ABSTRACT
Objective: To analyze the electrophysiological characteristics and the therapeutic efficacy of irrigated-tip catheter radiofrequency ablation(RFA) without radiation for pregnant women with focal atrial tachycardia(AT) originating from the right atrial appendage (RAA). Methods: Data from 55 women with focal AT, who underwent radiofrequency ablation (RFA) in the First Affiliated Hospital of Zhengzhou University from October 2016 to March 2019, were screened. 2 non-pregnant women with right atrial appendage tachycardia (RAAT) and 4 pregnant women with non-RAAT were excluded. The remaining 49 cases were divided into RAAT during pregnancy group (n=6, including 4 cases of tachycardia-induced cardiomyopathy) and non-pregnant and non-RAAT group (control, n=43). Under the guidance of three-dimensional mapping system, the earliest activation site was identified, RFA with the irrigated catheter without x-ray fluoroscopy was performed in RAAT patients during pregnancy, all patients in control group underwent non-zero-ray ablation. Patients were followed up at 3, 6, 12 months post procedure, and yearly follow up thereafter in outpatient clinic. Electrocardiogram or Holter monitoring was performed during follow up. AT recurrence and surgical complications were recorded during follow up. At 6 months after RFA, echocardiography examination and laboratory examination including N-terminal B-type brain natriuretic peptide measurement were performed in the pregnant patients, delivery results were also recorded in the pregnant patients. The electrophysiological characteristics of RAAT during pregnancy were analyzed, the therapeutic efficacy of RFA was compared between the two groups. Results: This study is a retrospective study. Age ((30.7±6.2)years vs. (57.2±11.7)years), left ventricular ejection fraction ((46.0±12.8)% vs. (60.1±5.9)%), proportions of organic heart disease (0% vs. 58%) were significantly lower in the RAAT patients during pregnancy group than in control group (P<0.05), while proportions of patients with persistent tachycardia (100% vs. 7%), symptoms of chest distress and palpitation (6/6 vs. 49%) and left ventricular ejection farction≤50% (4/6 vs. 9%) were significantly higher in RAAT group than in control group (P<0.05), heart rate was similar between the two groups ((163.7±11.1)beats/minutes vs. (153.7±15.2)beats/minutes, P>0.05). The characteristic P-wave morphology was observed in RAAT patients during pregnancy, i.e, P wave was mostly upright (5/6) in inferior-leads (Ⅱ, Ⅲ, aVF) and in lead I and aVL, deep and wide negative P wave was found in V1 lead (5/6), and gradually became positive from V2-V6. The mean tachycardia cycle length was (361.7±38.5) ms. Three-dimensional mapping showed that the origin points of the 6 RAAT pregnant patients were all scattered in the local region, the local region was ablated accordingly, 2 patients (2/6) received extensive ablation of local areas. Immediate successful rate was similar between the two groups (6/6 vs. 93%). During follow up ((15.3±4.0) months), no complications were observed after RFA, postoperative recurrence rate was similar (1/6 vs. 12%). Uncomplicated delivery was reported in all 6 pregnant RAAT post ablation. Normal cardiac structure and function was observed in the 4 pregnant patients with tachycardia-induced cardiomyopathy post ablation. Compared to pre-ablation phase, reduced left atrial dimension ((30.3±1.3) mm vs. (36.8±6.7) mm, P>0.05), increased left ventricular ejection fraction ((64.0±2.9)% vs. (39.8±10.7)%), reduced left ventricular end-diastolic dimension ((44.8±4.0) mm vs. (60.0±2.9) mm) and reduced N-terminal B-type natriuretic peptide value ((136.2±47.5) ng/L vs. (3 408.4±901.3) ng/L) were observed at 6 months post ablation (P<0.05). Conclusion: The electrophysiological characteristics are suggestive for focal AT originating from RAA during pregnancy. Under the guidance of 3-dimension activation mapping, no fluoroscopic RFA with irrigated-tip catheter is a safe and effective strategy for the treatment of focal RAAT during pregnancy.
Subject(s)
Female , Humans , Pregnancy , Atrial Appendage/surgery , Retrospective Studies , Stroke Volume , Tachycardia , Treatment Outcome , Ventricular Function, LeftABSTRACT
Aim To observe the effects of astaxanthin ( ASTX) on the expression of collegeⅠ( ColⅠ) and type Ⅲcollagen ( Col Ⅲ) of cardiac fibroblasts( CFs) which caused by transforming growth factor β1 ( TGF-β1) and to explore its mechanism of action. Methods CFs were induced by TGF-β1 , and then pretreated with different concentrations of ASTX ( 0 , 5 , 10 , 20 , 40, 80, 160 μmol·L-1) for 24 h. MTT assay was used to determine the activity of CFs. The activation of ROS in CFs cells was detected by DCFH-DA kit. Smad3 gene was silenced by siRNA technique, and re-al-time PCR was used to detect the expression of ColⅠ, Col Ⅲ mRNA before and after Smad3 silencing. Western blot was used to detect the expression of ColⅠ, Col Ⅲ and Smad3 protein levels before and after Smad3 silencing. Results ASTX had no obvious cyto-toxicity in the range of 0 ～20 μmol · L-1 , and could significantly reduce ROS production induced by TGF-β1 in CFs (P<0.05). In addition, ASTX significant-ly inhibited the expression of ColⅠand ColⅢmRNA and protein ( P<0.01 ) of TGF-β1-induced CFs in a concentration-dependent manner. Also, ASTX could significantly down-regulate phosphorylation of Smad3 in TGF-β1-induced CFs ( P <0.01 ) . The expression of Col Ⅰ and Col Ⅲ mRNA and protein was also signifi-cantly down-regulated by Smad3 gene silencing ( P <0.01 ) . Conclusions ASTX can effectively inhibit the expression of Col Ⅰ, Col Ⅲ mRNA and protein of TGF-β1-induced CFs, and the possible mechanism may involve the down-regulation of Smad3 phosphoryla-tion.