This study was conducted to determine the incidence of abnormal signal averaged
electrocardiogram (+ve SAECG) in dilated cardiomyopathy (DCM) either ischemic or non-ischemic,
and to determine factorswhichmay affect SAECGinthese subsets ofpatients. One hundredpatients
with DCM were includedinthe study51 males and49 females, theirmeanagewas 62.255.6years.
Fifty-nine patients were ischemic and 41 were non-ischemic. The incidence of+ve SAECGin all
study population was 38% with a significant higher incidence of +ve SAECGinischemicDCM
(49.1%) versusnonischemicDCM(21.9%)p<0.05 andsignificantlyprolongedQRSdurationinturn
ischemic DCM compared to ischemic group (112.8 +12ms.Vs.lO9.8 +11.7ms respectively). In
ischemic DCM, variables which was associated with increased incidence of +ve SAECG were:
decreased serum K+, increased cardiothoracic ratio detected chest x- ray, pasthistory ofinferior
myocardial infarction, increased left ventricular volumes and dimensions, decreased fractional
shortening and ejection fraction and increased wall motion abnormalities. Factors, which were
associated with decreased incidence of +ve SAECG, were captopril therapy and past history of
thrombolytic therapy. In non ischemic group, factors which were significantly associated with
increased incidence of +veSAECG were: decreased serum K+ increased cardiothoracic ratio,
increased left ventricular volumes anddimensions andincreasedleftventricularmass. Factor,which
was associated with decreased incidence of +ve SAECG, was captopril therapy. So, it can be
concluded that, there is a high incidence of abnormal SAECG in patients with DCM and this
incidence is affected by the etiology ofDCM(Ischemic or nonIschemic), clinical, pharmacological,
laboratory, echocardiographic characteristics of patients studied, so these variablesmust be inmind
on studying incidence andprognostic significance of SAECGinDCMpatients. |
