Dear Editor:
We have recently read the article by Gutiérrez Morlote et al,1 published in the Revista Española de Cardiología, about which we should like to make a few comments. In the reported study, the authors describe the cases of 2 patients whose headaches could have been the consequence of myocardial ischemia. The authors state that the International Headache Society define the diagnostic criteria for "cardiac cephalgia" as the presence of intense headache, worsened by exertion, that develops concomitantly with acute myocardial ischemia and resolves without recurrence after efficient treatment of the myocardial ischemia.2 In their article,1 they report 2 cases of this entity; the first fulfills these diagnostic criteria, as there is a decrease in the ST segment on the electrocardiogram during the headache as well as a documented increase in markers of myocardial damage, together with the lack of recurrence of the headache following treatment with nitrates. The second case, however, describes a patient with no evidence of myocardial ischemia during the headache episodes since, as the authors state, no electrocardiogram or other test for detection of ischemia was performed; it was simply a case of headache that ceased after treatment with nitrates (which could be attributed to a placebo effect). Accordingly, this case cannot be stated to comply with the diagnostic criteria for the entity in question.2
When a new syndrome appears in the medical literature, it is of great interest to report to the scientific community newly diagnosed cases which may enhance our knowledge. However, this should be done prudently and rigorously, avoiding incitement to search for the process, as this will only lead to diagnostic errors.
The onset of headache as a consequence of myocardial ischemia is possible through various mechanisms. It may concern a reported headache, similar to that described by some patients in the nucha, the neck or the palate; it may be related with the release of neurohormones, or simply be due to hemodynamic changes. In fact, episodes of angina are often associated with the simultaneous rise in blood pressure, which could also give rise to a headache. Nonetheless, for the time being, we should consider cardiac cephalgia as a very unusual entity,3 with specific diagnostic criteria,2,3 that may or may not be underdiagnosed, but which we should definitely avoid overdiagnosing. Otherwise, cardiologists may start to receive in our offices patients with headache in order to rule out a possible ischemic heart disease and emergency departments may begin requesting electrocardiograms, enzyme determinations and cardiologic evaluations for all patients with this symptom.