High-Grade Atrioventricular Blocks-Reply

Abstract

In Reply.— We appreciate the comments of Dr Phibbs, which support the views we expressed in the editorial. Suspicion of high-grade AV block varies from patient to patient. We agree with Dr Phibbs that in an overwhelming majority of patients, the suspicion that high-grade AV block may be the cause of unexplained syncope usually arises if the patient has chronic bifascicular or trifascicular block. However, on rare occasions, an AV block can occur and cause syncope, even in patients with normal AV and intraventricular conduction times (Figure). The rhythm strip is of a 40-year-old cardiologist with a history of recurrent syncope. The patient did not have electrophysiological studies and it is not known whether such studies would have been useful. This patient's record emphasizes once again the major thrust of our editorial; namely, that we do not know all the answers and there is a need for clinical judgment in