Objective Through analyzing BKCa channel expression in atrial fibroblasts in patients with sinus rhythm and atrial fibrillation (AF), to explore the mechanism of myocardial fibrosis and provide new therapeutic strategies for the treatment and reversal of AF structure reconstruction. Methods We selected 10 patients of rheumatic heart valvular disease who underwent valve replacement surgery. They were 5 patients with sinus rhythm (a sinus rhythm group, 2 males and 3 females with an average age of 49.1±8.3 years) and 5 with AF (an AF group, 3 males and 2 females with an average age of 50.3±5.8 years). About 100 mg tissue was obtained from the right auricula dextra, and the atrial fibroblasts were cultured by tissue block adherence method, and the expression of BKCa channel genes and proteins in cultured fibroblasts was detected by quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting methods. Results (1) The general data of 10 patients between the AF group and the sinus rhythm group were compared. There was no significant difference between the two groups in age (t=1.21, P=0.67) and sex (t=2.56, P=0.75). There was statistical difference in the left atrial diameter and the right atrium diameter between the two groups (t=19.45, P=0.01; t=23.52, P=0.06); (2) the mRNA expression of BKCa subunit was detected by qRT-PCR method, and there was no significant difference in the mRNA expression of BKCa α and BKCa β1 between the two groups (t=3.14, P=0.79; t=2.88, P=0.69); (3) the expression of BKCa protein was detected by western blotting method, and there was no significant difference in the protein expression of BKCa α and BKCa β1 between the two groups (t=0.55, P=0.31; t=0.73, P=0.46). Conclusion BKCa pathway may not be involved in the pathogenesis and maintenance of AF, but it may play an important role in the process of myocardial fibrosis.
This article presented the clinical diagnosis and management of a patient with severe aortic regurgitation and moderate aortic stenosis who underwent transcatheter aortic valve replacement complicated with coronary obstruction and retroperitoneal hematoma. The hemodynamics collapsed during the procedure, and transcatheter aortic valve replacement was performed under support of extracorporeal membrane oxygenation and coronary protection. After a negative coronary angiography, the wire was extracted, but a repeated angiography showed left coronary obstruction, so a coronary stent was implanted to the ostium of left coronary artery through the grid of the valve stent. Abdominal CT showed a giant retroperitoneal hematoma 2 weeks after transcatheter aortic valve replacement, and the emergent angiography indicated contrast leakage from left external iliac artery, so a balloon compression was performed followed by a covered stent implantation. This article also provided the clinical characteristics, risk factors and management of coronary obstruction and vascular complication for clinical reference.