Indian Pacing and Electrophysiology Journal最新文献

Congenital long QT syndrome (LQTS) is a rare hereditary cardiac disorder characterized by prolongation of the QT interval on electrocardiogram (ECG), predisposing affected individuals to life-threatening arrhythmias. We present a case of a newborn with congenital LQTS and 2:1 atrioventricular (AV) block who presented with bradycardia and QT prolongation. Continuous intravenous lidocaine infusion was initiated, because of hypoglycemia with beta-blockers, resulting in stabilization of AV conduction and prevention of malignant arrhythmias. This case underscores the potential utility of lidocaine as an adjunctive therapy in managing refractory arrhythmias in newborns with congenital LQTS and AV conduction abnormalities.

Introduction: There is no prior report of an Aveir leadless pacemaker implantation into the atrial appendage via the internal jugular vein.

Case: A 44-year-old female patient with history of multiple ablations for sinus node dysfunction presented with symptomatic bradycardia. The patient had femoral veins <9mm, chronic pain at the femoral vein insertion sites, as well as a recent car accident with persistent leg pain due to femoral fractures. Placement of a leadless pacemaker was decided based on patient discretion. An Abbott Aveir AR leadless pacemaker was implanted via left internal jugular vein access without complication. Post device implantation showed threshold of 0.75V @0.4 ms, impedance of 340 Ω, Pwave of 4.4 mV. Six-month follow-up demonstrated a threshold of 0.5 V @0.2 milliseconds, impedance of 300 Ω and Pwave of 7.2 mV with 92 % pacing and predicted longevity of 12.7 years.

Discussion: The follow-up showed no complications in the patient. A similar approach may be feasible for other patients needing atrial leadless pacing, in which the transfemoral approach is not preferred.

Conclusion: Implantation of the Aveir AR leadless pacemaker into the right atrial appendage is feasible via the left internal jugular vein.

Introduction: Unipolar radiofrequency (RF) ablation using half-normal saline irrigation (UNIP-HNS) and bipolar RF ablation using normal saline irrigation (BIP-NS) are effective to treat arrhythmias from inside thick myocardium. However, differences between these two ablations when using a long application time had not fully been studied.

Methods: UNIP-HNS, BIP-NS and unipolar RF ablation using normal saline irrigation (UNIP-NS) were applied for 120 s (30 W and 20-g contact) to porcine endocardial wall (≧15.0 mm thickness).

Results: All ablations (30 applications each in UNIP-HNS and BIP-NS, and 20 applications in UNIP-NS) were successfully accomplished without steam-pop. Total impedance decline was largest in BIP-NS followed by UNIP-HNS and UNIP-NS. UNIP-HNS created larger surface lesions and greater maximum lesion width under the surface than those by UNIP-NS and BIP-NS. Endocardial lesion depth in UNIP-HNS and BIP-NS were deeper than that in UNIP-NS, but with no difference between UNIP-HNS and BIP-NS, when selecting non-transmural lesions. Similar results were obtained when all lesions (non-transmural and transmural) were included and endocardial lesion depth of the transmural lesions (13/30 applications of BIP-NS) was estimated as 50 % of the myocardial thickness. Lesion length in the transverse myocardial wall (endocardial plus epicardial lesions) was greatest in BIP-NS.

Conclusions: Longer application time ablation (30 W) targeting the thick myocardium was performable in UNIP-HNS and BIP-NS. Since a transmural lesion and/or a deeper lesion into the myocardial wall are created, BIP-NS is preferable if two ablation catheters can be positioned on either side of the target.

Unexplained change in parameters, despite good lead positions or odd ECG patterns following implant should lead to suspicion of lead swap, amongst other possibilities. An easy way to confirm this is by paying careful attention to device EGMs and recording the ECG by switching off one channel, and pacing single channel (in either AAI or VVI mode).

Leadless pacemakers have demonstrated potential as a transvenous pacing option in Adult Congenital Heart Disease patients. Aveir™ single-chamber (VR) leadless pacemakers have demonstrated safety in patients without congenital heart disease in a dual chamber approach. We present a case of dual-chamber pacing using the Aveir dual-chamber (DR) leadless pacemaker in a patient with repaired dextro-transposition of the great arteries with ventricular septal defect (VSD) surgical closure. A 26-year-old male patient with a history of transposition of the great arteries status post arterial switch and VSD repair neonatally had complicated second degree atrioventricular block and sinus node dysfunction necessitating pacemaker placement. Epicardial single-chamber ventricular pacemaker was placed neonatally, which was switched to dual-chamber pacemaker at age 17 due to malfunction. Recent fracture of pacemaker leads led to implantation of new dual chamber leadless pacemaker. Removal of previous pacemaker leads via mechanical extraction occurred and implantation of Aveir DR leadless pacemaker was performed under anesthesia via right femoral vein access without complication. Follow-up demonstrated Aveir VR threshold of 1.0V@0.2 ms, R-wave of 8.9mV, impedance of 490Ω, and the Aveir AR threshold of 0.75V@0.2 ms, P-wave of 3.7mV, and impedance of 400Ω. This case demonstrates safety and efficacy of dual chamber leadless pacemaker implantation in an ACHD patient.

Background: Macroreentrant atrial tachycardia (ATs) through epicardial conduction is depicted as a focal AT on 3-D mapping, i.e., pseudo-focal AT. A new feature of the Rhythmia mapping system (Boston Scientific), the "LUMIPOINT module", can highlight all electrocardiograms (EGMs) above a threshold determined by an adjustable confidence slider (CS). Lowering the CS (L-CS) may highlight undetected electrograms (EGMs) at the nominal CS setting, potentially enabling visualization of the critical isthmus of pseudo-focal ATs.

Methods and results: This study included 3 ATs after linear ablation of two left atrial roof-dependent ATs (cases 1 and 2) and one peri-mitral flutter (case 3). All ATs were diagnosed as pseudo-focal AT according to an electrophysiological study and the Rhythmia mapping system with the LUMIPOINT module. The L-CS method consisted of the following steps: 1. Set the LUMIPOINT activation window to the time difference before and after the linear ablation line. 2. Highlight the two regions before and after the linear ablation line. 3. Gradually lower the CS value from the nominal setting of 85 % by 5-10 %. By the L-CS method in cases 1-3, the 2-sided highlighted areas before and after the prior linear ablation lesion gradually expanded and eventually fused. EGMs at the fusion sites of the highlighted areas exhibited fragmented EGMs with a low voltage, where a single-shot ablation terminated the targeted ATs.

Conclusion: The L-CS method was useful for the visualization of residual gaps and identification of targeted ablation sites in cases of pseudo-focal AT after linear ablation of macroreentrant ATs.

Introduction: Conventional three-lead ambulatory electrocardiogram recording (3L-AECG) is used for the quantitative diagnosis of arrhythmias. However, the lack of crucial information, such as QRS morphology and orientation, renders the 3L-AECG incomplete for planning electrophysiological interventions. The 12-lead AECG (12L-AECG) merges the temporal resolution 3L-AECG with the spatial resolution of the standard electrocardiogram (S-ECG). Although it provides more detail, it is not widely used. This study aimed to verify whether the seven-electrode 12L-AECG and S-ECG have similar waveforms.

Methods: A questionnaire consisting of 240 side-by-side comparisons (12 leads from 20 patients) was created. These consisted of a QRS registered using the 12L-AECG and a QRS from the same patient, registered using the S-ECG. The questionnaire was submitted to cardiologists trained in electrophysiology. For each comparison, the evaluator assigned "similar" or "different" depending on their own judgment.

Results: Five cardiologists completed the questionnaire, resulting in 1200 answers. The AECG-12 was similar to the ECG in 84.50 % of the instances (95 % confidence interval [CI] 83.20-86.50). The interobserver agreement was moderate (0.542, p < 0.001). The similarity between specific leads ranged up to 98 % (95 % CI 92.96-99.76). No significant differences were found among patients (p = 0.407).

Conclusion: The seven-electrode 12L-AECG and S-ECG produced comparable waveforms. This similarity supports the use of 12L-AECG for accurate arrhythmia tracking and assists in planning electrophysiological procedures.

We described a premature ventricular contraction arising from the left coronary sinus cusp, in which we discussed about the interpretations of the signals recorded there. Our case provided further insights into the interpretation of signals recorded at the coronary sinus cusp during premature ventricular contraction ablation.