Ventricular Arrhythmias Group Research Articles

Hospital Outcomes of Spontaneous Coronary Artery Dissection With Concurrent Ventricular Arrhythmias

BackgroundWhile patients with spontaneous coronary artery dissection (SCAD) occasionally present with concurrent ventricular arrhythmias (VA), the impact of VA on in-hospital outcomes in the United States (US) is not well-established. This study aims to analyze in-hospital outcomes of patients with SCAD and concurrent VA and to determine the factors associated with VA occurrence in this high-risk population in the US. MethodsUsing the Nationwide Readmissions Database, our study included patients age 18 years or older who had SCAD between 2017 and 2020. We categorized the cohort into 2 groups depending on the presence of VA during hospitalization. In-hospital outcomes were assessed between SCAD patients with VA and those without. Weighted analysis was performed. We analyzed the independent factors associated with VA occurring among SCAD patients through univariable and multivariable analyses. ResultsEight hundred seventy-seven SCAD patients were included in the study: 118 (13.5%) with VA and 759 (86.6%) without. SCAD patients with concurrent VA were associated with higher rates of early mortality (10.2% vs 2.0%; P < .01), prolonged index hospital stay (≥7 days) (33.1% vs 11.7%; P < .01), and non-home discharge (21.2% vs 5.9%; P < .01). The length of hospital stay was longer in the SCAD with concurrent VA group (7.39 days vs 3.58 days; P < .01), and the median cumulative cost of hospitalization was also higher in this group ($31,451 vs $13,802; P < .01). SCAD patients with concurrent VA had increased in-hospital adverse events: acute heart failure, cardiac arrest, cardiogenic shock, cerebral infarction, pulmonary edema, and acute kidney injury. In multivariable analysis, the independent factors associated with VA occurrence among SCAD patients were chronic liver disease (aOR, 3.42; 95% CI, 1.43-8.20; P < .01) and heart failure (aOR, 5.63; 95% CI, 3.36-9.42; P < .01). ConclusionsConcurrence of VA among SCAD patients was associated with poorer in-hospital outcomes. Heart failure and chronic liver disease were the independent factors associated with VA occurrence in SCAD patients.

Abstract 13027: Hospital Outcomes and Predictors of Spontaneous Coronary Artery Dissection With Concurrent Ventricular Arrhythmias

Background: While spontaneous coronary artery dissection (SCAD) patients can present with ventricular arrhythmias (VAs), the in-hospital outcomes among these patients are not well-established. Objective: This study aimed to analyze the in-hospital outcomes of patients with SCAD and concurrent VAs, and to determine the predictors of VAs occurrence in this population. Methods: Using the Nationwide Readmissions Database, our study included patients aged 18 years or older who had SCAD between 2017 and 2020. We categorized the cohort into two groups depending on the presence of VAs during hospitalization. The in-hospital outcomes were assessed between two groups. Through multivariable analysis, we further analyzed the predictors of VAs occurrence among SCAD patients. Results: Our study included 160 (13.45%) SCAD patients with concurrent VAs and 1,030 (86.55%) SCAD patients without concurrent VAs between 2017 and 2020. SCAD patients with concurrent VA were associated with higher rates of early mortality (11.88% vs. 2.04%, p&lt;0.01), prolonged index hospital stay (≥7 days) (31.25% vs. 12.82%, p&lt;0.01), and non-home discharge (21.88% vs. 6.50%, p&lt;0.01). The length of hospital stay was longer in the SCAD with concurrent VAs group (6.93 days vs. 3.73 days, p&lt;0.01), and the median cumulative cost of hospitalization was also higher in this group ($31,450 vs. $14,664, p&lt;0.01). SCAD with concurrent VAs patients also had poorer in-hospital adverse events. In multivariable analysis, the independent predictors for VAs occurrence among SCAD patients were chronic liver disease (aOR: 2.18; 95% CI: 1.15- 4.12, p=0.02) and heart failure (aOR: 3.40; 95%CI: 2.30- 5.02, p&lt;0.01). Conclusion: Ventricular arrhythmias among SCAD patients were associated with poorer in-hospital outcomes. Heart failure and chronic liver disease were the predictors of VAs in SCAD patients. This highlights the importance of closely monitor and aggressive VAs management among these high-risk patients.

Correlation between maternally expressed gene 3 expression and heart rate variability in heart failure patients with ventricular arrhythmia.

The aim of the study was to analyse the correlation between maternally expressed gene 3 (MEG3) expression and heart rate variability (HRV) in heart failure patients with ventricular arrhythmia (VA). A total of 130 heart failure patients, treated from July 2018 to March 2021, were prospectively selected and divided into a non-VA group (n = 85) and a VA group (n = 45) according to the presence or absence of VA. The correlations of serum MEG3 expression and HRV with cardiac function indicators were investigated by Pearson correlation analysis. Receiver operating characteristic (ROC) curves were plotted to assess the predictive value of MEG3, HRV and their combination for the occurrence of heart failure complicated with VA. The VA group had a higher left atrial diameter (LAD) and left ventricular end-diastolic diameter (LVEDD) but lower left ventricular ejection fraction (LVEF) and ratio of mitral early diastolic peak velocity (E) to late peak atrial filling velocity (A) (E/A) than the non-VA group (p < 0.05). The serum MEG3 expression was negatively correlated with: standard deviation of the average RR intervals calculated over five-minute segments in the 24-hour record (SDANN), SDANN index, standard deviation of normal-to-normal RR interval (SDNN) index, percentage of differences between adjacent normal RR intervals exceeding 50 ms (PNN50), root mean square of successive difference (RMSSD), low frequency (LF), high frequency (HF), very low frequency (VLF), LVEF and E/A (r < 0, p < 0.05). The serum MEG3 expression was positively correlated with LAD and LVEDD (r > 0, p < 0.05). The areas under the ROC curves of MEG3, SDANN, SDANN index, SDNN index, PNN50, RMSSD, LF, HF, VLF and their combination for the prediction of the occurrence of heart failure complicated with VA were 0.812, 0.731, 0.737, 0.689, 0.860, 0.783, 0.791, 0.856, 0.769 and 0.966, respectively. MEG3 combined with HRV can effectively predict the occurrence of heart failure complicated with VA.

Relationship between myocardial bridging and fatal ventricular arrhythmias in patients with hypertrophic cardiomyopathy: the HCM-MB study.

Myocardial bridging (MB) and hypertrophic cardiomyopathy (HCM) are associated with the risk of fatal ventricular arrhythmias (VAs). The goal of the study was to determine the relationship between MB and fatal VAs in HCM patients with implantable cardiac defibrillators (ICD). Atotal of 108 HCM patients (mean age: 46.6 ± 13.6years; male:73) were enrolled in this retrospective study. All patients underwent transthoracic echocardiography and coronary computed tomography angiography. Fatal VAs including sustained ventricular tachycardia and ventricular fibrillation were documented in ICD records. There were documented fatal VAs in 29 (26.8%) patients during amean follow-up time of 71.3 ± 30.9months. Compared with the other groups, the fatal VA group had a higher incidence of the following: presence of MB (82.8 vs. 38%, p < 0.001), deep MB (62.1 vs. 6.3%, p < 0.001), very deep MB (24.1 vs. 0%, p < 0.001), long MB (65.5 vs. 11.4%, p < 0.001), presence of > 1MB (17.2 vs. 0%, p = 0.001), and MB of the left anterior descending artery (79.3 vs. 17.7%, p < 0.001) . Sudden cardiac death (SCD) risk score (hazard ratio: 1.194; 95% CI: 1.071-1.330; p = 0.001) and presence of MB (hazard ratio: 3.815; 95% CI: 1.41-10.284; p = 0.008) were found to be independent predictors of fatal VAs in HCM patients. The current data suggest that the SCD risk score and presence of MB were independent risk factors for fatal VAs in patients with HCM. In addition to conventional risk factors, the coronary anatomical course can provide clinicians with valuable information when assessing the risk of fatal VAs in HCM patients.

Magnetic Resonance Left Ventricle Mass-Index/Fibrosis: Long-Term Predictors for Ventricular Arrhythmia in Hypertrophic Cardiomyopathy—A Retrospective Registry

Objective: We aimed to study the long-term association of LV mass index (LVMI) and myocardial fibrosis with ventricular arrhythmia (VA) in a population of patients with confirmed hypertrophic cardiomyopathy (HCM) using cardiac magnetic resonance imaging (CMR). Methods: We retrospectively analyzed the data in consecutive HCM patients confirmed on CMR referred to an HCM clinic between January 2008 and October 2018. Patients were followed up yearly following diagnosis. Baseline demographics, risk factors and clinical outcomes from cardiac monitoring and an implanted cardioverter defibrillator (ICD) were analyzed for association of LVMI and LV late gadolinium enhancement (LVLGE) with VA. Patients were then allocated to one of two groups according to the presence of VA (Group A) or absence of VA (Group B) during the follow-up period. The transthoracic echocardiogram (TTE) and CMR parameters were compared between the two groups. Results: A total of 247 patients with confirmed HCM (age 56.2 ± 16.6, male = 71%) were studied over the follow-up period of 7 ± 3.3 years (95% CI = 6.6-7.4 years). LVMI derived from CMR was higher in Group A (91.1 ± 28.1 g/m2 vs. 78.8 ± 28.3 g/m2, p = 0.003) when compared to Group B. LVLGE was higher in Group A (7.3 ± 6.3% vs. 4.7 ± 4.3%, p = 0.001) when compared to Group B. Multivariable Cox regression analysis showed LVMI (hazard ratio (HR) = 1.02, 95% CI = 1.001-1.03, p = 0.03) and LVLGE (HR = 1.04, 95% CI = 1.001-1.08, p = 0.04) to be independent predictors for VA. Receiver operative curves showed higher LVMI and LVLGE with a cut-off of 85 g/m2 and 6%, respectively, to be associated with VA. Conclusions: LVMI and LVLGE are strongly associated with VA over long-term follow-up. LVMI requires more thorough studies to consider it as a risk stratification tool in patients with HCM.

Electrocardiographic and electrophysiological characteristics of ventricular arrhythmias from the right bundle branch of the moderator band

There are little data on ventricular arrhythmias (VAs) originating from the right bundle branch (RBB) of the moderator band (MB) (MB-RBB VAs) in a cohort of patients. The purpose of this study was to investigate the electrocardiographic and electrophysiological characteristics of MB-RBB VAs. Sixteen patients with MB-RBB VAs and 5 patients with right ventricular (RV) anterior papillary muscle (APM) VAs (RV-APM VAs) were studied under the guidance of intracardiac echocardiography. The MB-RBB VAs group demonstrated a typical left bundle branch block pattern with left superior axis deviation and a narrower QRS complex during VAs (P < .001) as compared with the RV-APM VAs group. Furthermore, the MB-RBB VAs group had a shorter rS interval, a sharper slope of the S wave downstroke without notching in leads V1 and V2, and a shorter r wave duration in lead V2. A leading RBB potential at the target during VAs was observed for all patients in the MB-RBB VAs group, which was also present during sinus rhythm for all patients, except for 2 with RBB block at baseline. Ablation of the leading RBB potential effectively eliminated the arrhythmia. In the RV-APM VAs group, no Purkinje potential at the target was identified in any patient during VAs. QRS morphology of MB-RBB VAs is characterized by a typical left bundle branch block pattern with a relatively narrow QRS complex, short r wave and rS durations, and a sharp S wave downstroke without notching in leads V1 and V2. Mapping and ablation of the leading RBB potential are effective in eliminating VAs.

Impact of ventricular arrhythmia on LVAD implantation admission outcomes

Ventricular arrhythmias (VAs) are common after left ventricular assist device (LVAD) implantation though data are mixed on whether these events have an impact on mortality. The National Inpatient Sample (NIS) database from 2002-2019 was queried for LVAD implantation admissions. Secondary ICD codes were analyzed to assess for the occurrence of VAs during this admission. Propensity score matching (PSM) was used to control for confounding variables between those with versus without VAs. The NIS database from 2002-2019 contained 43 936 admissions with LVAD implantation. VAs occurred in 19 985 (45.4%) patients. After PSM, the study cohort consisted of 39 989 patients, 19 985 (50.0%) of which had a secondary diagnosis of VA during the admission. When compared to those without VA, those with VA were at no higher risk for in-hospital mortality (adjusted odds ratio 1.011, 99.9% CI 0.956-1.069, p=0.699). Those with a VA were at higher risk for cardiogenic shock and requiring mechanical ventilation, tracheostomy, and percutaneous endoscopic gastrostomy placement. Patients with a VA were also at lower risk for device thrombosis. Conversely, the VA group was at no higher risk for stroke. In comparing trends from 2002 to 2019, the incidence of VAs has increased, while the mortality rate of those with and without VAs has decreased during this same period. In this retrospective study of the NIS database, VAs were common (45.4%) during the LVAD implantation admission. However, the occurrence of VAs during the implantation admission did not alter in-hospital mortality. More longitudinal studies are required to assess the long-term impact of VAs on mortality. In comparing trends from 2002-2019, the incidence of VAs has increased, while the mortality rate of those with and without VAs has decreased.

Prognostic Significance of Ventricular Arrhythmias in 13444 Patients With Acute Coronary Syndrome: A Retrospective Cohort Study Based on Routine Clinical Data (NIHR Health Informatics Collaborative VA-ACS Study).

BackgroundA minority of acute coronary syndrome (ACS) cases are associated with ventricular arrhythmias (VA) and/or cardiac arrest (CA). We investigated the effect of VA/CA at the time of ACS on long‐term outcomes.Methods and ResultsWe analyzed routine clinical data from 5 National Health Service trusts in the United Kingdom, collected between 2010 and 2017 by the National Institute for Health Research Health Informatics Collaborative. A total of 13 444 patients with ACS, 376 (2.8%) of whom had concurrent VA, survived to hospital discharge and were followed up for a median of 3.42 years. Patients with VA or CA at index presentation had significantly increased risks of subsequent VA during follow‐up (VA group: adjusted hazard ratio [HR], 4.15 [95% CI, 2.42–7.09]; CA group: adjusted HR, 2.60 [95% CI, 1.23–5.48]). Patients who suffered a CA in the context of ACS and survived to discharge also had a 36% increase in long‐term mortality (adjusted HR, 1.36 [95% CI, 1.04–1.78]), although the concurrent diagnosis of VA alone during ACS did not affect all‐cause mortality (adjusted HR, 1.03 [95% CI, 0.80–1.33]).ConclusionsPatients who develop VA or CA during ACS who survive to discharge have increased risks of subsequent VA, whereas those who have CA during ACS also have an increase in long‐term mortality. These individuals may represent a subgroup at greater risk of subsequent arrhythmic events as a result of intrinsically lower thresholds for developing VA.

B-PO03-165 MEAN SCAR ENTROPY PREDICTS VENTRICULAR ARRHYTHMIAS EVENTS IN HYPERTROPHIC CARDIOMYOPATHY USING LATE GADOLINIUM ENHANCEMENT CARDIAC MAGNETIC RESONANCE

Ventricular arrhythmias (VAs) is associated with sudden cardiac death (SCD) in hypertrophic cardiomyopathy (HCM). Previous studies have found late gadolinium enhanced (LGE) on cardiac magnetic resonance (CMR)was independently associated with VAs in HCM. Risk stratification of VAs remains complex and LGE is present in the majority of HCM patients. This study was to determine whether the LGE by CMR derived entropy within the scar and the left ventricular (LV) myocardium predicts VAs in HCM. Consecutive HCM patients with scar by LGE-CMR were included. Routine left ventricular function parameters including LV ejection fraction (LVEF) and %LGE defined as percentage of LGE to LV mass (%LGE) using software CVI 42. The scar heterogeneity, quantified by entropy within the scar and LV myocardium was derived. The presence of VAs was defined as previous aborted cardiac arrest, documented sustained ventricular tachycardia (VT) and non-stained VT (nsVT) by Holter or implantable cardiac devices (ICD) monitoring. A total of 68 HCM patients (54.6 ±14.3 years, 69.1% male, LVEF 67.2 ±12.9 %) with LGE CMR were enrolled with a median follow-up of 25 (IQR 13-13) months. Thirty-one patients in VAs group and 37 patients in No-VAs group were included. From multivariable analysis, higher entropy of the scar (Hazard ratio [HR] 2.682;95% confidence interval [CI]:1.022 to 7.037; P=0.039) was independently associated with VAs, after adjusting for LVEF, %LGE, the LV maximal wall thickness (MWT) and the left atrium (LA) diameter. High entropy within the scar was an independent predictor of VAs and may indicate an arrhythmogenic scar. It seemed to be valuable for assessing the clinical status of VAs in HCM patients.

Minimising radiation exposure in catheter ablation of ventricular arrhythmias

BackgroundConventional fluoroscopy guided catheter ablation (CA) is an established treatment option for ventricular arrhythmias (VAs). However, with the complex nature of most procedures, patients and staff bare an increased radiation exposure. Near-zero or zero-fluoroscopy CA is an alternative method which could substantially reduce or even eliminate the radiation dose. Our aim was to analyse procedural outcomes with fluoroscopy minimising approach for treatment of VAs in patients with structurally normal hearts (SNH) and structural heart disease (SHD).MethodsFifty-two (age 53.4 ± 17.8 years, 38 male, 14 female) consecutive patients who underwent CA of VAs in our institution between May 2018 and December 2019 were included. Procedures were performed primarily with the aid of the three-dimensional electro-anatomical mapping system and intra-cardiac echocardiography. Fluoroscopy was considered only in left ventricular (LV) summit mapping for coronary angiography and when epicardial approach was planned. Acute and long-term procedural outcomes were analysed.ResultsSixty CA procedures were performed. Twenty-five patients had SHD-related VAs (Group 1) and 27 patients had SNH (Group 2). While Group 1 had significantly higher total procedural time (256.9 ± 71.7 vs 123.6 ± 42.2 min; p < 0.001) compared to Group 2, overall procedural success rate [77.4% (24/31) vs 89.7% (26/29); p = 0.20)] and recurrence rate after the first procedure [8/25, (32%) vs 8/27, (29.6%); p = 0.85] were similar in both groups. Fluoroscopy was used in 3 procedures in Group 1 where epicardial approach was needed and in 4 procedures in Group 2 where LV summit VAs were ablated. Overall procedure-related major complication rate was 5%.ConclusionsFluoroscopy minimising approach for CA of VAs is feasible and safe in patients with SHD and SNH. Fluoroscopy could not be completely abolished in VAs with epicardial and LV summit substrate location.

Long-term efficacy and safety of hydroquinidine in patients with Brugada syndrome

Abstract Background Brugada syndrome (BrS) is an inherited channelopathy with an increased risk of supraventricular, ventricular arrhythmias (VAs) and sudden cardiac death (SCD). Implantable cardioverter-defibrillator (ICD) is a cornerstone of SCD prevention, but it does not reduce the incidence of life-threatening VAs and it can carry substantial complications. Hydroquinidine (HQ) is a class IA antiarrhythmic drug used for electrical storms, to reduce ICD's appropriate discharges and as an alternative to ICD in children with BrS or in patients with a contraindication to ICD. Nevertheless, HQ's side effects may undermine treatment compliance. Purpose The aim of this study was to evaluate the efficacy and safety of HQ in reducing VAs (ventricular fibrillation, sustained and non-sustained ventricular tachycardia) inducibility at electrophysiology study (EPS) and atrial fibrillation/flutter (AF/AFL) or VAs recurrence in patients with BrS. Methods From the prospective Piedmont Brugada Registry, patients treated with HQ were selected and divided into three groups according to the indication for HQ initiation: index EPS positive for VAs induction (group 1), secondary prevention of AF/AFl (group 2), secondary prevention of VAs (group 3). In group 3 recurrence of VAs was monitored by implantable devices or by periodic 24-hour ECG Holter monitoring. In 5 patients HQ was started for reasons different from the above mentioned, so they were considered only for safety outcomes. Safety was assessed considering the occurrence of HQ side effects and their impact on treatment discontinuation. Results A total of 98 patients (79 males, 80,6%) were included. Median follow-up was 61 months (IQR 31–89 months). None of the baseline clinical characteristics was associated with arrhythmic recurrences. Among 46 patients in group 1 HQ was effective in reducing EPS inducibility in 91.9% of patients (p&amp;lt;0.0001); in group 2 (31 patients) HQ reduced palpitations [before HQ 83,8%, with HQ 27,6%, RRR 67.1%, NNT 1.8; p&amp;lt;0.0001] and no AF/AFL recurrence was recorded during follow-up (p&amp;lt;0.0001); in group 3 (17 patients; 70.6% with ICD/LR implanted) VAs recurrences were significantly reduced in patients with HQ (5.9% recurrence rate, p&amp;lt;0.0001). Overall, no cardiac arrest occurred during follow-up. At ECG, HQ determined a significant increase in QTc duration (V5-lead mean QTc duration pre-HQ 406 ms vs with HQ 428 ms; p=0.001). Overall, 28.6% of patients presented HQ-related side effects, mainly due to gastrointestinal intolerance (18.3%). Treatment discontinuation rate was 25% but only about half of these patients discontinued HQ for adverse events (29.2% for GI intolerance, 16.7% for drug-induced QTc prolongation, 8.3% for elevated liver enzymes; 45.8% self-discontinuation). Conclusions In patients with BrS, HQ was effective in reducing VAs inducibility at EPS, AF/AFL and VAs recurrences; moreover, it was effective in reducing symptoms. Overall, HQ proved to be safe and well-tolerated. Funding Acknowledgement Type of funding source: None

Ventricular arrhythmias in Takotsubo Syndrome: incidence, predictors and clinical outcomes.

To investigate predictors of the occurrence of subacute ventricular arrhythmias (VAs), defined as any VAs presenting after 48 h from admission in patients with Takotsubo Syndrome (TTS), and to evaluate the related in-hospital mortality. This is a retrospective single-center study enrolling patients admitted between 2012 and 2017 with TTS according to International Takotsubo diagnostic criteria. Data collection included ECG on admission and at 48 h, telemetry monitoring and transthoracic echocardiogram. We enrolled 93 patients; during in-hospital stay (mean 14 ± 16 days) subacute VAs occurred in 25% of patients (VAs group). Life-threatening VAs occurred in 6% of patients (3 sustained ventricular tachycardia, 1 torsade de pointes, 1 ventricular fibrillation) and not life-threatening VAs in 19% (6 non-sustained ventricular tachycardia and 12 premature ventricular contractions > 2000 in 24 h). Mortality was higher in the VAs than in the non-VAs group (P = 0.03), without differences in terms of life-threatening and not life-threatening subacute VAs (P = 0.65) and VAs on admission (P = 0.25). Logistic regression identified the following independent predictors of subacute VAs occurrence: VAs on admission {odds ratio [OR] 22.5 (3.9-131.8), P = 0.001]}, New York Heart Association (NYHA) class III-IV on admission [OR 6.7 (1.3- 34.0), P = 0.021] and QTc at 48 h [OR 1.01 (1.00-1.03), P = 0.046]. TTS patients with VAs and NYHA class III-IV on admission and higher QTc at 48 h are at increased risk of subacute VAs occurrence, associated with higher in-hospital mortality. Awareness of this potential complication is critical for proper patients management.

Detection of arrhythmogenic substrate within QRS complex in patients with cardiac sarcoidosis using wavelet-transformed ECG.

Signal-averaged electrocardiography (SAECG) has been known to be useful for prediction of lethal ventricular arrhythmias (VA). However, this technique has limitations in patients with intraventricular conduction disturbance (IVCD), which is common in cardiac sarcoidosis (CS). Meanwhile, wavelet-transformed ECG (WTECG) has been reported to be useful for detecting arrhythmogenic substrate hidden within QRS complex. The objective of this study was to assess the utility of WTECG for detecting arrhythmogenic substrate in patients with CS. Forty-four CS patients including 18 patients with VA were retrospectively investigated. The parameters on the signal-averaged electrocardiography (SAECG) and the power of frequency components on WTECG were compared between VA group and non-VA group. Eighteen patients have VA (VT: n = 17, VF: n = 1). LP were detected in 17 in VA group and 24 in non-VA group. WTECG showed that high-frequency components (HFC; 80-150Hz) were developed in VA group. Peak power value at 150Hz (P150) was significantly higher in VA group than that in non-VA group (442.9 ± 160.2 vs 316.7 ± 100.8, p = 0.006). The receiver operating characteristic (ROC) curve analysis showed an optimal cutoff point of 336 of P150 for detecting patients with VA, with 82.4% sensitivity, 61.5% specificity, and area under the curve of 0.74 (95% confidence interval [CI] 0.59-0.89). WTECG may be useful for detecting CS patients who are prone to VA.

Revascularisation of chronic total occlusions and recurrence rate of ventricular arrhythmias

Background The impact of revascularisation of chronic total occlusions (CTO) on the incidence of ventricular arrhythmias (VA) remains to be elucidated. Methods Based on prospectively gathered data, the recurrence rate of VAs following CTO treatment was retrospectively investigated. Patients presenting with VAs as clinical indication for CTO revascularisation were retrospectively selected out of three Belgian CTO registries (i.e. Ziekenhuis Oost-Limburg, UZ Leuven and CHR de la Citadelle). Freedom of VAs was defined as absence of non-sustained or sustained tachycardias (VT), ventricular fibrillations (Vfib) and ventricular extrasystoles (VES; <2500 VES/24 h). Long-term outcome in terms of reoccurrence of VAs was evaluated by reviewing patient records. Results Between 2011 and 2019, 912 patients underwent a CTO-PCI across three Belgian centres. In total 43 patients (5%) presented with VAs as clinical indication for CTO revascularisation. Overall follow-up was 723 (391 − 1144) days. Fourteen (33%), 18 (42%), 5 (11%) and 6 (14%) presented with >2500 VES/24 hrs, non-sustained VT, sustained VT and Vfib, respectively. In those patients with a one-year follow-up available (n = 34), overall recurrence rate of VAs was 38% (within VA group: VES: 25%, non-sustained VT: 46%; sustained VT: 25% and Vfib: 60%). Conclusion Based on this retrospective data analysis, CTO revascularisation, in patients presenting with VAs as the main clinical indication, seems to beneficially impact the incidence of VAs, which ultimately might result in improved patients’ outcome.

Genetic Variants on SCN5A, KCNQ1, and KCNH2 in Patients with Ventricular Arrhythmias during Acute Myocardial Infarction in a Chinese Population

Objective: Acute myocardial infarction (AMI) remains a leading cause of morbidity and mortality worldwide. About half of sudden deaths from AMI are mainly because of malignant ventricular arrhythmias (VA) after AMI. The sodium channel gene SCN5A and potassium channel genes KCNQ1 and KCNH2 have been widely reported to be genetic risk factors for arrhythmia including Brugada syndrome and long QT syndrome (LQTS). A few studies reported the association of SCN5A variant with ventricular tachycardia (VT)/ventricular fibrillation (VF) complicating AMI. However, little is known about the role of KCNQ1 and KCNH2 in AMI with VA (AMI_VA). This study focuses on investigating the potential variants on SCN5A, KCNQ1, and KCNH2 contributing to AMI with VA in a Chinese population. Materials and Methods: In total, 139 patients with AMI_VA, and 337 patients with AMI only, were included. Thirty exonic sites were selected to be screened. Sanger sequencing was used to detect variants. A subsequent association study was also performed between AMI_VA and AMI. Results: Twelve variants [5 on KCNH2(NM_000238.3), 3 on KCNQ1(NM_000218.2), and 4 on SCN5A(NM_198056.2)] were identified in AMI_VA patients. Only 5 (KCNH2: c.2690A>C; KCNQ1: c.1927G>A, c.1343delC; SCN5A: c.1673A>G, c.3578G>A) of them are missense variants. Two (KCNQ1: c.1343delC and SCN5A: c.3578G>A) of the missense variants were predicted to be clinically pathogenic. All these variants were further genotyped in an AMI without VA group. The association study identified a statistically significant difference in genotype frequency of KCNH2: c.1539C>T and KCNH2: c.1467C>T between the AMI and AMI_VA groups. Moreover, 2 rare variants (KCNQ1: c.1944C>T and SCN5A: c.3621C>T) showed an elevated allelic frequency (more than 1.5-fold) in the AMI_VA group when compared to the AMI group. Conclusion: Twelve variants (predicting from benign/VUS to pathogenic) were identified on KCNH2, KCNQ1, and SCN5A in patients with AMI_VA. Genotype frequency comparison between AMI_VA and AMI identified 2 significant common variants on KCNH2. Meanwhile, the allelic frequency of 2 rare variants on KCNQ1 and SCN5A, respectively, were identified to be enriched in AMI_VA, although there was no statistical significance. The present study suggests that the ion-channel genes KCNH2, KCNQ1, and SCN5A may contribute to the pathogenesis of VA during AMI.

Clinical significance of J wave in prediction of ventricular arrhythmia in patients with acute myocardial infarction

BackgroundJ wave syndrome and myocardial ischemia are related with malignant ventricular arrhythmia (VA). The characteristics of dynamic J wave in patients with early phase of acute myocardial infarction (AMI) and subsequent VA or electrical storm (ES) have not been well evaluated. ObjectiveWe investigated the utility of J wave in the prediction of VA and ES in patients within the early phase of AMI. MethodsThis study retrospectively enrolled 208 patients (mean age 69±15 years, 171 males) with AMI. Of them, 50 patients had experienced VA during hospitalization and 24 had ES. The clinical and electrocardiographic characteristics of these patients with and without VA were compared. ResultsPatients with VA had a higher incidence of chronic kidney disease (CKD) and J wave compared with those without VA. The hazard ratio (HR) of J wave for VA was 4.31 (p<0.01) and CKD was 2.64 (p<0.01). In the VA group, ES patients had a higher incidence of diabetes mellitus (DM) (HR 2.73, p=0.02) and J wave (HR 4.21, p<0.01). If the AMI patients had J wave, the OR for mortality was 2.14 (p=0.03), VA events was 6.23 (p<0.01), and ES events was 12.15 (p<0.01). If VA patients had J wave, the mortality rate will significantly increase (OR 68.62, p=0.01). ConclusionThe AMI patients who develop VA in the early phase of AMI had a higher incidence of J wave and CKD, and those who develop ES had a higher incidence of J wave and DM. It seems that J wave in AMI patients is a poor prognostic factor, and we found that J wave will increase mortality, VA events, and ES events. The majority locations of J wave were inferior leads although there was no relationship between the locations and VA incidence. If the VA patients had inferior or lateral J wave, it would further increase the risk of mortality.

Prognostic Significance of Complex Ventricular Arrhythmias Complicating ST-Segment Elevation Myocardial Infarction

The aim of the study was to assess the clinical significance of complex ventricular arrhythmias (VAs) (sustained ventricular tachycardia [sVT] and ventricular fibrillation [VF]) in patients with ST-segment elevation myocardial infarction (STEMI) depending on timing of arrhythmia. We analyzed 4,363 consecutive patients with STEMI treated invasively between 2004 and 2014. The median follow-up was 69.6 months (range: 0 to 139.8 months). The study population was divided into 2 main groups; VA group encompassed 476 patients (10.91%) with VAs, whereas 3,887 subjects (89.09%) without VT or VF were included into the control group. In VA population, prereperfusion VA (34.24%; n = 163) was the most common arrhythmia, whereas reperfusion-induced, early postreperfusion, and late postreperfusion VAs were diagnosed in 103 (21.64%), 103 (21.64%), and 107 (22.48%) patients, respectively. Every type of sVT or VF complicating STEMI portended significantly worse in-hospital prognosis, however a late onset arrhythmia was associated with the highest (over fivefold) and reperfusion-induced VA with the lowest (less than threefold) increase in mortality risk compared with the control group. On the contrary, long-term mortality was significantly increased only in subjects with late postreperfusion and prereperfusion VAs compared with VA-free population (43.93% and 36.81%, respectively vs 22.58%; p <0.001). Apart from cardiogenic shock on admission, late postreperfusion (hazard ratio 3.39) and prereperfusion VAs (hazard ratio 2.76) were the strongest independent predictors of death in the analyzed population. In conclusion, 1 in 10 patients with STEMI treated invasively was affected by sVT or VF. The clinical impact of VAs was strongly dependent on timing of arrhythmia.

The protective effects of dexmedetomidine on perioperative myocardial injury in patients with hypertensive myocardial hypertrophy

The purpose of this study was to evaluate the effects of dexmedetomidine (DEX) on patients with hypertensive myocardial hypertrophy. Fifty four patients with hypertensive myocardial hypertrophy were enrolled in the study and were randomly divided into two groups (n=27). Patients in groupD were pretreated with DEX (1 μg/kg) before induction and then maintain with 0.5 μg/(kg·h) DEX. Patients in group C were pretreated with saline at the same time. All patients were connected with holter recorder 2 h before anesthesia and were continuously recorded for 24 h. Blood sample were collected to measure ischemia modified albumin(IMA) and serum cardiac troponin I (cTnI) at the time of T0 (before induction), T1(1 h after surgery), T2(4 h after surgery), T3(12 h after surgery) and T4(24 h after surgery). The surgery time, blood loss and side effect of two groups were recorded at the same time. The serum IMA level in group D was lower than that of group C at the time of T1, T2 and T3 (P<0.05). The serum cTnI in group C was higher than that of group D at the time of T1, T2, T3 and T4 (P<0.05). Changes of ST and complicated ventricular arrhythmias ingroup D were lower than those of group C (P<0.05). DEX could reduce the incidence of myocardial damage, changes of ST and complicated ventricular arrhythmias in patients with hypertensive myocardial hypertrophy.

Impact of citrate pretreatment on ventricular arrhythmia and myocardial capase-3 expression in ischemia/reperfusion injury

Ischemia/reperfusion (I/R) injury often triggers ventricular arrhythmia. Citrate binds calcium ions, forming a soluble calcium citrate complex that may reduce I/R injury by affecting calcium ion concentration. We tested the effects of citrate pretreatment on ventricular heart rate and related factors in a rat I/R model. Fifty male Sprague Dawley rats weighing 350-400 g were randomly divided into equally sized control (A), model (B), and 0.1 M (C), 0.05 M (D), and 0.025 M (E) citrate groups. An I/R model was established by ligating the left anterior descending coronary artery. Serum calcium ion concentration was measured before and after citrate treatment. Triphenyltetrazolium chloride staining and spectrophotometry were used to determine infarction area and caspase-3 protein levels in myocardial tissue, respectively. Polymerase chain reaction was performed to test myocardial calmodulin (CAM) expression. The frequency of ventricular arrhythmia in group B was significantly higher than in the sham surgery group (P < 0.05). Citrate pretreatment resulted in lower and higher frequencies than those observed in the model and control groups, respectively, in a dose-independent manner. The most obvious reduction in ventricular arrhythmia was seen in Group D. Serum calcium ion concentration decreased markedly after citrate treatment (P < 0.05), with a specific pattern emerging over time. Infarction area and caspase-3 and CAM levels were significantly lower in the citrate groups compared with the model group (P < 0.05). Citrate can reduce myocardial cell apoptosis, alleviating ventricular arrhythmia and protecting the myocardium by reducing serum calcium ion concentration and downregulating caspase-3 and CAM expression.

Prevention of ventricular arrhythmia complicating acute myocardial infarction by local cardiac denervation

BackgroundAugmentation of sympathetic nerve activity after acute myocardial infarction (AMI) contributes to fatal arrhythmia. In this study, we investigated whether local ablation of the coronary sinus (CS) and great cardiac vein (GCV) peripheral nerves could reduce ventricular arrhythmias (VA) in a canine AMI model. MethodsTwenty-one anesthetized dogs were randomly assigned into the sham-operated, MI and MI-ablation groups, respectively. The incidence and duration of VA were monitored among different groups. The ventricular effective refractory period (ERP), the ERP dispersion and the ventricular fibrillation threshold (VFT) were measured during the experiments. Norepinephrine (NE) levels in CS blood and cardiac tissue were also detected in this study. ResultsThe incidence and duration of VA in MI-ablation group were significantly reduced as compared to the MI dogs (p<0.05). Furthermore, local cardiac denervation drastically prolonged the ventricular ERP in the ischemia area, decreased the ERP dispersion, and reduced NE levels in CS blood (P<0.05). VFT also showed an increased trend in the AMI-ablation group. ConclusionsThe results of this study indicate that, in the canine AMI model, local ablation of CS and GCV peripheral nerves reduces VA occurrence and improves ventricular electrical stability with no obvious effects on heart rate, mean arterial pressure and infarct size. This study suggests that local cardiac denervation may prevent ventricular arrhythmias complicating AMI.