RESUMEN
Air pollution exposure is a risk factor for arrhythmia. The atrioventricular (AV) conduction axis is key for the passage of electrical signals to ventricles. We investigated whether environmental nanoparticles (NPs) reach the AV axis and whether they are associated with ultrastructural cell damage. Here, we demonstrate the detection of the shape, size, and composition of NPs by transmission electron microscopy (TEM) and energy-dispersive X-ray spectrometry (EDX) in 10 subjects from Metropolitan Mexico City (MMC) with a mean age of 25.3 ± 5.9 and a 71-year-old subject without cardiac pathology. We found that in every case, Fe, Ti, Al, Hg, Cu, Bi, and/or Si spherical or acicular NPs with a mean size of 36 ± 17 nm were present in the AV axis in situ, freely and as conglomerates, within the mitochondria, sarcomeres, lysosomes, lipofuscin, and/or intercalated disks and gap junctions of Purkinje and transitional cells, telocytes, macrophages, endothelium, and adjacent atrial and ventricular fibers. Erythrocytes were found to transfer NPs to the endothelium. Purkinje fibers with increased lysosomal activity and totally disordered myofilaments and fragmented Z-disks exhibited NP conglomerates in association with gap junctions and intercalated disks. AV conduction axis pathology caused by environmental NPs is a plausible and modifiable risk factor for understanding common arrhythmias and reentrant tachycardia. Anthropogenic, industrial, e-waste, and indoor NPs reach pacemaker regions, thereby increasing potential mechanisms that disrupt the electrical impulse pathways of the heart. The cardiotoxic, oxidative, and abnormal electric performance effects of NPs in pacemaker locations warrant extensive research. Cardiac arrhythmias associated with nanoparticle effects could be preventable.
Asunto(s)
Residuos Electrónicos , Mercurio , Nanopartículas , Taquicardia por Reentrada en el Nodo Atrioventricular , Anciano , Arritmias Cardíacas/inducido químicamente , Nodo Atrioventricular , Humanos , Residuos Industriales , México , TitanioRESUMEN
Primary cardiac tumors are uncommon clinical entities with an incidence of 0.0017% to 0.03% of all autopsies. Cystic tumor of the atrioventricular (AV) node, also known as mesothelioma of the AV node, is a benign congenital tumor that is located in the triangle of Koch in the AV nodal region of the atrial septum of the heart. It comprises of 2.7% of cardiac tumors and is the most common primary cardiac tumor causing sudden death. We herein review the etiology, presentation, differential diagnosis, diagnosis, management, surgical approaches and outcomes of this rare tumor.
RESUMEN
Patients who undergo radiofrequency ablation of the atrioventricular (AV) node rarely develop acute major complications. A 41-year-old Caucasian male smoker, was admitted to the Pulmology Teaching Hospital at Belgrade, Serbia, for sharp persistent chest pain, fever and fatigue following AV node radiofrequency ablation for arrhythmia. Chest X-ray showed obtuse right costo-phrenic angle and laminar atelectasis in the right lower lung lobe. The plasma D-dimer level was elevated. A perfusion lung scan showed multiple bilateral perfusion defects and multislice computed tomography showed thrombotic mass in the right pulmonary artery. Genetic analysis revealed that he was heterozygous for the prothrombin Factor V (FV) Leiden and MTHFR C677T mutations. Therapy started with intravenous heparin, followed by warfarin. He had no other episodes over a 2-year follow-up. Lifelong oral anticoagulant therapy was recommended.