Activation pattern of the coronary sinus facilitates the differentiation for ventricular outflow tract arrhythmias.

INTRODUCTION: The accuracy of surface ECG algorithms for predicting the origin of outflow tract ventricular arrhythmias (OT-VAs) might be questioned. Intracardiac electrograms recorded at anatomic landmarks could provide new predictive insights. We aim to evaluate the efficacy of a novel criterion utilizing the activation pattern of the coronary sinus (CS) in localizing OT-VAs, including VAs originating from the right ventricular outflow tract (RVOT), endocardial left ventricular outflow tract (Endo-LVOT), and epicardial left ventricular outflow tract (Epi-LVOT). METHODS: We measured the ventricular activation time of the mitral annulus (MA) from the onset of the earliest QRS complex of VAs to the initial deflection over the isoelectric line at local signals, namely the QRS-MA interval. The activation at 3 and 12 o'clock of the MA was recorded as the QRS-MA3 and QRS-MA12 intervals, respectively. Their predictive values were compared to previous ECG algorithms. RESULTS: A total of 68 patients with OT-VAs were enrolled (51 for development and 17 for validation). From early to late, the ventricular activation sequences at MA12 were as follows: Epi-LVOT, Endo-LVOT, and RVOT. In LBBB morphology OT-VAs, the QRS-MA12 interval was significantly earlier for LVOT origins than RVOT origins. In the combined cohort of development and validation cohort, a cut-off value of ≤10 ms predicted the LVOT origin with a sensitivity of 100% and specificity of 78%. The QRS-MA12 interval ≤ -24 ms additionally predicted epicardial LVOT sites of origin. CONCLUSIONS: The QRS-MA interval could accurately differentiate the OT-VAs localization.

Real-world assessment of multipolar and point-by-point mapping for premature ventricular contraction ablation.

AIMS: We aimed to assess the acute and midterm efficacy of premature ventricular contraction (PVC) ablation guided by multielectrode and point-by-point (PbP) mapping. METHODS AND RESULTS: This is a retrospective, international multicentre study of consecutive patients referred for PVC ablation in 10 hospital centres from January 2017 to December 2021. Based on the mapping approach, two cohorts were identified: the 'Multipolar group', where a dedicated high-density mapping catheter was employed, and the 'PbP group', where mapping was performed with the ablation catheter. Procedural endpoints, safety, and acute (procedural) and midterm efficacies were assessed. Of the 698 patients included in this study, 592 received activation mapping [46% males, median age of 55 (41-65) years]-248 patients in the Multipolar group and 344 patients in the PbP group. A higher number of activation points [432 (217-843) vs. 95 (42-185), P < 0.001], reduced mapping time (40 ± 38 vs. 61 ± 50 min, P < 0.001), and shorter procedure time (124 ± 60 vs. 143 ± 63 min, P < 0.001) were reported in the Multipolar group. Both groups had high acute success rates (84.7% with Multipolar mapping vs. 81.3% with PbP mapping, P = 0.63), as well as midterm efficacy (83.4% vs. 77.4%, P = 0.08), with no significant differences in the risk of adverse events (6.0% vs. 3.5%, P = 0.24). However, for left-sided PVC ablation specifically, there was a higher midterm efficacy in the Multipolar group (80.7% vs. 69.5%, P = 0.04), with multipolar mapping being an independent predictor of success [adjusted OR = 2.231 (95% CI, 1.476-5.108), P = 0.02]. CONCLUSION: The acute and midterm efficacies of PVC ablation are high with both multipolar and PbP mapping, although the former allows for quicker procedures and may potentially improve the outcomes of left-sided PVC ablation.

Association between excess catecholamine synthesis and polymorphic premature ventricular contraction.

BACKGROUND: The reasons for the etiology of premature ventricular contractions (PVCs) are not specifically known. Many patients are resistant to medical treatment, and a factor that would predict response to medical treatment cannot be identified. This study aims to investigate if a high catecholamine level results in polymorphic PVC. METHODS: This study was obtained by prospective data registry analysis. A total of 100 patients, 50 from the PVC group, and 50 from the control group have been evaluated. The participants who were included in the patient group had a polymorphic PVC of 5% or more in their 24-h Holter evaluations. Metanephrine showing the level of adrenaline and normetanephrine, showing the level of noradrenaline levels have been measured from these urine samples. RESULT: There was no difference between the two groups in terms of biochemical and essential characteristics. Normetanephrine level has been significantly higher in the PVC group compared to the control group (323.9 ± 208.9 µg to 129.25 ± 67.88 µg; p < 0.001). Similarly, metanephrine level has also been higher in the PVC group (124.75 ± 82.43 µg to 52.615 ± 36,54 µg; p < 0.001). A positive and moderate correlation has been identified between the number and ratio of PVC and the metanephrine and normetanephrine levels. CONCLUSION: In this study, we found that the catecholamine levels were higher in the polymorphic PVC group than in the healthy volunteers. Also, an increase in the number and rate of PVC has been observed as the catecholamine levels increased. CLINICAL TRIAL REGISTRATION: Urine Levels of Metanephrine and Normetanephrine in Patients With Frequent PVC; ClinicalTrials.gov number NCT03447002.

Successful ablation of premature ventricular contractions originating from the posterior-superior process of the left ventricle approaching from the right atrium in a 13-year-old male.

This is a case of a 13-year-old male with frequent premature ventricular contractions with QRS configurations of the left superior axis and left bundle branch block, which originated from the posterior-superior process of the left ventricle. Premature ventricular contractions were successfully eliminated by delivering radiofrequency energy to the inferior wall of the right atrium without causing either junctional rhythm or atrioventricular block. Ventricular arrhythmias originating from this site have been sporadically reported in adults; however, this is the first report in a child.

Insight from the microelectrodes in case of two different types of premature ventricular contractions originating from left ventricular summit.

Premature ventricular contraction (PVC) is usually eliminated in the earliest activation site based on the conventional electrode of ablation catheter. However, the large size electrode may contain far-field potential. The QDOT MICRO ablation catheter has three micro electrodes with 0.33 mm electrode length, in addition to the conventional electrode with 3.5 mm electrode length. The micro electrodes can reflect only near-field potential. A 78-year-old with symptomatic frequent PVCs underwent catheter ablation. PVC-1 showed good pace-mapping in distal great cardiac vein (GCV). The local bipolar electrograms in the conventional electrode of ablation catheter preceded the PVC-QRS onset by 32 ms in distal GCV and 13 ms in left coronary cusp (LCC), but those in the micro electrodes preceded only by 13 ms both in distal GCV and LCC. PVC-1 was eliminated by radiofrequency (RF) application, not in distal GCV, but in LCC. PVC-2 showed good pace-mapping in LCC. The local bipolar electrograms in both the conventional electrode and the micro electrodes of ablation catheter preceded the PVC-QRS onset by 32 ms in LCC. PVC-2 was eliminated by RF application in LCC. Comparing the local electrograms of micro electrodes and the conventional electrodes may be important for identifying depth of the origin of PVCs.

[Evidence mapping of Chinese patent medicines in treatment of premature ventricular contractions].

This study employed evidence mapping to systematically sort out the clinical studies about the treatment of premature ventricular contractions with Chinese patent medicines and to reveal the distribution of evidence in this field. The articles about the treatment of premature ventricular contractions with Chinese patent medicines were searched against PubMed, Cochrane Library, Web of Science, CNKI, Wanfang, and VIP with the time interval from January 2016 to December 2022. Evidence was analyzed and presented by charts and graphs combined with text. According to the inclusion and exclusion criteria, 164 papers were included, including 147 interventional studies, 4 observational studies, and 13 systematic reviews. A total of 27 Chinese patent medicines were involved, in which Shensong Yangxin Capsules and Wenxin Granules had high frequency. There were off-label uses in clinical practice. In recent years, the number of articles published in this field showed a decreasing trend. Eight types of outcome indicators were used in interventional studies. Ambulatory electrocardiography, clinical response rate, safety, and echocardiography had high frequency, while the rate of ß-blocker decompensation, major cardiovascular events, and pharmaceutical economic indicators were rarely reported. The evaluation was one-sided. The low quality of the included articles reduced the reliability of the findings. In the future, the clinical use of medicines should be standardized, and the quality of clinical studies should be improved. Comprehensive clinical evaluation should be carried out to provide a sound scientific basis for the treatment of premature ventricular contractions with Chinese patent medicines.

Unipolar and bipolar electrograms to predict successful ablation site of premature ventricular contractions originating from the free wall of the tricuspid annulus.

INTRODUCTION: This study aimed to identify the characteristics of unipolar and bipolar electrogram (UniEGM and BiEGM) in guiding successful ablation of premature ventricular contractions (PVCs) originating from the free wall of the ventricular aspect of the tricuspid annulus (TA). We hypothesized that the negative concordance pattern (NCP) on the onset of UniEGM and BiEGM, together with the least value of the difference between the earliest BiEGM and UniEGM dV/dTmax, might improve the accuracy of conventional mapping. METHODS AND RESULTS: Thirty consecutive patients who underwent successful catheter ablation from February 2018 to July 2021 were retrospectively analyzed. The BiEGM and UniEGM for successful ablation sites were compared with those for non-successful ablation sites. Among the 30 patients, 30 successful and 26 nonsuccessful ablation sites were compared. The earliest activation time of the BiEGM (BiEGMoneset-QRS) was 25 ± 6 ms for the successful ablation sites and 21 ± 6 ms for the nonsuccessful ablation sites (p = .47). The value of the difference in the earliest BiEGM and UniEGM dV/dTmax differed between successful and nonsuccessful ablation sites (6.4 ± 3.6 ms vs. 10.4 ± 6.8 ms). NCP was observed at 90.0% and 42.3% of the successful and nonsuccessful ablation sites, respectively. Alignment of NCP and BiEGMonset-UniEGM ≤6 ms was applied as the mapping criterion for successful PVC suppression (73.1% sensitivity and 87.7% specificity). The area under the receiver-operating characteristic curve for this cutoff was 0.85. CONCLUSION: Mapping based on an NCP at the onset of the BiEGM and UniEGM and the least difference value of the earliest BiEGM and UniEGM dV/dTmax had an excellent predictive value for successful ablation. These strategies may reduce the number of radiofrequency catheter ablation (RFCA) applications for free-wall tricuspid annular PVCs.

Mechanisms and Risk Factors for Premature Ventricular Contraction Induced Cardiomyopathy.

Frequent premature ventricular contractions (PVCs) can cause a reversible form of cardiomyopathy in patients without structural heart disease. Because of the challenging nature of PVC-induced cardiomyopathy (PVICM), the mechanisms and risk factors for PVICM are still unclear. Based on the evidence from retrospective and observational studies, the risk factors for the development of PVICM, in addition to PVC exposure, include QRS duration, coupling interval and male sex. Based on animal models, abnormal calcium handling and cardiac remodeling may be the crucial mechanism underlying the development of cardiomyopathy. We have summarized the current knowledge on PVICM in this review. Understanding these mechanisms and risk factors is important for the diagnosis and management of this condition, which can lead to heart failure if left untreated.

Use of a QDOT MICRO catheter to identify a premature ventricular contraction origin in the right ventricular anterior papillary muscle in a repaired truncus arteriosus.

The ventricular papillary muscles (VPMs) can be a source of premature ventricular contractions (PVCs). Catheter ablation of VPM PVCs is challenging because of the anatomical complexity, such as the apical structures in proximity to the ventricular walls. The QDOT MICRO catheter (Biosense Webster, Diamond Bar, CA, USA) has microelectrodes embedded along the circumference of its distal tip and can provide information on which side of its tip myocardial activation is earlier. This repaired truncus arteriosus case demonstrates the usefulness of the microelectrode recording in identifying a PVC origin in a right VPM apex close to the right ventricular anterior wall.

Two pacing pulses at short interval on premature ventricular contraction: What is the mechanism?

To understand the seemingly complex behavior of a pacemaker, it is important to carefully read the ECG and understand the manufacturer-specific behavior. This report focuses on the interesting ECG acquired from a patient with a pacemaker operating in DDD mode during a routine outpatient clinic examination.

Mechanisms, time course and predictability of premature ventricular contractions cardiomyopathy-an update on its development and resolution.

Frequent premature ventricular contractions (PVCs) associated left ventricular systolic dysfunction (LVSD) is a well-known clinical scenario and numerous predictors for cardiomyopathy (CMP) development have been already thoroughly described. It may present as a "pure" form of dissynchrony-induced cardiomyopathy or it may be an aggravating component of a multifactorial structural heart disease. However, the precise risk to develop PVC-induced CMP (which would allow for tailored-patient monitoring and/or early treatment) and the degree of CMP reversibility after PVC suppression/elimination (which may permit appropriate candidate selection for therapy) are unclear. Moreover, there is limited data regarding the time course of CMP development and resolution after arrhythmia suppression. Even less known are the other components of PVC-induced CMP, such as right ventricular (RV) and atrial myopathies. This review targets to synthetize the most recent information in this regard and bring a deeper understanding of this heart failure scenario. The mechanisms, time course (both in experimental models and clinical experiences) and predictors of reverse-remodelling after arrhythmia suppression are described. The novel experience hereby presented may aid everyday clinical practice, promoting a new paradigm involving more complex, multi-level and multi-modality evaluation and possible earlier intervention at least in some patient subsets.

Contemporary clinical management of monomorphic idiopathic premature ventricular contractions: results of the European Heart Rhythm Association survey.

On behalf of the European Heart Rhythm Association, we designed a survey, whose aim was to understand the trend(s) in the clinical management of idiopathic monomorphic premature ventricular contractions (PVCs) among European cardiologists and cardiac electrophysiologists. A total of 202 participants in the survey answered 27 multiple-choice questions on the clinical presentation, diagnosis and treatment of idiopathic monomorphic PVCs. The most common symptom in patients with idiopathic monomorphic PVCs is palpitations, according to the majority of responders (87%), followed by fatigue (29%) and dizziness (18%). Complete blood cell count, renal function with electrolytes levels, and thyroid function are the blood tests requested by the majority of respondents (65%, 92%, and 93%, respectively). Coronary artery disease and structural heart disease needs to be ruled out, according to the vast majority of participants (99%). A 24-h Holter ECG is the preferred ECG modality to assess the burden of PVCs (86% of respondents). Among the different option treatments, beta-blockers and class I antiarrhythmic drugs are by far (81% of respondents) the preferred pharmacological option in comparison with calcium antagonists and class III antiarrhythmic drugs. Catheter ablation has also a good reputation: 99% of responders are keen to use it, especially in patients with high burden of PVCs and when signs of cardiomyopathy occur.

Risk Factors and Heart Rate Variability Associated with Left Ventricular Enlargement in Patients with Frequent Premature Ventricular Contractions.

INTRODUCTION: Premature ventricular contractions (PVCs) were now well recognized to carry the risk of inducing left ventricular (LV) enlargement and were closely related to the cardiac autonomic nervous activity quantified by heart rate variability (HRV) analysis. However, the relationship between LV enlargement and HRV in patients with frequent PVCs is still unclear. This study aimed to investigate the risk factors and HRV for LV enlargement in patients with frequent PVCs. METHODS: Patients with frequent PVCs (n = 571), whose PVC burden counts >10,000/24 h or PVC burden >10%, were recruited. Patients were divided into LV enlargement group (n = 161), defined as female left ventricular end-diastolic diameter (LVEDD) >49.8 mm or male LVEDD >54.2 mm, and LV normal group (n = 410). Two groups were compared on their clinical, electrocardiographic, and HRV parameters. Logistic regression analysis was used to predict the risk factors of LV enlargement in patients with frequent PVCs. The parameters of echocardiography, Holter monitoring, and HRV were collected after ablation. RESULTS: There were significant differences between the patients with left enlargement and with normal LV structure, in terms of sex, left ventricular ejection fraction (LVEF), level of N-terminal pro-brain natriuretic peptide (NT-proBNP), 24-h PVC burden, with nonsustained ventricular tachycardia, multifocal PVCs, QRS duration of PVC, and values of very low-frequency power of HRV parameter (all p < 0.05). Multivariate analysis showed that female gender (odds ratio [OR] = 2.753, p < 0.001), increased NT-proBNP (OR = 1.011, p = 0.022), increased LVEF (OR = 0.292, p < 0.001), increased 24-h PVC burden (OR = 1.594, p < 0.001), increased standard deviation of all NN intervals (SDNN) (OR = 1.100, p = 0.003), increased the proportion of consecutive NN intervals that differ by more than 50 ms (pNN50) (OR = 0.844, p = 0.026) were predictors for LV enlargement in patients with frequent PVCs. 84.4% (54/64) of patients with LV enlargement at baseline had normalized their LV structure after ablation. The values of SDNN, standard deviation of the averages of NN intervals in all 5-min segments, the square root of the mean of the sum of the squares of differences between adjacent NN intervals, pNN50, low-frequency power (LF), LF/high-frequency power ratio of patients were significantly decreased after ablation (all p < 0.05). CONCLUSION: Female gender, increased level of NT-proBNP, lower LVEF, higher PVC burden, increased sympathetic parameters SDNN, and reduced parasympathetic parameters pNN50 were the independent risk factors of LV enlargement in patients with frequent PVCs. LV enlargement induced by PVCs can be reversible after PVC elimination by ablation. The activities of sympathetic and parasympathetic were reduced after ablation.

A rare cause of idiopathic right outflow tract premature ventricular contraction: Type-4 renal tubular acidosis.

The premature ventricular contractions (PVCs) have usually good prognosis in patients without structural heart disease. In case of left ventricular ejection fraction depression or symptoms, antiarrhythmic drugs or cardiac ablations could be an option for management. We present a case of a patient with high burden of PVC admitted for cardiac ablation. Preoperative assessment revealed hyperkalemia and metabolic acidosis which ended up with type-4 renal tubular acidosis (RTA). Its rare cause and management may draw attention to the possibility of type -4 RTA as the cause of the PVC, and hyperkalemia.

Interventricular septum angle obtained from cardiac computed tomography for origin differentiation of outflow tract ventricular arrhythmia between left and right.

AIMS: Our objective was to explore whether the accuracy of the transitional zone index (TZI) for outflow tract ventricular arrhythmias (OT-VAs) origin is affected by cardiac rotation and the additive value of interventricular septum angle (IVSa) obtained from coronary computed tomography angiography (CCTA). METHODS: Standard 12-lead ECGs of OT-VAs with inferior axis in consecutive patients undergoing both CCTA examination and successful ablation were retrospectively analyzed. The IVSa was defined as an angle between the long axis of IVS and sagittal axis of the body from CCTA. RESULTS: 64 patients (31 men; mean age 54.2 ± 11.6 years) were enrolled. The OT-VAs exhibited right ventricular outflow tract origin in 46 (71.9%) patients and 36 (78.3%) were diagnosed correctly by TZI. The left ventricular outflow tract origin OT-VAs was observed in 18 (28.1%) patients and 16 (88.9%) were diagnosed correctly by TZI. The patients were then divided into TZI correct group (n = 52) and TZI incorrect group (n = 12). In the TZI incorrect group, 11/12 (91.7%) cases were R/S transition in lead V3 with the TZ score during premature ventricular contractions [2.8(2.5-3.4)], and the TZI between -1.5 and 0. The IVSa was significantly larger in the TZI incorrect group than correct group (52.0 ± 6.9° vs. 39.0 ± 6.1°; p < .0001). The IVSa ≥46° predicted TZI incorrect with 92% sensitivity, 94% specificity, and 94% accuracy. CONCLUSION: The IVSa is a novel cardiac rotation index that reliably improves TZI to differentiate the OT-VAs origin, especially for the OT-VAs with lead V3 R/S transition.

Adaptive support ventilation as an effective treatment option for central sleep apnea in an older adult with heart failure with preserved ejection fraction: a case report.

BACKGROUND: Adaptive support ventilation (ASV) is a proposed treatment option for central sleep apnea (CSA). Although the effectiveness of ASV remains unclear, some studies have reported promising results regarding the use of ASV in patients with heart failure with preserved ejection fraction (HfpEF). To illustrate the importance of suspecting and diagnosing sleep-disordered breathing (SDB) in older adults unable to recognize symptoms, we discuss a case in which ASV was effective in a patient with CSA and HfpEF, based on changes in the Holter electrocardiogram (ECG). CASE PRESENTATION: An 82-year-old man presented to our hospital with vomiting on April 19, 2021. Approximately 10 years before admission, he was diagnosed with type 1 diabetes mellitus and recently required full support from his wife for daily activities due to cognitive dysfunction. Two days before admission, his wife was unable to administer insulin due to excessively high glucose levels, which were displayed as "high" on the patient's glucose meter; therefore, we diagnosed the patient with diabetic ketoacidosis. After recovery, we initiated intensive insulin therapy for glycemic control. However, the patient exhibited excessive daytime sleepiness, and numerous premature ventricular contractions were observed on his ECG monitor despite the absence of hypoglycemia. As we suspected sleep-disordered breathing (SDB), we performed portable polysomnography (PSG), which revealed CSA. PSG revealed a central type of apnea and hypopnea due to an apnea-hypopnea index of 37.6, which was > 5. Moreover, the patient had daytime sleepiness; thus, we diagnosed him with CSA. We performed ASV and observed its effect using portable PSG and Holter ECG. His episodes of apnea and hypopnea were resolved, and an apparent improvement was confirmed through Holter ECG. CONCLUSION: Medical staff should carefully monitor adult adults for signs of or risk factors for SDB to prevent serious complications. Future studies on ASV should focus on older patients with arrhythmia, as the prevalence of CSA may be underreported in this population and determine the effectiveness of ASV in patients with HfpEF, especially in older adults.

Could premature ventricular contractions lead to atrial remodeling?

BACKGROUND: Premature ventricular contraction (PVC) is a frequent kind of arrhythmia that affects around 1% of the general population. While PVC most frequently impairs ventricular function in structurally normal heart, retrograde ventriculo-atrial conduction can occur in people with PVC. These retrograde atrial activations may mimic pulmonary vein-derived atrial ectopies. As a result, PVC may raise the risk of atrial fibrillation (AF) by retrograde ventriculo-atrial conduction. The Four-Dimensional Automated Left Atrial Quantification (4D Auto LAQ) tool is a left atrial analytical approach that utilizes three-dimensional volume data to quantify the volume, as well as LA longitudinal and circumferential strains. The purpose of this study was to determine if clinical diagnosis of PVC is connected with abnormal LA function as determined by LA strain evaluation utilizing a 4D Auto LAQ compared to the healthy population. METHODS: The 58 patients with frequent PVCs and 53 healthy volunteers as a control group were enrolled in the study. Imaging was performed using the GE Vivid E95 echocardiography equipment (GE Healthcare; Vingmed Ultrasound, Horten, Norway) equipped with an M5S probe (frequency range: 1.5-4.6 MHz) and a 4V probe (frequency range: 1.5-4.0 MHz). Images were imported into and were selected for analysis using the EchoPAC203 software (GE Healthcare). The analysis mode was selected, followed by the volume and 4D Auto LAQ submodes. Following that, the sample point was positioned in the center of the mitral orifice in each of the three planes. The review function was used to acquire the LA parameters measured by 4D Auto LAQ, including volume and strain parameters. RESULTS: The maximum left atrial volume (LAVmax) and minimal left atrial volume (LAVmin) were significantly higher in the patient group (38.91 ± 9.72 vs. 46.31 ± 10.22, 17.75 ± 4.52 vs. 23.10 ± 7.13, respectively, all p values <.001). On the other hand left atrial reservoir longitudinal strain (LASr), conduit longitudinal strain (LAScd), contraction longitudinal strain (LASct), reservoir circumferential strain (LASr-c), conduit circumferential strain (LAScd-c), and contraction circumferential strain (LASct-c) were significantly lower in patient group (26.64 ± 5.64 vs.19.16 ± 4.58, -19.53 ± 3.72 vs. -11.28 ± 3.47, -10.34 ± 1.56 vs. -4.59 ± 1.49, 30.72 ± 4.04 vs. 19.31 ± 2.60, -19.91 ± 1.78 vs. -13.38 ± 2.85, -15.89 ± 6.37 vs. -9.24 ± 1.63, respectively, all p values <.001). CONCLUSIONS: The present study found that premature ventricular complexes can lead to atrial remodeling as well as ventricular remodeling in patients with PVC and 4D LAQ technology can quantitatively examine left atrial function and determine these alterations early.

Non-invasive localization of premature ventricular focus: A prospective multicenter study.

BACKGROUND: Accurate localization of premature ventricular contractions (PVC) focus is a prerequisite to successful catheter ablation. OBJECTIVE: The objective was to evaluate the software View Into Ventricular Onset (VIVO) accuracy at locating the anatomical origins for premature ventricular contractions. The VIVO device noninvasively creates a model of the patient's heart and torso, with exact locations of 12­lead ECG electrodes, and applies a mathematical algorithm from surface signals to determine the origin of the arrhythmia. We sought to compare the agreement between VIVO-predicted locations to invasive electroanatomical mapping results. METHODS: 51 consecutive patients who presented for PVC ablations at the study centers were recruited. VIVO images were collected at baseline preprocedure and all patients underwent invasive electroanatomical activation mapping of the clinical arrhythmia. Pacing was performed in pre-specified locations in the right and/or left ventricle. The successful sites of ablation and the pacing locations were compared to VIVO predicted locations. The results were adjudicated by physician experts in a blinded fashion. RESULTS: Seven patients were excluded from analyses. VIVO accurately identified the origin of the clinical premature ventricular contractions in 44/44 patients (100.00%). The accuracy in identifying the paced location for all patients (right and left sides of the heart) was 99.5% using the VIVO system. No adverse events were reported. CONCLUSIONS: VIVO is a novel noninvasive system that could be used to help guide ablation procedures with a high degree of accuracy. The VIVO algorithm is easy to use and may be useful in the workflow for ventricular arrhythmia ablation.

Short-coupled ventricular fibrillation represents a distinct phenotype among latent causes of unexplained cardiac arrest: a report from the CASPER registry.

AIMS: The term idiopathic ventricular fibrillation (IVF) describes survivors of unexplained cardiac arrest (UCA) without a specific diagnosis after clinical and genetic testing. Previous reports have described a subset of IVF individuals with ventricular arrhythmia initiated by short-coupled trigger premature ventricular contractions (PVCs) for which the term short-coupled ventricular fibrillation (SCVF) has been proposed. The aim of this article is to establish the phenotype and frequency of SCVF in a large cohort of UCA survivors. METHODS AND RESULTS: We performed a multicentre study including consecutive UCA survivors from the CASPER registry. Short-coupled ventricular fibrillation was defined as otherwise unexplained ventricular fibrillation initiated by a trigger PVC with a coupling interval of <350 ms. Among 364 UCA survivors, 24/364 (6.6%) met diagnostic criteria for SCVF. The diagnosis of SCVF was obtained in 19/24 (79%) individuals by documented ventricular fibrillation during follow-up. Ventricular arrhythmia was initiated by a mean PVC coupling interval of 274 ± 32 ms. Electrical storm occurred in 21% of SCVF probands but not in any UCA proband (P < 0.001). The median time to recurrent ventricular arrhythmia in SCVF was 31 months. Recurrent ventricular fibrillation resulted in quinidine administration in 12/24 SCVF (50%) with excellent arrhythmia control. CONCLUSION: Short-coupled ventricular fibrillation is a distinct primary arrhythmia syndrome accounting for at least 6.6% of UCA. As documentation of ventricular fibrillation onset is necessary for the diagnosis, most cases are diagnosed at the time of recurrent arrhythmia, thus the true prevalence of SCVF remains still unknown. Quinidine is effective in SCVF and should be considered as first-line treatment for patients with recurrent episodes.

Cardioprotective effects of sinomenine in myocardial ischemia/reperfusion injury in a rat model.

Background: Ischemia reperfusion (I/R) play an imperative role in the expansion of cardiovascular disease. Sinomenine (SM) has been exhibited to possess antioxidant, anticancer, anti-inflammatory, antiviral and anticarcinogenic properties. The aim of the study was scrutinized the cardioprotective effect of SM against I/R injury in rat. Methods: Rat were randomly divided into normal control (NC), I/R control and I/R + SM (5, 10 and 20 mg/kg), respectively. Ventricular arrhythmias, body weight and heart weight were estimated. Antioxidant, inflammatory cytokines, inflammatory mediators and plasmin system indicator were accessed. Results: Pre-treated SM group rats exhibited the reduction in the duration and incidence of ventricular fibrillation, ventricular ectopic beat (VEB) and ventricular tachycardia along with suppression of arrhythmia score during the ischemia (30 and 120 min). SM treated rats significantly (P < 0.001) altered the level of antioxidant parameters. SM treatment significantly (P < 0.001) repressed the level of creatine kinase MB (CK-MB), creatine kinase (CK) and troponin I (Tnl). SM treated rats significantly (P < 0.001) repressed the tissue factor (TF), thromboxane B2 (TXB2), plasminogen activator inhibitor 1 (PAI-1) and plasma fibrinogen (Fbg) and inflammatory cytokines and inflammatory mediators. Conclusion: Our result clearly indicated that SM plays anti-arrhythmia effect in I/R injury in the rats via alteration of oxidative stress and inflammatory reaction.