Conduction system findings in sudden death in young adults with a history of bronchial asthma

Abstract

Objectives. This study was conducted to determine whether there are any pathologic changes in the conduction system when death occurs suddenly in young adults with a history of bronchial asthma. Background. There is a worldwide increase in sudden death, especially in young adults with a history of bronchial asthma. Methods. We studied the conduction system by serial section examination in six male patients (16 to 23 years old) with a history of bronchial asthma who died suddenly. Results. The sinoatrial node artery was narrowed in two patients, with chronic inflammatory cells in three; it was fibrosed in one. The atrioventricular (AV) node was within the central fibrous body in three patients and isolated by fat in one. The AV bundle was markedly fragmented in five patients and fibrosed in two. The right and left bundle branches showed fat, fibrosis and disruption in five patients. Increased fibrosis on the summit of the ventricular septum with patchy fibrosis was present in five patients, and inflammatory cells in the conduction system were found in one. Conclusions. 1) There are distinct pathologic findings in the conduction system of young adults with a history of bronchial asthma who die suddenly. 2) The significant findings appear to be a markedly fragmented bundle and changes in the sinoatrial node that are not found in normal healthy young adults. 3) The changes in the conduction system may create an arrhythmic event, and sudden death may occur in some persons during an altered physiologic state. 4) We hypothesize that bronchial asthma may be associated with an alteration in immune complexes that affects the conduction system in some patients.