Selective his bundle pacing eliminates crochetage sign:A case report

BACKGROUND Crochetage sign is a specific electrocardiographic manifestation of ostium secundum atrial septal defects(ASDs),which is associated with the severity of the left-to-right shunt.Herein,we reported a case of selective his bundle pacing(SHBP)that eliminated crochetage sign in a patient with ostium secundum ASD.CASE SUMMARY A 77-year-old man was admitted with a 2-year history of chest tightness and shortness of breath.Transthoracic echocardiography revealed an ostium secundum ASD.Twelve-lead electrocardiogram revealed atrial fibrillation with a prolonged relative risk interval,incomplete right bundle branch block,and crochetage sign.The patient was diagnosed with an ostium secundum ASD,atrial fibrillation with a second-degree atrioventricular block,and heart failure.The patient was treated with selective his bundle pacemaker implantation.After the procedure,crochetage sign disappeared during his bundle pacing on the electrocardiogram.CONCLUSION S-HBP eliminated crochetage sign on electrocardiogram.Crochetage sign may be a manifestation of a conduction system disorder.

Effect of nifekalant on acute electrical remodelling in rapid atrial pacing canine model

Background Nifekalant may prevent atrial fibrillation （AF） and possibly be useful in treatment of atrial tachyarrhythmia in patients with severe heart failure. This study investigated the electophysiologic effect of nifekalant on the acute atrial remodeling in rapid atrial pacing （RAP） model of canine. Methods Twelve mongrel dogs subjected to rapid stimulation （400 beats/min） at left atrial appendage （LAA） for 24 hours, were randomized into the control group （rapid pacing only, n=6） and the nifekalant group （intravenous nifekalant therapy immediately after RAP, n=6）. Atrial electrophysiological parameters were measured in right atrium, coronary sinus, LAA, posterior wall of left atrium （PWLA） and left superior pulmonary vein （LSPV）, before and after the RAP. Results In the control group, the effective refractory periods （ERP） were shortened greatly at all sites, paced dogs had substantially shorter ERPs in the high right atrium, LAA, and LSPV, but fewer changes in the PWLA, the coefficient variation of ERP （COV ERP） was increased significantly. After rapid atrial stimulation, the inducibility of AF increased significantly [induction number： pre-RAP vs post-RAP, 1.00 ± 0.89 vs 8.17 ± 2.79, P〈0.01; duration of AF： pre-RAP vs post-RAP, （450.34± 362.59） ms vs （9975.77±4376.99） ms, P〈0.01]. In the nifekalant group, although the ERPs were prolonged at all sites compared with those in pre-RAP state, only the value at LSPV differed significantly from that in pre-RAP state [pre-RAP vs post-RAP, （102.50±5.24） ms vs （132.51 ±5.20） ms, P〈0.01]; the COV ERP did not change statistically in this group. The inducibility of AF slightly increased but insignificantly after pacing [induction number： pre-RAP vs post-RAP, 0.83 ±0.75 vs 1.67±0.82, P=0.19; duration of AF： pre-RAP vs post-RAP, （378.67±317.88） ms vs （1124.08± 1109.77） ms, P=0.06]. Conduction time values did not alter significantly in either of the two groups after RAP. Condusions In canine RAP model, nifekalant inhibited ERP shortening and ERP heterogeneity increasing, decreased AF induction. Nifekalant can reverse acute electrical remodeling effect in this model.

Combined use of three-dimensional rotational angiogram of left atrium and circular multi-electrode ablation catheter for pulmonary vein isolation

Background A novel circular pulmonary vein ablation catheter （PVAC） has been introduced for pulmonary vein isolation （PVI）.Accurate delineation of left atrium-pulmonary vein （LA-PV） anatomy is important for this technique.The aim of this study was to test whether the 3-dimensional rotational angiography （3D RTA） of the left atrium can facilitate PVI using PVAC technique.Methods Twenty patients with paroxysmal atrial fibrillation （AF） were enrolled in this study.The 3D RTA was reconstructed and registered with live fluoroscopy in all the patients.AF ablation was performed with a PVAC catheter in the navigation of registered 3D RTA.Results The 3DRTA image was successfully reconstructed and registered with live fluoroscopy in all patients （100%）.The LA-PV anatomy was delineated clearly in all patients.Navigation of the PVAC inside the registered 3D RTA,ensured accurate placement within the atrium to perform ablation,and the PVAC was correctly placed inside the PV ostium to verify the PVI.All the PVs were isolated.Total procedural time was （87.5±12.1） minutes,and fluoroscopy time was （20.1±6.3） minutes.Follow-up after （7.1±1.5） months showed freedom from AF in 70% （14/20） patients.No PV stenosis was observed.Conclusions Intraprocedure reconstructed and registered 3D RTA can clearly delineate the LA-PV anatomy in real-time.The results demonstrate the feasibility and reliability of combining use of 3DRA and PVAC in AF ablation procedures.