A rare cause of sudden cardiac arrest: primary cardiac lymphoma
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KeywordsVentricular Fibrillation Implantable Cardioverter Defibrillator International Prognostic Index Cardiac Tumor Sudden Cardiac Arrest
Sudden cardiac arrest is a leading cause of death in developed nations and about 40% of victims present with ventricular fibrillation at the time of first heart rhythm analysis . Acute myocardial ischemia is generally considered to be the most common factor triggering fatal arrhythmias . We report a rare case of sudden cardiac arrest due to ventricular fibrillation in a patient in whom diagnostic follow-up led to the diagnosis of a primary cardiac lymphoma (PCL).
Primary cardiac tumors are extremely rare and only a quarter of all cardiac tumors are malignant; 95% of these are sarcomas, 5% are lymphomas . PCLs are defined as non-Hodgkin’s lymphomas of different histology only involving the heart or the pericardium and usually arise in the right chambers of the heart . The majority of patients presents with symptoms of right heart failure . Arrhythmias are mostly described as atrial flatter or fibrillation, but lymphoma infiltration can also cause conduction disturbances. However, ventricular fibrillation is rarely described in the literature. Only one case of sudden death leading to the post mortem diagnosis of PCL and one case of ventricular tachycardia are documented in a review of 35 patients between 1960 and 2000 . In our patient, the PCL was localized in the right ventricle. Infiltration of the myocardium and/or conduction system most likely induced ventricular fibrillation. Echocardiography represents a very sensitive non-invasive technique for the identification of intracardial tumors, in particular as a first diagnostic approach [8, 9]. Up to 60% of PCLs are found by transthoracic echocardiography and 97–100% by the transesophageal approach . Most PCLs are of B cell lineage and about two-third is diagnosed as DLBCLs [2, 6]. A large study-based evaluation for the optimal therapeutic option is lacking due to the rarity and heterogeneous histology of PCLs. Ceresoli suggested that PCLs should be treated like bulky aggressive lymphomas arising in other primary sites . In a review of 40 cases from 1995 to 2002, chemotherapy alone was applied in 57.5% and in combination with radiation in 12.5% of patients . Antracycline-based chemotherapy resulted in 61% of complete remission (mean follow-up 17 months), whereas surgery did not seem to improve survival at all . Despite the treatment, approximately 60% of patients died within 2–4 months after diagnosis [2, 6]. Of note, to date the standard treatment of any DLBCL is an anti-CD20/antracycline-based chemotherapy. Generally, survived cardiac arrest due to ventricular fibrillation is a class I indication with evidence level A for an implantable cardioverter defibrillator (ICD) . However, PCLs per se are associated with a high-mortality rate within the first months after diagnosis. On the other hand, complete remission should abolish the arrhythmogenic substrate. In case of lymphoma recurrence, prognosis would be very limited. Therefore, we decided against the implantation of an ICD, even if another episode of ventricular fibrillation may occur.
In conclusion, PCL can be the cause of sudden cardiac arrest due to ventricular fibrillation. In our patient, an anti-CD20/antracycline-based chemotherapy led to complete remission (unconfirmed, CRu), and no relapse 14 months after the initial diagnosis. This case supports that PCL should be treated like bulky aggressive lymphomas arising in other primary sites.