What you see here is a pile of exploded pacemakers. No, pacemakers are not known to explode as a fault condition. However, when subjected to the extreme temperatures found in a crematorium oven, they come out looking like abalone shells after popping violently.
Apparently, previous Zn-Hg batteries used would explode loudly enough to damage an oven (one could only imagine what it did to the “patient”), but more current Li-ion batteries are a bit less catastrophic when they go off.
That’s about all we can glean from a web-based Danish-to-English translation of the original article
by Manedens Billede, found here. That, and that once a lightning strike caused an pacemaker to explode (see reference 1 in the paper).
Hat Tip: Biomedicine on Display