This article written by Ryan Halvorson discusses the benefits of isometric exercise, and how it can reduce your blood pressure. With nearly 1 out of every 3 adults having high blood pressure (Hypertension) something had to be done. So they did a trial on adults aged 18 and over who performed isometric exercises regularly for 4 weeks and at the end of the study they found that not only had their blood pressure dropped, but also their resting heart rates.
http://www.ideafit.com/fitness-library/isometric-exercise-helps-hypertension?