In the field of medicine and cardiology, there is perhaps no other condition or situation that stimulates an adrenalin rush for the healthcare team than a patient presenting with wide QRS complex tachycardia. These cases may be potentially fatal and are usually associated with worse outcomes. While the real-world experience in the evaluation and management of these cases can be chaotic situations, a careful, systematic and organized scrutiny of the electrocardiographic tracing is key to obtaining a correct diagnosis and proceeding with the right therapeutic management. An understanding of the physiological mechanisms of arrhythmia, the appreciation of scientific basis for electrocardiographic features and recognition of different criteria for diagnosis provides endless opportunities and “teachable moments” in medicine. For both learners and teachers, the academic discussion of these points and features can be an exciting journey and electrifyingly educational experience. This article provides a simplified yet beautifully complicated approach to diagnosing wide complex tachycardia.

OBJECTIVE: To explore the clinical and genetic characteristics of five children with Catecholaminergic polymorphic ventricular tachycardia (CPVT). METHODS: Five children with clinical manifestations consistent with CPVT admitted to the Department of Cardiology of Children's Hospital Affiliated to Zhengzhou University from November 2019 to November 2021 were selected as the study subjects. Their clinical data were collected. Potential variants were detected by whole exome sequencing, and Sanger sequencing was used to verify the candidate variants. All patients were treated with β-blocker propranolol and followed up. RESULTS: All patients had developed the disease during exercise and presented with syncope as the initial clinical manifestation. Electrocardiogram showed sinus bradycardia. The first onset age of the 5 patients were (10.4 ± 2.19) years, and the time of delayed diagnosis was (1.6 ± 2.19) years. All of the children were found to harbor de novo heterozygous missense variants of the RYR2 gene, including c.6916G>A (p.V2306I), c.527G>C (p.R176P), c.12271G>A (p.A4091T), c.506G>T (p.R169L) and c.6817G>A (p.G2273R). Among these, c.527G>C (p.R176P) and c.6817G>A (p.G2273R) were unreported previously. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the c.527G>C (p.R176P) was classified as a pathogenic variant (PS2+PM1+PM2_Supporting+PM5+PP3+PP4), and the c.6817G>A (p.G2273R) was classified as a likely pathogenic variant (PS2+PM2_Supporting+PP3+PP4). The symptoms of all children were significantly improved with the propranolol treatment, and none has developed syncope during the follow up. CONCLUSION Discovery of the c.527G>C (p.R176P) and c.6817G>A (p.G2273R) variants has expanded the mutational spectrum of the RYR2 gene. Genetic testing of CPVT patients can clarify the cause of the disease and provide a reference for their genetic counseling.
Child ; Humans ; Mutation ; Propranolol ; Ryanodine Receptor Calcium Release Channel/genetics* ; Syncope ; Tachycardia, Ventricular/diagnosis* ; United States

Objectives: This study sought to describe our institutional experience of repeated percutaneous stellate ganglion blockade (R-SGB) as a treatment option for drug-refractory electrical storm in patients with nonischemic cardiomyopathy (NICM). Methods: This prospective observational study included 8 consecutive NICM patients who had drug-refractory electrical storm and underwent R-SGB between June 1, 2021 and January 31, 2022. Lidocaine (5 ml, 1%) was injected in the vicinity of the left stellate ganglion under the guidance of ultrasound, once per day for 7 days. Data including clinical characteristics, immediate and long-term outcomes, and procedure related complications were collected. Results: The mean age was (51.5±13.6) years. All patients were male. 5 patients were diagnosed as dilated cardiomyopathy, 2 patients as arrhythmogenic right ventricular cardiomyopathy and 1 patient as hypertrophic cardiomyopathy. The left ventricular ejection fraction was 37.8%±6.6%. After the treatment of R-SGB, 6 (75%) patients were free of electrical storm. 24 hours Holter monitoring showed significant reduction in ventricular tachycardia (VT) episodes from 43.0 (13.3, 276.3) to 1.0 (0.3, 34.0) on the first day following R-SGB (P<0.05) and 0.5 (0.0, 19.3) after whole R-SGB process (P<0.05). There were no procedure-related major complications. The mean follow-up was (4.8±1.1) months, and the median time of recurrent VT was 2 months. Conclusion: Minimally invasive R-SGB is a safe and effective method to treat electrical storm in patients with NICM.
Humans ; Male ; Adult ; Middle Aged ; Aged ; Female ; Stroke Volume ; Stellate Ganglion/surgery* ; Ventricular Function, Left ; Cardiomyopathies/complications* ; Tachycardia, Ventricular/therapy* ; Treatment Outcome ; Catheter Ablation

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

Humans ; Cardiomyopathy, Hypertrophic/genetics* ; Mutation ; Phenotype ; Ryanodine Receptor Calcium Release Channel/genetics* ; Tachycardia, Ventricular/genetics*

Humans ; Cardiomyopathy, Hypertrophic/genetics* ; Mutation ; Phenotype ; Ryanodine Receptor Calcium Release Channel/genetics* ; Tachycardia, Ventricular/genetics*

Andersen Syndrome/genetics* ; Humans ; Syncope ; Tachycardia, Ventricular

Objective: To investigate the acute and long-term outcome of catheter ablation for the treatment of ventricular tachycardia (VT) in patients with arrhythmogenic left ventricular cardiomyopathy (ALVC). Methods: This retrospective, cross-sectional study enrolled ALVC patients undergoing radiofrequency ablation for the treatment of VT at the First Affiliated Hospital of Nanjing Medical University from January 2011 to December 2018 and collected their clinical characteristics and intraoperative electrophysiological examination. Patients were followed up every 6 months after radiofrequency ablation until August 2021. Echocardiographic results and VT recurrence post radiofrequency ablation were analysed. Results: Totally 12 patients were enrolled (mean age: (42±15) years, 11 males(11/12)). The mean of left ventricular end diastolic diameter (LVDd) and left ventricular ejection fraction (LVEF) were (51±5)mm and (65±5)%, respectively. Twelve VTs were induced in 10 patients during the electrophysiological study, and the mean tachycardia cycle length was (293±65) ms. Three-dimensional substrate mapping revealed the diseased area at endocardial site in one patient, at epicardial sites in the other 11 patients (involved endocardial sites in 2 cases) with the basal part near the mitral annulus being the predilection for the substrate (10/11). After the catheter ablation at the endocardial and epicardial sites respectively, the complete procedure endpoint was achieved in all patients (VT cannot be induced post ablation). The median follow-up time was 65 (25, 123) months. One patient was lost to follow-up, and the other 11 patients survived without VT. No significant cardiac function deterioration was detected by the echocardiographic examination ((51±5)mm vs. (52±5)mm, P>0.05 for LVDd, (65±5)% vs. (60±6)%, P>0.05 for LVEF) at the end of follow-up. Conclusion: After radiofrequency ablation, the complete procedure endpoint is achieved in ALVC patients, and the catheter ablation provides long-term ventricular tachycardia control during the long-term follow-up.
Adult ; Cardiomyopathies ; Catheter Ablation ; Cross-Sectional Studies ; Follow-Up Studies ; Humans ; Male ; Middle Aged ; Pericardium/surgery* ; Recurrence ; Retrospective Studies ; Stroke Volume ; Tachycardia, Ventricular/surgery* ; Treatment Outcome ; Ventricular Function, Left

BACKGROUND: Postural tachycardia syndrome (POTS) is a common childhood disease that seriously affects the patient's physical and mental health. This study aimed to investigate whether pre-treatment baseline left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) values were associated with symptom improvement after metoprolol therapy for children and adolescents with POTS. METHODS: This retrospective study evaluated 51 children and adolescents with POTS who received metoprolol therapy at the Peking University First Hospital between November 2010 and July 2019. All patients had completed a standing test or basic head-up tilt test and cardiac echocardiography before treatment. Treatment response was evaluated 3 months after starting metoprolol therapy. The pre-treatment baseline LVEF and LVFS values were evaluated for correlations with decreases in the symptom score after treatment (ΔSS). Multivariable analysis was performed using factors with a P value of <0.100 in the univariate analyses and the demographic characteristics. RESULTS: A comparison of responders and non-responders revealed no significant differences in demographic, hemodynamic characteristics, and urine specific gravity (all P > 0.050). However, responders had significantly higher baseline LVEF (71.09% ± 4.44% vs. 67.17% ± 4.88%, t = -2.789, P = 0.008) and LVFS values (40.00 [38.00, 42.00]% vs. 36.79% ± 4.11%, Z = -2.542, P = 0.010) than the non-responders. The baseline LVEF and LVFS were positively correlated with ΔSS (r = 0.378, P = 0.006; r = 0.363, P = 0.009), respectively. Logistic regression analysis revealed that LVEF was independently associated with the response to metoprolol therapy in children and adolescents with POTS (odds ratio: 1.201, 95% confidence interval: 1.039-1.387, P = 0.013). CONCLUSIONS Pre-treatment baseline LVEF was associated with symptom improvement after metoprolol treatment for children and adolescents with POTS.
Adolescent ; Child ; Humans ; Metoprolol/therapeutic use* ; Postural Orthostatic Tachycardia Syndrome/drug therapy* ; Retrospective Studies ; Stroke Volume ; Ventricular Function, Left

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.
Adult ; Arrhythmias, Cardiac ; Catheter Ablation ; Electrocardiography ; Follow-Up Studies ; Humans ; Male ; Middle Aged ; Retrospective Studies ; Tachycardia, Ventricular/surgery* ; Tetralogy of Fallot/surgery* ; Treatment Outcome ; Young Adult