ObjectiveTo investigate the indications and clinical effects of tricuspid cone reconstruction and tricuspid valve replacement in the treatment of downward displacement of tricuspid valve (Ebstein anomaly).MethodsThe clinical data of 22 patients with Ebstein anomaly who underwent surgical treatment in our hospital from January 2013 to March 2020 were collected. There were 7 males and 15 females, aged 4-56 (33.68±17.78) years. The patients were divided into two groups according to different surgical methods: a tricuspid cone reconstruction group (tricuspid valvuloplasty group, n=12) and a tricuspid valve replacement group (n=10). The curative effect of the two operative methods were compared.ResultsTwenty-two patients underwent surgical treatment under general anesthesia and cardiopulmonary bypass. One patient died of severe low cardiac output syndrome during operation. Downward displacement of tricuspid septum was found in 22 patients, and downward displacement of tricuspid septum and posterior septum in 21 patients, downward displacement of tricuspid in 8 patients. Twelve patients were treated with tricuspid valvuloplasty, 10 patients with tricuspid valve replacement, and patients with other intracardiac structural malformations were treated at the same time. Postoperative cardiac doppler ultrasound indicated no tricuspid regurgitation in 9 patients, mild regurgitation in 8 patients, and moderate regurgitation in 4 patients. No perivalvular leakage occurred in all patients undergoing valve replacement. Four patients developed degree Ⅲ atrioventricular block after operation, among whom 3 patients recovered to sinus rhythm and 1 patient implanted the permanent pacemaker. Twenty-one patients were cured and discharged after successful operation, and were followed up for 3 to 78 months, with a follow-up rate of 100.0%. During the follow-up period, there was no severe tricuspid regurgitation in tricuspid valvuloplasty group, but mild or moderate regurgitation was found. After tricuspid valve replacement, only 1 patient had mild regurgitation, and the rest patients had no valve regurgitation.ConclusionTricuspid valvuloplasty and tricuspid valve replacement are effective in the treatment of Ebstein anomaly, and the tricuspid regurgitation is less severe after tricuspid valve replacement operation. The operation method should be selected according to the different anatomical characteristics and condition of tricuspid valve. The combined intracardiac malformation or arrhythmia can be dealt with simultaneously.
Objective To observe the change of sino-atrial nodal tissue structure and ectopic pacing function after xenogenic sino-atrial nodal tissue transplanted into left ventricular wall, so as to provide new ideas for the treatment of sick sinus syndrome and severe atrioventricular block. Methods Seventy healthy rabbits were selected, male or female, and weighing 1.5-2.0 kg. Of them, 42 were used as reci pient animals and randomly divided into sham operation group, warm ischemia transplantation group, and cold ischemia transplantation group (n=14), the other 28 were used as donors of warm ischemia and cold ischemia transplantation groups, which were sibl ing of the recipients. In recipients, a 6-mm-long and about 2-mm-deep incision was made in the vascular sparse area of left ventricular free wall near the apex. In sham operation group, the incision was sutrued directly by 7-0 Prolene suture; in cold ischemia transplantation group, after the aortic roots cross-clamping, 4 ℃ cold crystalloid perfusion fluid infusion to cardiac arrest, then sinoatrial node were cut 5 mm × 3 mm for transplantation; in warm ischemia transplantation group, the same size of the sinus node tissue was captured for transplantation. After 1, 2, 3, and 4 weeks, 3 rabbits of each group were harvested to make bradycardia by stimulating bilateral vagus nerve and the cardiac electrical activity was observed; the transplanted sinus node histology and ultrastructural changes were observed. Results Thirty-six recipient rabbits survived (12 rabbits each group). At 1, 2, 3, and 4 weeks after bilateral vagus nerve stimulation, the cardiac electrical activity in each group was significantly slower, and showed sinus bradycardia. Four weeks after operation the heart rates of sham operation group, warm ischemia, and cold ischemia transplantation group were (81.17 ± 5.67), (82.42 ± 7.97), and (80.83 ± 6.95) beats/ minute, respectively; showing no significant difference among groups (P gt; 0.05). And no ectopic rhythm of ventricular pacing occurred. Sino-atrial nodal tissue survived in 6 of warm ischemic transplantation group and in 8 of cold ischemia transplantation group; showing no significant difference between two groups (P gt; 0.05). Two adjacent sinoatrial node cells, vacuole-l ike structure in the cytoplasm, a few scattered muscle microfilaments, and gap junctions between adjacent cells were found in transplanted sinus node. Conclusion The allograft sinus node can survive, but can not play a role in ectopic pacing.
Objective To study the influence of ischemia-reperfusion on the expression of the hyperpolarization activated cycl icnucleotide gated cation channel 4 (HCN4) and to discuss the mechanism of functional disturbance of sinoatrial node tissue (SANT) after ischemia reperfusion injury (IRI). Methods Eighty five healthy adult rabbits, weighing 2-3 kg, were randomly divided into 3 groups: control group [a suture passed under the root section of right coronary artery (RCA) without l igation, n=5], experimental group A (occluding the root section of RCA for 30 minutes, then loosening the root 2,4, 8 and 16 hours, n=10), experimental group B (occluding the root section of RCA for 1 hour, then loosening the root 2, 4,8 and 16 hours, n=10). At the end of the reperfusion, the SANT was cut off to do histopathological, transmission electronmicroscopical and immunohistochemical examinations and semi-quantitative analysis. Results The result of HE stainingshowed that patho-injure of sinoatrial node cell (SANC) happened in experimental groups A and B after 2 hours of reperfusion, the longer the reperfusion time was, the more serious patho-injure of SANC was after 4 and 8 hours of reperfusion, SANC reached peak of damage after 8 to 16 hours of reperfusion; patho-injure of SANC was more serious in experimental group B than in experimental group A at the same reperfusion time. Immunohistochemical staining showed that the expression of HCN4 located in cellular membrane and cytoplasm in the central area of SANC and gradually decreased from the center to borderl ine. The integral absorbance values of HCN4 expression in the control group (397.40 ± 34.11) was significantly higher than those in the experimental group A (306.20 ± 35.77, 216.60 ± 18.59, 155.40 ± 19.11 and 135.00 ± 12.30) and in the experimental group B (253.70 ± 35.66, 138.70 ± 13.28, 79.10 ± 9.60 and 69.20 ± 8.42) after 2, 4, 8 and 16 hours of reperfusion (P lt; 0.05). With reperfusion time, the expression of HCN4 of SANC decreased, which was lowest after 8 hours of reperfusion; showing significant difference among 2, 4 and 8 hours after reperfusion (P lt; 0.05) and no significant difference between 8 and 16 hours after reperfusion (P gt; 0.05). At the same reperfusion time, the expression of HCN4 was higher in the experimental group A than in the experimental group B. The result of transmission electron microscope showed that ultramicrostructure of SANC was damaged after reperfusion in experimental groups A and B. The longer the reperfusion time was, the more serious ultramicrostructure damage of SANC was, and reached the peak of damage after 8 hours of reperfusion. Ultramicrostructure of SANC was not different between 8 and 16 hours of reperfusion. At the same reperfusion time, the ultramicrostructure damage of SANC was moreserious in experimental group B than in experimental group A. Conclusion IRI is harmful to the morphous and structure ofSANC, and effects the expression of HCN4 of SANC, which is concerned with functional disturbance and arrhythmia.