Case study:
The case study involves a 73 year-old asymptomatic Caucasian male with a
previous history of aortic root and bioprosthetic aortic valve
replacement (AVR) for a 5.8cm ascending aortic aneurysm in 2018 recently
attended a routine follow-up transthoracic echocardiography (TTE) at
their local hospital. A transvenous dual chamber pacemaker was implanted
following the aortic root and AVR for postsurgical transient atrial
fibrillation with permanent atrioventricular heart block. The TTE showed
a well seated bioprosthetic aortic valve with normal peak and mean
gradients and good biventricular function. However, the TTE also clearly
demonstrated a ventricular pacing lead originating from the superior
aspect of the right atrium, crossing both the atrial septum and mitral
valve embedding into the lateral left ventricular (LV) wall
(figure one ).
The patient was transferred to a tertiary centre for a transoesophageal
echocardiogram (TOE) to assess the risk of lead derived intra-cardiac
thrombus and discussion at the multi-disciplinary team meeting for
potential lead extraction. A 12-lead electrocardiogram
(figure two ) and chest x-ray (figure
three ) was performed following admission to the tertiary centre showed
underlying atrial fibrillation with a VVI pacemaker induced right bundle
branch block morphology. During the TOE three-dimensional imaging was
obtained which demonstrated the right ventricular lead crossing the
atrial septum through a patent patent foremen ovale and crossing the
anterolateral aspect of the mitral valve between A1 and P1/2 scallops
with mild mitral regurgitation. A small sessile mass attached to the
lead in the left atrium measuring 11 x 5mm was visualised consistent
with thrombus (Figures four - seven ). Infective
endocarditis was initially considered as a differential diagnosis
especially in the context of an AVR but excluded as the patient did not
exhibit any major findings on the Duke criteria such as positive blood
cultures or signs of pyrexia. As the patient was high risk for systemic
emboli, anticoagulation with warfarin (5mg) and subcutaneous Tinzaparin
(16,000 units) was offered and advised that a repeat TOE was required
prior to lead removal in six months.