A 57‐year‐old white man with no significant medical history was brought to the emergency department with complaints of not feeling well for 2 weeks. He also mentioned generalized weakness, vague abdominal discomfort, coffee‐ground vomiting, heart burn, and 2 episodes of syncope. Initial workup revealed pancytopenia, transaminitis, acute kidney injury, and positive stool guaiac test. Initial EKG showed complete heart block with ventricular rate of 41 and nonspecific intraventricular conduction block. The electrolytes and cardiac markers were with in normal limits. A temporary transvenous pacemaker was placed. A transthoracic echocardiogram was completely unremarkable except for moderate left ventricular hypertrophy. There was no wall motion abnormality, and left ventricular ejection fraction was 60%. Serum antibody test for viruses (coxsackie B group, ECHO, cytomegalovirus, adenovirus, influenza, parainfluenza, hepatitis B, and so on), toxoplasma, and mycoplasma were all negative. The patient had 100% paced rhythm, so it was decided to place a permanent pacemaker after 5 days. Patient underwent bidirectional endoscopy for workup of severe anemia, which was unremarkable except for Candida esophagitis. Initial peripheral blood smear was remarkable for presence of significant left shift and occasional blast cells. The bone marrow biopsy pathology was consistent with acute myeloid leukemia (AML) with maturation. Patient's karyotypes were reported; he had monosomy 7, a poor prognostic factor in AML patients. He underwent successful remission‐induction with a daunorubicin, cladribine, and cytararabine (ARA‐C)–based chemotherapy regimen.
The incidence of heart block in acute leukemia patients is unknown. Kiyohiko Hatake et al. reported 1 case of high‐degree AV block with subsequent demonstration of leukemic infiltration into the bundle of His. Lawrence C. Maguire et al. reported a case of 2:1 heart block in a patient with AML treated successfully with a single dose of localized radiation therapy to the heart.
Cardiac involvement in acute leukemia is common. Infiltrative cardiomyopathy, caused by tumors or autoimmune diseases, may result in complete heart block. There are no guidelines available for management of complete heart block in acute leukemia, as it is unclear in most cases whether heart block is secondary to leukemia. More studies are needed as local treatment with radiotherapy may be curative. Our patient was treated with permanent pacemaker placement.
To cite this abstract:Kumar S, Shahani S, Kocheril A. An Unusual Case of Complete Heart Block. Abstract published at Hospital Medicine 2013, May 16-19, National Harbor, Md. Abstract 240. Journal of Hospital Medicine. 2013; 8 (suppl 2). https://www.shmabstracts.com/abstract/an-unusual-case-of-complete-heart-block/. Accessed March 29, 2020.