Radiofrequency catheter ablation of ventricular tachycardia in patients post surgical repair of tetralogy of Fallot / 中华心血管病杂志

Objective: To investigate the clinical and electrophysiological features of ventricular tachycardia (VT) in tetralogy of Fallot (TOF) patients post surgical repair (rTOF) and to analyze the therapeutic effect and prognosis of radiofrequency ablation of rTOF-VT. Methods: This is a retrospective study. Consecutive patients with rTOF-VT, who were treated in Fuwai Hospital from January 2015 to March 2020, were enrolled. All the patients underwent right ventricular voltage mapping following routine cardiac electrophysiological examination, followed by linear or homogenizing radiofrequency ablation based on the low-voltage substrate. The clinical features, 3-dimentional electrophysiological substrate mapping, radiofrequency ablation and long-term prognosis of the enrolled patients were analyzed. Acute ablation success was defined as completion of linear or homogenizing ablation or intraoperative evoked VT as destination of the procedure. Patients were followed up at 3 and 6 months post operation and every year thereafter. The endpoints were sudden cardiac death (SCD) and recurrence of ventricular tachycardia. Results: A total of 20 patients with rTOF-VT were enrolled including 14 males with an age of (35.8±11.8) years. The electrocardiogram identified 23 types of ventricular tachycardia, 19 of which were originated from right ventricular inflow tract outlet. The most common clinical manifestations were heart murmur (19 cases, 95%) and syncope (4 cases, 25%). Electroanatomical substrate mapping was performed in 20 patients and evidenced localized or diffuse scar or low-voltage area of right ventricle. Intraoperative electrophysiological tests provoked ventricular tachycardia in 6 patients (30%), including 5 patients with hemodynamics disturbance. The acute success rate of radiofrequency ablation was 95% (19/20). The follow-up time was (31.1±17.7) months and the recurrence rate of ventricular tachycardia was 30% during follow-up period and 5 cases received repeat radiofrequency ablation and there was no recurrent ventricular tachycardia during follow-up post repeat radiofrequency ablation. Conclusions: The voltage substrate mapping under sinus rhythm is a feasible mapping method for rTOF-VT. Linear or flaky radiofrequency ablation of the slow conduction zone is safe and effective treatment strategy, the recurrence rate after the first radiofrequency ablation is still high, and the effectiveness of repeat radiofrequency ablation is satisfactory in this patient cohort.

Relationships of High-sensitive C-reactive Protein and P-wave Dispersion in Lone Atrial Fibrillation / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Current evidence links atrial fibrillation (AF) to the inflammation. Inflammatory indexes such as high-sensitive C-reactive protein (hs-CRP) have been related to the development and persistence of AF. However, the role of inflammation in the atrial electrophysiological remodeling indexed by P-wave dispersion (P d ) remains unclear.</p><p><b>METHODS</b>The study consisted of 71 patients with lone paroxysmal AF (AF group) and 71 age- and gender-matched controls of paroxysmal supraventricular tachycardia without history of AF (control group). Electrocardiography, P d , hs-CRP, and other clinical characteristics were compared between the two groups.</p><p><b>RESULTS</b>There was no significant difference between the two groups regarding age, gender, hyperlipidemia, etc. Compared to controls, left atrial diameter (44 ± 7 vs 39 ± 7 mm), P d (49 ± 13 vs 26 ± 8 ms), and hs-CRP (2.17 [1.46-2.89] vs 1.12 [0.74-1.41] mg/L) were increased (P < 0.05), respectively. Linear regression identified hs-CRP as an independent correlation of P d level both in the total population and the AF group (r = 0.464 and 0.313; P < 0.001, respectively). Multiple logistic regression revealed hs-CRP as an independent determinant of AF (odds ratio [OR] =15.430, 95% confidence interval: 6.031-39.476: P <0.001). Further adjusted for P d , both P d and hs-CRP were independent predictors for AF, but the OR for hs-CRP in predicting AF has been attenuated from 15.430 to 6.246.</p><p><b>CONCLUSIONS</b>In lone AF, P d and plasma hs-CRP concentration are inter-associated and related to AF. The interaction between hs-CRP and AF may be mediated by P d , suggesting an important role of inflammation in the atrial electrophysiological remodeling predisposing to AF.</p>

Optimized Fluoroscopy Setting and Appropriate Project Position Can Reduce X-ray Radiation Doses Rates during Electrophysiology Procedures / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Nonfluoroscopic three-dimensional electroanatomical system is widely used nowadays, but X-ray remains indispensable for complex electrophysiology procedures. This study aimed to evaluate the value of optimized parameter setting and different projection position to reduce X-ray radiation dose rates.</p><p><b>METHODS</b>From June 2013 to October 2013, 105 consecutive patients who underwent complex ablation were enrolled in the study. After the ablation, the radiation dose rates were measured by two different settings (default setting and optimized setting) with three projection positions (posteroanterior [PA] projection; left anterior oblique [LAO] 30° projection; and LAO 45° projection). The parameter of preset voltage, pulse width, critical voltage, peak voltage, noise reduction, edge enhancement, pulse rate, and dose per frame was modified in the optimized setting.</p><p><b>RESULTS</b>The optimized setting reduced radiation dose rates by 87.5% (1.7 Gy/min vs. 13.6 Gy/min, P < 0.001) in PA, 87.3% (2.5 Gy/min vs. 19.7 Gy/min, P < 0.001) in LAO 30°, 85.9% (3.1 Gy/min vs. 22.1 Gy/min, P < 0.001) in LAO 45°. Increase the angle of projection position will increase the radiation dose rate.</p><p><b>CONCLUSIONS</b>We can reduce X-ray radiation dose rates by adjusting the parameter setting of X-ray system. Avoiding oblique projection of large angle is another way to reduce X-ray radiation dose rates.</p>

Improved approach to atrial septum puncture: experience in 539 cases / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The transseptal puncture technique has been widely used in therapeutic left atrium catheterization. But this technique may lead to some life-threatening complications. It can not be used widely because it is restricted by economy and deferring the transseptal puncture procedure. The aim of this study was to introduce a simple and safe transseptal puncture procedure.</p><p><b>METHODS</b>The distal of coronary sinus (CS) electrode was positioned close to the lateral margin of heart, which was about at 3 o'clock at left anterior oblique (LAO) 30° referred to whole cardiac profile. It was then used as the marker for the level of fossa ovalis at posterior-anterior projection to guide the pull of transseptal needle. The midpoint between the distal CS and the posterior margin of heart at right anterior oblique (RAO) 45° view was considered as the location of fossa ovalis. Once the puncture was succeeded, the guidewire was introduced to the left superior pulmonary vein via puncture sheath after the needle was retrieved. The end of outer sheath was introduced into left atrium with the protection of guidewire. It was applied in 539 patients (316 male, 223 female; (53 ± 16) years old) who underwent catheter ablation of atrial fibrillation or left-sided atrioventricular accessory pathway.</p><p><b>RESULTS</b>This transseptal approach reached 100.0% success and was succeeded in 98.9% with the first attempt. The first attempt puncture was aborted due to greater resistance to needle advancement or smaller needle curve in six patients. However, the second attempts were all succeeded after the needle curve was reshaped. There was no tamponade and embolism occurred.</p><p><b>CONCLUSION</b>The atrial septum puncture approach using the location of distal CS electrode as important marker and the guidewire for protection when sending outer sheath into left atrium is reliable and safe.</p>