bluuebunny/crossref_metadata_2025 huggingface dataset:
Non-revascularized chronic total occlusion is associated with worse outcomes in post-MI drug-refractory electrical storm patients treated by catheter ablation
Authors: Cojocaru C , Nastasa A , Iorgulescu C , Bogdan S , Popescu S , Gondos V , Vatasescu R
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Background/Introduction

Outcomes in post-myocardial infarction (MI) patients which are referred for catheter ablation (CA) for drug-refractory electrical storm (ES) are influenced both by patient characteristics and procedural results. Previous data has shown higher risk for the first incident ES episode in the presence of non-revascularized chronic total occlusions (nCTOs). However, the prognostic effect of nCTOs in post-ES ablation patients is relatively unknown.

Purpose

We evaluated the impact of the presence of nCTO on all-cause mortality and sustained VT recurrence rate after CA for ES in post-MI patients.

Methods

In this single centre retrospective longitudinal study, we included consecutive post-MI patients referred for CA for drug-refractory ES. The median follow-up interval was 34.36 (7.25-63.65) months. CA outcome was defined by the absence or presence of residual sustained monomorphic VT at end-procedural programmed ventricular stimulation (PVS). Coronary angiography was performed prior to ablation in all patients.

Results

Sixty-four patients were included (85.9% (n = 55) males, age 62.64 ± 11.13 years). The mean left ventricular ejection fraction (LVEF) was 31.41 ± 10.99. There were 18.8% (n = 12) patients with nCTOs. Residual sustained monomorphic VT inducibility was documented in 28.1% (n = 18) cases. There were 29.7% (n = 19) deaths and sustained VT recurrences, respectively, during the monitored interval. Nine out of twelve (75%) nCTO patients died during follow-up. The presence of a nCTO induced a borderline significant higher risk of sustained VT recurrence during follow-up (HR 2.527, CI.95% 0.992 – 6.435, p = 0.052) in univariable Cox regression. In addition to age and residual sustained monomorphic VT at PVS, a multivariable Cox regression model identified the presence of nCTO as an independent predictor for all-cause mortality (HR 3.194, CI 95% 1.212-8.420, p = 0.019) (Figure 1).

Conclusion(s)

The presence of a nCTO in post-MI patients may be associated with higher all-cause mortality and sustained VT recurrences after ablation for drug-refractory electrical storm.
Ventricular conduction is a marker for arrhythmic risk in overlap sodium channel disease
Authors: Wijeyeratne Y , Tanck M W , Mckeown P P , Probst V , Crotti L , Page S , Galvin J , Petzer E , Horie M , Roden D , Veltmann C , Makita N , Aiba T , Ackerman M J , Behr E R
Published: May 2023

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): National Institute of Health Research

St George's, University of London

Background

SCN5A-E1784K (c.5350G>A) is the most common variant associated with the LQT3 long QT syndrome (LQTS) and Brugada syndrome (BrS). It exhibits incomplete penetrance and can manifest variably as a mixed clinical phenotype of LQTS, BrS and/or conduction disorders (1-4). This presents a challenge for risk stratification and optimal management. We aimed to describe the clinical characteristics and risk markers in a large, well characterised international cohort of SCN5A-E1784K subjects and identify demographic and/or ECG parameters associated with event free survival.

Methods

Comprehensive clinical data, including initial presentation and follow-up data, were collected from SCN5A-E1784K subjects. Outcome ‘events’ included sudden death, aborted cardiac arrest, and documented VF or VT or arrhythmic syncope. ‘Lethal events’ included sudden death, aborted cardiac arrest or documented VF or VT. Associations between clinical characteristics and event free survival were investigated using Cox proportional hazard regression models.

Results

SCN5A-E1784K subjects (n=231) were recruited from 16 centres. Median follow up was 24.9 years (15.2 - 43.3) and 45 individuals (19%) experienced an event. Lethal events were observed in 14 subjects (6%). Figure 1 shows event (A) and lethal event (B) free survival in SCN5A-E1784K subjects. Higher QRS duration (corrected for age) was associated with shorter event-free interval. QRS duration was the only characteristic associated with increased risk with a hazard ratio (HR) of 1.04 or 1.05 per ms for events and lethal events, respectively. The observed survival for events and lethal events for QRS tertiles are shown in Figure 2.

Discussion

Ventricular myocardial conduction, as evidenced by QRS duration, appears to play a role in the risk of arrhythmic events in patients with SCN5A-E1784K. Corrected QT interval and BrS phenotype were, however, not associated with risk. This provides an important opportunity for the personalisation of risk stratification of these patients, whose management can otherwise be very challenging. Figures
Resting heart rate does not refine risk stratification of sudden cardiac death in the general population
Authors: Warming P E , Aagesen F N , Garcia R , Lynge T H , Jabbari R , Prescott E , Banner J , Tfelt-Hansen J
Published: May 2023

Funding Acknowledgements

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): Horizon 2020

Background

Sudden cardiac death (SCD) is a major public health issue in which most events occur in the general population. Although resting heart rate is associated with SCD, its added value regarding prediction is unknown. Methods for risk stratification and prediction are needed to help prevent future SCD.

Purpose

The aim of this study was to assess the association between resting heart rate (RHR) and SCD in the general population.

Methods

Participants from the Copenhagen City Heart Study in sinus rhythm with baseline RHR between 40 and 120 bpm were followed from 1993 to 2016. Deaths were adjudicated, by two cardiologists, using death certificates and autopsy reports. Associations between RHR and SCD was investigated using cause specific cox models. The added value of RHR in predicting SCD was investigated by adding RHR to an already published prediction model (including age, sex, cholesterol, statin use, hypertension, systolic and diastolic blood pressure, current smoking status, diabetes, and body mass index (Bogle 2018)). RHR was evaluated as a continuous covariate with a linear effect. Prediction performance measures were evaluated using bootstrap cross validation.

Results

The study included 10,099 participants of which 8,986 fulfilled inclusion criteria (median age 60 (25%-75%: 47-70), 57% female). During 24 years of follow-up 4,668 deaths including 656 SCD were observed. Mean RHR was 73 bpm (SD 12.4). Increasing HR was associated with incidence of SCD (HR 1.18 (95% CI: 1.12-1.26) per 10 bmp), however, almost to the same extend with death from other causes (HR 1.14 (1.11-1.17). History of AMI and baseline hypertension were differentially associated with the two outcomes, but not RHR (figure 1). We find no added value when including RHR in a prediction model (AUC at 10 years 80.6 vs 80.4 (figure 2), Brier score 3.1 vs 3.1). Allowing for a more flexible RHR-fit (non-linear effect and interaction) did not improve predictions.

All results were consistent in sensitivity analyses (only individuals <70 years at entry, censoring after 10 years of follow up, only the most certain SCD diagnoses).

Conclusion

In the general population, even if RHR was associated with SCD, it did not refine risk stratification when added to a model previously published.
Artificial intelligence predicts all-cause and cardiovascular mortalities using 12-lead electrocardiography in sinus rhythm
Authors: Park J W , Kwon O S , Kim D H , Yu H T , Kim T H , Uhm J S , Joung B Y , Lee M H , Hwang C , Pak H N
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Introduction

Electrocardiography (ECG) can be easily obtained at a low cost and includes voltage and time interval representing heart conditions. We hypothesized that artificial intelligence (AI) detects a subtle abnormality in 12-lead ECG and may predict individual mortality.

Methods

Among 502,411 population in UK Biobank, 42,096 individuals had 12-lead ECG from 2013 to 2022. Among population with available ECG, 4,512 individuals were enrolled in this study adjusting the following inclusion criteria; age under 60 years, sinus rhythm, PR interval 120~200ms, QTc interval 350~460ms, and QRS duration 70~100ms. We developed and tested convolutional neural network (CNN) model to predict all cause death, cardiovascular (CV) death, or sudden cardiac arrest (SCA). The study population were divided into train (80%), validation (10%), and test (20%) set.

Results

Among 4,512 patients with median 3.7 years [IQR; 2.7-5.1] of follow-up, the rate of all-cause mortality was 11.6% (524). In overall study population, median age was 55.5 years and proportion of male sex was 42.2%. The patients with all-cause death were older (p<0.001) and had more comorbidities (p<0.001). In the train set, CNN model showed 0.93 in AUC for predicting all-cause death. In the test set, CNN model showed consistent good performance power (AUC 0.90) for all-cause death. In subgroup analysis, 102 of 4153 (2.46%) and 57 of 4065 (1.40%) patients experienced CV death and SCA, respectively. The performance power in test set were 0.90 in AUC for CV death and 0.87 in AUC for SCA.

Conclusions

AI detects and predicts future all-cause death, CV death, and SCA in median of 2.6 years by analyzing standard 12-lead ECG in generally looking normal sinus rhythm.
Association of ivabradin use with ventricular arrhythmias in heart failure patients
Authors: Pay L , Yumurtas A C Y , Tezen O T , Cetin T C , Keskin K K , Eren S E , Cinier G C , Hayiroglu M I H , Cinar T C , Tekkesin A I T
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Background/Introduction

Heart failure patients with reduced left ventricular function are at high risk for ventricular arrhythmias and sudden cardiac death. Ivabradine, a specific inhibitor of the If current in the sinoatrial node, provides heart rate reduction in sinus rhythm and angina control in chronic coronary syndromes.

Purpose

The effect of ivabradine on ventricular arrhythmias in heart failure patients has not been fully elucidated. In this study, we aimed to investigate the effect of ivabradine use on life-threatening arrhythmias and long-term mortality in heart failure patients.

Methods

In this retrospective study, 1639 patients with heart failure were included. Patients were divided into two groups as ivabradine users and non-users. Patients presenting with ventricular tachycardia, presence of ventricular extra systole and ventricular tachycardia in 24-hour rhythm monitoring, appropriate ICD shocks and long-term mortality outcomes were evaluated according to ivabradine use.

Results

After adjustment for clinical variables, admission with ventricular tachycardia had 3.0 higher rates in ivabradine non-users (95% CI: 1.5 – 10.2). According to the adjusted model for all variables, approximately 4.1 times more appropriate ICD shocks were observed in the ivabradine non-users than the users (95% CI: 1.8 – 9.6). Long-term mortality did not differ between these groups after adjustment for all covariates.

Conclusion

The use of ivabradine reduced the appropriate ICD discharge in heart failure patients with low ejection fraction. Ivabradine has a potential in the treatment of ventricular arrhythmias in heart failure patients.
Ablation of left ventricle summit PVCs using guidewire and 2F octapolar microcatheter mapping
Authors: Constan De La Revilla E , Sanchez Millan P , Cabrera Borrego E
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Background

Ventricular arrhythmias originating in the left ventricular summit region are especially difficult to map and ablate. The development of microcatheters allows access to the septal coronary venous system, which facilitates its mapping.

Purpose

To describe the strategy for mapping and ablation of ventricular LV-Summit extrasystoles in the first 6 cases at our center, performed using a 2F octapolar microcatheter, as well as the results obtained.

Methods

6 cases of left ventricular summit PVCs were recruited between January 2019 and October 2022. TTE and/or MRI were performed as well as initial Holter, evidencing a high density of PVCs. The studies were carried out with intracardiac echo and anatomical reconstruction with a navigator. The coronary sinus was cannulated with a 6F guide catheter for venography. Mapping of the septal coronary venous system was performed with a 4F vertebral catheter and angioplasty guidewire, connecting the guidewire to the polygraph where good precocity (up to -30 ms) was obtained with a QS pattern in the monopolar lead during PVCs. An octapolar catheter was advanced, obtaining maximum precocity and appreciating fragmented late potentials and local abnormal ventricular activities (LAVA) during sinus rhythm with greater precocity during extrasystole and achieving a topostimulation of 95% concordance with PVCs. Radiofrequency applications were made with an irrigated contact catheter in the areas facing the octapolar catheter until acute suppression of PVC was achieved and its absence was verified after infusion of isoprenaline.

Results

The mean age of the sample was 60 years, 3 of them women, with a mean LVEF of 51% and a daily average of PVCs of 17.28%. Three of the patients had previously studied cardiomyopathies. After ablation, antiarrhythmics were stopped in 80% of cases and beta-blockers in 40%. The percentage of PVCs was significantly reduced (mean after the procedure 4.4%, p = 0.04) with a single recurrence at follow-up. No complications were recorded.

Conclusions

The microcatheter-guided ablation of the septal coronary venous system is a safe and effective procedure for the removal of left ventricular summit PVCs.
Long term results of catheter ablation in patients presented with ventricular storm
Authors: Coteli C , Zekeriyayev S , Ates A H , Yorgun H , Aytemir K
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Background and Objective

Catheter ablation is a treatment option in patients with ventricular tachycardia (VT storm, especially when refractory to medical treatment. In this trial, we aimed to evaluate the long-term results of catheter ablation in patients with VT storm.

Method

Between January 2015 and January 2022T, we enrolled a total of 65 VT storm patients who underwent catheter ablation. All patients who have either documented episodes of VT or appropriate ICD shocks more than 3in the last 24 hours. Medical treatment with antiarrhythmic drugs was given to all patients before catheter ablation. After the procedure, all-cause mortality, hospitalization due to stroke/myocardial infarction/heart failure, ICD shocks, and anti-tachycardia pacing therapies were recorded during follow-up.

Results

Among the whole study population (the median age is 65 years (17-85); 56 (86.2%) males) 37 (56.9%) had ischemic CMP, 24 (36.9%) had non-ischemic CMP whose 8 were ARVD, and 3 (4.6%) HCMP. The median left ventricle ejection fraction was 30% (12 – 65%). Activation mapping was performed in 60 patients, and the critical isthmus was ablated in 60 patients whose 22 had more than one critical ablation site. In 3 patients, only substrate mapping was performed, and substrate homogenization was done. In 2 patients, premature ventricular ectopy, which inducted VT, ablation was performed. Epicardial mapping was performed in 23 patients (35.4%). The median follow-up duration was 23 months (1-94 months). During follow-up, 23 patients died, 43 were hospitalized, and four presented again with VS storm. In 13 patients, appropriate shock/pacing therapy was observed. After the index procedure, re-do catheter ablation of ventricular tachycardia was performed in 8 patients. The mean postprocedural VT-free survival time was estimated at 76.5 months (SE:5.0, 95% CI: 66.6-86.4).

Conclusion

Catheter ablation therapy is an effective option for both acute and long-term management of patients with VT storms. However, postprocedural mortality and morbidity remain high in long-term follow-up duration. Long-term results may be related to the comorbidities and nature of underlying cardiac disorders.
Sex differences in catheter ablation for ventricular tachycardia in structural heart disease: a single center 10-years experience
Authors: Tanese N , D'angelo G , Cireddu M , Baratto F , Della Bella P , Bisceglia C
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Background

Women are underrepresented in studies concerning ventricular tachycardia (VT) catheter ablation (CA). Different etiologies and type of structural heart diseases (SHD) are well established in women; nonetheless conflicting results about efficacy and safety of CA in women have been reported.

Purpose

To evaluate acute and long-term outcome of VT CA in SHD in women compared to men in a high-volume tertiary Center.

Methods

All consecutive procedures were included from January 2010 to December 2021. Clinical characteristics, VT etiologies and procedure data of female patients were compared to male population. Catheter ablation was performed according to standard protocol in our center. In mappable VTs, the reentry circuit was characterized, and ablation aimed at VT interruption during radiofrequency (RF); otherwise, a substrate modification approach aiming at late potentials abolition or ablation at sites of slow conduction during sinus rhythm was performed. Following ablation, prevention of any VT inducibility and substrate modification was considered ablation endpoint. Acute results, complications, and VT recurrences during follow up were analyzed comparing the two groups.

Results

Among 1608 overall VT CA procedures, 141 procedures were performed in 117 women. Female were younger, with less comorbidities, less ischemic VT etiology and higher left ventricular ejection fraction (LVEF) as compared to men (Table 1). They were also less likely ICD carriers. No significant differences were found with regards to: epicardial approach (39.7% vs 35.3%, p=0.68); VT inducibility at baseline (57.4% vs 67.6%, p=0.14), VT termination during RF (87.6% vs 77.6%, p=0.51), and prevention of any VT inducibility at the programmed electrical stimulation (PES) after ablation (79.5% vs 78.1%, p=0.7). Major complications occurred in 4.9% of females as compared to 4.3% of male patients. At median follow-up of 25 months, VT recurrences occurred in 24.7% of female population and 27.5% of male group (p=0.42). Cumulative VT-free survival was comparable in both groups (Figure 2).

Conclusions

Women with SHD have favorable acute and long-term outcome of VT ablation, despite a high prevalence of non-ischemic etiologies. VT recurrence rate and procedure safety is comparable to male patients, suggesting that catheter ablation can be offered as an effective treatment to women with refractory ventricular arrhythmias.
Determining physiological VT ablation targets in the era of early VT ablation
Authors: Burg M , Anderson R D , Gonna H , Al-Shaheen A , Shapira E , Ben-Dor A , Hayam G , Baron T , Masse S , Nanthakumar K
Published: May 2023

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): Professor Nanthakumar is a recipient of the Mid-career Investigator Award from the Heart & Stroke Foundation of Ontario.

Background

Ablation targets in the era of early ventricular tachycardia (VT) ablation will likely be driven by substrate-based physiological target approaches rather than activation mapping. Decrement evoked potentials (DeEP) have been co-localized to the diastolic VT circuit and are used as a method to perform VT ablation when VT cannot or should not be induced.1 Traditionally these potentials are evoked by a single extrastimulus. The incremental utility of a second extrastimulus in detecting these potentials has not been evaluated.

Purpose

We studied the utility of the second extra stimulus (S3) in detecting substrate ablation over the first extra stimulus (S2) following a drivetrain (S1) of 8 beats at 600ms.

Methods

DeEP was measured as the time difference between the pacing stimulus and the nearfield local activation delay on the bipolar electrogram during the S1 drivetrain and after the S2 or S3 respectively. Decrement of ≥10ms was considered a positive DeEP site. A total of 157 sites from 6 patients with VT were analysed. The incremental value of S3-induced DeEP was compared to the S2-induced DeEP.

Results

The mean decrement was significantly greater on the S3 compared to the S2 (41.8±35.6ms for S3 vs 25.8±20.4ms for S2, P <0.0001). The mean incremental value of the S3 was 15.9ms (95% CI, 11.5-20.3ms). From the 157 intracardiac electrograms studied, 79.1% had a positive DeEP with S2 alone. At the same electrode locations, an additional S3 evoked DeEP in 82.2% of sites.

Conclusion

When physiological substrate is present on the first extra stimulus, the second extra stimulus magnifies the identification of the target. However, we found in our study that the second extrastimulus uncovered a hidden arrhythmogenic substrate in only 3.1% additional mapped sites. Consequently, the utility of the second extrastimulus in identification of hidden substrate needs to be balanced with the risk of induction of potentially unstable rhythms.
Safety and efficacy of intra-coronary chilled saline infusion during epicardial ablation in the left ventricular summit
Authors: Banavalikar B , Shenthar J , Krishnappa D , Padmanabhan D , Reddy S
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Background

The left ventricular (LV) summit is the most common epicardial site of idiopathic premature ventricular complexes (PVC) and is frequently associated with PVC-induced cardiomyopathy. Catheter ablation in the LV summit can be challenging due to its proximity with the major coronaries.

Hypothesis: Infusion of chilled saline (5-10 degree Celsius) into the left main coronary artery cools the endothelium during epicardial ablation in the LV summit and therefore, protects the coronaries from thermal damage.

Purpose

To determine the safety and efficacy of intra-coronary chilled saline infusion during epicardial ablation in the LV summit.

Methods

Patients with symptomatic idiopathic PVC from the LV summit formed the study population. Those with significant coronary artery disease (coronary stenosis >50%) or with a scar on cardiac MRI were excluded from the study. Irrigated ablation was performed in the epicardium either percutaneously or transvenously via the distal great cardiac vein (GCV). A coronary angiogram (CAG) was always performed before RF ablation (RFA) to delineate the distance of the ablation catheter from the proximal coronaries. Chilled saline (5-10 degree Celsius) was administered into the left main coronary artery (LMCA) via Judkins catheter at a constant rate of 50 ml/min throughout the entire duration of ablation. Post-RFA, CAG was repeated to exclude any damage to the coronary arteries.

Results

Between January 2020 and July 2022, 37 patients (mean age 47.2±11.6 years; 16 females) underwent epicardial ablation in the LV summit accompanied by intra-coronary chilled saline infusion. The mean LV ejection fraction was 46.6±7.9%, and 15 patients had LVEF <50% (PVC-induced cardiomyopathy). Epicardial ablation was performed percutaneously in six patients, whereas in 21 patients, it was done transvenously in the distal GCV. Chilled saline was infused into the LMCA during the entire duration of RFA without any untoward effect in any of the patients. Acute procedural success (complete elimination of the clinical PVC) was achieved in 34 out of the 37 patients. At a mean follow-up of 17±7.9 months, 35 patients (91.8%) were asymptomatic and free from the clinical arrhythmia.

Conclusion

Intra-coronary chilled saline administered during epicardial ablation in the LV summit is safe and effective in preventing RF-induced thermal injury to the proximal coronary arteries.
Stereotactic arrhythmia radiotherapy for ventricular tachycardia does not appear to alter QRS duration and QTc interval: a secondary analysis of the prospective STARNL-1 trial
Authors: Hoeksema W F , Van Der Ree M H , Dieleman E M T , Visser J , Planken R N , De Bruin-Bon R H A , De Jong R M A J , Kemme M J B , Balt J C , Balgobind B V , Postema P G
Published: May 2023

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): Dutch Heart Foundation grant to dr. P.G. Postema, MD PhD

Background

Stereotactic arrhythmia radiotherapy (STAR) has evolved as promising bail-out treatment in patients with therapy-refractory ventricular tachycardia (VT). The mechanism of action of STAR in preventing VT has yet to be elucidated and further understanding could improve this technique in the future. Preclinical studies reported an increase in conduction velocity and consequently a decrease in conduction intervals on electrocardiograms (ECGs) within the first months after STAR, although this has not yet been evaluated in detail in prospective studies.

Purpose

To evaluate the early effects of STAR on ventricular conduction as electrocardiographically assessed.

Methods

The STARNL-1 was a prospective, monocenter, pre-post intervention study. Six patients with VT recurrences despite optimal doses of anti-arrhythmic drugs (AADs), after one or more unsuccessful catheter ablation(s), were considered therapy-refractory. Patients were treated with a single fraction of 25 Gy. ECG evaluation included ECGs recorded pre-therapy, at 3 hours, 12 hours, 24 hours, 1 month, and 3 months after therapy. For an additional assessment, only patients in whom AADs remained unchanged up to 3 months after STAR were selected. QRS duration and QT interval were measured by a single observer using digital callipers. Four consecutive beats were used to measure and calculate a mean QRS duration and QT interval per ECG. This study was not powered to evaluate for significant changes in ECG parameters.

Results

All patients were male, all suffered from ischaemic cardiomyopathy, and all completed 3-month follow-up. One patient presented with atrial fibrillation on ECG recordings, and three patients with a paced rhythm. Four patients (66.7%) were selected for an additional assessment, two patients (P1 and P2, 33.3%) underwent changes in AAD dose and were therefore excluded. Figure 1 shows a line graph of the QRS duration and QTc interval of all STARNL-1 patients during 3-month follow-up. As can be appreciated from Figure 1, QRS duration and QTc interval did not appear to be altered between pre-therapy and 3 months after therapy. When excluding P1 and P2, QRS duration and QTc interval also did not appear to be altered between pre-therapy and 3 months after therapy.

Conclusion(s)

STAR for VT does not appear to alter QRS duration and QTc interval within the first 3 months after therapy.
QRS complex and T wave planarity for the prediction of death and appropriate shocks in recipients of prophylactic implantable defibrillators
Authors: Novotny T , Hnatkova K , Andrsova I , Vandenberk B , Sprenkeler D J , Junttila J , Reichlin T , Schloegl S , Friede T , Bauer A , Willems R , Schmidt G , Sticherling C , Zabel M , Malik M
Published: May 2023

Funding Acknowledgements

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): European Community’s 7th Framework Programme (HEALTH-F2-2009-602299) Ministry of Health, Czech Republic

Background

Three-dimensional (e.g., vectorcardiography) loops of normal physiologic QRS complex and T wave are known to be planar. Non-planarity of these electrocardiogram (ECG) loops was described in cardiac patients, mainly in relation to ischemic heart disease, but predictive values of the extent of non-planarity of the loops have not been systematically researched.

Methods

Pre-implantation digital ECGs were collected in 1948 cardiac patients (381 females, median age 65, inter-quartile range 56 – 72 years, 62% ischemic heart disease) who obtained an implantable cardioverter-defibrillator (ICD) for primary prophylactic reasons. In each ECG, QRS and T wave 3-dimensional loops were constructed using singular value decomposition and the non-planarity of the loops was measured as the relative power of the 3rd, least significant decomposition component. The non-planarity (i.e., the spatial twist) of the loops was related to all-cause mortality and to appropriate ICD shocks that occurred during the first 5 years after device implantation. This predictive power was compared to that of age, heart rate, left ventricular ejection fraction, QRS duration, spatial QRS-T angle, QTc interval, and T-peak to T-end interval.

Results

Non-planarity of the QRS loop was significantly associated with follow-up deaths despite ICD protection (p<0.001 both univariably and in multivariable Cox regression analysis) but was less powerfully associated with appropriate ICD shocks. Non-planarity of the T wave loop was significantly associated with appropriate ICD shocks during follow-up (p<0.001 both univariably and in multivariable Cox regression analysis) but was not associated with mortality during follow-up (Table). This was also seen in significant separation of Kaplan-Meier event probability curves (Figure).

Conclusions

The analysed data of recipients of prophylactic ICDs suggest that non-planarity of QRS complex and T wave loops offers distinction between patients who are at greater risk of death despite ICD protection and those who are likely to utilize the defibrillator protection.
Relation between recovering right ventricular function and appropriate ICD Therapy
Authors: Chiba T , Kajiyama T , Komai Y , Takanashi Y , Yoshino Y , Ryuzaki S , Kitagawa M , Ito R , Nakano M , Nakano M , Kondo Y , Kobayashi Y
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Background

Right ventricular fractional area change (RVFAC) as right ventricular function is recently referred as an independent predictor of sudden cardiac death (SCD). Light ventricular function is related with SCD and adopted as a criteria of ICD implantation for primary prophylaxis. The purpose of this study was to evaluate the association of RVFAC and appropriate ICD therapy.

Methods

Consecutive patients who underwent initial ICD implantation for any diseases except for hypertrophic cardiomyopathy and Brugada syndrome and long QT syndrome were retrospectively enrolled from 2012 to 2018. Transthoracic echocardiographic parameters before ICD implantation were evaluated to investigate the association with appropriate ICD therapy. We analyzed RV function of patients undergoing echocardiography one year after implantation. RVFAC was measured by one physician and one echocardiologist.

Results

In total, 172 patients (60.3±13.6 years, 131 males) including 63 ischemic cardiomyopathy were enrolled. Ninety patients received an ICD as a secondary prophylaxis. Mean LVEF and RVFAC were 38.3±14.3% and 35.8±8.82%, respectively. There was no correlation between RVFAC and LVEF (correlation coefficient =0.274). Regarding appropriate ICD therapy events, the best cut-off value of RVFAC was 34.8%. The odds ratio of low RVFAC was 2.731 (95%CI: 1.456-5.121, P<0.001, Fig.1). Secondary prophylactic cohort with low RVFAC significantly showed highest incidence of appropriate ICD therapy. In multivariate analysis, only low RVFAC was an independent predictor of appropriate ICD therapy (hazard ratio 3.53, 95%CI:1.78- 6.99, P<0.001). Among patients with RV dysfunction, RVFAC was normalized in 39% patients during follow up. This recovered group showed significantly lower incidence of appropriate ICD therapy than non-recovered group (P=0.037). In multivariate analysis, recovered RVFAC was related to decrease of appropriate ICD therapy rather than recovered LVEF. In patents without LV dysfunction, recovered RVFAC was significantly associated with lower incidence of ICD therapy (P=0.023, Fig.2)

Conclusion

RVFAC and RV function improvement may be important to stratify the prognosis of ICD patients.
Zero or near-zero x-ray pacemaker implantation in paediatric patients. dream or reality?
Authors: Silvetti M S , Pazzano V , Battipaglia I , Saputo F A , Tamburri I , Campisi M , Battista V , Silvetti G , Drago F
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Background/Introduction

Transvenous implantation of pacemaker is performed with fluoroscopy for leads’ insertion and implantation in the heart. This implies radiation exposure for patients and operators. Fluoroscopy allows a two-dimensional view of lead movements, and sometimes it is difficult to implant lead in the complex heart anatomy, or in alternative right ventricular (RV) pacing sites, that often requires higher radiation doses. These alternative pacing sites may prevent pacing-induced ventricular dysfunction. They are his bundle pacing area (HBP), ventricular septum close to the conduction system area (VS), RV outflow tract (RVOT). The use of three-dimensional-electroanatomic mapping system (3D-EAM) may reduce fluoroscopy and guide lead implantation. Published median fluoroscopy data for similar procedure are: 6 mGy (1), 13 mGy and 231 microGy/m2 (2).

Purpose

of this study is to seek out if a 3D-EAM-guided transvenous implantation into RV alternative sites pacing in paediatric patients can be accomplished with zero or near-zero X-rays.

Methods

Retrospective analysis of children and adolescents with congenital or acquired (idiopathic) complete atrioventricular block (CAVB) without other congenital heart defects who underwent 3D-EAM-guided pacing in alternative RV sites. The implant procedure was divided in 4 steps: 1-contrast venography; 2- 3D mapping: with a steerable catheter (femoral vein), the 3D-EAM acquired geometric reconstruction of the right heart and a pacing map identified RV sites with narrower paced QRS; 3-axillary vein puncture; 4-lead and pacemaker implantation: 3D-EAM guided stylet-directed screw-in lead implantation toward desired RV sites. Data are reported as median (25th-75th centiles).

Results

54 CAVB patients (42 females), underwent 3D EAM-guided pacing (27 VVIR, 27 DDD) at age 11.5 (7.7-14) years, weight 42 (26-54) kg. Pacing sites were: 10 HBP, 4 RVOT, 40 VS (Figure 1). Procedure time was 170 (143-193) min, total fluoroscopy exposure and that of the 4 steps are reported in Table 1. The lowest exposures were: 0.2 mGy, 8 microGy/m2 (VVIR) and 0.6 mGy, 15 microGy/m2 (DDD). Paced QRS was 115 (100-120) ms.

Conclusions

3D-EAM-guided alternative RV pacing sites was accomplished with very low fluoroscopic exposure, close to zero in some cases. Therefore, with 3D-EAM we can significantly reduce radiological doses also in difficult pacing procedures in paediatric patients, thus reducing radiological risks and preserving ventricular function. The dream is becoming reality.
Safety and efficacy of automatic capture threshold algorithms in left bundle branch area pacing
Authors: Ghiglieno C , Dell'era G , Veroli A , D'amico A , De Vecchi F , Porcellini S , Santagostino M , Patti G
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Background

Automatic capture algorithms periodically measure the minimal quantity of current needed for pacing, self-adjusting output to guarantee consistent myocardial capture, enhancing patient safety in case of an unexpected rise in threshold and reducing current drain. Left bundle branch area pacing (LBBAP) is an emerging conduction system pacing (CSP) technique which overcomes technical issues and weaknesses of pure Hisian pacing.

Purpose

The aim of our study was to evaluate safety and efficacy of automatic threshold algorithms in a population of patients with LBBAP.

Methods

We prospectively enrolled patients receiving LBBAP with different companies which provide LBBAP material) and we evaluated automatic capture threshold algorithms safety and accuracy at 24 hours and at 3 months after implantation. Moreover, when available, home monitoring was used for follow up.

Results

We included 45 consecutive patients who underwent LBBAP from January 2022 to August 2022. At 24 hours, mean manual LBBAP threshold was 0.5±0.2 V at 0.4 msec, while automatic LBBAP threshold was 0.5±0.3 V at 0.4 msec (p = 0.30). At 3 months mean manual LBBAP threshold was 0.6±0.2V at 0.4 msec vs 0.6±0.2V at 0.4 msec (p = 0.25). Sensing and impedance measures where optimal at 24 hours and improved during 3 months follow up, respectively from 13.7±4.8 mV to 13.9±4.8 mV (p = 0.6) and from 460.1±130 Ohm to 417.1±96.2 Ohm (p = 0.1).

Conclusion

Automatic threshold algorithms are able to effectively measure LBBAP capture threshold both in the acute phase and during follow up. The possibility to safely use automatic threshold algorithms, thus preserving battery and protecting patients against possible future threshold rises, represents another advantage of LBBAP.
Lowest peak central venous pressure correlates with highest invasive arterial blood pressure as a method for optimising AV delay in post-surgical temporary pacing
Authors: Tindale A , Cretu I , Meng H , Mason M J , Francis D P
Published: May 2023

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): British Heart Foundation.

Background

Atrioventricular (AV) delay optimisation has been performed using a variety of methods, including doppler outflow and alternating blood pressure algorithms. Patients after cardiac surgery are usually invasively monitored with arterial and central venous pressure (CVP) lines.

Purpose

We aimed to see if the CVP line could be used to optimise AV delays in temporary pacing for situations where the arterial line is absent or non-functional.

Methods

11 patients in sinus rhythm but with temporary pacemakers after cardiac surgery were studied. Each patient underwent alternating optimisation algorithms where they were subjected to 8 transitions between a reference AV delay of 120ms and a tested AV delay ranging from 40ms to 280 ms. Testing was terminated after the AV delay occurred when native conduction occurred i.e after they began AAI pacing. All patients were paced at 80 bpm.

Arterial blood pressure (ABP) and CVP were recorded from radial arterial lines and central venous lines in the internal jugular vein during the transitions. The optimal point was defined as the AV delay generating the maximum systolic blood pressure. The CVP was measured in 3 ways: peak pressure, mean pressure, and area under the curve. Central venous pressure tracings were corrected for respiration using a "fit-a-curve" function. All analysis was performed in Python.

Results

Individual pressure readings.

There was a negative correlation between individual ABP and Peak CVP pressure readings (R= -0.539, p=0<0.001). A representative example for a single patient is shown in Figure 1 and for all data in Figure 2. A similar relationship, albeit less strong, was seen between ABP and Mean CVP (R= -0.281, p=0.046). There was no significant relationship between ABP and CVP AUC (R = -0.281, p=0.130).

Optimum pressure settings:

There was a strong correlation between the optimum AV delay as defined by the highest ABP and the optimum AVD as defined by the lowest peak CVP (R = 0.672, p=0.03). There was no significant relationship between the optimum AVD delay as defined by peak ABP and the optimum AVD defined by either mean CVP nor CVP AUC (R=0.269, p=0.452 for both).

Conclusions

There is an inverse relationship between individual measurements of arterial blood pressure and both peak and mean central venous pressure. The optimal AVD as defined by the highest ABP correlates with the optimal AVD as defined by the lowest peak CVP measurement. However, this method does require correction for respiratory artefact.
Electrocardiographic predictors of atrial mechanical sensing in patients with leadless VDD pacemakers
Authors: Hofer D , Perucchini F , Zehetleitner S , Saguner A , Haeberlin A , Steffel J , Breitenstein A
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Background

Leadless pacemakers (LP) capable of VDD function are a cornerstone of modern pacemaker therapy reducing complications in elderly patients while enabling atrioventricular synchrony through mechanical sensing of atrial contraction. Because mechanical sensing is less reliable than electrical sensing, the reliability of VDD function in LP varies. We evaluated the p-wave amplitude from patient ECGs as a predictor for successful VDD function in LP.

Materials and methods

Consecutive patients undergoing LP implantation capable of VDD function were included in this multi-center retrospective cohort study. As VDD function is mainly dependent on the A4 signal amplitude in the current generation of the device, ECG parameters pre-implantation were evaluated separately and in combination for association with A4 signal amplitude post-implantation.

Results

122 Patients (mean age 81, female 44%, mean BMI 25.9 kg/m2) were included. Main indication for LP implantation was AV-Block (70%). BMI-adjusted P-wave amplitude demonstrated a statistically significant positive correlation with A4 signal amplitude in leads I, II, aVL, aVF, aVR, V1 and V2 (all p<0.05). A p-wave amplitude of at least 0.1mV had a specificity of 72% (95%-CI 50%-89%) for a good A4 signal. A sum of at least 0.2mV of p-wave amplitudes in V1 and aVL predicts a specificity of 83% (95%-CI 67-100%) for a good A4 signal.

Conclusions

P-wave amplitudes in selected ECG leads can predict A4 signal amplitude and therefore the reliability of VDD function in LP.
Usefulness of parahisian pacing for risk prediction of pacemaker implantation after TAVI
Authors: Notarangelo M , Dinatale A , Crocamo A , Vrenozaj R , Bearzot L , Gonzi G , Guidorossi A , Tadonio I , Vignali L , Niccoli G , Ardissino D
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Background

Conduction disturbances determining pacemaker implantation are a significant concern in patients undergoing Transcatheter Aortic Valve Implantation (TAVI), a procedure that is nowadays spreading even in the low-risk population.

OBJECTIVE

The aim of the study was to evaluate the role of the parahisian pacing, a method to directly identify the conduction system anatomical variability, in predicting the iatrogenic damage risk conditioning pacemaker implantation after TAVI.

Methods

Between October 2021 and November 2022 we prospectively collected clinical features, ECG, procedural and imaging data (cardiac CT and echocardiography) of every patient who underwent electrophysiological study for pre-existing or worsening conduction disorders within 48 hours after TAVI procedures in our centre. After having recorded the HV interval, parahisian stimulation at decreasing energy output was performed (CL 600 ms, 25V to 0.5V x 2 ms) with definition of the loss of capture pattern related to the three anatomical variations of His bundle described by Kawashima (1).

Fisher’s exact test was used for statistical analysis; p-value <0.05 was considered statistically significant.

Results

Out of 110 TAVI performed, a total of 31 patients with conduction disorders have been studied. Patients who developed permanent 3rd degree AV block after the procedure were excluded. Mean age was 82.6±4.4 years; 21 patients (67.7%) were males. 11 patients (35.5%) had a pre-existing conduction disorder worsened after TAVI, 13 patients (41.9%) developed newly-onset LBBB; 8 (25.8%) also developed 1st degree AV block. The total number of patients who underwent PM implantation was 16 (51.6%). The anatomical variables (membranous septum <3mm and/or septal cusps calcifications) and type of valve implanted were not significantly associated with PM implantation (p = NS). An HV interval <70 ms was registered in 20 (64.5%) patients (Fig. 1); 7 of them underwent PM implantation as they developed paroxysmal 3rd degree AV block. These 7 patients all had type 2 or type 3 pattern during parahisian stimulation. None of the patients undergoing PM implantation presented a type 1 pattern during parahisian stimulation. A significant protective value (p = 0.02) for PM implantation in patients with type 1 pattern was observed (Fig. 2).

Conclusions

Parahisian stimulation can be a useful tool to define the conduction system anatomical variability. It can also be helpful to predict the conduction system damage risk during TAVI, conditioning PM implantation. Our data need to be confirmed in a larger population.
Ventricular tachycardia as presenting arrhythmia as a determinant of appropriate implantable cardioverter-defibrillator therapy in secondary prevention
Authors: Noordman A B P , Rienstra M , Blaauw Y , Mulder B A , Maass A H
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Background

Sudden cardiac death (SCD) is a leading cause of death. The implantable cardioverter-defibrillator (ICD) is an established therapy to prevent SCD in patients with prior ventricular tachycardia (VT) or ventricular fibrillation (VF). Determination of patient characteristics related to ICD therapies may provide targets for more intensive monitoring or management of ventricular arrhythmias. Therefore, we aimed to find determinants of appropriate ICD therapy.

Methods

In this retrospective, single-centre study, 223 consecutive secondary prevention ICD recipients were included. Data was obtained on medical history, laboratory measurements, electrocardiography and echocardiography. The primary outcome was appropriate ICD therapy, which included shock and antitachycardia pacing (ATP) given for VF or VT. Backward stepwise Cox regression analysis was performed to find determinants of appropriate therapy.

Results

The median age of the study population was 65.3 years (interquartile range (IQR) 55.4 – 72.0 years). 188 (84.3%) patients were male. 153 (68.6%) patients had ischemic heart disease. During a median follow-up duration of 6.00 years (interquartile range (IQR) 4.85 – 7.70 years), appropriate ICD therapy occurred in 89 (39.9%) patients, appropriate ICD shock in 65 (29.1%) patients, death in 55 (24.7%), inappropriate shock in 11 (4.9%) and device-related complications in 18 (8.1%). VT as index arrhythmia, QRS fragmentation and diminished right ventricular function were determinants of appropriate device therapy. Interestingly, whereas the majority of patients (141 (63.2%)) had an ICD implanted for initial presentation with VF, the first occurrence of appropriate therapy during follow-up was for monomorphic VT in the majority of patients (84 (94.4%)).

Conclusion

In patients with a secondary prevention ICD indication, VT as presenting arrhythmia is a determinant of appropriate ICD therapy during follow-up. Most ICD therapies during follow-up were applied for monomorphic VT.