Hypertrophy due to chronic volume overloading in the dog heart. A morphometric study.

Cardiac hypertrophy due to chronic volume overloading was produced in dogs by experimental complete AV-block. Ten weeks after operation a quantitative electron microscopic study was carried out for determination of the volume density of contractile material and mitochondria. The results were compared with a two-week group and normal dogs. The ratio of the volume density of contractile material and mitochondria is nearly constant during the course of developing hypertrophy.