The CT-verified Data Collection Study to Investigate the Correlation Between the Leadless Pacemaker Tip Location and Echo, ECG

Inclusion Criteria: * Patients aged above 18 years old * Patients who are willing to provide Informed Consent * Patients with Class I or II indications who plan to receive a leadless pacemaker, including SSS, AVB, AF with bradycardia, etc. * Patients who plan to conduct a cardiac CT scan after implantation Exclusion Criteria: * Patients with lead retention * Patients had heart valve replacement * Patients diagnosed with ischemic heart diseases * Patients who are allergic to or refuse to use contrast in CT scans * Patients who are pregnant or have a plan for pregnancy during the study * Patients with medical conditions that would limit study participation * Patients already enrolled in another clinical trial which would impact participation of this study