If right heart outflow increases, then blood will build up in the left heart more quickly. Can see fromgraph, this increases cardiac output as above. This measurement is from an isolated heart. (The lungs holdonly 2-3 beats worth of blood, and only a tiny imbalnce in cardiac outputs would cause oedema, orcollapse the low pressure pulmonary vesseles. No mechanism, other than starling's, is sufficiently rapid oraccurate to balance them.