“If You Hear Hoof Beats, Think Horses, Not Zebras”
02 February 2018
21 March 2018
05 July 2018 (online)
The very interesting case report by Fleissner et al represents an example of a diagnostic mistake where a diagnosis of a common disease was made, but a rare one was found. The authors are to be congratulated on their courage to report this “negative” case, because learning does not always come from success, but also from mistakes. If mistakes are not reported, learning from them is impossible. Fortunately, in this case the patient received an adequate therapy and had a comparatively good outcome.
Looking at the echocardiography video retrospectively, one easily recognizes that it does not show the typical features of a lead endocarditis. As the authors comment, a thoracic computed tomography scan would have been appropriate, but was not performed. In this case, although the ultrasound picture does not show a clear pacemaker lead vegetation, the clinical picture of the patient together with the higher incidence of lead endocarditis compared with a cardiac tumor led the authors to pursue the diagnosis of a lead infection. The recommendations for the management of pacemaker lead infections from 2010, and the Heart Rhythm Society Expert Consensus Statement on cardiovascular implantable electronic device lead management and extraction from 2017, unfortunately not cited in the case report, show a class I indication for lead removal in cases of definitive lead endocarditis.
What is to be learned here? It seems that—although “common is common and rare is rare” is a valid medical principle—sometimes the sound of hoof beats should lead to consider the possibility of zebras, not only of horses.
- 1 Fleißner F, Molitoris U, Rösler W, Kühn C. . Primary cardiac B-non-Hodgkin lymphoma disguised as a pacemaker endocarditis. Thorac Cardiovasc Surg Rep. 2018
- 2 Baddour LM, Epstein AE, Erickson CC. , et al; American Heart Association Rheumatic Fever, Endocarditis, and Kawasaki Disease Committee; Council on Cardiovascular Disease in Young; Council on Cardiovascular Surgery and Anesthesia; Council on Cardiovascular Nursing; Council on Clinical Cardiology; Interdisciplinary Council on Quality of Care; American Heart Association. Update on cardiovascular implantable electronic device infections and their management: a scientific statement from the American Heart Association. Circulation 2010; 121 (03) 458-477
- 3 Kusumoto FM, Bailey KR, Chaouki AS. , et al. Systematic review for the 2017 AHA/ACC/HRS Guideline for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death: a report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society. Heart Rhythm 2017; S1547-5271(17)31251-1