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.
A Visual Guide to Atrial Fibrillation; Abnormal Heartbeat and Driving Concerns; AFib and Pregnancy: What You Need to Know; further reading. Slideshow: A Visual Guide to Atrial Fibrillation; What Are the Symptoms of Atrial Fibrillation? Atrial Fibrillation (AFib) Myths and Facts; Atrial Fibrillation-Topic Overview; Atrial Fibrillation-What Increases Your Risk