ALS patients are more vulnerable to Venous thromboembolism; here are some journal papers on this issue . . . one patient suffered from resultant pulmonary embolism and died after implant of pacer . . . they also had history of blood clots. Few patients have encountered this issue based on their online comments.

Venous thromboembolism after diaphragm pacing in amyotrophic lateral sclerosis
Venous thromboembolism after diaphragm pacing in amyotrophic lateral sclerosis - PubMed

Venous Thromboembolism
What is Venous Thromboembolism? | CDC

Venous thromboembolism in amyotrophic lateral sclerosis: a prospective study
Venous thromboembolism in amyotrophic lateral sclerosis: a prospective study - PubMed