All Direct Subsidized and Unsubsidized Loans disbursed between July 1, 2014 and June 30, 2015 carry a fixed interest rate of 4.66% for undergraduates. Graduate or professional students receiving a Direct Unsubsidized Loan disbursed between July 1, 2014 and June 30, 2015 will have a fixed interest rate of 6.21%.
There is a problem when the valve that controls what blood is good and what blood is used, no longer is strong enough to control this flow. Heart valves get damaged or simply wear out. I think you are asking what causes blood to flow in the wrong direction. My guess is that it would be a faulty heart valve.
Pulmonary hypertension is high blood pressure within the artery that connects the lungs and heart. It forces the heart to work harder to transfer blood between the heart and lungs, which may lead to an enlargement of the right side. Thyroid problems, whether they involve an underactive or overactive thyroid, can cause a heart to enlarge.