Heart Rate Turbulence Risk Factor for Cardiac Mortality
Abnormal heart rate turbulence onset and slope tied to cardiac mortality in low-risk patients
FRIDAY, March 11 (HealthDay News) -- Abnormal heart rate turbulence (HRT) is independently associated with increased cardiac mortality risk for low-, intermediate-, and high-risk individuals, while C-reactive protein (CRP) is associated with an increased cardiac mortality risk only in those who are low risk, according to a study published in the February issue of the Journal of Cardiovascular Electrophysiology.
Phyllis K. Stein, Ph.D., from the Washington University School of Medicine in St. Louis, and Joshua I. Barzilay, M.D., from Kaiser Permanente of Georgia in Atlanta, studied 24-hour Holter recordings from 1,272 individuals to determine if HRT and CRP independently add to the traditional cardiac mortality risk factors. Participants aged 65 and older were stratified as low, intermediate, and high risk for cardiovascular disease (CVD).
The researchers found that the abnormal HRT onset and slope values in low-risk participants were significantly associated with cardiac mortality (hazard ratio [HR], 7.9). In the intermediate- and high-risk groups, abnormal HRT slope, or slope and onset values were associated with a lower increase in cardiac mortality (HRs, 2.7 and 2.2, respectively). Increased CRP levels were associated with an increased risk of cardiac mortality only in low-risk individuals (HR, 2.5).
"Both HRT and CRP contribute significantly to risk stratification of older adults without evidence for CVD; HRT further adds to risk prediction for those with isolated subclinical or established CVD," the authors write.