IMPORTANCE OF NOTCHING AND SLURRING OF THE RESTING QRS COMPLEX IN THEDIAGNOSIS OF CORONARY-ARTERY DISEASE

Data on the correlation of coronary artery disease (CAD) and electroca rdiographic findings are, except for Q waves, still controversial. The purpose of this study was to determine whether QRS complex notching a nd slurring (N&S) is of significant value as a diagnostic discriminato r in the detection of CAD. This study comprised 500 consecutive patien ts aged between 24 and 81 years (mean, 53.4 years) who underwent coron ary angiography because of chest pain. Patients were evaluated for CAD , angiographic evidence of myocardial infarction (MI), N&S, and abnorm al Q waves. Of these 500 patients, 418 had CAD, and 370 of these had s ignificant (greater than or equal to 70%) coronary artery obstruction. The remaining 82 patients had normal coronary arteries. The data reve aled that the distribution of N&S in the patients with or without CAD was similar in both the inferior and limb leads (P > .05). But the per centage of N&S in more than two contiguous limb leads was higher in th e patients with CAD than in the patients without CAD. Notching and slu rring in at least one limb lead was found to be of no value in the dia gnosis of MI, of wall motion abnormalities, and of significant obstruc tion. Notching and slurring in the anterior leads is more sensitive bu t less specific than abnormal Q waves in the same leads in the detecti on of significant obstruction, anterior MI, and anterior wall motion a bnormalities. Notching and slurring in the anterior leads has as much importance as abnormal anterior Q waves in the detection of angiograph ic evidence of anterior infarct, of anterior wall motion abnormalities , and of significant coronary artery obstruction. The specificity of N &S in more than two contiguous leads was greater than the specificity of N&S in at least one inferior lead for detecting CAD. Thus, N&S in m ore than two contiguous leads was more valuable than N&S in at least o ne limb lead in the diagnosis of CAD. Nevertheless, as a diagnostic cr iterion, N&S is not superior to the presence of abnormal Q waves in th e detection of significant obstruction, wall motion abnormalities, and angiographic evidence of infarct.