Detecting and managing device leads inadvertently placed in the left ventricle
ABSTRACT
Inadvertent malpositioning of a cardiac implantable electronic device lead into the left ventricle is a rare complication of transvenous pacing and defibrillation. Rapid identification of lead position is critical during implantation and just after the procedure, with immediate correction required if malpositioning is detected. If lead misplacement is discovered late after implantation, the lead should be surgically removed or chronic anticoagulation with warfarin should be instituted.
KEY POINTS
- During device implantation, fluoroscopy in progressively lateral left anterior oblique views should be used to ensure correct lead position.
- After implantation, malposition can almost always be detected promptly by examining a 12-lead electrocardiogram for the paced QRS morphology and by lateral chest radiography.
- Echocardiography and computed tomography may enhance diagnostic accuracy and clarify equivocal findings.
- Late surgical correction of a malpositioned lead is best done when a patient is undergoing cardiac surgery for other reasons.
- Long-term warfarin therapy is recommended to prevent thromboembolism if malpositioning cannot be corrected.
MANAGING MALPOSITIONED LEADS
Inadvertent left ventricular lead placement provides a nidus for thrombus formation. When inadvertent left ventricular lead malposition is identified acutely, correction of the lead position should be performed immediately by an experienced electrophysiologist.
Treatment of left ventricular lead misplacement discovered late after implantation includes lead removal or chronic anticoagulation with warfarin to prevent thromboemboli.
Long-term anticoagulation
No thromboembolic events have been reported2 in patients with lead malposition who take warfarin and maintain an international normalized ratio of 2.5 to 3.5.
Antiplatelet agents are not enough by themselves.16
The use of direct oral anticoagulants has not been explored in this setting. Use of dabigatran in patients with mechanical heart valves was associated with increased rates of thromboembolic and bleeding complications compared with warfarin.29 Based on these results and an overall lack of evidence, we do not recommend substituting a direct oral anticoagulant for warfarin in the setting of malpositioned left ventricular leads.
Late percutaneous removal
Late lead removal is most appropriate if cardiac surgery is planned for other reasons. Although percutaneous extraction of a malpositioned left ventricular lead was first described over 25 years ago,13 the safety of this procedure remains uncertain.
Kosmidou et al17 reported two cases of percutaneous removal of inadvertent transarterial leads employing standard interventional cardiology methods for cerebral embolic protection. Distal embolic filter wires were deployed in the left and right internal carotid arteries. A covered stent was deployed at the arterial entry site simultaneously with lead removal, providing immediate and effective hemostasis. Similar protection should be considered during transvenous access and extraction via an atrial septal or patent foramen ovale.
Nevertheless, not even transesophageal echocardiography can reliably exclude adhered thrombi, and the risk of embolization of fibrous adhesions or thrombi has been cited as a pivotal contraindication to percutaneous lead extraction regardless of modality.16
