Syncope Due to Iatrogenic Cava Vein Obstruction: Rare Complication of Cardiac Implantable Electronic Device Leads.

A 77-year-old female patient with multiple pacemaker leads experienced hypotension and syncope during right heart catheterization. Imaging studies revealed a stenotic inferior vena cava with superior vena cava obstruction and well-developed retrograde collateral vessels, suggesting that balloon obstruction of the sole venous return site caused low cardiac output leading to syncope.

Iatrogenic vertebral artery injury during catheter ablation treated using coil embolization.

The internal jugular vein (IJV) is occasionally used for blood access during catheter ablation. Additionally, accidental injury of the vertebral artery during an IJV puncture is a rare complication that can result in catastrophic events, such as death. However, vascular access complications cannot be completely prevented despite the introduction of ultrasound-guided punctures. Here, we present a case of a patient with symptomatic paroxysmal atrial fibrillation that required catheter ablation.

Clinical Significance of Atrial Tachyarrhythmia Duration for Ventricular Arrhythmia in Patients With Cardiac Resynchronization Therapy.

BACKGROUND: Atrial tachyarrhythmias (ATAs) are reportedly associated with ventricular arrhythmias (VAs). However, little is known about the association between ATA duration and the risk of VA. We investigated the relationship between ATA duration and subsequent VA in patients with a cardiac resynchronization therapy defibrillator (CRT-D).Methods and Results: We investigated associations between the longest ATA duration during the first year after cardiac resynchronization therapy (CRT) implantation and VA and VA relevant to ATA (VAATA) in 160 CRT-D patients. ATAs occurred in 63 patients in the first year. During a median follow-up of 925 days from 1 year after CRT implantation, 40 patients experienced 483 VAs. Kaplan-Meier analysis showed a significantly higher risk of VA in patients with than without ATA in the first year (log rank P=0.0057). Hazard ratios (HR) of VA (HR 2.36, 2.10, and 3.04 for ATA >30s, >6 min and >24 h, respectively) and only VAATA (HR 4.50, 5.59, and 11.79 for ATA >30s, >6 min and >24 h, respectively) increased according to the duration of ATA. In multivariate analysis, ATA >24 h was an independent predictor of subsequent VA (HR 2.42; P=0.02). CONCLUSIONS: Patients with ATA >24 h in the first year after CRT had a higher risk of subsequent VA and VAATA. The risk of VA, including VAATA, increased with the longest ATA duration.

N-terminal pro atrial natriuretic peptide as a prognostic marker of cardiac resynchronization therapy recipients.

Background: Although the dynamic changes of atrial natriuretic peptide (ANP) expressions in a failing heart are well-documented, the clinical implications of detailed measurements of each ANP molecular form processed from proANP remain unclear. Methods: Patients screening was conducted on patients who were eligible for cardiac resynchronization therapy (CRT) between 2014 and 2019 in our institution. Blood samples and echocardiographic parameters were collected on the day before and six months after implantation. Total ANP, proANP, and N-terminal fragment of proANP (NT-proANP) were examined as predictive biomarkers for cardiac death, left ventricular assist device implantation, and heart failure hospitalization following CRT implantation. Results: A total of 86 subjects (mean age 70 years, 64 males) who underwent successful CRT implantation were enrolled. Plasma levels of total ANP, proANP, and NT-proANP were not normally distributed [25.8 pM (interquartile range: 11.1-53.1), 2.2 pM (1.0-5.4), and 4.1 nM (2.4-7.1), respectively]. Over a median follow-up of 2.7 years, 31 patients (2 deaths and 29 heart failure hospitalizations) reached the endpoints. Among the different ANP forms, only NT-proANP emerged as an independent predictor of the composite outcome (adjusted odds ratio of 2.542 in those with levels above vs. below the median, 95 % confidence interval 1.151-5.615, p = 0.021). NT-proANP levels were associated with left atrial volume and left diastolic functional parameters and decreased in response to echocardiographic improvements at six months post-implantation (16 ± 44 % decrease in responders vs 18 ± 60 % increase in non-responders, p = 0.005). Conclusion: Pre-implantation NT-proANP levels could serve as a predictive factor for clinical outcomes in recipients of CRT.

Interference of cardiac implantable electronic devices and computed tomography imaging in the current era with a phantom model.

Introduction: Cardiac implantable electronic devices are used in patients with cardiac rhythm disorders. Computed tomography irradiation is not prohibited for patients with cardiac implantable electronic devices, despite adverse events being reported. Hence, appropriate preparation and knowledge are required before computed tomography irradiation can be carried out in these patients. Since there is limited knowledge or literature about the influence of computed tomography irradiation in cases with recent cardiac implantable electronic devices, we aimed to evaluate the adverse events and elucidate the necessary and sufficient safety measures associated with this therapy. Methods and Results: We placed cardiac implantable electronic devices on an anthropomorphic phantom model and observed their electrical activity in electrograms, while various protocols of computed tomography irradiation were implemented and adverse events evaluated. Oversensing with pauses of up to 3.2 s was observed in standard computed tomography protocols, but ventricular tachyarrhythmia or other clinically significant events could not be confirmed. Oversensing with pauses of up to 8.0 s was observed and ventricular tachyarrhythmia was detected in the maximum-dose protocols. However, treatments such as antitachycardia pacing or shock therapy for ventricular tachyarrhythmia were not observed because of their absence. Conclusion: Computed tomography irradiation for patients using cardiac implantable electronic devices is highly unlikely to cause clinically significant adverse events with the device settings and computed tomography protocols currently being used. Changing or monitoring the device settings routinely before computed tomography irradiation is not necessarily required for most patients.

Transvenous lead extraction versus surgical lead extraction or conservative treatment for cardiac implantable electronic device infections: Propensity score-weighted analyses of a nationwide claim-based database.

INTRODUCTION: Infection is one of the most important complications associated with cardiac implantable electronic device (CIED) therapy. The number of reports comparing the outcomes of transvenous lead extraction (TLE), surgical lead extraction, and conservative treatment for CIED infections using a real-world database is limited. This study investigated the association between the treatment strategies for CIED infections and their outcomes. METHODS: We performed a retrospective analysis of 3605 patients with CIED infections admitted to 681 hospitals using a nationwide claim-based database collected between April 2012 and March 2018. RESULTS: We divided the 3605 patients into TLE (n = 938 [26%]), surgical lead extraction (n = 182 [5.0%]), and conservative treatment (n = 2485 [69%]) groups. TLE was performed more frequently in younger patients and at larger hospitals (p for trend < .001 for both). The rate of TLE increased during the study period, whereas that of surgical lead extraction decreased (p for trend < .001 for both). TLE was associated with lower in-hospital mortality (vs. surgical lead extraction: odds ratio [OR], 0.20; 95% CI, 0.06-0.70; vs. conservative treatment: OR, 0.45; 95% CI: 0.22-0.94) and lower 30-day readmission rates (vs. surgical lead extraction: OR, 0.18; 95% CI: 0.06-0.56; vs. conservative treatment: OR, 0.06; 95% CI, 0.03-0.13) in propensity score-weighted analyses. CONCLUSIONS: Only 26% of patients hospitalized for CIED infections received TLE. TLE was associated with significantly lower in-hospital mortality and 30-day recurrence rates than surgical lead extraction and conservative treatment, suggesting that TLE should be more widely recommended as a first-line treatment for CIED infections.

Clinical Predictors of Pacing Device Implantation in Implantable Cardiac Monitor Recipients for Unexplained Syncope.

Background: Implantable cardiac monitors (ICMs) help investigate the cause of unexplained syncope, but the probability and predictors of needing a pacing device thereafter remain unclear. Methods: We retrospectively analyzed the data of patients who received ICM insertion for unexplained syncope with suspected arrhythmic etiology. The data were obtained from a nationwide database obtained between April 1, 2012 and March 31, 2020. Multivariable mixed-effects survival analysis was performed to identify predictors of pacing device implantation (PDI), and a risk score model was developed accordingly. Results: In total, 2905 patients (age: 72 years [range: 60-78]) implanted with ICMs to investigate the cause of syncope were analyzed. During the median follow-up period of 128 days (range: 68-209) days, 473 patients (16%) underwent PDI. Older age, history of atrial fibrillation, bundle branch block (BBB), and diabetes were independent predictors of PDI in multivariable analysis. A risk score model was developed with scores ranging from 0 to 32 points. When patients with the lowest quartile score (0-13 points) were used as a reference, those with higher quartiles had a higher risk of PDI (second quartile: 14-15 points, hazard ratio [HR]: 3.86, 95% confidence interval [CI]: 2.62-5.68; third quartile: 16-18 points, HR: 4.67, 95% CI: 3.14-6.94; fourth quartile: 19-32 points, HR: 6.59, 95% CI: 4.47-9.71). Conclusions: The 4 identified predictors are easily assessed during the initial evaluation of patients with syncope. They may help identify patients with a higher risk of requiring permanent PDI.

Contexte: Les moniteurs cardiaques implantables (MCI) aident à déterminer la cause d'une syncope inexpliquée, mais la probabilité et les facteurs prédictifs du besoin d'un dispositif de stimulation cardiaque par la suite demeurent incertains. Méthodologie: Nous avons analysé de façon rétrospective les données de patients s'étant fait implanter un MCI après une syncope inexpliquée et chez lesquels une étiologie d'arythmie était soupçonnée. Les données proviennent d'une base de données nationale et s'étendent du 1er avril 2012 au 31 mars 2020. Une analyse de survie multivariable à effets mixtes a été effectuée pour cibler les facteurs prédictifs de l'implantation d'un dispositif de stimulation cardiaque (IDSC), et un modèle de score de risque a été conçu en conséquence. Résultats: Au total, les cas de 2905 patients (âge : 72 ans [écart interquartile (ÉI) : 60-78]) ayant reçu un MCI pour déterminer la cause de la syncope ont été analysés. Durant la période de suivi médiane de 128 jours (ÉI : 68-209), 473 patients (16 %) ont subi une IDSC. L'âge avancé, les antécédents de fibrillation auriculaire, le bloc de branche et le diabète étaient des facteurs prédictifs indépendants de l'IDSC dans l'analyse multivariable. Un modèle de score de risque a été conçu, les scores allant de 0 à 32 points. Lorsque les patients ayant un score dans le quartile inférieur (0 à 13 points) étaient utilisés à titre de référence, ceux ayant un score dans les quartiles supérieurs avaient un risque plus élevé d'IDSC (deuxième quartile : 14-15 points, rapport des risques instantanés [RRI] : 3,86, intervalle de confiance [IC] à 95 % de 2,62 à 5,68; troisième quartile : 16-18 points, RRI : 4,67, IC à 95 % de 3,14 à 6,94; quatrième quartile : 19-32 points, RRI : 6,59, IC à 95 % de 4,47 à 9,71). Conclusions: Les quatre facteurs prédictifs ciblés sont faciles à évaluer durant l'évaluation initiale des patients ayant subi une syncope. Ils peuvent aider à repérer les patients présentant un risque plus élevé d'avoir besoin d'un dispositif de stimulation cardiaque permanent.

Adding interactive face-to-face lectures to passive lectures effectively reduces radiation exposure during atrial fibrillation ablation.

BACKGROUND: Radiation exposure remains a major concern for electrophysiologists and patients. This study aimed to investigate the effect of altering awareness of radiation exposure during atrial fibrillation ablation using interactive face-to-face (FTF) lectures compared to passive lectures. METHODS: Patients who underwent their first catheter ablation with radiofrequency energy for atrial fibrillation between January 2014 and December 2020 were included in this study. All operators attended an e-learning lecture on radiation exposure before catheter ablation. The addition of FTF lectures to this lecture was introduced in 2018. The effect on radiation exposure was compared between the pre-FTF and FTF periods by comparing fluoroscopy time and radiation dose. RESULTS: A total of 896 patients [mean age, 66 ±â€¯11 years; 603 men (67 %)] were included in this study. For pre-FTF (n = 345), only pulmonary vein isolation (PVI) was performed in 112 patients and PVI with additional ablation in 233 patients. For FTF lectures (n = 551), PVI-only was performed in 302 patients and PVI with additional ablation in 249 patients. Fluoroscopy time, cumulative air kerma, and cumulative air kerma per time significantly reduced after FTF introduction in both PVI-only group [pre-FTF and FTF; 37 ±â€¯15 min and 16 ±â€¯10 min (p < 0.0001), 477 ±â€¯582 mGy and 108 ±â€¯156 mGy (p < 0.0001), 11 ±â€¯12 mGy/min, and 5 ±â€¯6 mGy/min (p < 0.0001), respectively] and PVI with additional ablation group [pre-FTF and FTF; 48 ±â€¯17 min and 15 ±â€¯13 min (p < 0.0001), 613 ±â€¯483 mGy and 68 ±â€¯96 mGy (p < 0.0001), 12 ±â€¯10 mGy/min, and 4 ±â€¯4 mGy/min (p < 0.0001), respectively]. There were no significant differences in intraoperative complications between the two periods. CONCLUSIONS: FTF lectures can reduce radiation exposure.

Differences in patient characteristics, clinical practice and outcomes of cardiac implantable electric device therapy between Japan and the USA: a cross-sectional study using data from nationally representative administrative databases.

OBJECTIVES: To identify differences in patient characteristics, clinical practice and outcomes of cardiac implantable electronic device (CIED) therapy between Japan and the USA. DESIGN: A cross-sectional study. SETTING: Nationally representative administrative databases from Japan and the USA containing hospitalisations with first-time implantations of pacemakers, implantable cardioverter-defibrillators (ICD) and cardiac-resynchronisation therapy with or without defibrillators (CRTP/CRTD). PARTICIPANTS: Patients hospitalised with first-time implantations of CIEDs. OUTCOME MEASURES: In-hospital mortality, in-hospital complication and 30-day readmission rates. RESULTS: Overall, 107 339 (median age 78 (71-84), 48 415 women) and 295 584 (age 76 (67-83), 127 349 women) records with CIED implantations were included from Japan and the USA, respectively. Proportion of women in defibrillator recipients was lower in Japan than in the USA (ICD, 21% vs 28%, p<0.001; CRTD, 24% vs 29%, p<0.001). Length of stay after CIED implantation was longer in Japan than in the USA for all device types (conventional pacemaker, 8(7-11) vs 1 (1-3) days, p<0.001; leadless pacemaker, 5 (3-9) vs 2 (1-5) days, p<0.001; ICD, 8 (7-11) vs 1 (1-3) days, p<0.001, CRTP, 9 (7-13) vs 2 (1-4) days, p<0.001; CRTD, 9 (8-14) vs 2 (1-4) days, p<0.001). In-hospital mortality after CIED implantation was similar between Japan and the USA ((OR) (95% CI), conventional pacemaker 0.58 (0.83 to 1.004); ICD 0.77 (0.57 to 1.03); CRTP 0.85 (0.51 to 1.44); CRTD 1.11 (0.81 to 1.51)), except that after leadless pacemaker implantation in Japan was lower than that in the USA (0.32 (0.23 to 0.43)). 30-day readmission rates were lower in Japan than in the USA for all device types (conventional pacemaker 0.55 (0.53 to 0.57); leadless pacemaker 0.50 (0.43 to 0.58); ICD 0.54 (0.49 to 0.58); CRTP 0.51 (0.42 to 0.62); CRTD 0.57 (0.51 to 0.64)). CONCLUSIONS: International variations in patient characteristics, practice and outcomes were observed. In-hospital mortality after CIED implantation was similar between Japan and the USA, except in cases of leadless pacemaker recipients.

Structural characteristics of patients with superior vena cava foci initiating atrial fibrillation: Analysis with electrocardiogram-triggered computed tomography.

INTRODUCTION: The superior vena cava (SVC) is the most common source of non-pulmonary vein foci in atrial fibrillation (AF); therefore, predicting the existence of non-pulmonary vein foci before the catheter ablation procedure helps construct a proper ablation strategy in preparation for SVC isolation. This study aimed to clarify the structural characteristics of patients with SVC foci initiating AF. METHODS: We enrolled 331 consecutive patients with AF who underwent cardiac computed tomography imaging before radiofrequency catheter ablation treatment, and they were divided into SVC (+) and (-) groups based on the presence or absence of SVC foci initiating AF. RESULTS: The SVC (+) group (n = 27) exhibited SVC crescent signs-defined as a curve-shaped SVC with two narrow pointed ends-more frequently (37% vs. 9%, p < .001), and larger right atrial volume (95.6 ± 20.8 vs. 80.5 ± 26.1 mL, p = .004) than the SVC (-) group (n = 304). Multivariate logistic regression analysis revealed that the SVC crescent sign (odds ratio, 8.88; 95% confidence interval [CI], 3.21-24.60) and right atrial volume (odds ratio, 1.03; 95% CI, 1.01-1.04) were independent predictors of SVC foci. CONCLUSION: Patients with SVC foci exhibited more frequent SVC crescent signs and larger right atrial volumes, and these characteristics may help clinicians choose the appropriate ablation technology.

Incessant non-sustained ventricular tachycardia immediately after MitraClip placement: a case report.

Background: MitraClip therapy has become an alternative therapy for primary and secondary mitral regurgitation (MR) in patients at high surgical risk. However, this procedure is associated with several complications. Case summary: The patient was a 93-year-old male with severe MR caused by prolapse of the mid-posterior mitral leaflet (P2) and atrial enlargement. His heart failure (HF) continued to worsen, requiring hospitalization. Considering his high surgical risk, the heart team chose MitraClip treatment. After one clip was placed in the centre of the mitral valve (P2 lateral side), MR severity was reduced from severe to trivial. However, immediately after grasping, incessant non-sustained ventricular tachycardia (VT) with a heart rate of 150 beats/min occurred. Since there were no significant ST-T changes on electrocardiogram and no left ventricular (LV) wall motion abnormalities on echocardiography, ischaemic heart disease was ruled out, and pacing with a temporary pacemaker, potassium level correction, and intravenous amiodarone administration were performed. The frequency of VT decreased but it did not disappear. Diuretics were administered for HF, and VT disappeared within a few hours, with no recurrence, probably due to a decrease in the LV chamber size after diuresis. Discussion: The VT waveform showed a right bundle branch block pattern with a superior axis. Furthermore, a negative lead I and a transition zone with an abrupt change from V4 to V5 indicated that PVC/VT arose from the posterior papillary muscle area. The probable cause was mechanical extension of the posterior medial papillary muscle as a result of leaflet grasping, with resolution following appropriate volume management.

Impact of Pre-Ablation Direct Current Cardioversion for Persistent Atrial Fibrillation to Predict Recurrence of Atrial Fibrillation after Catheter Ablation.

The efficacy of direct current (DC) cardioversion before catheter ablation (CA) for persistent atrial fibrillation (PerAF) patients remains controversial. We hypothesized that maintenance of sinus rhythm (SR) by pre-ablation DC cardioversion may predict the outcome of CA in patients with PerAF. A total of 383 PerAF patients with no or mild symptoms (EHRA I/II) who had undergone DC cardioversion before CA (301 males, 65 ± 10 years old, mean atrial fibrillation (AF) duration: 25 ± 47 months) were retrospectively enrolled. Whether or not SR was maintained at least 24 hour after DC cardioversion, patients were divided into two groups, namely, the DC-SR group and DC-AF group, and then all were followed until AF recurrence after CA. After DC cardioversion, 281 (73%) patients were categorized into the DC-SR group, and 102 (27%) were categorized into the DC-AF group. A total of 195 patients underwent CA at an average of 83 (54-145) days after DC cardioversion, including 161 (83%) in the DC-SR group and 34 (17%) in the DC-AF group. During follow-up (median: 15 [10-25] months), the number of patients who were free from AF was significantly higher in the DC-SR group compared with the DC-AF group (61.5% versus 38.3%, P < 0.0001). Multivariate analysis revealed that the DC-SR group (hazard ratio [HR]: 0.45, 95% confidence interval [CI]: 0.21-0.99, P = 0.047) and age at first AF diagnosis (HR: 0.95, 95% CI: 0.91-1.00, P = 0.039) were the independent predictors for being AF-free after CA. In conclusion, the 24-hour rhythm outcome of pre-ablation DC cardioversion and age at first AF diagnosis may predict the recurrence of AF after CA in patients with PerAF.

Successful recovery from refractory hypoxia due to right-to-left shunting associated with iatrogenic atrial septal defect after catheter ablation in a patient with a left-ventricular assist device: a case report.

Background: Catheter ablation (CA) has been reported to be an effective therapeutic option for ventricular arrhythmias, even in patients with a left-ventricular assist device (LVAD). However, the issues of right-to-left shunting due to iatrogenic atrial septal defect (iASD) associated with procedures for CA have not been well documented. We describe a rare case of refractory hypoxia associated with right-to-left shunting via iASD after CA through the transseptal approach in an LVAD patient. Case summary: A 52-year-old Asian man with a continuous-flow implantable LVAD and progressive right ventricular (RV) dysfunction was admitted because of refractory ventricular tachycardia (VT) and subsequent right heart failure. Since VT could not be controlled by intravenous administration of multiple antiarrhythmic drugs, VT ablation via the transseptal approach was performed. Ventricular tachycardia was terminated to the sinus rhythm after VT ablation; however, hypoxia associated with significant right-to-left shunting across the iASD was detected. Intensive medical management, such as an adjusted mechanical ventilator to increase pulmonary vascular compliance and adjustment of LVAD pump speed, as well as the use of intravenous inotropes to support impaired RV function successfully stabilized the haemodynamic and improved hypoxia for the disappearance of right-to-left shunting. Echocardiography at 7 months after CA showed that the significant iASD and right-to-left shunting had disappeared. Discussion: The evaluation of RV function prior to VT ablation via the transseptal approach is important in the postoperative management of patients with LVAD, because RV dysfunction may cause refractory hypoxia due to iASD.

Paroxysmal atrial fibrillation as a predictor of pacemaker implantation in patients with unexplained syncope.

BACKGROUND: Recent studies using an implantable loop recorder (ILR) have reported on clinical predictors of pacemaker implantation in patients with unexplained syncope. However, atrial fibrillation (AF) was not included as a risk factor; this may be because the precise mechanism of AF (persistent or paroxysmal) has not been explicitly investigated. Thus, this study aimed to investigate the relationship between paroxysmal AF and cardiac syncope recurrence requiring pacemaker implantation in patients with an ILR owing to unexplained syncope. METHODS: We included consecutive patients who underwent ILR implantation for unexplained syncope between September 2010 and July 2020. ILR implantation was indicated for syncope that could not be explained even after comprehensive evaluation. RESULTS: Overall, 128 patients (72 men; mean age, 62.5 ±â€¯21.1 years) underwent ILR evaluation. Paroxysmal AF was diagnosed before ILR implantation in 32 patients. Bradyarrhythmia with an indication for pacemaker implantation was detected in 33 patients. The number of syncopal episodes (≥ 3) in the previous 2 years, history of paroxysmal AF/asymptomatic sinus arrest, and bundle branch block were independent predictors of pacemaker implantation. Among patients with a history of paroxysmal AF, the PR interval was longer in those who required pacemaker implantation than in those who did not (194.8 vs 168.8 ms; p = 0.0356). CONCLUSIONS: Paroxysmal AF is a significant predictor of recurrent syncope, leading to pacemaker implantation in patients with unexplained syncope. Careful history taking of paroxysmal AF is essential, and aggressive use of ILR is recommended to detect bradycardic events.