Hello and thank you for asking HCM.
I have read the history of your husband and i will try to explain to you what happened.
-your husband had a catheter put for a pacemaker procedure. For the pacemaker to wotk they need to send some thin wires to the heart throught veins. To do so,doctors need to be sure that blood will not clot while passing the wire,so they use anticoagulants (blood thinner) that prevents the formation of
blood clots.
Now lets get back at the catheter and why his bladder didn't empty.
Having blood thinners,means that your blood wont clot fast. So probably even a momevent of the catheter,damaged the blood walls (even a small scratch,or stone) so he had blood in his bladder that didn't get out from the catheter in time.
This blood with the passing of time cloated and blocked the catheter. Thats why your husband had the need to go to the ER and change his catheter,it was blocked from the clots. It hapens and its normal. thats why,everytime a person puts a catheter,every doctor recomand to have plenty of liquids.
If you have any other question,feel free to contact me.
Dr.Endri Katro