Digoxin toxicity in renal failure: role of the electrocardiogram

Clinical manifestations of elderly patients with digitalis intoxication in the emergency department

This study aimed to determine the clinical characteristics of elderly patients diagnosed with digitalis intoxication, on the Emergency Department, University Hospital Complex, A Coruña, Spain. During the study period (January-September 2008) cases were included in which digitalis intoxication was confirmed by plasma digoxin levels. We collected data on age, gender, base-line diseases, therapeutic indications for digoxin, functional classification, ejection fraction, plasma digoxin levels, creatinine clearance, ions, gasometry, electrocardiogram, concomitant medication, symptomatology and treatment. The results were: mean age 82.0 ± 6.6 years, predominantly female subjects (83.7%). The most prevalent pathologies were cardiac valvulopathy (81.0%), hypertension (68.3%) and ischemic cardiopathy (46.3%), 95.1% had a background of cardiac insufficiency, and 52.6% were in functional grade III. The mean digoxin level was 2.7 ± 0.69 ng/ml, 23.1% of the patients had a creatinine clearance of less than 60 ml/min/1.73 m(2) and 2.6% had a severely reduced glomerular filtration rate (GFR) (clearance<30 ml/min/1.73 m(2)). A negative correlation was found between digoxin levels and clearance (r = -0.22; p = 0.18) and between the levels and cardiac frequency (r = -0.35; p = 0.026). Of the patients, 47.5% presented bradycardia and 87.8% arrhythmias, most frequently auricular fibrillation. The most frequent symptoms were nausea (54.8%), fatigue (42.9%), vomiting (33.3%) and anorexia (28.6%). We conclude that clinical digestive symptoms in elderly women who are taking digitalis, with bradycardia and impaired renal functioning, should lead us to suspect digitalis intoxication.