p.59 抽出テキスト

............................................................ 11.2 Radiation therapy in pacemaker

patients An increasing number of patients with CIEDs are referred for radiotherapy,757 with a reported annual rate of 4.33 treatments per 100 000 person-years. Radiotherapy uses high-energy ionizing radiation including X-rays, gamma rays, and charged particles, which might cause software and hardware errors in CIEDs, especially when photon radiation beam energy exceeds 610 MV, and the radiation dose to the device is high (>210 Gy).758,759 Hard errors are rare, and are most often due to direct irradiation to the device. This can cause irreversible hardware damage, requiring device replacement. Soft errors are more common, and are associated with secondary neutron production by irradiation.760 Such errors typically include resets of the device without causing structural damage, and can be solved without replacement.757,759 Electromagnetic interference during radiotherapy can cause oversensing, although this very rarely occurs in clinical practice.760 Device relocation before radiotherapy is very rarely recommended, and only if the current location of the device interferes

Evaluating magnetic resonance imaging in pacemaker patients

MRI following conditions of use and standardized

workflow (Class I) MRI Alternative

imaging technique MRI following

appropriate standardized workflow (Class IIa) MRI only if benefits

outweigh risk (max. 1.5T, SAR < 1.5 W/Kg)

(Class IIb) (Class IIa)

Presence of abandoned leads

MRI-conditional system

Past exemption period after implementation Alternative imaging

mode available

N

Y

Presence of epicardial leads, or connected fractured leads, or lead adaptors/extenders

Y

N N

N

Strongly reconsider

MRIa Y

Y N Y

Figure 14 Flowchart for evaluating magnetic resonance imaging in pacemaker patients. MRI = magnetic resonance imaging; SAR = specific absorption rate. aConsider only if there is no imaging alternative and the result of the test is crucial for applying life-saving therapies for the patient.

Recommendations for performing magnetic resonance imaging in pacemaker patients

Recommendations Classa Levelb

In patients with MRI-conditional pacemaker systems,c MRIs can be performed safely following the manufacturer’s instructions.745,753755 I A In patients with non-MRI-conditional pacemaker systems, MRI should be considered if no alternative imaging mode is available and if no epicardial leads, abandoned or damaged leads, or lead adaptors/extenders are present.744,746 IIa B MRI may be considered in pacemaker patients with abandoned transvenous leads if no alternative imaging modality is available.748751 IIb C

MRI = magnetic resonance imaging. aClass of recommendation. bLevel of evidence. cCombination of MRI-conditional generator and lead(s) from the same manufacturer. ESC 2021 Downloaded from academic.oup.com/eurheartj/article/42/35/3427/6358547 by guest on 07 October 2026