Heart rate variability may predict risk of disease in premature infants

Measuring variability of heart rate may identify premature infants at risk of developing necrotizing enterocolitis, a serious inflammatory condition that can lead to death, according to Penn State College of Medicine researchers.

Necrotizing enterocolitis, or NEC, may lead to destruction of the intestinal wall and vital organ failure. It affects 6 to 10 percent of premature infants within the first two weeks of life.

"NEC is currently diagnosed by a combination of laboratory and radiology tests, usually done when the disease is already significant," said Kim Doheny, director of clinical research in newborn medicine and assistant professor of pediatrics. "Since NEC progresses so rapidly and the symptoms develop suddenly, a non-invasive biomarker that allows early detection of patients at risk is required as a matter of urgency."

Heart rate fluctuates in the intervals between beats, and contributors to this fluctuation are measured through mathematical analysis. One of these contributors is the parasympathetic nervous system - the system that controls digestive responses and regulates the organs during rest - represented through measurement of high-frequency energy distribution. The researchers studied 70 infants born at 28 to 35 weeks within the first five to eight days of life. The babies were stable with no sign of illness.

The researchers then measured heart rate variability in the infants to test whether measuring the high-frequency component of heart rate variability may be used as a way to predict an infant's NEC risk before disease onset. They reported the results in Neurogastroenterology & Motility.

Of the 70 infants studied, nine who later developed NEC had decreased high frequency in the heart rate variability, suggesting reduced parasympathetic nervous system activity. Of all the infants with a decreased high-frequency heart rate variability, 50 percent developed the disease. In contrast, 98 percent of those with a higher high-frequency value did not get the disease.

What Is Necrotizing Enterocolitis?

Necrotizing enterocolitis (NEC) is inflammation and death of intestinal tissue. It may involve just the lining of the intestine or the entire thickness of the intestine. In severe cases, the intestine may even perforate (a hole develops in the wall of the intestine). If this happens, the bacteria normally found only in the intestine can leak into the abdomen and cause widespread infection. This is considered a medical emergency.

NEC is most common in premature infants. It usually develops within two weeks of birth. Up to 80 percent of cases occur in premature babies, according to Children’s Hospital Cleveland Clinic. (CHCC). Around 10 percent of infants who weigh less than 3 pounds and 5 ounces develop NEC, states the Boston Children’s Hospital. (BCH)

NEC is a very dangerous disease that can progress quickly. Immediate medical attention is strongly urged if your baby shows possible symptoms.