â¢ One plate is pushed beneath the other, or equivalent description. â¢ A trench may be formed at the subduction zone. (ii) Explain how subduction leads to volcanic activity. (2 points: 1 point for a correct explanation of one plate being pushed down and melted and 1. point for a correct explanation of molten material /magma rising to the surface near the zone)
Symptoms of atrial fibrillation occur when the upper chambers of the heart (atria) beat in a disorganized fashion. Atrial fibrillation is a type of arrhythmia. Characteristic symptoms include shortness of breath, palpitations, and lightheadedness.
During atrial fibrillation, the heart's two upper chambers (the atria) beat chaotically and irregularly â out of coordination with the two lower chambers (the ventricles) of the heart. Atrial fibrillation symptoms often include heart palpitations, shortness of breath and weakness. Episodes of atrial fibrillation can come and go, or you may develop atrial fibrillation that doesn't go away and may require treatment.