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.
It may come and go. Atrial fibrillation may cause a person to have symptoms, such as episodes of shortness of breath, dizziness or light-headedness. Some feel a thumping in the chest, called palpitations. There are other causes for irregular heart rate besides AF so see your doctor or healthcare practitioner if you have symptoms.