33 Serologymay be performed to detect the presence of markers of
myocardial inflammation and myocyte damage.
44 Endomyocardial biopsymay have a role, but the risks and
benefits are debated. What is, however, clear is that a tissue
histological diagnosis provides important prognostic
information which may (as in the case of sarcoidosis) have an
impact on treatment.^4 Biopsy may be recommended to
exclude treatable causes such as sarcoidosis and giant cell
myocarditis, if these are thought likely. In research centres,
biopsy specimens may be analysed by immunohistochemical
and molecular biological techniques to determine the
presence or absence of low grade inflammation and viral
persistence.
Frequency of follow up will depend on the severity of
involvement at initial presentation. The course of the disease at
early follow up is a useful indicator of long term prognosis with
improvement or deterioration occurring in most cases within six
months to one year of diagnosis.
The possibility that the patient’s cardiomyopathy may be
familial should be explored by taking a detailed family history,
but incomplete and age-related penetrance make family
screening problematic. The decision to evaluate (usually first
degree) relatives should be individualised, based on the extent of
disease within a family, the levels of anxiety among patients and
relatives, the presence of suggestive symptoms and the extent of
local experience in the evaluation of dilated cardiomyopathy.
RReeffeerreenncceess
1 Sugrue DD, Rodeheffer RJ, Codd MB et al. The clinical course of idio-
pathic dilated cardiomyopathy. A population-based study. Ann Intern
Med 1992; 111177 : 117–23.
2 Mancini DM, Fleming K, Britton N, Simson MB. Predictive value of
abnormal signal-averaged electrocardiograms in patients with non-
ischemic cardiomyopathy. J Am Coll Cardiol1992; 1199 : 72A.
3 Yi G, Keeling PJ, Goldman JH. et al.Comparison of time domain and
spectral turbulence analysis of the signal-averaged electrocardiogram
for the prediction of prognosis in idiopathic dilated cardiomyopathy.
Clin Cardiol1996; 1199 : 800–8.
4 Felker GM, Thompson RE, Hare JM et al. Underlying causes and long-
term survival in patients with initially unexplained cardiomyopathy.
N Engl J Med2000; 334422 : 1077–84.