A answered. Atrial fibrillation can be caused by a number of different things that predispose the heart to arrhythmias. Most commonly, longstanding high blood pressure is the cause. Other causes include heart disease such as blockage in the coronary vessels or diseases such as pneumonia or COPD.
A board, typically with a hole for the thumb, which an artist can hold while painting and on which colors are mixed. 2. a. The range of colors used in a visual medium, in a picture, or by an artist: a limited palette.
In art, positive space contains the image that is intended as the focus of the piece of art, usually two-dimensional, as in a photograph, painting, etching or the like â¦ rather than sculpture. Negative space is the space around what the artist wants you to see.