Idiopathic Ventricular Tachycardia Research Articles

Cardiac Memory T Waves After Termination of Fascicular Ventricular Tachycardia in the Emergency Room

Left posterior fascicular tachycardia (LPFVT) is a common type of idiopathic ventricular tachycardia that might be misdiagnosed as supraventricular tachycardia. Memory T wave is an inverted T wave that is seen after altered depolarization states such as pacemaker rhythm, ablated accessory pathways, ventricular tachycardia, or intermittent bundle branch blocks. Herein, we presented a young male patient who was admitted to the emergency room with FVT. After termination of tachycardia negative T waves (memory T wave) were seen. Memory T waves might be seen after the termination of FVT and must be differentiated from other causes of inverted T waves such as ischemia.

The relationship between epicardial adipose tissue volume on coronary computed tomography angiography and idiopathic ventricular tachycardia: a propensity score matching case-control study in Chinese population.

Large epicardial adipose tissue (EAT) volume is associated with the incidence of premature ventricular beats. The relationship between EAT volume and idiopathic ventricular tachycardia (IVT) is not yet clear. We aimed to investigate the effect of EAT volume on the risk of IVT. This is a retrospective consecutive case-control study from January 2020 to September 2022. IVT patients (n=81) and control patients (n=162) undergoing coronary computed tomography angiography (CCTA) were retrospectively recruited. The patients in the control group were all hospitalized patients for different reasons, such as chest tightness, shortness of breath, chest pain, and so on. Demographic parameters and clinical characteristics of each individual were collected from the patient's medical records. We selected evaluation criteria for the conduct of a 1:1 propensity score (PS)-adjusted analysis. Multivariable logistic analysis was used to investigate risk factors for IVT. Furthermore, the impact of EAT volume on cardiac repolarization indices was assessed in IVT patients. Patients with IVT had a larger EAT volume than control group patients in the unadjusted cohort. Variables with P<0.10 in the univariable analysis and important factors were included in the multivariable analysis model, including body mass index (BMI), left ventricular ejection fraction (LVEF), early peak/artial peak (E/A) ratios <1, EAT attenuation, and EAT volume (per increase 10 mL). The multivariable logistic analysis found that EAT volume [per increase 10 mL, odds ratio (OR): 1.29, 95% confidence interval (CI): 1.17-1.41, P<0.001] was an independent risk factor for IVT. EAT volume (per increase 10 mL, OR: 1.43, 95% CI: 1.25-1.64, P<0.001) independent effect was demonstrated in the PS adjusted cohort (n=57 in both groups). The area under the curve of EAT volume to predict the risk of IVT patients in the PS adjusted cohort was 0.859. The sensitivity and specificity were 86.0%, and 75.4%, respectively. Furthermore, A large EAT volume of IVT patients had a longer time in Tp-e, and Tp-e/QTc, compared with low EAT volume. Patients with IVT had increased EAT volume compared to control subjects. Our study revealed that large EAT volume is associated with an extended repolarization process in IVT patients. These insights are essential for understanding the mechanisms linking EAT with IVT.

Outcomes of single-procedure radiofrequency catheter ablation for idiopathic ventricular arrhythmias: a single-centre retrospective cohort study

ObjectivesRadiofrequency catheter ablation is the first-line treatment for idiopathic premature ventricular complexes (PVCs) and ventricular tachycardias (VTs). However, the outcomes were less compared among the categories. The study aims to...

P 023: Idiopathic left fascicular ventricular tachycardia in pregnancy

Ventricular tachycardia (VT) can occasionally cause complications in pregnancy. In structurally normal heart, VT that arises in the left ventricle is uncommon and is termed as idiopathic left fascicular VT (ILVT). We report a case of 32-year-old lady, gravida 4 para 3 who presented to us at 34 weeks of pregnancy with symptomatic stable cardiac arrythmia with heart rate of 160 beats per minute. Electrocardiogram showed wide complex tachycardia with positive initial R wave at aVR and capture beats suggestive of ILVT. Echocardiogram was normal. She received IV verapamil 25 mg in total which failed to revert to sinus rhythm and hence, she underwent emergency Caesarean section followed by synchronized cardioversion urgently in operation theatre. Post cardioversion ECG showed sinus rhythm with memory T waves at chest leads. She was scheduled radiofrequency ablation later. This case highlights the importance of attaining the diagnosis of ILVT with distinctive ECG changes. Left ventricular outflow tract (LVOT) VT morphology depends on the site of origin, with either LBBB or early precordial transition in leads V1 to V2 or RBBB pattern in V1 with broad monophasic R in the precordial leads. In addition, there will be an R:S amplitude ratio of 30% or more or an R:QRS duration ratio of 50% in leads V1–2 with other features like capture beats and fusion beats. ILVT responds well with verapamil and can be cured with cardiac ablation, with success rates of more than 90%. ILVT though difficult to diagnose, it has distinctive ECG features which can lead to its diagnosis for appropriate treatment to be given accordingly. ILVT in pregnant patients generally has a good prognosis.

Upper turnaround point in a reentry circuit of the idiopathic left posterior fascicular ventricular tachycardia.

The anatomic extent of the reentry circuit in idiopathic left posterior fascicular ventricular tachycardia (LPF-VT) is yet to be fully elucidated. We hypothesized that entrainment mapping could be used to delineate the reentry circuit of an LPF-VT, especially including the upper turnaround point. Twenty-three consecutive LPF-VT patients (mean age, 29±9 years, 18 males) were included. We performed overdrive pacing with entrainment attempts at the left bundle branch (LBB) and the left His bundle (HB) region. Overdrive pacing from the LBB region showed concealed fusion in all 23 patients (post-pacing interval [PPI], 322.1±64.3ms; tachycardia cycle length [TCL], 319.0±61.6ms; PPI-TCL, 3.1±4.6ms) with a long stimulus-to-QRS interval (287.9±58.0ms, approximately 90% of the TCL). Pacing from the same LBB region at a slightly faster pacing rate showed manifest fusion with antidromic conduction to the LBB and minimal in-and-out time to the LBB potential (PPI-TCL, 21.3±13.7ms). Overdrive pacing from the left HB region showed manifest fusion with a long PPI-TCL (53.9±22.5ms). Our pacing study results suggest that the upper turnaround point in a reentry circuit of the LPF-VT may extend to the proximal His-Purkinje conduction system near the LBB region but below the left HB region. The LPF may constitute the retrograde limb of the reentry circuit.

Anesthetic Management for Ventricular Tachycardia Ablation: A National Anesthesia Clinical Outcomes Registry Analysis

Objectives: We analyzed anesthetic management trends during ventricular tachycardia (VT) ablation, hypothesizing that (1) monitored anesthesia care (MAC) is more commonly used than general anesthesia (GA), (2) MAC use significantly increased after release of the 2019 Expert Consensus Statement on Catheter Ablation of Ventricular Arrhythmias, and (3) anesthetic approach varies based on patient and hospital characteristics. Design: Retrospective study. Setting: National Anesthesia Clinical Outcomes Registry data. Participants: Patients ≥18 years who underwent elective VT ablation between 2013-2021. Interventions: None. Measurements and main results: Covariates were selected a priori within multivariate models, and interrupted time-series analysis was performed. Of the 15,505 patients who underwent VT ablation between 2013-2021, 9,790 (63.1%) received GA. After the 2019 Expert Consensus Statement on Catheter Ablation of Ventricular Arrhythmias supported avoidance of GA, no statistically significant increase in MAC was evident (immediate change in intercept post-consensus statement release AOR 1.41, p=0.1629; change in slope post-consensus statement release AOR 1.06 per quarter, p=0.1591). Multivariate analysis demonstrated that sex, ASA physical status, age, and geographic location were statistically significantly associated with anesthetic approach. Conclusions: GA has remained the primary anesthetic type for VT ablation despite the 2019 Expert Consensus Statement on Catheter Ablation of Ventricular Arrhythmias suggesting its avoidance in idiopathic VT. Achieving widespread clinical practice change is an ongoing challenge in medicine, emphasizing the importance of developing effective implementation strategies to facilitate awareness of guideline release and subsequent adherence to and adoption of recommendations.

Differentiating Origins of Outflow Tract Ventricular Arrhythmias: The Correction of Transitional Zone Index Is Not Superior to the Original One

Introduction: Our team once proposed a correction of transitional zone index (CTZI) based on the transitional zone index (TZI) in view of achieving a more precise prediction of outflow tract ventricular arrhythmia (OTVA). The predictive accuracy of these two electrocardiogram (ECG) algorithms has not been validated and compared. The purpose of this study was to compare the predictive accuracy of TZI and CTZI in a much larger population with idiopathic OTVA. Methods: The predictive accuracy of TZI and CTZI was compared in 695 individuals with idiopathic premature ventricular complex or ventricular tachycardia which exhibited a left bundle branch block pattern and inferior axis QRS morphology. Receiver operating characteristic curve analysis, decision curve analysis, and calibration curve were used to compare the predictive accuracy of TZI and CTZI. Results: TZI and CTZI manifested the similar area under the curve. While a TZI of <0 predicted a left ventricular outflow tract (LVOT) origin with a high specificity of 88.2% but a low sensitivity of 67.1%, a CTZI of <0 yielded a high sensitivity of 84.3% but a low specificity of 59.5% in the overall analysis. Similar results were yielded in the sub-analysis of participants with a precordial transition occurring at lead V3. In the sub-analysis of participants with a TZI = 0, CTZI demonstrated a bit higher but not satisfactory predictive accuracy than TZI. Conclusion: Based on the scientific spirit of self-criticism and seeking truth from facts, our team disproves the correction of TZI proposed previously.

Long-term results of catheter ablation of idiopathic and structural ventricular tachycardia

Catheter ablation of ventricular tachycardia (VTs) has emerged as an effective treatment modality. Ablation procedures for idiopathic VTs depends on the anatomical origin of the arrhythmias, is highly effective in certain cases, and has been implemented as afirst-line therapy in recent European guidelines. In contrast, catheter ablation of VTs in patients with structural heart disease has asignificant risk of arrhythmia recurrence. Interventional treatment for patients with ischemic cardiomyopathy was studied in multiple randomized multicenter trials and it was shown that catheter ablation was more effective in arrhythmia suppression compared to conservative treatment modalities. Catheter ablation of nonischemic cardiomyopathy suffers from far higher rates of arrhythmia recurrences as documented in several long-term studies and often needs complex procedures with or without epicardial mapping and ablation. There is still no clear proof of amortality benefit from catheter ablation of VTs in patients with or without structural heart disease. Nevertheless, recent guidelines recommend catheter ablation as an alternative to implantation of cardioverter-defibrillators (ICD) in selected cases.

Sex Related Differences in Electrocardiography.

Since its implementation into the clinical medicine by Willem Einthoven electrocardiography had become one of crucial diagnostic method in cardiology. In spite of this fact effects of gender differences on parameters of electrocardiographic recordings started to be studied only recently. Sex related differences in physiological ECG are only minimal in childhood but there are developing during adolescence reflecting rapidly evolving differences particularly in hormonal secretion and activity of an autonomic nervous system. The heart rate is approximately 7 % higher in women than in men, PQ and QRS intervals are longer in men while QT interval is longer in women. The ST segment in females is flatter but generally the sex-related differences in ST-T waveform patterns are relatively very small with higher level of ST segment and taller T wave in men. The effects of sex-related differences, including sex hormones, on cardiac cell injury and death and their influence in determining rhythmogenesis and action potential configuration and conduction play an important role in clinics. Women have a higher prevalence of sick sinus syndrome, inappropriate sinus tachycardia, atrioventricular nodal reentry tachycardia, idiopathic right ventricular tachycardia, and arrhythmic events in the long QT syndrome. In contrast, men have a higher prevalence of atrioventricular block, carotid sinus syndrome, atrial fibrillation, supraventricular tachycardia due to accessory pathways, Wolff-Parkinson-White syndrome, reentrant ventricular tachycardia, ventricular fibrillation and sudden death, and the Brugada syndrome.

Idiopathic fascicular ventricular tachycardia in children: a challenging arrythmia worth recognizing.

Idiopathic fascicular ventricular tachycardia in children: a challenging arrythmia worth recognizing.

Impact of Radiofrequency Ablation in Patients With Idiopathic Ventricular Tachycardia on Left Ventricular Ejection Fraction

Impact of Radiofrequency Ablation in Patients With Idiopathic Ventricular Tachycardia on Left Ventricular Ejection Fraction

Independent Association between Epicardial Adipose Tissue Volume and Recurrence of Idiopathic Ventricular Tachycardia after Ablation

Independent Association between Epicardial Adipose Tissue Volume and Recurrence of Idiopathic Ventricular Tachycardia after Ablation

Effect of ventricular tachycardia ablation on symptoms and health-related quality of life: data from a single-center registry

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): ALF grants (County Council of Östergotland). Background Ventricular tachycardia (VT) is a significant cause of morbidity and mortality (1). Implantable cardioverter-defibrillators can terminate the arrhythmia and reduce the risk of sudden cardiac death but do not lower the risk of recurrence (2). Thus, the use of VT ablation as a method of prevention of VT recurrence has increased (3). Most articles have focused on the procedure’s efficacy and complications as opposed to data concerning arrhythmia-related symptoms and health-related quality of life (HRQoL). Purpose We sought to examine the effect of VT ablation on patients’ symptoms and HRQoL during a one-year follow-up period. Method Patients referred for catheter ablation of VT to our university hospital between June 2012 and June 2020 were asked to fill in the validated ASTA (Arrhythmia-Specific questionnaire in Tachycardia and Arrhythmia) questionnaire for the assessment of symptoms and HRQoL before and one year after the index procedure. Results One hundred sixty-one patients filled out the ASTA questionnaire before the index procedure and 133 (83 %) at one-year follow-up. Four patients died during follow-up. Of the 133 patients eligible for analysis, 53 had ischemic VT, 45 had non-ischemic VT, and 35 had idiopathic VT. Sixty patients were also followed up in detail concerning arrhythmia recurrence by screening ICD interrogation reports, ECGs, and Holter registrations. Repeated measures analysis of variance showed a significant reduction of symptoms and improvement of HRQoL irrespective of patients’ background disease (ASTA-symptom score: whole population, as well as subpopulations p&amp;lt;0.001, figure 1, ASTA-HRQoL score: whole population as well as subpopulations p&amp;lt;0.001, figure 2) after 1.6 procedures, while 41 % of patients did not report any arrhythmia-related symptoms after one year. Sixty-eight percent of the patients did not suffer any recurrence during the first year after catheter ablation, and the major complication rate was 7%. Conclusions Catheter ablation of VT effectively reduces arrhythmia-related symptoms and improves HRQoL irrespective of patients' background disease during a follow-up period of one year.

PO-04-062 CRYOABLATION OF INTRAMURAL SUBSTRATE IN AN IDIOPATHIC CRUX VT MAPPED BY NAVIGATING OTHERWISE INACCESSIBLE CS ANATOMY USING 2FR MAPPING CATHETER

Idiopathic cardiac crux VTs are are difficult to map and ablate due to their inaccessible location often requiring epicardial ablation. We report a unique case of a recurrent idiopathic crux VT originating near a trifurcated confluence of CS branches that required extensive mapping only accessible with the 2Fr EP catheter that was successfully ablated with cryoablation (due to proximity to coronary artery) from within the CS and the site-opposite (epicardially). Case Report A 40 year old man with idiopathic VT (normal Echo and cardiac MRI without LGE), prior endocardial VT ablation (RV septum and mid MCV), asthma, OSA, and the Arnold-Chiari malformation, was noted to have continued symptomatic PVCs and monomorphic wide-complex tachycardia at 164 bpm. A monomorphic VT (Figure) with CL 320-380 ms was only inducible with isoproterenol infusion at 20mcg/kg/min. We attempted to better define the CS anatomy and assess if there is a route via the CS to reach the Crux. The main body CS was noted to have a trifurcation into the MCV, a posterolateral branch and an anterior branch (extension of the CS main body) all meeting at an area of confluence (Figure 1). Detailed mapping was made possible using the CS-L telescoping catheter to carry the smaller 2French EP Star catheter deep into the multiple CS branches. We noted that the proximal MCV was 28ms early in VT (but not the best pace match) and the proximal lateral CS branch across from the MCV early site within the confluence had the best pace match. This suggests the origin was likely deep in between the two sites with the exit closer to the lateral branch site. Given that we noted that the PDA is in borderline proximity (5-6mm) to the site of ablation on coronary angiography, we chose to use to cryoablation (8 minute lesions) at the confluence of these branches at the marked sites to mitigate coronary injury. VT terminated with ablations at this site. Epicardial mapping was performed and no scar was noted. An additional single lesion was performed at the site opposite from the confluence with the best pace-map and VT was no longer inducible on repeat testing with isoproterenol. CSL telescoping catheter harboring the EP star catheter can be used to overcome challenging CS anatomy to bracket the Crux VT origin. Cryoablation (not without risk completely) can be potentially effective for Crux VTs approached from CS, especially if within borderline proximity to a coronary artery.

PO-05-068 MAJOR VASCULAR COMPLICATIONS IN A LARGE COHORT OF PATIENTS UNDERGOING CATHETER ABLATION FOR VPB/VT IN A HIGH-VOLUME, TERTIARY EP CENTER

Catheter ablation is an established treatment method both in patients with idiopathic premature ventricular complexes (PVC) or ventricular tachycardia (VT) and in structural heart disease (SHD) VT. Major vascular complications (MVCs) are the most frequent in these populations. A retrospective study investigating the incidence of MVCs in large-volume, specialized VT center and analyzing their predictors. We included PVC/VT patients who had their first ablation procedure between August 2006 - December 2020. The procedures were performed under conscious sedation except for patients who were on mechanical ventilation because of hemodynamical or electrical instabilit. Activation mapping supported by an electroanatomic mapping system was used in idiopathic cases. In SHD, substrate mapping using an electroanatomic mapping system and pacemapping was employed as a prerequisite for complete substrate modification during spontaneous rhythm or pacing. Activation and entrainment mapping for well-tolerated VTs were rarely used. The goal of ablation was to abolish all inducible VTs. A specific institutional tracking system for complications of invasive procedures was used to collect all periprocedural complications that were subsequently adjudicated. MVCs were defined as those that result in permanent injury or death, require intervention or treatment, prolong hospitalization (>48 hrs) or require new hospitalization. Idiopathic PVC/VT ablation was performed in 656 pts (males: 50%, age: 51 ± 17 years, re-ablations: 15%). SHD VT was ablated in 1637 pts (males: 88%, age: 63 ± 13 years, re-ablations: 30%, ischemic cardiomyopathy: 65%, left ventricular ejection fraction: 34 ± 13%, electrical storm: 24%). In idiopathic PVC/VT, MVCs were observed in 2.4 % (4.0% in males vs. 0.9% in females, P <0.01). In SHD, the rate of MVCs reached 3.5 % (2.8% in males vs. 9.4% in females, P <0.00001). Based on the multivariable regression model, the composite risk score to predict MVCs was proposed that was calculated as a sum of risk points for age (0, 1, 2, and 3 points for <50, 50–59, 60–69, and ≥70 years, respectively), female gender (2 points), and serum creatinine >1.3mg/dL (2 points), range 0–7 (Figure). While in an idiopathic setting, MVCs were more frequent in males, which may reflect a higher proportion of more complex LV ablations and arterial access, there was a significant female predominance in MVCs in SHD. The composite risk score predicts the risk of MVCs independently of VT cause.

The predictive value of Tp-Te interval, Tp-Te/QT ratio, and QRS-T angle of idiopathic ventricular tachycardia in patients with ventricular premature beats.

Identify idiopathic ventricular tachycardia in patients with ventricular premature beats was required to have effectively treatment. The aim of this study is to investigate the predictive value of Tp-Te interval, Tp-Te/QT ratio, and QRS-T angle of idiopathic ventricular tachycardia in patients with idiopathic ventricular premature beats. One hundred and seventy-eightpatients who had undergone premature ventricular complex/ventricular tachycardia (PVC/VT) ablation between January 1,2020 and August 30, 2022 constituted our study population as ventricular arrhythmia group. Seventy-fivehealthy people were selected as control group. Patients with no episode of VT were classified as PVC group, while with any episode of VT that has the same morphology with PVC were classified as PVC with VT group. Patients in PVC with VT group were divided into two groups: nonsustained VT group (duration of any episode of VT below 30 s) and sustained VT group (duration of any episode of VT over 30 s). Tp-Te interval, Tp-Te/QT ratio and QRS-T angle were compared in groups. Tp-Te interval, Tp-Te/QT ratio and patients with increased QRS-T angle in PVC with VT group were higher or more than those in PVC group (p < .001). The value of combined diagnosis of these indexes was higher. Tp-Te interval was longer in the sustained VT group compared to the nonsustained VT group (p = .009). Tp-Te interval, Tp-Te/QT ratio, and QRS-T angle may have a predictive value of presence of idiopathic VTin patients with premature beats and the combined prediction of these indexes is more valuable. Tp-Te interval maybe helpful for prediction of sustained idiopathic VT.

Idiopathic Ventricular Tachycardia.

Idiopathic ventricular tachycardia (VT) is an important cause of morbidity and less commonly, mortality in patients with structurally normal hearts. Appropriate diagnosis and management are predicated on an understanding of the mechanism, relevant cardiac anatomy, and associated ECG signatures. Catheter ablation is a viable strategy to adequately treat and potentially provide a cure in patients that are intolerant to medications or when these are ineffective. In this review, we discuss special approaches and considerations for effective and safe ablation of VT arising from the right ventricular outflow tract, left ventricular outflow tract, left ventricular fascicles, papillary muscles, and moderator band.

Catheter ablation of idiopathic left fascicular ventricular tachycardia: Implications of false tendons for mapping and ablation.

The anatomical substrate for idiopathic left ventricular tachycardia (ILVT) remains speculative. Purkinje networks surrounding false tendons (FTs) might be involved in the reentrant circuit of ILVT. The objective was to evaluate the anatomical and electrophysiological features of false tendons FTs in relation to ILVT. Intracardiac echocardiography (ICE) was conducted on patients with ILVT. The relationship of the FTs with ILVT was determined using electro-anatomical mapping. Electrophysiological evaluation and radiofrequency ablation were conducted in 23 consecutive patients with ILVT. FTs were identified in 19/23 cases (82.6%) with P1 potentials during VT recorded at the FT in 14 of these patients (73.7%). Three FT types were identified. In type 1, the FT attached the septum to the base of the posteromedial papillary muscle (PPM) (4/19); type 2 FTs ran between the septum and the PPM apex (3/19), while in type 3, the connection occurred between the septum and apex (11/19) or between the septum and the LV free wall (1/19). The effective ILVT ablation sites were situated at the FT-PPM (3/19) and the FT-septum (16/19) attachment sites. This series demonstrates the association between Purkinje fibers and FTs during catheter ablation of ILVT and verifies that left ventricular FTs are an important substrate in this type of tachycardia.

Repetitive multiform narrow complex tachycardia

A 73-year-old man presented to the emergency department with palpitations. After experiencing transient exertional palpitations and dyspnea a few months earlier, investigation revealed moderate left ventricular dysfunction and extensive coronary artery disease with evidence of prior inferior infarction. He underwent bypass grafting and remained symptom free with normalization of his ejection fraction until the current presentation. Figure 1 demonstrates his presenting rhythm that did not respond to adenosine but terminated with intravenous diltiazem. What is the most likely mechanism of the tachycardia? Figure 1 shows a regular narrow complex tachycardia with 3 distinct alternating QRS morphologies: (1) right bundle branch block (RBBB), V1 R 120 ms, V4 precordial transition, left superior axis; (2) RBBB, V1 rsRʹ 100 ms, positive precordial concordance, left superior axis; and (3) RBBB, V1 R 100 ms, positive precordial concordance, left superior axis. The RBBB and left superior axis of all 3 morphologies suggest that the ventricles are activated via the left posterior fascicle, or at the very least, there is early engagement of this fascicle. While supraventricular tachycardia with aberrant conduction is theoretically possible, varying ventricular morphologies in this fashion, lack of termination with adenosine, and the relatively narrow QRS duration (<130 ms) would make this less likely. Together with the response to diltiazem, the overall evidence suggests ventricular tachycardia involving the left posterior fascicle. The classic form of idiopathic fascicular ventricular tachycardia involves the left posterior fascicle, in which there is slow antegrade conduction along abnormal Purkinje fibers in the mid-septum (resulting in P1 potentials) and conduction over the left posterior fascicle (resulting in P2 potentials).1Nogami A. Naito S. Tada H. et al.Demonstration of diastolic and presystolic Purkinje potentials as critical potentials in a macroreentry circuit of verapamil-sensitive idiopathic left ventricular tachycardia.J Am Coll Cardiol. 2000; 36: 811-823Crossref PubMed Scopus (218) Google Scholar In any individual patient, variable relationships of the abnormal Purkinje fiber to the left posterior fascicle can result in a more basal or apical site of breakout to the left ventricle; these differences can often be suggested on the surface electrocardiogram by the width of the QRS complex and the precordial transition.2Liu Q. Shehata M. Jiang R. et al.Macroreentrant loop in ventricular tachycardia from the left posterior fascicle: new implications for mapping and ablation.Circ Arrhythm Electrophysiol. 2016; 9e004272Crossref Scopus (7) Google Scholar,3Ma W. Lu F. Shehata M. et al.Catheter ablation of idiopathic left posterior fascicular ventricular tachycardia: predicting the site of origin via mapping and electrocardiography.Circ Arrhythm Electrophysiol. 2017; 10e005240Crossref PubMed Scopus (1) Google Scholar Sung et al4Sung R.K. Kim A.M. Tseng Z.H. et al.Diagnosis and ablation of multiform fascicular tachycardia.J Cardiovasc Electrophysiol. 2013; 24: 297-304Crossref PubMed Scopus (29) Google Scholar described multiform fascicular QRS complexes due to alternate conduction over the left anterior fascicle and the left posterior fascicle from the septal fascicle, but the QRS forms described in the present report are different. Idiopathic fascicular ventricular tachycardia typically occurs in patients with structurally normal hearts, which was not the case in the present report. However, abnormal Purkinje fibers have also been implicated in a minority of patients with ischemic ventricular tachycardia and extension of inferoposterior scar to the left posterior fascicle.5Bogun F. Good E. Reich S. et al.Role of Purkinje fibers in post-infarction ventricular tachycardia.J Am Coll Cardiol. 2006; 48: 2500-2507Crossref PubMed Scopus (121) Google Scholar In this case, it was hypothesized that different QRS morphologies were due to varying sites of left ventricular breakout (Figure 2). The patient underwent electrophysiology study, where multiple episodes of ventricular tachycardia were able to be induced with ventricular extrastimuli similar to those seen on presentation. Ablation of the left posterior fascicle was undertaken, with subsequent noninducibility and no further episodes after 12 months of follow-up.

Anaesthetic management of pregnant patient with idiopathic ventricular tachycardia for emergency caesarean section

Anaesthetic management of pregnant patient with idiopathic ventricular tachycardia for emergency caesarean section