Playing off a Valentine theme, Gov. John Baldacci has declared today “A Day for Hearts: Congenital Heart Defect Awareness Day.”

The governor, whose younger brother Paul Baldacci died suddenly of an inherited heart condition in January, made the proclamation Monday in conjunction with the southern Maine organization Precious Hearts.

Paul Baldacci’s unexpected death at 48 was determined to have been caused by a faulty heart valve, a previously undetected genetic defect. The finding has prompted Maine’s governor and other blood relatives to be tested for the same disorder. According to a spokeswoman at Baldacci’s office Monday, the governor’s recent electrocardiogram was normal.

Precious Hearts’ membership is composed of parents and families of children who are born with heart defects. The organization is affiliated with the Barbara Bush Children’s Hospital at Maine Medical Center in Portland. The group’s mission is to raise public awareness about the 35 different types of heart defects known to be genetic in nature.

According to Precious Hearts, congenital heart defects are the most common birth defect in the United States. About 40,000 babies a year, or one in every 25 infants, are born with a heart deformity.

Some cardiac defects are immediately life-threatening. Infants may undergo emergency surgery, the implantation of a pacemaker or other device and intensive pharmaceutical management.

But other defects cause no immediate symptoms and may go undetected for many years. In these cases, the defect may cause the heart to work harder than it should or to lose its ability to pump blood effectively. Heart chambers may become enlarged, and the organ’s walls may lose their elasticity. These changes develop slowly and may escape notice until an apparently healthy individual experiences acute symptoms of chest pain, shortness of breath and fatigue. In extreme cases, sudden death can result.

Bangor pediatric cardiologist Angela Gilladoga said heart defect rates in Maine are on par with national statistics. Using a stethoscope, most physicians can identify the harmless and common “innocent murmur” of young children’s hearts, she said, and know when to investigate further.

“It is the harsher or louder or more intense sounds that clue you in that this is not quite normal,” she said.

Gilladoga said parents should investigate their family histories of sudden, unexpected cardiac death and take seriously any complaints their young children may make of chest pain or shortness of breath while exercising. Poor color and a weak pulse in the wrist may indicate a problem as well, she said.

High school athletes are often victims of undetected heart defects. In Madawaska last summer, 16-year-old athlete Kenny Sirois collapsed and died while running home in an impromptu race with his brother, Mark. The cause was determined to be hypertrophic cardiomyopathy, a heart valve weakness that over time causes the left ventricle to enlarge, thicken and lose tone. The condition would most likely have been found with a standard electrocardiogram and probably could have been managed with lifestyle changes and medications, according to the boys’ mother, Wendy Sirois.

Paul Baldacci, who ran the family’s landmark restaurant, Momma Baldacci’s, was found dead Jan. 26 at the governor’s Bangor home, where he had been living while his brother occupies the Blaine House in Augusta.