The inability of the heart muscle to pump blood at a life-sustaining rate is best defined as:

 There are lots of signs of heart failure which you should not ignore. Better see your doctor and seek emergency treatment if you experience chest pain, fainting, rapid or irregular heartbeat coupled with shortness of breath. 

science-ocean floors and habitats study guide by volleyballqueen3817 a major advance in ocean-floor mapping. list four sections of the ocean floor. algae that use sunlight to produce their own food through photosynthesis. all of the feeding relationships that exist in a habitat. drying out, predators, find food.