This study is intended to compare the feasibility, safety and efficacy of Ensite-NavX zero-fluoroscopic navigation system to conventional fluoroscopic X-ray approach as to performing single-chamber pacemaker implantation.

Permanent pacemaker is a well-established treatment to treat patients with a wide range of heart rhythm disturbances.

Fluoroscopy is the imaging modality routinely used for cardiac device implantation and electrophysiological procedures.Due to the rising concern regarding the harmful effects of radiation exposure to both the patients and operation staffs, novel 3D mapping systems have been developed and implemented in electrophysiological procedure for the navigation of catheters inside the heart chambers.

Ensite NavX system can be used for cardiac imaging as a reliable and safe zero-fluoroscopy approach for implantation of single- or dual-chamber permanent pacemaker in patients. Our method offered a choice for some special population of patient in whom radiation exposure need to be avoided or in the extreme circumstances when the X-ray machine is out-of-order.

Inclusion Criteria:

• Sick Sinus Syndrome
• complete Atrioventricular Block
• high degree second Degree Atrioventricular Block
• Bradycardia

Exclusion Criteria:

• pacemaker replacement
• severe structural l cardiac malformations
• severe cardiac enlargement
• venous malformations