Hi Dr. I have been diagnosed with Atrial and ventricular ectopics. When not anxious and when at rest and not performing heavy exercise all seems well. However when walking up a steep hill or putting my heart under load the irregularities begin. Following every 3rd beat there appears to be a pause in my heart beat followed by a thud. Can I cause myself damage if I continue this level of exercise. Can these irregular beats cause heart failure under the conditions described. I am 65 years old, BP145/85, cholesterol 5.7, thyroid fine and have not had a heart attack. I m not over weight, 92kgs, 186cm tall, and am fairly active living on a small farm in Australia.