>> WE HAD EXPERIENCED TWO MISCARRIAGES PRIOR
TO BECOMING PREGNANT WITH GRACE.
SO ONCE WE MADE IT THROUGH THAT 12TH, 13TH WEEK
OF THE PREGNANCY, WE KIND OF FELT LIKE,
OK, THINGS ARE GREAT.
>> WE'RE BEYOND THAT--THAT HUMP,
THAT HURDLE WE HADN'T CLEARED WITH TWO MISCARRIAGES,
AND NOW HERE IT WAS, LIKE, GREAT, YOU KNOW.
>> THINGS ARE LOOKING UP.
>> YEAH, CLEAR SAILING FROM HERE ON OUT.
>> SO THEN WE APPROACHED THE 20-WEEK ANATOMY SCAN
AND WENT TO THE DOCTOR'S OFFICE.
AND I COULD TELL THAT THE TECHNICIAN WAS STICKING ON
THE HEART FOR A VERY LONG PERIOD OF TIME.
AND SHE LEFT THE ROOM AND BROUGHT IN OUR
MATERNAL/FETAL MEDICINE DOCTOR.
AND SHE SAID, YOU KNOW, "YOUR BABY HAS A CONGENITAL
HEART DEFECT, AND IT'S REFERRED TO AS TRANSPOSITION
OF THE GREAT ARTERIES."
>> ALL OF HEART SURGERY IS 50 YEARS OLD,
AND WE'VE COME FROM A SITUATION OF BEING ABLE
TO TREAT NOTHING TO BEING ABLE TO AT LEAST DEAL WITH MOST,
IF NOT THE VAST MAJORITY OF, CONGENITAL HEART DEFECTS
IN A WAY THAT ALLOWS CHILDREN TO GROW INTO ADULTHOOD.
>> WE LIVE IN AN ERA WHERE THERE ARE VERY FEW THINGS
THAT WE REALLY CAN'T TAKE CARE OF WITH EXCELLENT
OUTCOME AFTER BIRTH.
>> ONLY TIME WILL TELL WHAT THE LONG-TERM OUTCOME REALLY IS.
>> AND AS WE FOLLOW THEM FORWARD IN TIME,
THERE MAY BE NEW THINGS THAT WE'LL LEARN ABOUT THEM.
BUT THE GOOD NEWS IS THAT THE VAST MAJORITY OF THESE
PATIENTS PERFORM EXCELLENTLY AND GO ON TO LEAD HAPPY,
HEALTHY LIVES.
>> TRANSPOSITION OF THE GREAT ARTERIES IS A COMPLEX
CONGENITAL HEART LESION WHERE THE TWO GREAT VESSELS
THAT COME OUT OF THE HEART, THE AORTA,
WHICH TAKES BLOOD FROM THE LEFT VENTRICLE TO THE REST
OF THE BODY, AND THE PULMONARY ARTERY,
WHICH COMES OFF THE RIGHT VENTRICLE AND GOES
TO THE LUNGS, ARE ESSENTIALLY SWITCHED.
>> THE BLOOD THAT COMES BACK FROM THE BODY GOES BACK OUT
TO THE BODY AGAIN, AND THE BLOOD THAT COMES BACK
FROM THE LUNGS GOES TO THE LUNGS AGAIN.
AND OBVIOUSLY, THAT DOESN'T WORK.
>> BLOOD IS JUST GOING IN TWO SEPARATE CIRCULATIONS
IN A CIRCLE, AND YOU DON'T GET ANY OXYGENATION TO THE BODY.
SO THESE CHILDREN CAN GET INTO TROUBLE VERY QUICKLY
AFTER BIRTH.
>> IN ORDER TO UNDERSTAND AND TO COMPREHEND ANY
OF THE DIFFERENT FORMS OF HEART DISEASE THAT EXIST,
IT'S VERY IMPORTANT TO MAKE SURE WE UNDERSTAND WHAT
THE HEALTHY OR THE NORMAL HEART LOOKS LIKE.
THE NORMAL HEART HAS TWO SIDES,
A RIGHT SIDE AND A LEFT SIDE,
AND FOUR CHAMBERS, THE TOP RECEIVING CHAMBERS,
OR ATRIUM, AND THE LOWER CHAMBERS,
WHICH ARE THICK-WALLED PUMPING CHAMBERS
CALLED VENTRICLES.
RED BLOOD CELL WILL COME FROM EITHER THE SUPERIOR
VENA CAVA OR THE INFERIOR VENA CAVA AND ENTER
INTO THE RIGHT ATRIUM.
THE BLOOD THEN FLOWS ACROSS THE TRICUSPID VALVE
TO THE RIGHT VENTRICLE.
THE RIGHT VENTRICLE THEN SQUEEZES AND EJECTS THAT
BLOOD CELL INTO A VESSEL CALLED THE PULMONARY ARTERY.
THE PULMONARY ARTERY SPLITS INTO TWO VESSELS,
EACH GOING TO THE LUNGS.
AS THAT RED BLOOD CELL MAKES ITS WAY THROUGH THE LUNG,
IT RETURNS THROUGH THE PULMONARY VEINS TO THE LEFT ATRIUM.
THAT BLOOD IS NOW OXYGENATED.
IT'S PICKED UP OXYGEN, THEN GOES ACROSS THE MITRAL VALVE
INTO THE LEFT VENTRICLE, WHICH DOES MOST OF THE WORK
IN TERMS OF DELIVERY OF BLOOD FLOW TO THE BODY.
THAT BLOOD CELL IS NOW EJECTED INTO THE AORTA
TO SOME ORGAN OR MUSCLE OR SKIN IN THE HUMAN BODY.
NOW, THERE ARE SOME SIGNIFICANT DIFFERENCES
BETWEEN THE HEART IN THE NEWBORN AND THE HEART
IN THE FETUS.
>> THE HEART ACTUALLY IS-- ASSUMES ITS ALMOST
COMPLETE ANATOMY OFTEN BEFORE A WOMAN WOULD EVEN
KNOW SHE WAS PREGNANT.
>> THE HEART IS ACTUALLY FUNCTIONING AND PUMPING
BLOOD TO THE BABY THROUGHOUT MOST OF FETAL LIFE.
>> BECAUSE THE LUNGS ARE COLLAPSED IN THE FETUS
AND IT'S REALLY THE PLACENTA THROUGH WHICH MUCH
OF THE OXYGENATION TAKES PLACE THROUGH THE MOTHER,
THERE ARE VARIOUS BYPASS PATHWAYS WITHIN THE FETAL
HEART THAT DIRECT BLOOD AWAY FROM THE LUNG.
THE FIRST IS A STRUCTURE CALLED THE FORAMEN OVALE.
THAT'S COMMUNICATION BETWEEN THE TWO TOP CHAMBERS
OF THE HEART THAT ALLOWS FOR BLOOD TO GO FROM THE RIGHT
ATRIUM TO THE LEFT ATRIUM.
IN FACT, BECAUSE THERE IS VERY LITTLE BLOOD THAT'S
RETURNING FROM THE LUNG WHICH WOULD NORMALLY GO
TO THE LEFT SIDE, THE MAJORITY OF BLOOD THAT FILLS THE LEFT
ATRIUM AND LEFT VENTRICLE IS COMING ACROSS THE FORAMEN
OVALE FROM THE RIGHT SIDE.
BECAUSE THE LUNGS ARE COLLAPSED,
THERE'S HIGH PRESSURE, HIGH RESISTANCE IN THE LUNGS.
AS BLOOD IS EJECTED OUT THE RIGHT VENTRICLE AND ENTERS
INTO THE MAIN PULMONARY ARTERY,
VERY LITTLE GOES DOWN INTO THE LUNGS THEMSELVES.
THE MAJORITY GOES INTO A STRUCTURE CALLED THE DUCTUS
ARTERIOSUS, WHICH IS THE SECOND IMPORTANT
COMMUNICATION BETWEEN THE PULMONARY ARTERY
AND THE DESCENDING AORTA.
THE THIRD STRUCTURE THAT'S IMPORTANT THAT CONNECTS
THE UMBILICAL VEIN TO THE FETAL CIRCULATION IS A SITE--
A JUNCTION-- CALLED THE DUCTUS VENOSUS.
THAT ACTS AS SOMEWHAT OF A RESISTER,
IF YOU WILL, IN TERMS OF CONTROLLING THE RETURN
OF BLOOD FROM THE PLACENTA TO THE FETAL CIRCULATION.
BIRTH IS A WONDERFUL PROCESS AND AN AMAZING PROCESS,
AND THERE'S A DRAMATIC CHANGE THAT TAKES PLACE IN
WHAT WE CALL THE FETAL TRANSITION,
THIS TRANSITION OF THE CIRCULATION FROM FETAL LIFE
TO NEONATAL LIFE.
AS SOON AS THE CORD IS CLAMPED,
THE DUCTUS VENOSUS CEASES TO CARRY BLOOD TO THE HEART,
AND IT BEGINS TO CONSTRICT WITHIN THE FIRST FEW HOURS
OR DAYS OF LIFE.
THE VERY FIRST THING THAT HAPPENS WHEN A FETUS IS BORN
IS IT TAKES ITS FIRST BREATH,
THE LUNGS EXPAND, AND SO THE RESISTANCE OR PRESSURE
IN THE LUNGS DROP, AND THAT PROMOTES BLOOD FLOW
INTO THE LUNG ITSELF.
THE DUCTUS ARTERIOSUS BEGINS TO CONSTRICT
AND IS TYPICALLY FULLY CLOSED WITHIN 24 TO 48 HOURS
OF LIFE, AND BLOOD IS NOW THEN FULLY DIRECTED
INTO THE LUNG.
AS THE BLOOD RETURNS TO THE LEFT SIDE OF THE HEART,
AFTER TRAVERSING THE PULMONARY CIRCULATION
AND PICKING UP OXYGEN, THE PRESSURE IN THE LEFT ATRIUM
RISES JUST A BIT, AND THE TRAP DOOR OF THE FORAMEN
OVALE, WHICH WAS OPEN BEFORE BIRTH,
NOW BEGINS TO CLOSE, USUALLY WITHIN THE FIRST FEW DAYS
OF LIFE.