KLAMATH FALLS, Ore. – The heart is the most poetic of body parts. We use it to convey the characteristics of people: dear heart, lion heart, brave heart, black heart, cold-hearted, true heart.

Turn of phrase belies the fact that the heart is a hard working muscle, stimulated by electrical impulse. This has become an ever-present thought for me in the last two months, as my best friend has lived with atrial fibrillation (AFib).