Chronic digoxin toxicity and significantly elevated BNP levels in the presence of mild heart failure

B-Type Natriuretic Peptides (BNP) and Tissue Doppler E/e´ Before and After 4 Weeks Standard Treatment of African Heart Failure Subjects: The ABU-BNP Longitudinal Survey

BACKGROUND

The study aimed at determining the response of BNP and tissue Doppler (TD) E/e´ to standard heart failure (HF) therapy in an African black population as data on these are lacking in Africa. BNP assessment in relation to HF severity and its association with its predictors were also determined.

METHODS

It was a longitudinal-analytical study with a one month follow-up among 100 HF patients seen at Ahmadu Bello University Teaching Hospital, Zaria-Nigeria. Two-way Repeated Measures ANOVA determined BNP levels before and after treatment according to the HF severity. Wilcoxon-Signed Ranks test determined the difference in BNP and TD E/e´ before and after treatment. Pearson's correlation assessed log-transformed BNP's association with its predictors.

RESULTS

BNP significantly (p<0.001) rose with increasing severity of HF from 386.6 ± 186.5 pg/mL to 581.7 ± 299.0 pg/mL to 805.0 ± 484.0 pg/mL in the NYHA II-IV HF, respectively, with consequent fall in a similar fashion following treatment. The Median (IQR) BNP levels reduced significantly (p<0.001) from 450 (362.5, 712.5) to 275.0 (225, 375.2) pg/mL with a 38.9% reduction over 4 weeks associated with significant improvement in TD E/e´, structural and functional parameters. Ln10BNP was significantly (p<0.001) positively correlated to TD E/e´ before (r=0.51) and after treatment (r=0.43). Likewise, Ln10BNP was significantly (p<0.05) negatively correlated to ejection fraction & fractional shortening before and after treatment.

CONCLUSION

BNP and tissue Doppler can serve as useful tools in the assessment of the effectiveness of African HF treatment and functional capacity over 4 weeks. TD E/e´ may be a reliable non-invasive estimate of left ventricular filling pressures and diastolic dysfunction.

Toxic levels of glycosides in herbal medication: a potential cause of hyperkalaemia

We report a previously healthy man presenting with life-threatening hyperkalaemia and heart failure. The only possible cause was thought to be the long list of herbal medications he was taking, several of which contained significant amounts of cardiac glycosides. Hyperkalaemia is known to be associated with digoxin toxicity and we present this as the likely cause in this case, and emphasize the importance of a thorough drug history in forming a differential diagnosis.

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.