Kalıcı Kalp Pili Takılanlarda Sağ Ventrikül Çıkış Yolu ve Apikal Elektrod Yerleşimlerinin Elektrokardiyografik Parametrelere Etkileri

Right ventricular outflow tract (RVOT) pacing is an alternative pacing site to apical pacing. RVOT pacing seems to be superior to apical pacing in terms of hemodynamic support while providing synchronous activation similar to native conduction pattern. In order to increase the cardiac output and synchronize ventricular activation pattern the paced QRS complex duration should be as narrow as possible according to previous biventricular pacing applications. However, it is not well established how much RVOT pacing will change the paced QRS time and other various electrocardiographic intervals in comparison to apical pacing. To investigate this, we undertook a prospective clinical study consisting of 16 patients in whom the ventricular leads were positioned and fixed in the RVOT. In 11 of these patients, time intervals of various electrocardiographic parameters including QRS, QTc, JTc, TTc, QTd, JTd, and TTd were measured from ECG recordings taken on RVOT and apical pacing sites during pacemaker implantation. Mean QRS time in RVOT position was significantly decreased in contrast to apical position (127 ± 26 vs 155 ± 21, p=0.004). Although QTc, JTc and TTc intervals increased in duration when paced from RVOT, only JTc reached statistical significance (p=0.01). We did not detect any significant change in other parameters. We did not observe any complication during and after the procedure in all 16 patients. In conclusion, RVOT pacing significantly diminishes the mean QRS duration as compared to apical pacing. It is a safe and easy applicable technique while providing synchronous activation pattern similar to native conduction and can be considered as an alternative site of permanent pacing. (Türk Kardiyol Dern Arş 2004; 32: 152-157)