Giant right atrial thrombus associated with ICD lead externalized conductors: a case report.

INTRODUCTION: Narrow calibre ICD leads are prone to present insulation defects and conductor externalization. Close follow-up of these leads is recommended but as long as their electrical function is maintained, no prophyllactic replacement or extraction is advised. Although the risk of thrombus formation involving externalized conductors has been described, this risk seems considered as negligible compared with the risk of a prophylactic lead extraction. However, when an intracavitar thrombus is identified, the safest therapeutic approach remains undetermined. CASE
PRESENTATION: In the present clinical vignette, we describe the case of a giant thrombus developed along the externalized portion of an electrically functional ICD lead. In this case, the thrombus was successfully treated with a systemic oral anticoagulation. DISCUSSION: This case report supports the concept of a prolonged anticoagulation for both the diagnosis and the long-term treatment of thrombus developed along externalized ICD leads, in particular when the patient prefers to avoid or postpone the risk of a trans-venous lead extraction.

ICD conductor extrusion can be associated with an increased risk of intracavitary thrombus formation.

In such situation, systemic oral anticoagulation can be helpful for both the diagnostic and treatment of the patient.

Individual patient profile and wishes should guide the long-term therapy.

Introduction

Narrow calibre ICD leads have been recalled due to increased risk of insulation failure and cable extrusions. Regular fluoroscopic screening of these leads is recommended. But, as long as they remain electrically functional, no prophylactic replacement or extraction is advised. However, when an intracavitar thrombus involving externalized conductors is identified, the safest therapeutic approach remains undetermined.

Case presentation

A 45-year-old Caucasian man suffering from arythmogenic right ventricular dysplasia, and implanted 8 years earlier with a Saint Jude Medical Riata lead, presented to our emergency department after he received an appropriate therapy for a prolonged episode of slow VT. During his last follow-up (3 months before), an externalization of the conductors at the distal part of the ICD lead was diagnosed, but, the ICD lead remaining electrically functional, the patient was reassured. During his stay at the emergency, the physical exam was normal but a transthoracic echocardiography was performed and identified an endocavitary mass appended to the ICD lead. A 3-dimensional transoesophageal echocardiography confirmed the presence of a large irregular right atrial mass (3 × 2 cm) attached to the ICD lead in the right atrium (Figure and Supplementary material online, ), precisely where the fluoroscopic investigation identified the conductor externalization (Figure , arrows). The CRP being normal, the primary hypothesis was an endocavitary thrombus and the patient was therefore anticoagulated. After 2 months of treatment with acenocoumarol (Target INR = 3), the atrial mass had completely disappeared, confirming thus the suspected diagnosis. At this stage, the patient was proposed for a transvenous lead extraction with reimplantation of a new high voltage lead. However, he declined and opted for a prolonged anticoagulation. At his last follow-up, 9 months after discharge, an echocardiography was performed, confirming the absence of thrombus recurrence.

A 3-dimensional transoesophageal echocardiography showing a large thrombus attached along the ICD lead in the right atrium, precisely where fluoroscopic investigation identified the conductor externalization (see Figure ).

Antero-posterior fluoroscopic examination of the riata lead demonstrating a clear conductor externalization (arrows) in the right atrium.

Discussion

Although narrow calibre ICD leads with insulation defects and conductor externalization are presumed to increase the thrombogenic risk, very few reports were published to document this specific problem., In our opinion, this risk should be taken into account in the clinical decision making process to explant or abandon ICD leads with insulation failure. In this case, the ICD lead remaining electrically functional, our patient opted for a long-term anticoagulation. Although it might be suggested that a lead extraction would have been a more definite solution with only a limited risk if performed in experienced centres, the risk of thrombus still exists, even with non-advisory leads. Therefore, we believe that individual patient profile and wishes should guide the therapy.

Supplementary material

Supplementary material is available at European Heart Journal - Case Reports online.

Consent: The author/s confirm that written consent for submission and publication of this case report including image(s) and associated text has been obtained from the patient in line with COPE guidance.

Conflict of interest: none declared.

Click here for additional data file.

	Events
2008	Reanimated of sudden cardiac arrest— diagnostic: VT/VF
	Primary cardiac disease: Arrhythmogenic right ventricular dysplasia
	Implantation of SJM Riata lead
2015	Several appropriate ICD therapy
	Generator change due to battery depletion
November 2016	Conductor externalization identified during routine ICD follow-up
January 2017	Appropriate ICD therapy for VT
	TEE/TEO identify a large intracavitary mass where the conductors are externalized
	Oral AC is started
May 2017	TEE check: atrial thrombus has disappeared
September 2017	Recurrence of VT appropriately treated
	Patient under OAC
	No thrombus recurrence