Polymorphism of the clinical picture.

There is increasing evidence that a cardiomyopathy with preferential, mild to moderate (at least in the early phase) RV involvement, characterized by some peculiar segmental wall motion abnormalities and by adipose or fibro-adipose tissue infiltration, is the underlying anomaly in a wide spectrum of clinical conditions. At one end of this spectrum stand malignant ventricular tachyarrhythmias which are infrequent and generally symptomatic. Common features in the majority of cases are frequent and sometimes complex PVBs, mostly, though not exclusively, originating in the RV, which may be asymptomatic, exercise-related only in some cases, and are often associated with T-wave abnormalities. Then, at the other end of this spectrum we may find patients without arrhythmias complaining of precordial pain. Physical examination in the minor form subgroups is generally negative as, in most cases, are non-invasive investigations. Diagnosis in these minor form subgroups is thus mainly based on right ventriculography and RV biopsy, although the diagnostic criteria are not yet completely defined. So, we are now often faced with the dilemma of whether or not to submit these patients to invasive investigations which, at the moment, seem the most appropriate diagnostic approach.