Drake has Patent Ductus Arteriosus (aka PDA).
Figure A shows the interior of a           normal heart and normal blood flow. Figure B shows a heart with patent ductus           arteriosus. The defect connects the aorta with the pulmonary artery. This           allows oxygen-rich blood from the aorta to mix with oxygen-poor blood in the           pulmonary artery.
What Is Patent Ductus Arteriosus?
           Patent ductus arteriosus (PDA) is a heart problem           that occurs soon after birth in some babies. In PDA, abnormal blood flow occurs           between two of the major arteries connected to the heart. 
           Before birth, the two major arteries—the aorta           and the pulmonary (PULL-mun-ary) artery—are connected by a blood vessel           called the ductus arteriosus. This vessel is an essential part of fetal blood           circulation. 
           Within minutes or up to a few days after birth, the           vessel is supposed to close as part of the normal changes occurring in the           baby's circulation. 
           In some babies, however, the ductus arteriosus           remains open (patent). This opening allows oxygen-rich blood from the aorta to           mix with oxygen-poor blood from the pulmonary artery. This can put strain on           the heart and increase blood pressure in the lung arteries.
Overview
           A PDA is a type of           congenital           heart defect. A congenital heart defect is any type of heart problem           that’s present at birth.
           If your baby has a PDA but an otherwise normal           heart, the PDA may shrink and go away. Some children need treatment to close           their PDAs. 
           If your baby is born with another heart defect (in           addition to PDA) that decreases blood flow from the heart to the lungs or that           decreases the flow of oxygen-rich blood to the body, medicine may be given to           keep the ductus arteriosus open. 
           This helps maintain blood flow and oxygen levels           until doctors can do corrective surgery for the heart defect.
          Outlook
           PDA is a relatively common congenital heart defect           in the United States. The condition occurs more often in premature infants (on           average, occurring in about 8 of every 1,000 births). However, PDA also occurs           in full-term infants (on average, occurring in about 2 of every 1,000 births).           
           Premature babies who have PDA are more vulnerable           to its effects. PDA is twice as common in girls as it is in boys.
Revised June 2009