Humans ; Arrhythmias, Cardiac ; Tachycardia, Ventricular/surgery*

Non-reentrant focal tachycardias occur spontaneously, facilitated by catecholamine infusion, but they cannot be initiated or terminated with programmed stimulation. These tachycardias exhibit early activation before the QRS, however, do not typically show the mid-diastolic potential that is crucial for reentrant tachycardia maintenance. Electrophysiological studies are useful for distinguishing focal from macro-reentrant ventricular tachycardia. We report herein a case of patient without a history of structural heart disease who presented with a focal Purkinje ventricular tachycardia and heart failure. The focal Purkinje ventricular tachycardia was eliminated by radiofrequency catheter ablation. All of the patien's symptoms were improved after ablation.
Adult ; Cardiomyopathies/*surgery ; Catheter Ablation/*methods ; Humans ; Male ; Tachycardia, Ventricular/*surgery ; Ventricular Dysfunction/surgery

Adult ; Denervation ; methods ; Humans ; Kidney ; innervation ; Male ; Tachycardia, Ventricular ; surgery

Catheter Ablation ; Child, Preschool ; Humans ; Infant ; Tachycardia, Ventricular ; surgery

Catheter Ablation ; methods ; Child ; Epicardial Mapping ; Female ; Heart Aneurysm ; complications ; surgery ; Humans ; Tachycardia, Ventricular ; complications ; surgery

This study was performed to assess the influence of the cryoinjury on the dynamics of wavefronts and to determine whether they can convert ventricular fibrillation (VF) to ventricular tachycardia (VT) in fibrillating right ventricular (RV) of swines using an optical mapping system. A cryoinjury with a diameter of 12 mm was created on the epicardium of perfused RV of swines (n = 6) and optical mapping were taken from baseline until 10 minutes after the cryoinjury. Out of 35 cryoinjuries, the images were possible to be interpreted in 32. The optical action potential could not be observed in either the cryoinjury or peri-injury sites at 1 and 3 minutes, was observed in only the cryoinjury site at 5 minutes, and recovered in both sites at 10 minutes. The cycle length of the tachycardia was 135.9 +/- 23.6 msec at baseline, 176.2 +/- 79.3 msec at 1 minute, 187.6 +/- 97.9 msec at 3 minutes, 185.5 19.2 msec at 5 minutes, and 152.1 +/- 64.1 msec at 10 minutes. The cycle lengths at 1, 3, and 5 minutes after the cryoinjury were significantly more prolonged than that at baseline (p = 0.001, p = 0.006, p = 0.016). After the cryoinjury, the VF changed to VT in 9 (28.0%), and terminated in 2 (6.3%). These changes were observed mainly within 5 minutes after cryoinjury. The cryoinjury had anti-fibrillatory effects on the tissue with VF. This phenomenon was related to a decreasing mass and stabilizing wavefronts.
Ventricular Fibrillation/*physiopathology ; Tachycardia, Ventricular/*physiopathology ; Swine ; Heart Ventricles/*physiopathology/surgery ; Female ; Disease Models, Animal ; *Cryosurgery ; Animals

Adrenalectomy ; Female ; Humans ; Pheochromocytoma ; diagnosis ; surgery ; Tachycardia, Ventricular ; diagnosis ; Tomography, X-Ray Computed

BACKGROUNDThe aim of this study was to clarify the electrocardiographic characteristics of repetitive monomorphic ventricular tachycardia (RMVT) originating from the left ventricular outflow tract, and to describe the results of treatment with radiofrequency catheter ablation (RFCA).

METHODSRoutine 12-lead surface electrocardiography and electrophysiological studies were performed on 11 RMVT patients with no organic heart disease, who were subsequently treated with RFCA directed at targets identified by pace mapping.

RESULTSThe surface electrocardiogram QRS characteristics of RMVT included an atypical left bundle branch block and right axis deviation, with a low amplitude "rs" or "rS" pattern in lead I, an "rS" or "RS" pattern in V1, and a precordial R wave transition zone in V2 or V3. In 1 patient, a small S wave was observed in V5. Using pace mapping techniques, we selected the left coronary cusp as the ablation target. RMVT was eliminated in all 11 patients immediately after radiofrequency energy delivered. During a follow-up of 13 +/- 7 months, RMVT recurred in only 1 patient.

CONCLUSIONRMVT originating from the left ventricular outflow tract has specific electrocardiographic characteristics, and can be successfully and safely cured using RFCA directed at the left coronary cusp.

Adolescent ; Adult ; Catheter Ablation ; Electrocardiography ; Female ; Humans ; Male ; Middle Aged ; Tachycardia, Ventricular ; physiopathology ; surgery ; Treatment Outcome

Systemic sclerosis (SS) is a connective tissue disease and cardiac involvement is common. Primary cardiac involvement such as conduction system disturbances and arrhythmias can also occur. However, reports of sustained ventricular tachycardia (VT) are rare. We report a case of catheter ablation of sustained ventricular tachycardia in a patient with systemic sclerosis using a conventional mapping system. A 64-yr-old woman with a 10-yr history of SS was referred for management of her ventricular tachycardia. There was no structural abnormality in cardiac chambers. However, electrophysiologic study revealed electrical substrate of ventricular tachycardia which could be ablated with pacemapping and substrate mapping. This case demonstrated successful conventional mapping and catheter ablation in a hemodynamically unstable patient with SS.
*Catheter Ablation ; Electrocardiography ; Female ; Humans ; Middle Aged ; Scleroderma, Systemic/*complications/*diagnosis ; Tachycardia, Ventricular/*etiology/physiopathology/*surgery

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.
Atrial Appendage/surgery* ; Female ; Humans ; Pregnancy ; Retrospective Studies ; Stroke Volume ; Tachycardia ; Treatment Outcome ; Ventricular Function, Left