Histopathological and Quantitative Lesions of the Cardiac Conduction System and Its Vascularization Related to Chronic Cocaine Abusers and Sudden Unexpected Death

Abstract

Cocaine abuse is associated with multiple cardiovascular events, including myocardial infarction, arrhythmias, and sudden death. A total of 40 hearts were studied. The purpose of this study was to compare the cardiac conduction tissue and its vascularization in 20 young adults without a history of drug use and/or arrhythmias and 20 hearts of young adults with a history of chronic cocaine use who have died of sudden unexpected death, in which toxicological analyzes were performed in blood and urine as a means to establish chronic cocaine use. We have applied serial histological sections, techniques of morphometry, and image analysis to quantify the density and affectation of connective/adipose tissue of the conduction system and intramyocardial vessels. The conduction system after chronic cocaine use showed potentially lethal changes with an increase in connective/adipose tissue at the level of the intranodal or perinodal tissue of the sinus node in 35% (7 hearts) and the atrioventricular node in 75% (15 hearts), with the most affected structure being the left bundle branch and the AV nodal artery (100%, 20 hearts). In conclusion, the histopathologic changes in nodes, the perinodal area, and small vessels may be a morphological substrate that offers an explanation about the mechanism of arrhythmias and sudden death in this population.