Sudden Death Due to Infiltration of Left Bundle Branches by Interventricular Septal Cardiac Fibroma

Abstract

Cardiac fibromas are benign conditions; however, their location and size may cause ventricular arrhythmias and sudden cardiac death. We report a case of a 68-year-old female who died suddenly. Postmortem investigation detected a huge cardiac fibroma in the pars muscularis of the interventricular septum, occupying almost the entire muscular septum, and restricting the volume of left ventricular chamber. Histological examination revealed numerous foci of calcification in the alternating complex interlacing or strictly parallel collagenous fiber mass. Tumor mass was mainly demarcated, but in some places, fibrous infiltration of surrounding working cardiac muscle was found. We present a case when direct tumor involvement in the descending left bundle branches was evidenced. Mainly, the branches of septal fascicle were disrupted, entrapped, and degenerated by the tumor mass. This case report emphasizes that postmortem histological examination of conduction system in all sudden cardiac death cases may substantially improve the accuracy of postmortem diagnosis.

Ventricular fibrillation and arrhythmia associated with cardiac fibromas involving both ventricles in a 1.5-year-old girl

“…Microscopically, the amount of collagen increases with age, whereas the degree of cellularity decreases with age [ 1 , 8 ]. Fibromas occurring in the interventricular septum can lead to compression of the atrioventricular node, cartilaginous metaplasia of the central fibrous body [ 5 ], and infiltration of the His bundle [ 8 , 15 ]. In this case report, a large fibroma of the right ventricle caused mechanical overload and increased stress on the central fibrous body presenting as focal osseous metaplasia.…”

Lesions of the Cardiac Conduction System and Sudden Death

“…The resulting bradyarrhythmia from these tumors can cause ventricular refractoriness leading to ventricular fibrillation 34 . Fibromas may be associated with Gorlin syndrome (nevoid basal cell carcinoma) 36 …”

“…The most common benign cardiac neoplasms (besides CTAVN) associated with AV block are fibroma [32][33][34][35][36][37] and are listed in Table 2. Fibroma is the most common.…”

“…34 Fibromas may be associated with Gorlin syndrome (nevoid basal cell carcinoma). 36 Most Common Metastatic Tumors Causing AV Block The preponderant malignant tumors are melanoma [39][40][41][42] and lung. [39][40][41][43][44][45][46][47] Other more frequent metastatic neoplasm causing heart block include lymphoma, 41,43,48 breast, 40,41 esophagus, 43 stomach, 41 kidney, 40 and leukemia.…”