Leads dislodged into the pulmonary vascular bed in patients with cardiac implantable electronic devices

Echocardiographic findings in patients with cardiac implantable electronic devices-analysis of factors predisposing to lead-associated changes

BACKGROUND

The constant interaction between intracardiac leads and the heart and veins results in excessive accumulation of fibrous connective tissue around the leads. The extent of this pathological phenomenon, which is visible on transesophageal echocardiography (TEE), and predisposing factors are not well defined.

METHODS

We examined 936 transesophageal echocardiograms prior to transvenous lead extraction (TLE) performed at a high-volume centre between 2015 and 2019.

RESULTS

The most important echocardiographic findings were fibrous binding sites between leads and cardiovascular structures, lead-to-lead adhesions, excessive lead loops, lead-dependent tricuspid dysfunction (LDTD), asymptomatic masses on endocardial leads (AMEL) and vegetations. Fibrotic reaction within the walls of the heart and veins correlated with the presence of lead loops (OR = 1.771; p < .01) and lead dwell time (OR = 1.111; p < .001). Women were more likely to have excessive lead loops (OR = 1.639; p < .01), and the occurrence of loops increase with the number of implanted leads (OR = 2.557; p < .001). Heart failure (OR = 4.016; p < .001), lead looping (OR = 2.603; p < .01) and longer cumulative lead dwell time (OR = 1.017; p < .05) increased the likelihood of LDTD. A variety of AMEL were identified in this study, most commonly in patients with older leads (OR = 1.043; p < .001).

CONCLUSIONS

Lead dwell time is the main factor predisposing to the occurrence of most lead-associated phenomena visualized by TEE in patients with cardiac implantable electronic devices (CIED). Excessive looping of the lead is an important cause of fibrous binding sites and LDTD. AMEL are frequently detected in CIED patients, and their various forms concurrent with vegetations could represent an evolutionary stage of lead-associated masses.

MRI of patients with implanted cardiac devices

Cardiac implanted electronic devices (CIEDs) have historically been regarded as a contraindication for performing magnetic resonance imaging (MRI), limiting the availability of this exam for large numbers of patients who may have otherwise benefited from the unique diagnostic capabilities of MRI. Interactions between CIEDs and the magnetic field associated with MRI systems have been documented, and include potential effects on CIED function, lead heating, and force/torque on the generator. Several device manufacturers have developed "MR-Conditional" CIEDs with specific hardware and software design changes to optimize the device for the MR environment. However, a substantial body of evidence has been accumulating that suggests that MRI may be safely performed in patients with either conditional or nonconditional CIEDs. Institutional policies and procedures, including preexam screening and assessment by skilled electrophysiology personnel and intraexam monitoring, allow MRI to be safely performed in CIED patients, as evidenced by at least two, large multicenter prospective studies and multiple smaller, single-institution studies. Cross-departmental collaboration and a robust safety infrastructure at sites that perform MRI should allow for the safe imaging of CIED patients who have a clinical indication for the study, regardless of the conditionality status of the device.

LEVEL OF EVIDENCE

5 Technical Efficacy: Stage 5 J. Magn. Reson. Imaging 2018;47:595-603.