Correspondence

Syncope

N Engl J Med 2001; 344:1098-1099April 5, 2001

Article

To the Editor:

Kapoor's excellent review of syncope (Dec. 21 issue)1 failed to mention arrhythmogenic right ventricular dysplasia as a possible cause of syncope. Although rare, this condition affects otherwise healthy young persons and can be fatal. Clinicians must have a high degree of suspicion in order to diagnose this condition, since the physical examination is often unremarkable. The classic electrocardiogram demonstrates inverted T waves in the right precordial leads, but it may be read as normal.2 Since this condition often only grossly affects the right ventricle, especially early in the disease process, the diagnosis may be missed on echocardiography. Subtle abnormalities of this chamber may be overlooked unless the reader of the echocardiogram is alerted to the suspicion of right ventricular dysplasia.

Since syncope in right ventricular dysplasia (and, for that matter, in patients with anomalous coronary arteries) often occurs during exertion3 in patients thought to have no structural heart disease, we disagree with Kapoor's statement that “episodes associated with exercise in athletes without heart disease are also examples of neurally mediated syncope.” We believe syncope during exertion in all patients deserves a thorough work-up, including echocardiography with careful attention to the right ventricle and a provocative test for arrhythmias such as an exercise stress test or an electrophysiologic study, before the condition is attributed to neurocardiogenic syncope.

Ralph J. Verdino, M.D.
Francis E. Marchlinski, M.D.
University of Pennsylvania Hospitals, Philadelphia, PA 19104

3 References

1. 1

   Kapoor WN. Syncope. N Engl J Med 2000;343:1856-1862
   Full Text | Web of Science | Medline

2. 2

   Marcus FI, Fontaine GH, Guiraudon G, et al. Right ventricular dysplasia: a report of 24 adult cases. Circulation 1982;65:384-398
   CrossRef | Web of Science | Medline

3. 3

   Corrado D, Basso C, Thiene G, et al. Spectrum of clinicopathologic manifestations of arrhythmogenic right ventricular cardiomyopathy/dysplasia: a multicenter study. J Am Coll Cardiol 1997;30:1512-1520
   CrossRef | Web of Science | Medline

To the Editor:

Dr. Kapoor correctly points out that syncope in elderly patients is particularly difficult to evaluate. In fact, some elderly patients will deny having episodes of syncope and present with only recurrent unexplained falls. In one study,1 carotid-sinus massage was performed on 132 consecutive patients older than 65 years of age who were referred to a syncope clinic for the investigation of recurrent unexplained dizziness, falls, and syncope. A total of 59 patients had persistent, reproducible carotid-sinus hypersensitivity, and 17 of them denied having episodes of syncope and presented instead with dizziness or falls of unknown origin; in 12 of these patients, loss of consciousness was witnessed during carotid-sinus massage, and the patients subsequently had retrograde amnesia concerning the event. Therefore, syncope should be included in the differential diagnosis of older patients who present with unexplained falls.

Francisco José Fernández-Fernández, M.D.
Pascual Sesma, M.D.
Hospital Arquitecto Marcide, 15405 Ferrol, Spain

1 References

1. 1

   McIntosh SJ, Lawson J, Kenny RA. Clinical characteristics of vasodepressor, cardioinhibitory, and mixed carotid sinus syndrome in the elderly. Am J Med 1993;95:203-208
   CrossRef | Web of Science | Medline

Author/Editor Response

Dr. Kapoor replies:

To the Editor: The comment made by Drs. Verdino and Marchlinski regarding right ventricular dysplasia entirely accords with the central point of my article that the most important factor in the evaluation of syncope is determining whether or not the patient has structural heart disease. I noted that episodes associated with exercise in athletes without heart disease are examples of neurally mediated syncope. Right ventricular dysplasia is certainly heart disease and would require the physician to consider arrhythmias and conduct an additional workup.

Concerning the detection of right ventricular dysplasia, I concur that a high index of suspicion is necessary. Exertional syncope in any patient merits evaluation with echocardiography and stress testing to discover any possible cardiac cause for this symptom. In addition to right ventricular dysplasia, more common causes such as ischemia, valvular heart disease, hypertrophic cardiomyopathy, and pulmonary hypertension also need to be considered, as I noted in Table 2 of my article. The careful evaluation of patients with exertional syncope is likely to uncover right ventricular dysplasia if it is present.

The comments of Drs. Fernández-Fernández and Sesma regarding falls in the elderly are relevant to the evaluation of falls. I focused specifically on syncope. Regarding the evaluation of falls in the elderly, I concur that brief arrhythmias must be considered, since some patients may not recall losses of consciousness and may therefore present with falls rather than with syncope.

Wishwa N. Kapoor, M.D.
University of Pittsburgh School of Medicine, Pittsburgh, PA 15213-2582