Symptoms that people may notice with Atrial fibrillation include:
Many, but by all means not everyone, will be aware of an altered sensation of their heart beat in the chest. Some people describe it as a fluttery feeling, others as an irregular pounding sensation. Others may only feel a 'funny' sensation in their throat.
Whilst this may be the only thing that some people notice others may feel dizzy or lightheaded particularly if their AF is at a very fast rate.
Breathlessness is relatively common, and usually much more noticeable, on exertion. This is for two reasons. First, the heart works less effeciently when the atria are not contributing to the pumping of the blood, and second the irregularity of the heart rhythm means many of the heart beats occur when the ventricles have relatively little blood in them making the pumping of the heart less efficient even though it may be working harder and faster.
A few people find that associated with their palpitations they quickly experience a full bladder and need to pass water. This may continue to occur for the duration of the palpitations. This is because the muscular walls of the atrium contain chemicals that stimulate the kidneys to pass more fluid. These are called natiuretic peptides. With the rapid heart beat more of these chemicals are released causing increased urine production.
Some people experience chest pain, tightness or chest discomfort. This may just be part of the sensation of the atrial fibrillation but it is worth pointing this out to your doctor as it might be angina caused by underlying coronary disease and uncovered by the increased workload that the heart is doing due to the fast heart rate.