Complete heart block ensuing from a metastatic small cell carcinoma: a case report

Abstract

Introduction Notwithstanding the diagnostic and therapeutic advancements, the incidence of cardiac metastases has increased in recent decades. Lung cancers are the most common primary malignant neoplasms with cardiac metastasis potential. The clinical presentation of cardiac metastases is either silent or vague, and largely depends on the infiltrated location and tumor burden. Although arrhythmias are not uncommon in metastatic cardiac tumors, complete heart block is relatively a rare manifestation. We present a case of complete heart block due to a metastatic small cell carcinoma in a 67-year-old male of African origin. Case presentation A 67-year-old male of African origin from rural Tanzania was referred to us for expert management. He is a retired agromechanic with over 30 years exposure to asbestos-containing brake linings. His past medical history was unremarkable, but the family-social history was evident for a heavy alcohol intake and chronic cigarette smoking. He presented with a 24-week history of progressive shortness of breath and an 8-week history of recurrent syncopal attacks coupled with a significant weight loss. He had normal echocardiographic findings, however, the electrocardiogram showed features of complete heart block. Chest X-ray showed a homogeneous opacification on the right side and computed tomography scan revealed a solid right lung mass with metastases to the liver, heart, bowels, and bone. He underwent bronchoscopy, which revealed an endobronchial mass obstructing the bronchus intermedius. Histological examination of a section of lung biopsy taken during bronchoscopy confirmed the diagnosis of a small cell carcinoma. The patient underwent dual chamber pacemaker implantation with successful sinus rhythm restoration. He made an informed refusal of chemotherapy and inevitably died 18 months post pacing. Conclusions Despite the advancements in medical diagnostics and management, lung cancers are often diagnosed in advanced stages, with an inevitable grave prognosis. Small cell carcinoma has the potential to metastasize to the heart, resulting in complete heart block.

An extensive surgical resection in stage T4 small cell lung cancer with cardiac invasion: A case report and literature review

“…After an extensive search, we discovered that none of the 7 precedents reported cases involving cardiac invasion of SCLC had surgical resection of the lung cancer ( Table 1 ) [ [8] , [9] , [10] , [11] , [12] , [13] , [14] ]. Most patients were not eligible for surgery because of poor health or the presence of multiple extrapulmonary metastases.…”

Cardiac metastasis from small cell lung cancer origin: A case report and review of the literature

“…Although echocardiography is excellent in the diagnosis of MCT, small field of view and insufficient acoustic window limit its application. Sometimes echocardiographic findings is normal in patients with cardiac metastases 14 . While CMR is the gold standard for the definition of the nature of intracardiac masses and their relationship to paracardiac structures 15 .…”

“…CMR allows optimal tumor characterization with superior depiction of soft tissues and provides accurate evaluation of cardiac structure and function to complement echocardiography and provide early detection and management 16,17 . The benefits of CMR over echocardiography in studying cardiac tumors has been recognized 14 . Previous study suggested that cardiac metastases can be mistaken for thrombi, endocarditis, or primary tumors in echocardiograms, supplemental imaging with CMR is often needed for further characterization 18,19 .…”

“…Sometimes echocardiographic findings is normal in patients with cardiac metastases. 14 While CMR is the gold standard for the definition of the nature of intracardiac masses and their relationship to paracardiac structures. 15 CMR allows optimal tumor characterization with superior depiction of soft tissues and provides accurate evaluation of cardiac structure and function to complement echocardiography and provide early detection and management.…”

“… 16 , 17 The benefits of CMR over echocardiography in studying cardiac tumors has been recognized. 14 Previous study suggested that cardiac metastases can be mistaken for thrombi, endocarditis, or primary tumors in echocardiograms, supplemental imaging with CMR is often needed for further characterization. 18 , 19 Though several studies have confirmed the value of 18F‐FDG PET/CT, 20 , 21 it has not yet achieved the status of a routine examination method to evaluate cardiac metastasis, perhaps due to high FDG uptake by the myocardium.…”