1993 Volume 34 Issue 3 Pages 269-278
To determine the clinical significance of ST-segment depression observed in paroxysmal supraventricular tachycardia (PSVT), we evaluated the 12-lead electrocardiogram (ECG) during spontaneous PSVT in 54 patients (27 men and 27 women: mean age±SD; 47±18 years), who came to our clinic for the treatment of PSVT. Coronary angiography was performed in 16 patients (16 to 74 years; mean=50±18) and treadmill exercise testing was performed in 21 patients. A cardiac electrophysiological study was carried out in 24 patients. During PSVT, ST-segment score was calculated as the sum of the ST-segment depression in 12 leads. The correlations between the ST-segment score, PSVT rate and age of the patient were analyzed as follows: The most significant positive correlation was observed between the ST-segment score and the PSVT rate (r=0.615, p<0.000001). The next most significant correlation was found between the PSVT rate and the age of the patient (r=-0.500, p=0.00011). A negative correlation was also observed between the ST-segment score and the age of the patient (r=-0.429, p=0.0012). In 13 of 16 patients, coronary angiography did not reveal any significant (≥75% in area) stenosis. Exercise testing induced significant ST-segment depression in 3 patients, of whom two had significant coronary artery lesions.PSVT was due to atrioventricular reentry via an overt (n=3) or concealed accessory pathway (n=15), atrioventricular nodal reentry (n=5) and sinus node reentry (n=1). In conclusion, patients with a faster PSVT rate revealed more pronounced ST-segment depression than did those with a slower PSVT rate, possibly reflecting the modified repolarization process instead of coronary artery involvement.
