Dynamic Changes of QRS Morphology of Premature Ventricular Contractions During Ablation in the Right Ventricular Outflow Tract: A Case Report

Electrocardiographic characteristics can be useful in differentiating between right ventricular outflow tract (RVOT) and aortic sinus cusp (ASC) ventricular arrhythmias. Ventricular arrhythmias originating from ASC, however, show preferential conduction to RVOT that may render the algorithms of electrocardiographic characteristics less reliable. Even though there are few reports describing ventricular arrhythmias with ASC origins and endocardial breakout sites of RVOT, progressive dynamic changes in QRS morphology of the ventricular arrhythmias during ablation obtained were rare.This case report describes a patient with symptomatic premature ventricular contractions of left ASC origin presenting an electrocardiogram (ECG) characteristic of right ventricular outflow tract before ablation. Pacing at right ventricular outflow tract reproduced an excellent pace map. When radiofrequency catheter ablation was applied to the right ventricular outflow tract, the QRS morphology of premature ventricular contractions progressively changed from ECG characteristics of right ventricular outflow tract origin to ECG characteristics of left ASC origin.Successful radiofrequency catheter ablation was achieved at the site of the earliest ventricular activation in the left ASC. The distance between the successful ablation site of the left ASC and the site with an excellent pace map of the RVOT was 20 mm.The ndings could be strong evidence for a preferential conduction via the myocardial bers from the ASC origin to the breakout site in the right ventricular outflow tract. This case demonstrates that ventricular arrhythmias with a single origin and exit shift may exhibit QRS morphology changes.

[The distribution of frequent premature ventricular contractions originated from left/right ventricular and characteristics of radiofrequency ablation]

OBJECTIVE

The aim of this study was to investigate the differences on origin distribution and radiofrequency ablation characteristics between premature ventricular contractions (PVC) from left and right ventricular.

METHODS

A total of 354 frequent PVC patients were enrolled. Two hundred and eighty patients were PVCs with right ventricular origin (group RV) and 74 patients with left ventricular origin (group LV). The age, gender, ablation power, temperature and duration, time of target potential before QRS onset, fluoroscopic time, procedure time and success rate were compared between the two groups.

RESULTS

Majority PVCs (79.10%) were of right ventricular origin, in which the most common site was at right ventricular outflow tract (RVOT) (55.93%); whereas, only 20.90% were of left ventricular. There were significantly differences between group RV and group LV in age [(44.7±13.6) yrs vs (49.6±15.9) yrs, P=0.017], gender [male: 35.4%(99) vs 55.4%(41), P=0.002], time of target potential before QRS onset [(37.9±16.2) ms vs (31.3±11.7) ms, P=0.008], procedure time [(85.1±36.9) min vs (100.8±45.5) min, P=0.017], fluoroscopic time [(12.3±9.2) min vs (15.9±10.8) min, P=0.028] and success rate (96.4% vs 89.2%, P=0.012).

CONCLUSIONS

Radiofrequency ablation of PVCs was a safe and effective method. Subjects with RV PVCs are younger and more females than subjects with LV PVCs. The radiofrequency ablation for RV PVCs was easier, and the success rate was higher than that for LV PVCs.

Effects of the Selective Stretch-Activated Channel Blocker GsMtx4 on Stretch-Induced Changes in Refractoriness in Isolated Rat Hearts and on Ventricular Premature Beats and Arrhythmias after Coronary Occlusion in Swine

Mechanical factors may contribute to ischemic ventricular arrhythmias. GsMtx4 peptide, a selective stretch-activated channel blocker, inhibits stretch-induced atrial arrhythmias. We aimed to assess whether GsMtx4 protects against ventricular ectopy and arrhythmias following coronary occlusion in swine. First, the effects of 170-nM GsMtx4 on the changes in the effective refractory period (ERP) induced by left ventricular (LV) dilatation were assessed in 8 isolated rat hearts. Then, 44 anesthetized, open-chest pigs subjected to 50-min left anterior descending artery occlusion and 2-h reperfusion were blindly allocated to GsMtx4 (57 μg/kg iv. bolus and 3.8 μg/kg/min infusion, calculated to attain the above concentration in plasma) or saline, starting 5-min before occlusion and continuing until after reflow. In rat hearts, LV distension induced progressive reductions in ERP (35±2, 32±2, and 29±2 ms at 0, 20, and 40 mmHg of LV end-diastolic pressure, respectively, P<0.001) that were prevented by GsMTx4 (33±2, 33±2, and 32±2 ms, respectively, P=0.002 for the interaction with LV end-diastolic pressure). Pigs receiving GsMtx4 had similar number of ventricular premature beats during the ischemic period as control pigs (110±28 vs. 103±21, respectively, P=0.842). There were not significant differences among treated and untreated animals in the incidence of ventricular fibrillation (13.6 vs. 22.7%, respectively, P=0.696) or tachycardia (36.4 vs. 50.0%, P=0.361) or in the number of ventricular tachycardia episodes during the occlusion period (1.8±0.7 vs. 5.5±2.6, P=0.323). Thus, GsMtx4 administered under these conditions does not suppress ventricular ectopy following coronary occlusion in swine. Whether it might protect against malignant arrhythmias should be tested in studies powered for these outcomes.

Differentiating the origin of outflow tract ventricular arrhythmia using a simple, novel approach

BACKGROUND

Numerous electrocardiographic (ECG) criteria have been proposed to identify localization of outflow tract ventricular arrhythmias (OT-VAs); however, in some cases, it is difficult to accurately localize the origin of OT-VA using the surface ECG.

OBJECTIVE

The purpose of this study was to assess a simple criterion for localization of OT-VAs during electrophysiology study.

METHODS

We measured the interval from the onset of the earliest QRS complex of premature ventricular contractions (PVCs) to the distal right ventricular apical signal (the QRS-RVA interval) in 66 patients (31 men aged 53.3 ± 14.0 years; right ventricular outflow tract [RVOT] origin in 37) referred for ablation of symptomatic outflow tract PVCs. We prospectively validated this criterion in 39 patients (22 men aged 52 ± 15 years; RVOT origin in 19).

RESULTS

Compared with patients with RVOT PVCs, the QRS-RVA interval was significantly longer in patients with left ventricular outflow tract (LVOT) PVCs (70 ± 14 vs 33.4±10 ms, P < .001). Receiver operating characteristic analysis showed that a QRS-RVA interval ≥49 ms had sensitivity, specificity, and positive and negative predictive values of 100%, 94.6%, 93.5%, and 100%, respectively, for prediction of an LVOT origin. The same analysis in the validation cohort showed sensitivity, specificity, and positive and negative predictive values of 94.7%, 95%, 95%, and 94.7%, respectively. When these data were combined, a QRS-RVA interval ≥49 ms had sensitivity, specificity, and positive and negative predictive values of 98%, 94.6%, 94.1%, and 98.1%, respectively, for prediction of an LVOT origin.

CONCLUSION

A QRS-RVA interval ≥49 ms suggests an LVOT origin. The QRS-RVA interval is a simple and accurate criterion for differentiating the origin of outflow tract arrhythmia during electrophysiology study; however, the accuracy of this criterion in identifying OT-VA from the right coronary cusp is limited.

Early repolarization, localization of J point elevation on ECG and arrhythmias

Final aim of this observational study was to determine correlation between localization of J point elevation and number of premature ventricular beats. The 52 patients (19-68 years old; 31 men and 21 women) were divided in two groups based on localization of J point elevation. First Group - 9 patients (5 men and 4 women) with J-point elevation ≥1 mm in ≥2 contiguous inferior and/or lateral leads on a standard 12-lead ECG reading, Second Group - other 43 (26 men and 17 women) patients with another localization of J point elevation. Total summarized number of premature ventricular contractions for each group was compared and analyzed. The results of the study shows that the number of premature ventricular beats in first group was 61% higher. Thus, in our opinion J-point elevation ≥1 mm in ≥2 contiguous inferior and/or lateral leads, is more arrhythmogenic. Data shows that this difference is statistically significant.

Comparative analysis of diagnostic 12-lead electrocardiography and 3-dimensional noninvasive mapping

The clinical utility of noninvasive electrocardiographic imaging has been demonstrated in a variety of conditions. It has recently been shown to have superior predictive accuracy and higher clinical value than validated 12-lead electrogram algorithms in the localization of arrhythmias arising from the ventricular outflow tract, and displays similar potential in other conditions.

Usefulness of ventricular premature complexes in asymptomatic patients ≤21 years as predictors of poor left ventricular function

Although ventricular premature complexes (VPCs) have been shown to correlate with decreased cardiac function in adults, the correlation of left ventricular (LV) function to VPCs in asymptomatic children remains unclear. The aim of this study was to determine the correlation of VPC burden with LV function in asymptomatic pediatric patients with structurally normal hearts. This was a retrospective analysis of patients aged ≤21 years with echocardiograms and 24-hour Holter monitors with ≥0.5% VPCs completed within 60 days of each other. LV fractional shortening (FS) was compared with VPC burden and VPC characteristics. Normal LV function was defined as FS ≥28%. Correlation between VPC burden and LV function was determined by regression analysis. Wilcoxon's rank-sum test was used to compare LV function with VPC characteristics. This study included 123 patients (77 male [63%]). The median age was 11.6 years (interquartile range 5.8 to 14.3). The median VPC burden was 11.2% (interquartile range 4.8% to 18.9%), and median FS was 36% (interquartile range 33% to 38%). There was no significant correlation between VPC burden and LV FS (p = 0.50). The presence of uniform versus multiform VPCs (p = 0.29), ventricular couplets (p = 0.37), or runs of ventricular ectopy (p = 0.19) were not associated with a decrease in LV FS. Twenty-two patients (18%) had VPC burden >24%, none of which had decreased LV FS. In conclusion, there was no significant relation between VPC burden or VPC characteristics and LV systolic function in this pediatric population with structurally normal hearts.

Early repolarization as a predictor of premature ventricular beats

Early repolarization pattern (ERP) is a common ECG variant, characterized by J point elevation manifested either as terminal QRS slurring (the transition from the QRS segment to the ST segment) or notching (a positive deflection inscribed on terminal QRS complex) associated with concave upward ST-segment elevation and prominent T waves in at least two contiguous leads. Aim of this observational study was to compare number of premature ventricular beats in the different groups of patients with early repolarization. The result of this observational study shows that there are: 1,74 fold higher number of premature ventricular beats in 41-74 year subgroup VS 19-40 year subgroup; 1,31 fold higher number of premature ventricular beats in male subgroup VS female subgroup (But this difference is not statistically significant, because t=1,49, p=0,141); 2,85 fold higher number of premature ventricular beats in CAD+ERP subgroup VS ERP without CAD subgroup; 1,74 fold higher number of premature ventricular beats in HF+ERP subgroup VS ERP without HF subgroup; 1,81 fold higher number of premature ventricular beats in CAD+ERP subgroup VS CAD without ERP subgroup; 1,58 fold higher number of premature ventricular beats in HF+ERP subgroup VS HF without ERP subgroup; So, CAD+ERP is very arrhythmogenic condition, after this is HF+ERP, Then Age. This study shows that ERP independently increase number of PVB in different groups (CAD, HF). This is principally new and very important result. Also the number of patients is enough to make this conclusion.

Giant coronary artery aneurysm with fistula to the pulmonary artery complicated by frequent ventricular premature contractions: a case report

Giant coronary artery aneurysm with a fistula is a rare condition. The presence of a giant aneurysm imposes considerable health risks. We report a case of a 67-year-old woman who presented with frequent ventricular premature contractions caused by a giant coronary aneurysm arising from a branch of the left anterior descending coronary artery that had a fistulous connection to the pulmonary artery. The patient was referred for cardiac surgery. The giant aneurysm was resected, and the proximal and distal openings were closed directly. The main pulmonary artery was opened longitudinally and the fistula was also closed directly. The patient's symptoms of frequent ventricular premature contractions disappeared postoperatively as confirmed by electrocardiography. Although the standard therapeutic strategies of the disease are not well established because of the rarity of this condition, our clinical results indicate that the surgical treatment is an effective choice.

[ETACISIN-INDUCED BRUGADA SYNDROME IN A PATIENT WITH LONG-STANDING SUPRAVENTRICULAR EXTRASYSTOLE]

Brugada syndrome is a commonest cause of malignant disorders of cardiac rhythm associated with sudden death. It is diagnosed based on characteristic ECG signs and ventricular arrhythmia. This paper reports a 49 year-old patient with long-standing latent BS manifest as supraventricular and transient blockade of the right branch of the His bundle. The ECG pattern of BS became apparent in association with a 7 day treatment with class IC antiarrhythmic agent etacisin. Diagnostic difficulties account for the fact that the disease was initially described as myocardial infarction. Diagnosis of BS was confirmed by an electrophysiological study in which stable ventricular tachycardia and fibrillation were induced by etacisin. A cardioverter defibrillator was implanted to the patient.

Subcutaneous nerve activity and spontaneous ventricular arrhythmias in ambulatory dogs

BACKGROUND

Stellate ganglion nerve activity (SGNA) is important in ventricular arrhythmogenesis. However, because thoracotomy is needed to access the stellate ganglion, it is difficult to use SGNA for risk stratification.

OBJECTIVE

The purpose of this study was to test the hypothesis that subcutaneous nerve activity (SCNA) in canines can be used to estimate SGNA and predict ventricular arrhythmia.

METHODS

We implanted radiotransmitters to continuously monitor left stellate ganglion and subcutaneous electrical activities in 7 ambulatory dogs with myocardial infarction, complete heart block, and nerve growth factor infusion to the left stellate ganglion.

RESULTS

Spontaneous ventricular tachycardia (VT) or ventricular fibrillation (VF) was documented in each dog. SCNA preceded a combined 61 episodes of VT and VF, 61 frequent bigeminy or couplets, and 61 premature ventricular contractions within 15 seconds in 70%, 59%, and 61% of arrhythmias, respectively. Similar incidence of 75%, 69%, and 62% was noted for SGNA. Progressive increase in SCNA [48.9 (95% confidence interval [CI] 39.3-58.5) vs 61.8 (95% CI 45.9-77.6) vs 75.1 (95% CI 57.5-92.7) mV-s] and SGNA [48.6 (95% CI 40.9-56.3) vs 58.5 (95% CI 47.5-69.4) vs 69.0 (95% CI 53.8-84.2) mV-s] integrated over 20-second intervals was demonstrated 60 seconds, 40 seconds, and 20 seconds before VT/VF (P <.05), respectively. The Pearson correlation coefficient for integrated SCNA and SGNA was 0.73 ± 0.18 (P <.0001 for all dogs, n = 5). Both SCNA and SGNA exhibited circadian variation.

CONCLUSION

SCNA can be used as an estimate of SGNA to predict susceptibility to VT and VF in a canine model of ventricular arrhythmia and sudden cardiac death.

Cellular mechanism of premature ventricular contraction-induced cardiomyopathy

BACKGROUND

Frequent premature ventricular contractions (PVCs) are associated with increased risk of sudden cardiac death and can cause secondary cardiomyopathy.

OBJECTIVE

We sought to determine the mechanism(s) responsible for prolonged refractory period and left ventricular (LV) dysfunction demonstrated in our canine model of PVC-induced cardiomyopathy.

METHODS

Single myocytes were isolated from LV free wall of PVC and control canines and used for patch-clamp recording, intracellular Ca(2+) measurements, and immunocytochemistry/confocal microscopy. LV tissues adjacent to the area of myocyte isolation were used for the immunoblot quantification of protein expression.

RESULTS

In the PVC group, LV ejection fraction decreased from 57.6% ± 1.5% to 30.4% ± 3.1% after ≥4 months of ventricular bigeminy. Compared to control myocytes, PVC myocytes had decreased densities of both outward (transient outward current [Ito] and inward rectifier current [IK1]) and inward (L-type Ca current [ICaL]) currents, but no consistent changes in rapid or slow delayed rectifier currents. The reduction in Ito, IK1, and ICaL was accompanied by decreased protein levels of their channel subunits. The extent of reduction in Ito, IK1, and ICaL varied among PVC myocytes, creating marked heterogeneity in action potential configurations and durations. PVC myocytes showed impaired Ca-induced Ca release from the sarcoplasmic reticulum (SR), without increase in SR Ca leak or decrease in SR Ca store. This was accompanied by a decrease in dyad scaffolding protein, junctophilin-2, and loss of Cav1.2 registry with Ca-releasing channels (ryanodine receptor 2).

CONCLUSION

PVCs increase dispersion of action potential configuration/duration, a risk factor for sudden cardiac death, because of the heterogeneous reduction in Ito, IK1, and ICaL. The excitation-contraction coupling is impaired because of the decrease in ICaL and Cav1.2 misalignment with respect to ryanodine receptor 2.

[A case of a villous tumor of the rectum with electrolyte depletion syndrome]

We report a case of a villous tumor of the rectum with electrolyte depletion syndrome (EDS). A 76-year-old woman developed general fatigue, and on investigation, we found a large laterally spreading tumor of the rectum using bowel enema and colon fiber. Pathologically, the biopsy specimen was graded Group 4. We intended to perform a laparoscopy-assisted low anterior resection in the patient. However, the operation was interrupted by a short-run type of ventricular premature contraction (VPC) due to EDS-induced hypokalemia. After treating the hypokalemia, low anterior resection or laparotomy was performed. The tumor was 19 × 13 cm in size and occupied the circumference of the rectum. Histological examination revealed well differentiated tubular adenocarcinomas with tubulovillous adenoma. Pathological staging was pTis, pN0, M0, stage 0 according to the Japanese Classification of Colorectal Carcinoma (8th edition). It is now 6 months after the operation and hypokalemia has not recurred in the patient.

Clinical and experimental evidence of supernormal excitability and conduction

True supernormality of excitability and conduction has been demonstrated in normal Purkinje fibers in in vitro studies. In the clinical setting, supernormality of conduction is manifested better than expected. This phenomenon is much more common than previously thought, particularly in the presence of certain clinical conditions. If a careful scanning of the cardiac cycle is performed on all patients with intermittent bundle branch block and second degree or advanced infranodal AV block, accessory pathways and mulfunctioning pacemakers, it is anticipated that a much larger amount of supernormal excitability and conduction will be unmasked.

Catheter ablation for premature ventricular contractions and ventricular tachycardia in patients with heart failure

Ventricular arrhythmias (VA) are a significant contributor to morbidity and mortality in patients with heart failure (HF). Implantable cardioverter defibrillators are effective in reducing mortality, but do not prevent arrhythmia recurrence. There is increasing recognition that frequent premature ventricular contractions or repetitive ventricular tachycardia may also lead to new onset ventricular dysfunction or deterioration of ventricular function in patients with pre-existing HF. Suppression of the arrhythmia may lead to recovery of ventricular function. Catheter ablation has emerged as a safe and effective treatment option for reducing arrhythmia recurrence and for suppression of PVCs but its efficacy is governed by the nature of the arrhythmias, the underlying HF substrate and the accessibility of the arrhythmia substrates to ablation.

A new hierarchical method for inter-patient heartbeat classification using random projections and RR intervals

BACKGROUND

The inter-patient classification schema and the Association for the Advancement of Medical Instrumentation (AAMI) standards are important to the construction and evaluation of automated heartbeat classification systems. The majority of previously proposed methods that take the above two aspects into consideration use the same features and classification method to classify different classes of heartbeats. The performance of the classification system is often unsatisfactory with respect to the ventricular ectopic beat (VEB) and supraventricular ectopic beat (SVEB).

METHODS

Based on the different characteristics of VEB and SVEB, a novel hierarchical heartbeat classification system was constructed. This was done in order to improve the classification performance of these two classes of heartbeats by using different features and classification methods. First, random projection and support vector machine (SVM) ensemble were used to detect VEB. Then, the ratio of the RR interval was compared to a predetermined threshold to detect SVEB. The optimal parameters for the classification models were selected on the training set and used in the independent testing set to assess the final performance of the classification system. Meanwhile, the effect of different lead configurations on the classification results was evaluated.

RESULTS

Results showed that the performance of this classification system was notably superior to that of other methods. The VEB detection sensitivity was 93.9% with a positive predictive value of 90.9%, and the SVEB detection sensitivity was 91.1% with a positive predictive value of 42.2%. In addition, this classification process was relatively fast.

CONCLUSIONS

A hierarchical heartbeat classification system was proposed based on the inter-patient data division to detect VEB and SVEB. It demonstrated better classification performance than existing methods. It can be regarded as a promising system for detecting VEB and SVEB of unknown patients in clinical practice.

Assessment of left-atrial strain parameters in patients with frequent ventricular ectopic beats without structural heart disease

Ventricular ectopic beats (VEBs) are often encountered in daily clinical practice. Clinical significance of VEBs seen in patients without structural cardiovascular diseases is controversial. We aimed to investigate the effects of VEBs on left atrium (LA) function using speckle tracking echocardiography with LA strain parameters. Patients with frequent VEBs (more than 30 times in 1 h, according to the Lown classification) were identified. Identified patients were evaluated by speckle tracking methods. There were 40 patients with frequent VEBs and 40 controls in our study. The general characteristics were similar of the study population. The LA global longitudinal strain parameters were significantly different. Global Peak atrial longitudinal strain (PALS) (38.39 ± 7.93 vs. 44.15 ± 6.71, p = 0.001) and peak atrial contraction strain (PACS) (16.37 ± 4.58 vs. 20.49 ± 3.65, p = 0.000) were revealed significantly lower in the VEBs group. Time to peak longitudinal strain (TPLS) was found significantly longer in the VEBs group [485.5 (352-641) vs. 435 (339-516.5) p = 0.000]. Number of VEBS was correlated with TPLS (r = 0.499, p = 0.000). PALS and PACS were negatively correlated with number of VEBs (r = -0.348, p = 0.002 and r = -0.444, p = 0.000, respectively). We described that in this study, The LA functions are affected by VEBs adversely. This deterioration is increasing as the number of VEBs.

[Shock shape representation of sinus heart rate based on cloud model]

The present paper is to analyze the trend of sinus heart rate RR interphase sequence after a single ventricular premature beat and to compare it with the two parameters, turbulence onset (TO) and turbulence slope (TS). Based on the acquisition of sinus rhythm concussion sample, we in this paper use a piecewise linearization method to extract its linear characteristics, following which we describe shock form with natural language through cloud model. In the process of acquisition, we use the exponential smoothing method to forecast the position where QRS wave may appear to assist QRS wave detection, and use template to judge whether current cardiac is sinus rhythm. And we choose some signals from MIT-BIH Arrhythmia Database to detect whether the algorithm is effective in Matlab. The results show that our method can correctly detect the changing trend of sinus heart rate. The proposed method can achieve real-time detection of sinus rhythm shocks, which is simple and easily implemented, so that it is effective as a supplementary method.

Sodium current reduction unmasks a structure-dependent substrate for arrhythmogenesis in the normal ventricles

Background

Organ-scale arrhythmogenic consequences of source-sink mismatch caused by impaired excitability remain unknown, hindering the understanding of pathophysiology in disease states like Brugada syndrome and ischemia.

Objective

We sought to determine whether sodium current (I_Na) reduction in the structurally normal heart unmasks a regionally heterogeneous substrate for the induction of sustained arrhythmia by premature ventricular contractions (PVCs).

Methods

We conducted simulations in rabbit ventricular computer models with 930 unique combinations of PVC location (10 sites) and coupling interval (250–400 ms), I_Na reduction (30 or 40% of normal levels), and post-PVC sinus rhythm (arrested or persistent). Geometric characteristics and source-sink mismatch were quantitatively analyzed by calculating ventricular wall thickness and a newly formulated 3D safety factor (SF), respectively.

Results

Reducing I_Na to 30% of its normal level created a substrate for sustained arrhythmia induction by establishing large regions of critical source-sink mismatch (SF<1) for ectopic wavefronts propagating from thin to thick tissue. In the same simulations but with 40% of normal I_Na, PVCs did not induce reentry because the volume of tissue with SF<1 was >95% smaller. Likewise, when post-PVC sinus activations were persistent instead of arrested, no ectopic excitations initiated sustained reentry because sinus activation breakthroughs engulfed the excitable gap.

Conclusion

Our new SF formulation can quantify ectopic wavefront propagation robustness in geometrically complex 3D tissue with impaired excitability. This novel methodology was applied to show that I_Na reduction precipitates source-sink mismatch, creating a potent substrate for sustained arrhythmia induction by PVCs originating near regions of ventricular wall expansion, such as the RV outflow tract.

[Predictors of high-grade ventricular arrhythmias in patients referred for the coronary angiography]

Ventricular arrhythmias (VA) are still the leading cause of sudden cardiac death (SCD). Therefore identification of predictors of high-grade (hg) VA and stratification of risk of fatal events remain important problems of cardiology. We analyzed data of 993 patients with and without hgVA according to 24 hours Holter monitoring referred for the coronary angiography. Patients with hgVA were older (57.2 ± 8.4 vs. 54.9 ± 8.3 years, p = 0.001), had lower left ventricular ejection fraction (LVEF) (51.6 ± 11.2 vs. 58.4 ± 7.6%, p < 0.001) and larger extent of LV wall motion abnormalities (10.8 ± 15.7% vs. 5.5 ± 10.9%, p = 0.001). Patients with hgVA more often had LV aneurysms and thrombi. These patients also had significantly greater LV end diastolic diameter (54.3 ± 7.4 vs. 49.9 ± 4.7 mm, p < 0.001), and more often had NYHA class III-IV chronic heart failure (28.1 vs. 15.5%, p < 0.001). According to multivariate analysis hgVA were independently associated with age, LV dilation and reduced LVEF (specificity and sensitivity of a mathematical model for prediction of hgVA were 78 and 49.5%, respectively). Each subsequent year of life increased risk of having hgVA by 1.2% (odds ratio [OR] 1.01; 95% confidence interval [CI] 1.01-1.05, p = 0.002), while 1 mm increase of LV size elevated risk of VA by 4.2% (OR 1.08; 95% CI 1.04-1.13, p < 0.001), and 1% lowering of LVEF increased risk of VA by 7% (OR 0.95; 95% CI 0.92-0.98, p < 0.001).

Multiform premature ventricular contractions and polymorphic ventricular tachycardia caused by Purkinje activity with slow conduction in idiopathic ventricular fibrillation

In several cases with idiopathic ventricular fibrillation (VF), VF was initiated by premature ventricular contractions (PVCs) from the Purkinje system. However, the precise characteristics of the Purkinje activity in patients with idiopathic VF remain unclear. We performed an electrophysiological study in a patient with idiopathic VF and examined the correlation between the Purkinje potential and the incidence of PVCs/polymorphic ventricular tachycardia (PMVT). In this case of idiopathic VF, the Purkinje activity caused multiform PVCs and PMVT. The The Purkinje activity and slow conduction of Purkinje fibers are associated with the occurrence of multiform PVCs and PMVT.

[Estimation of immune response parameters in patients with frequent premature ventricular contractions without signs of organic pathology of the cardiovascular system]

AIM

To study the specific features of an immune response and the role of infectious pathogens in the occurrence, development, and maintenance of ventricular ectopic activity in patients without signs of organic disease of the cardiovascular system (CVS).

SUBJECTS AND METHODS

The investigation enrolled 91 patients (27 men and 64 women with a mean age of 36.5 +/- 11.5 years) with premature ventricular contractions (PVC) without signs of organic CVS pathology. A control group comprised 31 healthy volunteers. In addition to standard physical examination, a study of N-terminal pro-brain natriuretic peptide (NT-proBNP) and cellular and humoral immune parameters was performed and the serological and molecular genetic markers of infections were determined in all the patients.

RESULTS

The persons with PVC, as compared to the control group, were recorded to have a higher NT-proBNP level (49.2 pg/ml versus 25.4 pg/ml; p = 0.001) accompanied by an increase in both the total number of PVC and the number of coupled PVC and the episodes of ventricular tachycardia. They were also found to have elevated CD3(+)HLA-DR+ (2.4% versus 1.56%) and CD3(+)CD95+ (27.6% versus 18.8%) counts (p = 0.001). In patients with a C-reactive protein level of more than 2 mg/l, the total number of PVC was larger than that in the other patients (p = 0.065). The patients with PVC did not show a statistically significant difference from the controls in the levels of antiviral and antibacterial antibodies. The people with PVC displayed a number of relationships between the infectious pathogen antibody titers and the ECG Holter monitoring and echocardiography readings.

CONCLUSION

In the patients with PVC without signs of organic CVS pathology, the parameters of an immune response were not different from those obtained in the control group, which was likely to be associated with the involvement of the immune system in the development and maintenance of ventricular arrhythmias.