Isolated XXXX in adult life. A prospective study.

@entity1 @entity8654 @entity339 @entity1353 @entity713 @entity1295 @entity5036 @entity299 @entity204 @entity616
BACKGROUND: The prognosis of @entity713 (CCHB) is usually considered favorable in adults. This belief is based on studies comprising a limited number of @entity1 and with rather short observation times. In the present study, the natural history of the disease was investigated by a prospective follow-up through decades of adult life of @entity1 with a large group having well-defined CCHB without structural @entity299 . METHODS AND RESULTS: The diagnostic criteria of CCHB proposed by Yater were applied. @entity1 registered as having CCHB in 1964, supplemented by younger @entity1 all without symptoms during their first 15 years of life, were selected. The study was limited to @entity1 with isolated, complete, permanent @entity616 . An interview was conducted with all @entity1 and clinical follow-up data obtained. There were finally 102 @entity1 , 61 @entity1 and 41 @entity1 . In November 1994, the time of observation, after the age of 15 years in survivors, was between 7 and 30 years. The mean age at follow-up or at @entity204 was 38 years, median age 37 years, and range 16 to 66 years. @entity8654 ( @entity8654 ) attacks occurred in 27 @entity1 , in 8 with a fatal outcome. The first attack was fatal in 6 of these 8 @entity1 . Nineteen survived and a pacemaker (PM) was implanted thereafter. Another 8 @entity1 received a PM because of repeated fainting spells, and 27 others have had a PM implanted for other reasons such as @entity1295 , effort @entity1353 , dizziness, ectopies during exercise tests, @entity339 , and a low ventricular rate (VR). VR decreased with age, with a mean rate at 15 years of 46 beats per minute (bpm), at 16 to 20 years of 43 bpm, at 21 to 30 years of 41 bpm, at 31 to 40 years of 40 bpm, and after 40 years of age of 39 bpm. @entity8654 attacks occurred in all 7 @entity1 with prolonged QTc time. Low VR at rest or at work, presence of @entity5036 pattern, low working capacity, and ectopies at rest and/or during effort were not statistically significant risk factors. @entity8654 attacks occurred in 6 @entity1 without any of these signs. @entity339 developed in 16 @entity1 and 4 died. A PM reduced the risk of @entity204 . A change to a @entity616 occurred in 6 @entity1 . CONCLUSIONS: Prophylactic PM treatment is recommended even for symptom-free adults with CCHB because of the high incidence of unpredictable @entity8654 attacks with considerable mortality from first attacks, a gradually decreasing VR, significant morbidity, and a high incidence of "acquired" @entity339 .
