Complete free wall isolation of arrhythmogenic persistent left superior vena cava.

INTRODUCTION: Persistent left superior vena cava (PLSVC) is one of the major sources of triggers and drivers of atrial fibrillation (AF). There has been no established PLSVC ablation procedure to eliminate the arrhythmogenicity along the entire length of PLSVC. METHODS AND RESULTS: A 70-year-old woman with a history of two previous catheter ablations for AF, mitral valvuloplasty, and an unroofed coronary sinus-type atrial septal defect closure underwent the redo AF ablations. The AF trigger and driver were identified within the patient's enlarged PLSVC. The AF was treated by complete PLSVC free wall isolation. CONCLUSION: Complete PLSVC free wall isolation may be an effective ablation method to eliminate the arrhythmogenicity along the entire length of the PLSVC.

Quantitative analysis of fractionated electrogram area of left atrium during right atrial pacing as an indicator of left atrial electrical remodeling in patients with atrial fibrillation.

Background: The clinical significance of left atrial local electrogram fractionation after restoration of sinus rhythm in patients with atrial fibrillation (AF) has not been elucidated. Methods: We evaluated ultrahigh-resolution maps of the left atrium (LA) during RA pacing acquired after pulmonary vein isolation in 40 patients with AF. The association between low-voltage area (LVA, <0.5 mV), fractionated electrogram area (FEA, the highlighted area with LUMIPOINT™ Complex Activation), the interval from onset of LA activation to wavefront collision at the mitral isthmus (LA activation time), and wave propagation velocity (WPV) was evaluated quantitatively. Results: The total LVA, total FEA with ≥5.0 peaks or ≥7.0 peaks were 7.0 ± 7.9 cm2, 15.9 ± 12.9 cm2, and 5.2 ± 7.5 cm2, respectively. These areas were predominantly observed in the anteroseptal region. Total LVA, total FEA with ≥5.0 peaks, and total FEA with ≥5.0 peaks in the normal voltage area (NVA: ≥0.5 mV) correlated with LA activation time (R = 0.69, 0.75, and 0.71; each p < .0001). In the anterior wall, these areas correlated with regional mean WPV (R = -0.75, -0.83, and - 0.55; each p < .0001) and the extent of slow conduction area (SCA) with WPV <0.3 m/s (R = 0.89, 0.84, 0.33; p < .0001 for LVA and FEA, p < .05 for FEA located in NVA). The anterior wall FEA with ≥7.0 peaks and that in the NVA showed a better correlation in predicting anterior wall SCA (R = 0.92 and 0.86, each p < .0001). Conclusion: Quantitative analysis of FEA together with LVA may facilitate the assessment of LA electrical remodeling.

Pacing cycle length-dependent electrophysiologic changes in left atrium: Poor validity of using low-voltage area and slow conduction area under specific pacing cycle length as absolute substrates of atrial fibrillation.

BACKGROUND: Pacing cycle length (PCL)-dependent changes in left atrial (LA) electrophysiologic properties have not been fully elucidated. OBJECTIVE: We aimed to elucidate these changes using a high-resolution mapping system. METHODS: Forty-eight patients underwent atrial fibrillation ablation with RHYTHMIA HDx. Paired LA maps under a baseline PCL (600 ms) and rapid PCL (300 ms) were acquired after pulmonary vein isolation under right atrial appendage pacing. The PCL-dependent change in the low-voltage area (LVA; area with <0.5 mV bipolar voltage), LA activation time (interval from first LA activation to wavefront collision at lateral wall), regional mean voltage, regional mean wave propagation velocity, and slow conduction area (area with <0.3 m/s wave propagation velocity) were quantitatively analyzed. RESULTS: Under the rapid PCL, the total LVA was significantly increased (7.6 ± 9.5 cm2 vs 6.7 ± 7.6 cm2; P = .031), especially in patients with a 10 cm2 LVA on the baseline PCL map (21.5 ± 9.1 cm2 vs 18.1 ± 6.5 cm2; P = .013). The LA activation time was also prolonged (87.9 ± 16.2 ms vs 84.0 ± 14.0 ms; P < .0001). Although the rapid PCL did not decrease the regional mean voltage, it significantly decreased the regional mean wave propagation velocity and increased the slow conduction area in all measured regions. CONCLUSION: LVA and slow conduction area can be emphasized by rapid PCL LA mapping. There may be poor validity in using these areas as absolute atrial fibrillation substrates without considering the PCL-dependent changes.

The disease progression of end-stage atrial cardiomyopathy over three decades: a case report.

Background: Atrial cardiomyopathy (AtCM) has drawn attention as the pathophysiology related to cardiovascular events such as atrial tachyarrhythmia, congestive heart failure, and embolic stroke. As the concept of AtCM is relatively recent, the long-term clinical course of AtCM has not been reported. Case summary: Here, we describe a 78-year-old patient diagnosed with end-stage AtCM. He had started to visit our hospital due to paroxysmal atrial fibrillation (AF) and hypertrophic cardiomyopathy over three decades since the age of 45. During follow-up, he experienced cardiogenic embolism and pacemaker implantation due to sick sinus syndrome. At this time, he complained of palpitation due to AF and underwent catheter ablation. Regardless of de novo ablation, left atrial voltage mapping showed ultimately extensive scar in left atrium and pulmonary vein, suggesting that conventional AF ablation strategy was ineffective. From this finding, he was diagnosed with end-stage AtCM. In the review of the previous 12-lead electrocardiogram, P-wave amplitude was decreased, and PR duration was prolonged gradually. We performed only cavotricuspid isthmus ablation and ended the ablation session. After six months, he complained of dyspnoea on effort due to pacing-induced cardiomyopathy. Furthermore, before the cardiac resynchronization therapy with a defibrillator (CRT-D) upgrade, left atrial appendage thrombus was detected even under the administration of apixaban. After thrombolysis with warfarin, CRT-D upgrade the left ventricular ejection fraction was improved. Discussion: In this case, the patient slowly developed end-stage AtCM and experienced multiple cardiovascular events related to severe AtCM. We should care for the disease progression of AtCM with vigilance.

Recurrent Pericardial Effusion Resulting From Right Ventricular Free Wall Injury Caused by Leadless Pacemaker Tines.

An 87-year-old man developed delayed cardiac tamponade 55 min after leadless pacemaker implantation and recurrent pericardial effusion 20 days later. Electrocardiogram-gated enhanced cardiac computed tomography revealed that the leadless pacemaker tines on the lateral side had penetrated the right ventricular free wall. He underwent off-pump hemostatic surgery.

Early repolarization pattern associated with sudden cardiac death: long-term follow-up in patients with chronic heart failure.

BACKGROUND: Identification of patients with chronic heart failure (CHF) at a risk for sudden cardiac death (SCD) is an important objective. Early repolarization pattern (ERP) is associated with ventricular fibrillation in patients without structural heart diseases. Moreover, ERP was reported to be associated with SCD in patients with old myocardial infarction in a case-control study. However, little information is available on the prognostic significance of ERP in CHF patients. Thus, we aimed to investigate whether ERP is associated with SCD in CHF patients. METHODS AND RESULTS: The study population consisted of 132 consecutive outpatients with NYHA class I, II and III congestive heart failure and radionuclide left ventricular ejection fraction less than 40%. All patients underwent the standard 12-lead electrocardiogram at enrollment, where we assessed the presence of ERP using the criteria of J-point elevation ≥ 0.1 mV in at least 2 inferior or lateral leads. The primary endpoint of this study was SCD. At enrollment, 16 patients had ERP. During the follow-up period of 6.7 ± 3.5 years, 26 patients had SCD. Kaplan-Meier analysis showed that SCD was observed significantly more frequently in patients with ERP than in those without ERP (63% [10/16] vs 14% [16/116], P < 0.0001]. A multivariate Cox analysis revealed that ERP was significantly and independently associated with SCD (hazard ratio, 3.7; 95% confidence interval, 1.6-8.6; P = 0.002). CONCLUSION: ERP in inferior leads would be associated with an increased risk of SCD in CHF patients.

Left atrial anterolateral linear ablation for biatrial tachycardia via Bachmann's bundle, interatrial septum, and left atrial anterior wall under mitral isthmus block.

Biatrial tachycardia via Bachmann's bundle, interatrial septum, and left atrial anterior wall can be treated by left atrial anterolateral linear ablation without left atrial appendage isolation, even under mitral isthmus block.

First Report of Electromagnetic Interference Between Percutaneous Ventricular Assist Device and Implantable Cardioverter-Defibrillator.

Electromagnetic interference (EMI) between implantable left ventricular assist devices and cardiac implantable electronic devices has been observed. We demonstrated the first case of EMI between a percutaneous ventricular assist device and an implantable cardioverter-defibrillator, validated by an extra vivo simulation test. EMI might depend on the distance between devices. (Level of Difficulty: Advanced.).

Nifekalant unmasked residual gap of superior vena cava isolation by suppressing immediate recurrence of intra-superior vena cava fibrillation.

Nifekalant successfully suppressed intra-superior vena cava fibrillation, which complicated the evaluation of the gap of superior vena cava isolation.

Routine exercise testing could not predict T-wave oversensing in a patient after a subcutaneous implantable cardioverter-defibrillator implant.

Subcutaneous implantable cardioverter-defibrillators (S-ICDs) are susceptible to T-wave oversensing (TWOS) caused by high rate-dependent QRS-T morphology changes. We experienced an inappropriate S-ICD shock due to TWOS, which could not be predicted by routine exercise testing. A newly available high-pass filter might be effective for avoiding this.

Interferon Therapy Exacerbated Pulmonary Hypertension in a Patient with Hepatitis C Virus Infection: Pathogenic Interplay among Multiple Risk Factors.

Pulmonary arterial hypertension (PAH) is known to develop as a consequence of multiple genetic and/or non-genetic factors. A 27-year-old woman with chronic hepatitis C virus (HCV) infection developed severe PAH after interferon (IFN) therapy. Although most of the reported clinical courses of IFN-induced PAH are poor despite the discontinuation of IFN, the present patient was successfully treated with a triple combination therapy. In this report, we discuss the crosstalk among chronic HCV infection, IFN therapy, autoimmune disorders, and portal hypertension in the pathogenesis and development of PAH.

Continuous Renal Replacement Therapy for Pheochromocytoma Crisis With Multiple Organ Failure.

Pheochromocytoma crisis is a feared and potentially lethal complication associated with excess release of catecholamine from the tumor, which might lead to multiple organ failure (MOF). The definitive treatment for pheochromocytoma is surgical resection. To safely proceed with surgery, hemodynamic stabilization in the acute phase is indispensable, but it might be extremely challenging in case of pheochromocytoma crisis with MOF even if the sufficient pharmacological drugs would be administered. Catecholamine is a dialyzable substance and is removed by renal replacement therapy. In this report, we described 2 cases of pheochromocytoma crisis with MOF, in which we succeeded in controlling acute unstable hemodynamics by means of catecholamine removal with continuous renal replacement therapy. These cases suggest that continuous renal replacement therapy may be effective to manage unstable hemodynamics because of massive catecholamine excretion in patients with pheochromocytoma crisis and MOF.