Pace-Pacing and Clinical Electrophysiology最新文献

Background: The degree and time course of improvement in left ventricular (LV) function with treatment in patients with tachycardiomyopathy (TCMP) is highly variable. This study aims to clinically characterize the recovery of TCMP based on the extent and course of improvement in LV function and identify predictors of complete myocardial recovery.

Methods: In this prospective, single-center, observational study, patients with suspected TCMP who underwent successful tachyarrhythmia termination/control were included. Clinical and echocardiographic assessment of LV function was done at baseline, within 1 h after tachyarrhythmia termination, 24 h later, and at 12 weeks follow-up.

Results: Ninety-nine patients were enrolled in the study. Six patients had immediate normalization of LV ejection fraction (LVEF) with reversion to sinus rhythm and were labeled as "pseudo-TCMP"; the remaining 93 patients were included in the analysis. Based on complete versus partial normalization of LVEF at 12-week follow-up, 50 patients (53.8%) were labeled as completely recovered TCMP and 43 (46.2%) as partially recovered TCMP respectively. Causative arrhythmias included atrial fibrillation (38%), focal atrial tachycardia (28%), atrial flutter (22%), ventricular arrhythmias (11%), and orthodromic re-entrant tachycardia (2%). The LVEF at presentation was 0.25 ± 0.05 which improved to 0.36 ± 0.11 within 1 h after tachycardia termination (p < 0.0001), 0.41 ± 0.14 24 h later (p = 0.009) and to 0.52 ± 0.12 at 12 weeks follow-up (p < 0.0001). Male gender was the only differentiating statistically significant variable between completely recovered and partially recovered TCMP, 24 (48%) versus 30 (69.7%) respectively (p = 0.0339).

Conclusion: Nearly half of the TCMP patients have complete recovery of LV function at 12 weeks follow-up, while the other half have a partial recovery only. There was no robust predictor of complete myocardial recovery.

Immunotherapy has revolutionized cancer treatment in the last decade and has significantly improved patient survival. However, immunotherapy is associated with serious cardiac adverse events including myocarditis and conduction disturbances. In the literature, the mortality rate in patients with immunotherapy-associated myocarditis and complete AV block is reported to be approximately 60%. Current cardio-oncology guidelines provide a series of recommendations for the management of immune myocarditis (IM). However, there is no recommendation on whether or when pacemaker implantation should be performed in the setting of complete AV block associated with myocarditis. This gap in the literature has led to a trend in cardio-oncology practice to implant permanent pacemakers (PPMs) in a significant proportion of patients without waiting for a response to immunosuppressive therapy. However, in a significant proportion of patients undergoing PPM implantation, complete AV block resolves after immunosuppressive therapy. This suggests that in cases of complete AV block in the setting of IM, more robust clues are needed for PPM implantation. This review aims to present algorithms for the management of myocarditis and complete AV block, one of the most lethal complications of immunotherapy, to help fill this gap in the literature.

In a 55-year-old man with nonischemic cardiomyopathy, a unique tachycardia was recorded on a dual-chamber implantable cardioverter defibrillator (St. Jude Medical [Abbott]) as an automatic mode switch episode. This case report discusses the mechanism of tachycardia, how it can be differentiated from similar rhythms, and its clinical implications. The report explores device limitations in managing such tachycardias and presents reprograming strategies to prevent recurrence. This case emphasizes the importance of careful analysis of device-mediated arrhythmias and appropriate programming.

The importance of treating non-pulmonary vein (PV) foci is increasing with improvements in the durability of PV isolation. We describe two cases wherein non-PV foci were induced by mechanical irritation and conventional induction in the same area, which was impossible to induce after ablation, suggesting a relationship between mechanical irritation and induction of non-PV foci. In a recurrent case of non-PV foci, atrial fibrillation (AF) was induced only by mechanical irritation. No recurrence has been observed since the ablation of the area. Thus, treatment of the AF induction site with mechanical irritation could be considered an effective therapy for non-PV foci.

Bradycardia, atrial tachyarrhythmia, heart failure, residual shunts, and pulmonary hypertension (PH) are significant problems after congenital heart disease surgery. We performed His-bundle pacing (HBP) for drug-resistant PH with bradycardia in a woman post-total anomalous pulmonary venous return repair complicated by bradycardia, hypertension, PH, residual atrial shunts, and heart failure. Significant improvement in PH post-HBP was achieved without exacerbation of left ventricular function. We successfully closed the atrial shunts 12 months after HBP.

Background: The burden of atrial fibrillation (AF) hospitalizations in young patients is not well characterized. We aimed to study the burden, comorbidities, outcomes, and resource utilization of AF hospitalizations in young patients.

Methods: We conducted a retrospective analysis of all primary AF hospitalizations in patients 18-45 years of age using the National Inpatient Sample data from January 1, 2008 to December 31, 2019. We collected data on various clinical and socioeconomic features including demographics and clinical outcomes.

Results: AF hospitalizations decreased over time from 18.7 per 100,000 in 2008 to 13.0 per 100,000 in 2019 (p < 0.001). AF hospitalizations were higher amongst males compared to females (24.0 vs. 7.5 per 100,000), and higher in Black patients compared to other ethnicities (20.4 for Black vs. 15.6 for White vs. 8.5 Hispanic per 100,000). The utilization of electrical cardioversion increased from 17.6% in 2008 to 21.9% in 2019 (p < 0.001), and catheter ablation decreased from 7.1% in 2008 to 4.3% in 2019 (p < 0.001). Men were more likely to undergo electrical cardioversion than women (20.1% vs. 14.8%, p < 0.001). White patients were more likely to undergo electrical cardioversion (20.8% vs. 14.3% vs. 15.5%, p < 0.001) and catheter ablation (6.1% vs. 3.3% vs. 4.2%, p < 0.001) compared to Black and Hispanic patients, respectively. Patients in the highest income residence quartile were more likely to undergo electrical cardioversion (21.9% vs. 16.4%, p < 0.001) and catheter ablation (8.0% vs. 3.7%, p < 0.001) compared to patients in the lowest income residence quartile.

Conclusions: We found significant differences in inpatient AF management based on sex, ethnicity, and SES.

Background: Low-to-zero fluoroscopic navigation systems lower radiation exposure which improves health outcomes. Conventional x-ray fluoroscopy (CF) has long been the standard to guide to catheter location for cardiac ablation. With advancements in technology, alternative safety navigation systems have been developed. Three primary modalities commonly utilized are three-dimensional electroanatomic mapping (3D-EAM), magnetic navigation system (MNS), and intracardiac echocardiography (ICE), all of which can reduce radiation exposure during the procedure.

Objective: We aim to compare the efficacy and safety among ICE, EAM, MNS, and CF in ablation of atrioventricular nodal reentrant tachycardia (AVNRT).

Methods: This is a meta-analysis consisting of observational studies and randomized controlled trials, which evaluated the performance of navigation systems of catheter ablation in AVNRT patients. Primary endpoint was to access the AVNRT recurrence after the procedure during follow-up periods. Secondary endpoints were technical success, fluoroscopic time, fluoroscopic dose area product, radiofrequency ablation time, and adverse events. Random-effect model was applied for pooled estimated effects of included studies.

Results: A total of 21 studies (21 CF, 2 ICE, 9 EAM, 11 MNS) including 1716 patients who underwent catheter ablation for AVNRT treatment were analyzed. Of these, 16 were observational studies and 5 were randomized controlled trials.

Primary outcome: Point estimation of AVNRT recurrence showed ICE exhibited a pooled odds ratio (ORs) of 1.06 (95% confidence interval [CI]: 0.064-17.322), MNS with ORs of 0.51 (95% CI: 0.214-1.219], and EAM with ORs of 0.394 (95% CI: 0.119-1.305) when compared to CF.

Secondary outcomes: EAM had significant higher technical success with ORs of 2.781 (95% CI: 1.317-5.872) when compared to CF. Regarding fluoroscopy time, EAM showed the lowest time with mean differences (MD) of -10.348 min (95% CI: -13.385 to -7.3101) and P-score of 0.998. It was followed by MNS with MD of -3.712 min (95% CI: -7.128 to -0.295) and P-score of 0.586, ICE with MD of -1.150 min (95% CI: -6.963 to 4.662) with a P-score of 0.294 compared to CF, which has a P-score of 0.122. There were insignificant adverse events across the procedures.

Conclusion: AVNRT ablation navigated by low-to-zero fluoroscopic navigation systems achieves higher efficacy and comparable safety to conventional fluoroscopywhile also reducing risk of radiation exposure time.

Aims: In addition to well-documented tachycardias involving twin atrioventricular (AV) nodes, tachycardias involving a single node have been clinically experienced in right atrial isomerism (RAI). This study aimed to characterize the AV node involvement patterns and evaluate the outcome of ablation therapy in RAI patients with tachycardias.

Methods: We retrospectively analyzed the medical records of 16 RAI patients who underwent catheter ablation of tachycardias involving twin or single AV nodes at our center between April 2006 and March 2020.

Results: A total of 22 ablation procedures were performed in 16 patients. The median age and body weight were 2 years (range 20 months-31 years) and 11.2 kg (range 7.4-42 kg), respectively. Two QRS complexes were confirmed in 11/16 patients, and a single QRS complex in 5/16. The dominant AV node was anterior in 7/16. Four patterns of tachycardias were identified: tachycardias reciprocating between two AV nodes with retrograde conduction through the anterior AV node (3/16) or through the posterior AV node (4/16); and reentrant tachycardias involving the anterior AV node only (3/16) or posterior AV node only (6/16). Ablation successfully eliminated the tachycardias in 15/16 patients (93.8%). Recurrence was reported in 7/16 (44%) during a median follow-up period of 96.5 months. Five of those 7 patients underwent additional ablation, and the tachycardias were eliminated in 3/5 patients. None of the patients developed ventricular asynchrony after ablation.

Conclusion: Transcatheter ablation was effective in RAI patients with tachycardias involving twin or single AV nodes, and deterioration of the cardiac function was rare.

Introduction: Cold saline application through an irrigation catheter may induce reversible inhibition of submyocardial excitation, which may be used to identify in advance an ideal site for radiofrequency (RF) energy delivery around delicate areas.

Methods: An open irrigation catheter was positioned vertically or parallel with 10-g contact on coronary perfusing porcine hearts and the contacted myocardium was cooled by cold saline at 4°C (20 mL/min). A temperature electrode was inserted 2 mm below the myocardial surface (intra-myocardial temperature at approximately 2 mm below the surface [Temp-BS]). Pacing threshold inside the ventricular wall was measured using an eight-pole electrode plunge needle inserted 5-8 mm close to the ablation catheter, and percent increase of the pacing threshold by the cold saline application (%increase-PT) was calculated.

Results: During cooling, pacing at 10 V from the myocardial surface interrupted constant capture in 7/10 experiments in vertical and in 9/10 experiments in parallel ablation catheter contact. Minimum Temp-BS was not different in both catheter contact positions (25.9 ± 4.0°C in vertical vs. 25.4 ± 2.6°C in parallel). Large % increase-PT on the surface myocardium decreased as the myocardial depth became deeper, and > 150% increase was at a depth approximately 2-3 mm from the surface and > 120% increase around 6-7 mm from the surface. After cessation of cold saline application, the increased %increase-PT recovered to the pre-cooling values.

Conclusions: Cold saline application through an irrigation catheter reversibly inhibited submyocardial excitation. This simple method may have the potential to pre-determine the ideal ablation site in sensitive areas of the heart, although further studies and technological adjustments are required before clinical use.