Problem or Purpose: Eating disorders have the highest mortality rate of all psychiatric diagnoses and affect approximately 10% of adolescent girls and young women. The disorders are associated with serious medical complications and premature death from a myriad of causes; a high percentage of these premature deaths are linked to adverse cardiac events. Identifying reliable biomarkers of cardiac risk in this population is essential to improve health outcomes. The present study examines differences in cardiac risk indicators through electrocardiography (ECG) among asymptomatic women compared to women with subclinical and clinical eating disorder symptoms. Specifically, ECG waves examined across the three groups were: mean T wave amplitude, mean R wave amplitude, mean Tpeak-to-Tend, QT interval length, and QRS interval duration. We predicted women in the subclinical and clinical groups would show decreased T wave amplitude, decreased mean R wave amplitude, and increased QRS interval, QT interval, and Tpeak-Tend interval compared to asymptomatic patients.
Procedure: We collected 5 minutes and 30 seconds of cardiac data via 3-lead ECG in a community sample of women with clinical and subclinical symptoms across a 4-year recruitment period as part of an ongoing study of cardiac function in women with eating disorders (N=141). Eating disorder symptoms, body mass index, and biomarkers of cardiac risk were examined. We predicted a statistically significant effect of condition in the one-way MANOVA results.
Results: As predicted, results indicated a statistically significant effect of condition, Pillai’s Trace = .59, F(12, 268) = 9.40, p < .001. Follow-up tests showed mean R wave amplitude was significantly decreased among women with subclinical and clinical symptoms, indicating decreased force of ventricular contraction. Results further indicated T wave amplitude was significantly lower in women with subclinical and clinical symptoms, indicating blunted electrical signaling during repolarization. QT interval prolongation, increased QRS interval duration, and prolonged Tpeak-to-Tend intervals further displayed aberrant depolarization and repolarization processes in women with subclinical and clinical symptoms compared to asymptomatic women.
Conclusions and Implications: Women with clinical and subclinical eating disorder symptoms display aberrant cardiac biomarkers which distinguish them from women without symptoms. Mean R wave amplitude, T wave amplitude, QT interval prolongation, QRS interval duration, and Tpeak-to-Tend intervals are important cardiac biomarkers to assess in eating disorder patients, especially given that several of these markers have been linked previously to risk for sudden cardiac death within eating disorder populations and beyond.
Abby Herrick, ’17
St. Paul, MN
Linden Miles, ’17
Mariah Ravet, ’17
Elisabeth Sage, ’17