Transient changes in QRS morphology during a narrow complex tachycardia: What is the mechanism?

A22‐year‐old man with recurrent episodes of tachycardia inthe absence of structural heart disease underwent an electro-physiological evaluation. A narrow complex tachycardia (NCT)was induced by programmed by ventricular pacing. A transientchange in QRS morphology and H‐V interval in the middle of thetracing was noted during ongoing tachycardia (Figure1). What arethepossiblemechanismsoftachycardia and changes in QRS morphology

Inadvertent right ventricular apical exit after stereotactic body radiotherapy for ventricular tachycardia: Every cloud has a silver lining

A 78-year-old man suffering from gastric cancer with ischemic cardiomyopathy and recurrent ICD shocks consented to ventricular tachycardia (VT) ablation. He had a previous endocardial VT ablation 1 year ago, and a stereotactic radioablation for his recurrent VT 4 months ago. We planned again left ventricular endocardial mapping for his incessant slow VT suggesting an apical exit site (Figure 1A). However, the activation mapping of LV did not cover the whole VT cycle length, and we decide to map the right ventricular septal side instead of the epicardial access due to the patient's poor frailty. Fortunately, the mid-diastolic potential (MDP) was acquired in an unusual position (Figures 1A and 1B); however, the pericardial location of the mapping catheter was confirmed fluoroscopically (Figures 1C and 1D). An urgent surgical consultation was called for, and operative preparations were initiated. However, since no pericardial tamponade occurred and blood pressure remained stable, we continued the endo-epicardial ablation by ablating the MDP (Video 1)

Cardiac magnetic resonance-guided conducting channel delineation of an aneurysmal ventricular tachycardia with the same circuit in the reverse direction

A 54-year-old male patient with remote inferior wall myocardial infarction with inferoseptal left ventricular (LV) aneurysm (Figure 1A, Video 1) was referred for ablation of hemodynamically tolerated ventricular tachycardia (VT). Image processing (ADAS 3D Galgo Medical, Barcelona, Spain) was used to reconstruct myocardial scar from cardiac magnetic resonance (CMR) and to identify channels of heterogeneous tissue that could be directly involved in the VT reentry circuit (Figure 1B, Videos 2-4). Then, this 3-dimensional (3D) CMR analysis was uploaded into 3D electroanatomic mapping system (CARTO® Biosense Webster Inc., Diamond Bar, CA, USA)

Reply to letter to the editor: '2D LGE or 3D high-resolution LGE: Role of cardiovascular magnetic resonance imaging in the treatment of ventricular arrhythmias'

We are pleased that our paper raised interest among readers of the Anatolian Journal of Cardiology. Even though the late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) imaging was first established for ventricular tissue characterization in localizing ventricular tachycardia (VT) ablation targets (CMR-aided), it is by now widely used as a clinical tool to guide VT ablation (CMR-guided) through the detection of the arrhythmogenic substrate and conducting channels. While the CMR-derived information has been used alongside electroanatomic mapping (EAM) data to aid VT ablation (CMR-aided), the CMR-guided approaches, where EAM acquisition is completely avoided, make procedures faster, and the operator relies solely on imaging data.1 As the authors reported, the analysis of CMR images with software, which is known as ADAS (ADAS 3D, Barcelona, Spain), is very helpful for identifying these conducting channels.2 The preliminary results showed that the mean procedure duration was lower in CMR-guided when compared to CMR-aided and No-CMR substrate ablation (109 ± 61 vs. 206 ± 70 and 233 ± 48 minutes, respectively; P <.001 for both comparisons).1 VOYAGE is a prospective, randomized, multicenter controlled open-label study designed to compare in terms of efficacy, efficiency, and safety of a CMR-aided or guided workflow to standard EAM-guided VT ablation

The width of life is more important than the length of life

A 58-year-old man with previous inferior myocardial infarction (MI) was referred for cardiac resynchronization therapy pacemaker (CRT-P) for decreased left ventricular ejection fraction (LVEF; 45%) and left bundle branch block (LBBB) (Figure 1). He had New York Heart Association Class I functional classification but palpitation for 3 months. General physical and cardiac examinations were normal. On the admission day, the electrocardiogram showed a narrow QRS rhythm with and without tachycardia (Figures 2 and 3). Would you recommend or consider a CRT-P device or a CRT defibrillator or only an implantable cardioverter defibrillator (ICD) based on these clinical and electrocardiographic findings, or ablation or medical therapy only

Change in atrial activation patterns during narrow complex tachycardia: What is the mechanism?

A change in the coronary sinus (CS) activation pattern from an eccentric to a concentric pattern during the ablation of an orthodromic reciprocating tachycardia might falsely suggest the presence of a second (septal) accessory pathway (AP) during tachycardia or the successful ablation of the left lateral AP under ventricular pacing despite persistent and unaffected AP conduction. Complete or partial intra-atrial block should be suspected when an abrupt change in the atrial activation sequence is noted during catheter ablation at the posterolateral and lateral aspects of the mitral annulus. The correct anatomical position of the CS catheter plays a vital role in the differential diagnosis of this situation

Convergent double coronary sinus potentials during atrial tachycardia

The analysis of the patterns and timing of coronary sinus activation provides a rapid stratification of the most likely macro-re-entrant atrial tachycardias and points toward the likely origin of centrifugal ones by comparing the left atrial and coronary sinus activation sequence and morphology during sinus rhythm and atrial tachycardia. The analysis of both the near- and far-field electrogram morphology of atrial signals also gives important clues in determining the mechanism of the arrhythmia

The roles of pre–P-wave versus peri–P-wave fractionated electrograms for atrial substrate beyond entrainment response

Atrial tachycardia (AT) with alternating cycle lengths is sparsely reported, and, hence, the ideal mapping strategy has not been firmly established. Beyond the entrainment during tachycardia, some fragmentation characteristics might also give important clues for its possible participation in the macro–re-entrant circuit. We discuss a patient with prior atrial septal defect surgical closures who presented with dual macro–re-entrant ATs related to a fragmented area on the right atrial free wall (240 ms) and the cavotricuspid isthmus (260 ms), respectively. After ablation of the fastest AT on the lateral right atrial free wall, the cycle of the first AT changed to the second AT that was interrupted on cavotricuspid isthmus, proving the dual tachycardia mechanism. This case report addresses the utilization of electroanatomic mapping information as well as fractionated electrogram timing with respect to the surface P-wave as guides for ablation location

Stereotactic body radioablation therapy as an immediate and early term antiarrhythmic palliative therapeutic choice in patients with refractory ventricular tachycardia

Background: Stereotactic body radioablation therapy (SBRT) has recently been introduced with the ability to provide ablative energy noninvasively to arrhythmogenic substrate while reducing damage to normal cardiac tissue nearby and minimizing patients’ procedural risk. There is still debate regarding whether SBRT has a predominant effect in the early or late period after the procedure. We sought to assess the time course of SBRT’s efficacy as well as the value of using a blanking period following a SBRT session. Methods: Eight patients (mean age 58 ± 14 years) underwent eight SBRT sessions for refractory ventricular tachycardia (VT). SBRT was given using a linear accelerator device with a total dose of 25 Gy to the targeted area. Results: During a median follow-up of 8 months, all patients demonstrated VT recurrences; however, implantable cardioverter-defibrillator (ICD) and anti-tachycardia pacing therapies were significantly reduced with SBRT (8.46 to 0.83/per month, p = 0.047; 18.50 to 3.29/per month, p = 0.036, respectively). While analyzing the temporal SBRT outcomes, the 2 weeks to 3 months period demonstrated the most favorable outcomes. After 6 months, one patient was ICD therapy-free and the remaining patients demonstrated VT episodes. Conclusions: Our findings showed that the SBRT was associated with a marked reduction in the burden of VT and ICD interventions especially during first 3 months. Although SBRT does not seem to succeed complete termination of VT in long-term period, our findings support the strategy that SBRT can be utilized for immediate antiarrhythmic palliation in critically ill patients with otherwise untreatable refractory VT and electrical storm