arm and into my neck, shoulder and chest. Sometimes the pain is worse than others and will settle into my elbow joint like a dull ache. My left hand sometimes feels weak, like I am going to drop what I am holding, or like I can't keep my grip on an object. I dont know if this is related, but I have been feeling very tired. I notice I am winded by the simplest tasks. I have a sense of irregular heart beats, or rapid heart rate even when I am at rest. It varies is degrees of intensity, but on more than one occasion, I felt slightly dizzy and out of breath like I needed to sit down. I just don't feel myself and it's beginning to affect my daily life.