Risk factors and prognosis for clot formation on cardiac device leads

Pulmonary Thromboembolism and Myocarditis Resulting from a Large Pacing-Lead-Associated Right Ventricular Thrombus in a Dog with Chronic Cough as Presenting Sign

In the present case report, we describe the clinical course and postmortem findings of a 12-year-old Labrador retriever dog with a third-degree atrio-ventricular block that developed a chronic cough, and later dyspnea and weakness as a result of massive pulmonary thromboembolism 3 years after implantation of a transvenous permanent pacemaker. A large soft tissue mass was seen in the right ventricular chamber around the pacing lead with echocardiography. Initially, this was thought to be caused by mural bacterial endocarditis based on hyperthermia, severe leukocytosis and the appearance of runs of ventricular tachycardia, the latter suggesting myocardial damage. While blood culture results were pending, antibiotics were administered without a positive effect. Due to clinical deterioration, the owner elected for euthanasia and a post-mortem examination confirmed a right ventricular thrombus and surrounding myocarditis, without signs of bacterial infection, and a massive pulmonary thromboembolism. We conclude that pulmonary thromboembolism should be considered in dogs with a cough that have an endocardial pacing lead implanted. Serial screening for proteinuria before and after implantation of an endocardial pacing lead would allow timely initiation of prophylactic antiplatelet therapy. Local myocarditis can develop secondary to an intracavitary thrombus, which can subsequently lead to runs of ventricular tachycardia.

Intracardiac thrombi fluttering like hair in the wind at VT ablation

INTRODUCTION

Intracardiac echocardiography (ICE) reveals mobile thrombus on implantable electronic device leads in some patients undergoing electrophysiologic procedures.

METHODS

ICE was performed in a patient undergoing ventricular tachycardia (VT) ablation.

RESULTS

ICE showed extensive mobile thrombi on the implantable cardioverter defibrillator lead. Radiofrequency catheter ablation of VT from perimitral scar was safely performed via a retrograde aortic approach. After the procedure, chronic anticoagulation was initiated. CT-angiography of the chest 2 months later showed no pulmonary emboli.

CONCLUSIONS

The significance of these thrombi, as related to chronic pulmonary embolization, warrants further study.

Real-Time Embolization of a Massive Lead-Associated Thrombus Visualized by Transesophageal Echocardiography

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Lead-associated thrombus is often seen in transvenous CIEDs.

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Clinically apparent pulmonary embolism is uncommon.

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Lead-associated thrombus can be massive and associated with morbidity and mortality.

Clot in Lung, Clot in Heart: A Case Report of Tumor-Like Thrombus in Right Atrium

Tumor-like formation of thrombus in the right atrial cavity is rare. It may be mistaken for a myxoma. The exact pathophysiology of an isolated thrombus in the heart is still unclear. Management to prevent complications such as pulmonary thromboembolism depends on the clinical judgment of a cardiologist. This report describes a 76-year-old woman with right atrial thrombus causing subsequent pulmonary thromboembolism in right lung. She initially presented to us with pulmonary embolism, and later, an incidental finding of a mass in her right atrium revealed an association of thrombus in heart with thrombus in lung. The challenging management was to resect this thrombus which was fixed to atrial septum, and a trial of anticoagulation did not resolve it. Exact management of such incidental findings in right heart cavities is not well established. Some cases may benefit from resection of such formed fixed thrombus.

Cardiac implantable electronic device lead-based masses and atrial fibrillation ablation: a case-based illustration of periprocedural anticoagulation management strategies

INTRODUCTION

Cardiac implantable electronic device (CIED) leads frequently develop echogenic masses. However, the nature of these masses is not well understood. In patients in whom atrial fibrillation (AF) catheter ablation is planned, there is concern that transseptal puncture may result in cerebrovascular embolism of these masses. The optimal therapeutic strategy in this setting remains undefined.

METHODS

We describe six patients identified over a 6-year period (2008-2014) with device lead-based masses prior to or at the time of AF ablation. We examined the anticoagulation strategy and periprocedural management based on mass identification.

RESULTS

In all six patients (age 39-73; four males), the device lead mass was found in the right atrium. The average mass size was 11 ± 1.3 mm. The majority of patients were already on anticoagulation (5/6; 83 %), and an intensified anticoagulation regimen was initiated (INR goal 3.0). In all six patients, the size of the device lead mass decreased on repeat imaging. In two sixths (33 %) patients, the lead-based mass completely resolved within 2 months. The remaining four patients had persistent lead-based masses (average follow-up of 10.9 ± 9.6 months).

DISCUSSION

We describe a series of patients with CIED lead-based masses found at the time of ablation. These cases illustrate that lead-based masses can disappear while patients are on high-intensity anticoagulation, most compatible with a thrombotic origin. These early data will need to be assessed in larger cohorts for further validation and evaluation of safety.

Mobile thrombus on cardiac implantable electronic device leads of patients undergoing cardiac ablation: incidence, management, and outcomes

PURPOSE

The rates of cardiovascular implantable electronic device (CIED) implantations and cardiac ablation procedures are increasing worldwide. To date, the management of CIED lead thrombi in the peri-ablation period remains undefined and key clinical management questions remained unanswered. We sought to describe the clinical course and management strategies of patients with a CIED lead thrombus detected in the peri-ablative setting.

METHODS

We performed a retrospective analysis of all patients who underwent a cardiac ablation procedure at Mayo Clinic Rochester from 2000 to 2014. Patients were included in our study cohort if they had documented CIED lead thrombus noted on peri-ablation imaging studies. Electronic medical records were reviewed to determine the overall management strategy, outcomes, and embolic complications in these patients.

RESULTS

Our overall cohort included 1833 patients, with 27 (1.4 %) having both cardiac ablation procedures as well as CIED lead thrombus detected on imaging. Of these 27 patients, 21 were male (77 %), and the mean age was 59.2 years. The mean duration of follow-up was 16.5 months (range 3 days-48.3 months). Anticoagulation was an effective therapeutic strategy, with 11/14 (78.6 %) patients experiencing either resolution of the thrombus or reduction in size on re-imaging. For atrial fibrillation ablation, the most common management strategy was a deferment in ablation with initiation/intensification of anticoagulation medication. For ventricular tachycardia ablations, most procedures involved a modified approach with the use of a retrograde aortic approach to access the left ventricle. No patient had any documented embolic complications.

CONCLUSIONS

The incidence of lead thrombi in patients undergoing an ablation was small in our study cohort (1.4 %). Anticoagulation and deferral of ablation represented successful management strategies for atrial fibrillation ablation. For patients undergoing ventricular tachycardia ablation, a modified approach using retrograde aortic access to the ventricle was successful. In patients who are not on warfarin anticoagulation at the time of thrombus detection, we recommend initiation of this medication, with a goal INR of 2-3. For patients on warfarin at the time of thrombus detection, we recommend an intensification of anticoagulation with a goal INR of 3.0.

Pacemaker lead-associated thrombosis in cardiac resynchronisation therapy

Pacemaker lead-associated thrombosis is a possible complication of any cardiac implantable electronic device. We present a case of a middle-aged woman with a history of ischaemic left ventricular failure, who presented with fever and other non-specific symptoms 4 months after cardiac resynchronisation therapy. A transoesophageal echocardiogram confirmed a vegetation-like structure originating from the pacemaker lead in the right atrium. The patient was treated with intravenous antibiotics followed by open heart surgery in order to remove this mass as well as the pacing device, including all three pacing leads. Histology and culture of the retrieved mass confirmed a sterile thrombus with no features to suggest an infected mass (vegetation). The patient made an uncomplicated recovery and there were no long-term sequelae on follow-up during the 2 years after the event.