LONG–TERM EFFECT OF RADIOTHERAPY: A CASE OF PREMATURE ONSET OF INFRA–HISIAN CONDUCTION DISEASE

Abstract

Abstract New chemotherapy agents and radiotherapy have improved mortality and survival of patients with neoplastic diseases; however, such therapies can cause significant side effects. One of the main concerns about mediastinal radiotherapy is the occurrence of cardiovascular side effects a long time after the treatment. This is an important issue – especially for thoracic neoplasms with long term survival, such as Hodgkin‘s lymphoma– because of the increase in cardiovascular morbidity and mortality. We report the case of a 40 years old male with infra–Hisian atrioventricular block developed progressively about twenty years after receiving radiotherapy for Hodgkin lymphoma. The patient experienced episodes during effort of abrupt and sudden reduction of the cardiac frequency and a syncope due to effort with finding of remarkable bradycardia. He was subsequently admitted for asthenia, dyspnea due to mild–moderate effort and bradycardia found at the self monitoring. The electrocardiogram showed atrioventricular block 2:1 with right branch block and left anterior fascicular block. Heart rate monitoring after the admission showed almost persistent 2:1 AV block. We performed a transthoracic echocardiography showing valvular thickening attributed to former radiotherapy in the absence of any clinical history of interest. A RMC was performed and it excluded the presence of edema or pathologic late gadolinium enhancement. We performed an electrophysiologic study that showed impairment of the infra–Hisian conduction system. With continuous atrial stimulation with RR cycle 620 me we documented infrahisian Wenckebach point. Therefore, a dual chamber pacemaker was implanted. This case rase the need for new studies evaluating the incidente of radiation induced heart disease. Clinicians must pay attention to bradyarrhythmia–related symptoms in patients whit previous exposure to chest radiation because of possibile premature onset of conduction disturbances.