Fig. 1

Angiography and CT imaging of the congenital venous anatomy variant, and leadless pacemaker anchored position. A, B) non-selective venous angiography in RAO and LAO view via femoral vein. The yellow dotted line shows the tortuous and compensatory enlarged azygos vein drainage into RA directly. C) non-selective venous angiography of RV via right jugular vein. The yellow oval showed the tricuspid valve (TV). D). the leadless pacemaker anchored in RV septal via jugular vein. E, F) the post-procedural CT imaging of the venous angiography in anteroposterior (AP) and lateral view. The red arrow showed the abnormally tortuous and enlarged azygos. G) the 3-D image reconstruction. The yellow arrow showed the abnormally tortuous and enlarged azygos. The white arrow showed the hepatic vein directly drained into RA. H) the 3-D image reconstruction in AP view. The green asterisk showed the leadless pacemaker