Reduced Coronary Blood Flow in Adolescents with Anorexia Nervosa

Anorexia nervosa (AN), an eating disorder, accounts for 5.1 deaths /1000 person years. Cardiovascular complication such as decreased cardiac mass, cardiac dysfunction, valve regurgitation, pericardial effusion, bradycardia, prolonged QT and hypotension occur in ~80% of patients with AN, and account for ~30% of mortality. The link between malnourishment and cardiac dysfunction is not completely understood. Noninvasive measurements of coronary flow velocity (CFV) in the distal Left Anterior Descending coronary artery (LAD), using transthoracic Doppler echocardiography accurately reflect invasive measurements of LAD flow in pediatric patients.

Aim: Characterizing CFV in anorectic adolescents compared to healthy controls, in order to shed light on the pathophysiology of the cardiac involvement in AN.

Methods: CFVs were measured at the distal LAD in hospitalized adolescents with AN. Healthy adolescents 10-19y, recruited to the control group. Patients` heart rate (HR), orthostatic blood-pressure, blood-gas, electrolytes and ECG were documented.

Results: 42 adolescents with AN were included; 11/31 males/females, mean age: 15.4±2.3y, mean weight loss: 22.3±11%, mean admission BMI 16.8±2.9Kg/m², median percentile BMI for age/ gender 84.5±13.3%, minimal nocturnal HR: 38±6 beats per minute (bpm). 58 healthy controls were compared to the AN group (figure 1). LAD Peak diastolic velocity was 23.8±7.5cm/sec in the AN versus 37.6±8.9cm/sec in the controls; peak systolic velocity was 13.1±5 in AN and 19.6±4.5 in the controls; p<0.00001. Coronary blood volume/minute (DVTI*HR) was 568 in AN and 936 in the controls: p<0.00001 (Figure 2). Anorectic males were less stable than females with nocturnal bradycardia of 34.3±4.7bpm versus 39.1±5.7bpm, reaching heart rate of 45: 16.1±5.2days versus 10±5, yet no statistically significant difference was found in coronary flow between genders.

Conclusion: CFV is significantly lower in anorexia; it may lead to papillary muscle ischemia, electrical instability and valve regurgitation, fibrosis and future cardiomyopathy and may account for the cardiac complications in anorexia.