[Evaluation of the operator learning curve for radiofrequency ablation for atrioventricular nodal reentrant tachycardia].

Aim    The aim of this study was to determine the average minimum number of slow pathway ablation procedures required to reach a steady success rate among inexperienced operators.Material and Methods    We analyzed the consecutive AVNRT ablation procedures of three inexperienced operators for the rate of operational success and complications.Results    Operators performed a total of 156 AVNRT ablation procedures. There was no statistical significance between the three operators regarding the rate of success (p=0.69) and complications. There were significant differences between the operators in terms of procedure time, fluoroscopy time, and cumulative air kerma. The variability of procedure time and cumulative air kerma, both among three operators and within each operator, decreased significantly after the 25th case. Each operator was analyzed individually for the probability of success as related to the cumulative number of ablations. All trainee operators reached a success rate of 90 % at the 27th procedure.Conclusion    An average of 27 slow pathway ablation procedures should be performed by a beginner operator to achieve proficiency.

Integrating the Left Atrium Diameter to Improve the Predictive Ability of the Age, Creatinine, and Ejection Fraction Score for Atrial Fibrillation Recurrence After Cryoballoon Ablation.

BACKGROUND: Several clinical trials have assessed predictors for atrial fibrillation recurrence following cryoballoon catheter ablation. With these predictors, a practical and new scoring system can be developed to evaluate atrial fibrillation recurrence. The present study aimed to analyze the predictive value of the age, creatinine, and ejection fraction-left atrium score for potential recurrence of atrial fibrillation following cryoballoon catheter ablation in patients with symptomatic paroxysmal or persistent atrial fibrillation. METHODS: We retrospectively analyzed records of patients undergoing cryoballoon cath-eter ablation. atrial fibrillation recurrence was defined as an emerging atrial fibrillation episode around 12-month follow-up (with the exclusion of a 3-month blanking period). Univariate and multivariate analyses were performed to assess predictors of atrial fibrillation recurrence. In addition, receiver operating characteristic analysis was harnessed to evaluate the performance of the age, creatinine, and ejection fraction, left atrium score in determining the risk of atrial fibrillation recurrence. RESULTS: The study population comprised 106 subjects (age 52 ± 13 years, 63.2% women) with paroxysmal (84.9%, n = 90) or persistent (15.1%, n = 16) atrial fibrillation. age, creatinine, and ejection fraction, left atrium score was significantly higher in subjects with atrial fibrillation recurrence in comparison to those with the maintenance of sinus rhythm. However, on multivariate logistic regression analysis, only the age, creatinine, and ejection fraction, left atrium score (OR = 12.93, 95% CI: 2.22-75.21, P =.004) served as an independent predictor of atrial fibrillation recurrence following cryoballoon catheter ablation. CONCLUSION: Age, creatinine, and ejection fraction, left atrium score had an independent association with the risk of atrial fibrillation recurrence in subjects with atrial fibrillation undergoing cryoballoon catheter ablation. Therefore, this score might potentially serve as a useful tool for risk stratification of patients with atrial fibrillation.

Serum fibrinopeptide A is increased in patients with acute coronary syndrome.

OBJECTIVE: Acute coronary syndrome (ACS) is one of the leading causes of mortality, globally. Atherosclerosis is an underlying factor in ACS process and coagulative cascade is activated secondary to atherosclerotic plaque rupture. Fibrinopeptide A (FPA) takes an active role in thrombus formation and is an indicator of coagulative process. We aimed to evaluate serum FPA level in patients with ACS. METHODS: Patients diagnosed with ACS and chronic coronary syndrome (CCS), with non-obstructive coronary artery disease as a control group, were included in the study. Blood samples and demographic data of all patients were obtained at admission. Obtained data were compared between ACS and control groups. RESULTS: The study consisted of 107 patients with ACS and 69 patients with CCS. ACS group was older (p<0.001) with male preponderance (p<0.001), more likely to had hypertension (p<0.001), and had a higher smoking rate (p<0.001). Serum FPA level was highest in the ST elevated myocardial infarction group (p<0.001). FPA>3.38 ng/mL predicted ACS with 89.7% sensitivity and 78% specificity (AUC: 0.825, 95% CI 0.745-0.905; p<0.001). CONCLUSION: Serum FPA may be used for the differential diagnosis of ACS. In addition, patients with increased FPA may be considered to be given more aggressive antithrombotic medication.

Cardiovascular evaluation of pregnant women with hypertrophic cardiomyopathy.

BACKGROUND: The effect of physiological circulatory changes during pregnancy on hypertrophic cardiomyopathy (HCM) has been reported with limited data. This study aimed to provide information regarding outcomes of pregnant women with HCM and to identify predictors of major adverse cardiac event (MACE). METHODS: A total of 45 pregnancies with HCM were retrospectively reviewed. The primary endpoint was a MACE that occurred within an 8­week period after delivery, including maternal death, heart failure (HF), syncope, and malignant ventricular arrhythmias (VAs). Baseline and outcome data were analyzed for all patients. Patients with and without MACE were compared, and patients with obstructive HCM were compared with those who had non-obstructive HCM. The study population was divided into two subgroups of patients having or not having an implantable cardioverter defibrillator implantation (ICD). RESULTS: At least one MACE occurred in 11 patients (24.4%); six patients developed HF (13.3%), six had a ventricular tachyarrhythmia (13.3%), and two had syncope (4.4%). New York Heart Association functional class of ≥ II, presence of HF signs before pregnancy, increased left ventricular outflow tract (LVOT) gradient were significantly associated with MACE. Fatal VAs were seen during pregnancy in one of five HCM patients with ICD. In the ROC curve analysis, an LVOT gradient higher than 53.5 mm Hg predicted the presence of MACE with a sensitivity of 90.9% and a specificity of 73.5%. This study is the largest series in the literature representing pregnant women who had HCM and ICD. CONCLUSION: The current data suggest that HF and high LVOT gradients are important risk factors for the development of cardiac complications.

Surgical treatment of a difficult case of atrial tachycardia requiring multiple electrophysiologic procedures.

A 34-year-old male with incessant drug-refractory atrial tachycardia (AT) was referred to our clinic for catheter ablation. The procedure began with endocardial activation mapping. The earliest endocardial activation site was in the right atrial appendage (RAA). The procedure continued with mapping of the left atrium through a transseptal approach. The earliest local activation was recorded at the anterior site of the right pulmonary veins. Radiofrequency (RF) ablation of both localizations was performed synchronously but failed to terminate the arrhythmia. The procedure continued with isolation of the RAA using cryoballoon but failed again due to the anomalous structure of the RAA. Then, epicardial RF ablation was attempted but failed. Finally, AT could only be terminated by surgical excision of the RAA.

Quantitative assessment of left atrial functions by speckle tracking echocardiography in hypertensive patients with and without retinopathy.

PURPOSE: The association between hypertensive retinopathy and left atrial (LA) impairment is unknown. Accordingly, it was aimed to investigate the possible relationship between hypertensive retinopathy and LA phasic functions by means of two-dimensional speckle-tracking echocardiography (2D-STE). METHODS: A total of 124 hypertensive patients and 27 control subjects were included in the study. LA reservoir strain (LAS-S ), LA conduit strain (LAS-E ), and LA booster strain (LAS-A ) parameters were used to evaluate LA myocardial functions. RESULTS: Hypertensive patients (with and without retinopathy) displayed an obvious reduction in the LA reservoir strain (LAS-S ), and LA conduit strain (LAS-E ). Moreover, further impairment in LA reservoir and conduit strain was found in patients with hypertensive retinopathy than in the isolated hypertensive patients. There were no significant differences in LA booster strain (LAS-A ) among the three groups. Impaired LAS-S (OR: 0.764, CI: 0.657-0.888, and p < 0.001), LAS-E (OR: 0.754, CI: 0.634-0.897, and p = 0.001), and hypertension (HT) duration (OR: 2.345, CI: 1.568-3.507, and p < 0.001) were shown to be independent predictors of hypertensive retinopathy. CONCLUSION: Impaired LA reservoir and conduit strain may be used to predict hypertensive patients at higher risk of developing hypertensive retinopathy, and to determine which patients should be followed more closely for hypertensive retinopathy.

Evaluation of the relationship between diabetic retinopathy and left atrial deformation parameters.

BACKGROUND: Left ventricular systolic dysfunction (LVSD) may develop without coronary artery disease, hypertension (HT), or valvular pathologies in patients with diabetes mellitus (DM), which is defined as diabetic cardiomyopathy (DCM) and its pathophysiology is still unclear. Diabetic retinopathy (DR) is a microvascular complication of DM, and patients with DR have increased risk for the development of heart failure (HF). Two-dimensional speckle tracking echocardiography (2D-STE) evaluates longitudinal deformation in left atrium (LA) myocardium and previous studies utilizing 2D-STE have revealed the detrimental effects of DM on LA functions. Although some studies have shown the association between DR and left ventricle (LV) systolic functions, as far as the researchers of this study investigated, there is no study evaluating the relationship between LA deformation parameters and DR. Hence, we aimed to investigate the relationship between the presence and the degree of DR and LA deformation parameters. RESULTS: LA deformation parameters were analyzed in terms of LA reservoir, conduit, and contractile functions according to the degree of DR. LA reservoir strain value was 14.2 ± 3.6 in normal retina group, 12.2 ± 4.1 in non-proliferative diabetic retinopathy (NPDR) group, and 13 ± 3.7 in proliferative diabetic retinopathy (PDR) group (P = 0.04). LA contractile strain was 15.9 ± 6.8 in normal retina group, 13.1 ± 47.4 in NPDR group, and 9.9 ± 4.7 in PDR group (P < 0.001). LA conduit strain was 30.1 ± 6.6 in normal retina group, 25.3 ± 6.5 in NPDR group, and 22.9 ± 4.9 in PDR group (P < 0.001). Proportional odds regression for association between clinical data, echocardiographic parameters, and LA contractile strain function showed that increasing creatinine (from 0.7 to 1.0; OR 0.71; 95% CI 0.51-0.99; P = 0.04), DR presence (OR 0.24; 95% CI 0.11-0.50; P = 0.001), and increasing left atrial volume index (LAVI) (from 33.5 to 52.6; OR 0.62; 95% CI 0.43-0.89; P = 0.01) were associated with decreasing LA function; however, other variables indicated no association. CONCLUSIONS: Our results showed the relationship between LA deformation parameters and DR, although microvascular involvement is not a certainly defined cardiovascular risk factor. Further prospective studies are needed to determine the clinical importance of DR presence and its degree for deformation parameters.

Clinical Utility of Left Atrial Asynchrony and Mechanical Function in Patients with Hypertrophic Cardiomyopathy.

Background: The aim of this study was to examine whether left atrial dispersion and left atrial strain as measured by speckle tracking echocardiography and clinical parameters are predictors of the development of atrial fibrillation in patients with hypertrophic cardiomyopathy. Methods: A total of 151 patients (69% male, mean age 48.9 ± 14.2 years) with hypertrophic cardiomyopathy were included in the study. The patients' demographic, clinical, electrocardiographic, 2-dimensional classic and speckle tracking echocardiographic data were collected. Atrial fibrillation was identified by 12-lead electrocardiograms or 24-72 hours of Holter recordings during the follow-up period. Atrial dispersion was defined as the standard deviation of time to peak strain in 12 left atrial segments. Results: During the follow-up period, 40 patients (26%) developed atrial fibrillation. Peak atrial longitudinal strain (16.8 ± 6 vs. 22.1 ± 6.6, p ≤ 0.001) was significantly lower in the patients who developed atrial fibrillation than in those who did not. However, atrial dispersion was significantly higher in the group which developed atrial fibrillation (61 [46.7,78.6] vs. 41.3 [30.6-51], p ≤ 0.001). In multivariate Cox regression analysis, atrial dispersion (msn) (hazard ratio: 1.019, 95% confidence interval: 1.004-1.033, p = 0.01), peak atrial longitudinal strain, and age were found to be independent predictors of atrial fibrillation. Conclusions: In patients with hypertrophic cardiomyopathy, atrial dispersion, peak atrial longitudinal strain and age are predictive of the development of atrial fibrillation. Atrial dispersion measured by a speckle tracking-based method may provide further information on left atrial function in patients with hypertrophic cardiomyopathy or other disease states.

Predictors of positive response to beta-blockers for treatment of premature ventricular complexes.

BACKGROUND: The aim of the present study is to investigate the possible factors that might be predictive of effective antiarrhythmic effect of beta-blockers on premature ventricular complexes (PVC). METHODS: Data of 190 eligible consecutive patients to whom beta-blocker therapy had been initiated for treatment of PVC's were retrospectively evaluated. The Holter recording acquired before beta-blocker initiation and the first Holter acquired after beta blocker initiation during follow up was comprehensively evaluated for each patient. Parameters obtained from pre- and post-beta-blocker 24 h Holter recordings were compared with each other and possible predictors were evaluated for positive response to beta-blocker therapy. RESULTS: Sixty-one patients (32.1%) were observed to respond beta-blocker therapy with at least 50% reduction of daily PVC burden. Patients who responded to beta-blockers had significantly higher ratio of patients who had positive correlation between hourly heart rate and corresponding hourly PVC number (fast HR-PVC status) compared with non-responders (73.8% vs 48.1%, p < 0.001). Binary logistic regression analysis revealed PVC QRS width (Odds ratio: 0.971; p: 0.037) and fast HR-PVC status (Odds ratio: 2.935; p: 0.007) as the independent predictors of positive response to beta-blockers for treatment of PVC. CONCLUSION: Positive correlation between hourly heart rate and PVC incidence was found to be independent positive predictor and PVC QRS width was found to be independent negative predictor of beta-blocker success in our study. This observation might have important clinical implications to guide medical treatment of PVCs in clinical practice.

Bidirectional ventricular tachycardia induced by respiratory alkalosis mediated hypokalemia in a patient with acute ischemic heart failure.

Bidirectional ventricular tachycardia (BVT) is a rare arrhythmia that is generally observed in patients with catecholaminergic ventricular tachycardia or digoxin overdose. Herein, we present a case of BVT and electrical storm (ES) in an acute ischemic heart failure patient that is typically induced by hypokalemia. The patient was in invasive mechanical ventilator (MV) support and hypokalemia was related to acute respiratory alkalosis and that caused refractory hypokalemia despite intravenous (IV) potassium replacement. We also discuss our approach to solve refractory hypokalemia caused by respiratory alkalosis.

Evaluation of acute alterations in electrocardiographic parameters after cryoballoon ablation of atrial fibrillation and possible association with recurrence.

OBJECTIVE: This study aimed to evaluate the acute effect of cryoballoon ablation (CB-A) on electrocardiographic parameters that have been suggested to reflect heterogeneity in atrial conduction and ventricular repolarization. METHODS: A total of 67 patients (52.6±13.2 years, 43 men) without any exclusion criteria who had undergone CB-A for atrial fibrillation (AF) between January 01, 2015, and December 31, 2018, constituted our study population. Electrographic recordings obtained before and after the ablation procedure on the same day were retrospectively evaluated for the P-wave dispersion, QTc dispersion, Tp-Te interval, and Tp-Te/QT ratio. The pre- and post-ablation values were tested for significant differences. The association of the possible CB-A-related changes in these parameters with AF recurrence during follow-up was evaluated. RESULTS: P dispersion (30.1±6.8 vs. 35.9±9.4 ms, p<0.001), QT dispersion (20.7±7.5 vs. 24.0±8.8 ms, p<0.001), Tp-Te duration (on V5 83.6±8.1 vs. 110.2±9.5 ms, p<0.001), and Tp-Te/QT ratio (on V5 0.22±0.03 vs. 0.28±0.02, p<0.001) were observed to increase significantly after CB-A. There was no association between the magnitudes of change in any parameter and AF recurrence. CONCLUSION: CB-A had significant effects on electrocardiographic parameters related to atrial conduction and ventricular repolarization in the acute phase after CB-A. Further prospective studies are required to examine the time-related course of these alterations and their impact on clinical outcomes.

Comparison of subfoveal choroidal thickness and retinal nerve fiber layer thickness in patients with coronary slow flow phenomenon and microvascular angina: Optical coherence tomography based study.

BACKGROUND: The aim of this study was to evaluate and compare the subfoveal choroidal thickness (SFCT) and peripapillary retinal nerve fiber layer thickness (pRNFLT) in patients with microvascular angina (MA), coronary slow flow phenomenon (CSFP) and healthy controls. METHODS: Thirty-two consecutive patients with MA, 35 consecutive patients with CSFP and 40 age and sex-matched controls were enrolled. SFCT, average pRNFLT and four quadrants of pRNFLT were measured by spectral domain- optical coherence tomography (SD-OCT). RESULTS: The mean SCFT in patients with CSFP (267.57 ± 30.61 µm) was significantly thinner than those of patients with MA (288.84 ± 28.25 µm) and control (291.21 ± 31.75 µm) (p = 0.002) while SFCT of patients with MA were similar with those of controls. Patients with CSFP had thinner superior and inferior pRNFLT compared to patients with MA and controls (p < 0.001 and p = 0.005, respectively) while there were no significant differences in average pRNFLT, nasal and temporal quadrant of pRNFLTs among three groups. In the multivariate linear regression analyses, the presence of CSFP was found negatively correlated with SFCT and superior pRNFLT. CONCLUSION: Patients with CSFP had thinner SFCT, superior and inferior quadrants of pRNFLT proposing the presence of a generalized endothelial dysfunction and increased microvascular resistance in these patients.

Predictors of adequate intraprocedural premature ventricular complex (PVC) frequency during idiopathic PVC ablation.

BACKGROUND: The aim of the present study was to determine the predictors of adequate intraprocedural premature ventricular complex (PVC) frequency for successful mapping and ablation of idiopathic PVCs. METHODS: A total of 101 consecutive patients (45 men; age: 47.9 ± 14.2 years) who had undergone idiopathic PVC ablation between 01 November 2018 and 24 June 2020 constituted our study population. Clinical and demographic data, procedural details and 24 h rhythm recordings that had been recorded before the procedure were retrospectively evaluated. Total PVC burden and diurnal variability assessed by the ratio of night time (22:00-06:00) over day time (06:00-22:00) PVC burden was calculated. The relationship between hourly PVC number and heart rate was also evaluated for each patient. Clinical characteristics and Holter parameters were compared between groups with and without adequate intraprocedural frequency of PVCs that permitted activation mapping. RESULTS: In all, 27 patients (26.7%) had infrequent intraprocedural PVCs which necessitated isoproterenol infusion or cancellation of ablation procedure due to inability of activation mapping. PVC burden was significantly higher in the group with frequent intraprocedural PVCs (26.1 ± 9.4% vs 21.2 ± 10.3%; p: 0.026). There were no significant differences between groups regarding the relationship between hourly PVC number and heart rate or the ratio of night/day PVC burden. Binary logistic regression analysis revealed the 24 h Holter PVC burden as the sole parameter that is significant predictor of frequent intraprocedural PVCs permitting activation mapping. CONCLUSION: The 24 h PVC burden was the only predictor of adequate intraprocedural PVC frequency permitting activation mapping during idiopathic PVC ablation.

The relationship between hemoglobin A1c levels and thrombus load in patients with type 2 diabetes mellitus and non-ST-segment elevation myocardial infarction.

BACKGROUND: We aimed to investigate the relationship between hemoglobin A1c (HbA1c) and coronary thrombus load in type-2 diabetes mellitus (T2DM) patients with non-ST segment elevation myocardial infarction (NSTEMI). MATERIALS AND METHODS: Ninety diabetic patients with NSTEMI were recruited for the study. They were separated into two groups according to HbA1c levels. Forty-seven patients having HbA1c ≤6.5% formed Group-I (35 male, mean age 58 ± 10.5 years) and the remaining 43 patients with HbA1c >6.5% formed Group-II (23 male, mean age 58 ± 11.1 years). Both the groups were evaluated in terms of thrombolysis in myocardial infarction (TIMI) thrombus score and Syntax score. RESULTS: Baseline patient characteristics were comparable in both the groups. TIMI thrombus score and Syntax score were higher in Group II than in Group I (3.2 ± 1.4 vs. 4.7 ± 0.5 and 20.2 ± 3.4 vs. 26.3 ± 3.0 respectively, P < 0.05). No significant difference was found in other parameters. In stepwise linear regression analysis, prepercutaneous coronary intervention (PCI) and post-PCI TIMI frame number and HbA1c were significantly related to the coronary thrombus scale. However, no significant relationship has been found between thrombus formation and hypertension, previous PCI history, pre-PCI heart rate, pre-PCI cholesterol status, and high-sensitive troponin T. CONCLUSION: In NSTEMI with T2DM, increased HbA1c (HbA1c >6.5%) is related with coronary thrombus in the target vessel. In those patient population, strict anticoagulation should be considered to prevent potential adverse events.

Tp-Te interval and Tp-Te/QT ratio may be predictive of idiopathic ventricular tachycardia in patients with frequent outflow tract premature ventricular complexes.

BACKGROUND: The aim of present study is to evaluate the predictive value of QTc dispersion, Tp-Te interval and Tp-Te/QT ratio for idiopathic monomorphic outflow tract ventricular tachycardia (VT) occurrence in patients with frequent idiopathic outflow tract premature ventricular complexes (PVCs). METHODS: A total of 180 patients (49.2 ± 13.6 years, 74 male) who had undergone outflow tract PVC ablation between 01 January 2015 and 01 November 2018 constituted our study population. Patients with isolated outflow tract PVC without any VT recording on Holter recordings and without any inducible VT at EPS were classified as isolated PVC group. Patients with any episode of VT that has the same morphology with outflow tract PVC were classified as nonsustained or sustained VT groups based on the duration of VT episode. QTc dispersion, Tp-Te and Tp-Te/QT ratio values were calculated and compared between groups. RESULTS: There were 116 patients with isolated PVC, 35 patients with nonsustained VT and 29 patients with sustained VT. QTc dispersion, Tp-Te and Tp-Te/QT ratio values were significantly lower in patients with isolated PVC compared to patients with nonsustained or sustained VT episodes. Tpeak to Tend interval greater than 110.5 msec on derivation V6 predicted VT occurrence with 93.8% sensitivity and 82.8% specificity. Tpeak to Tend/QT interval greater than 0.27 on derivation V6 predicted VT occurrence with 93.8% sensitivity and 0.81% specificity. CONCLUSION: Tp-Te interval and Tp-Te/QT ratio on derivation V6 may aid in prediction of presence of outflow tract VT in clinical practice.

Association of C-Reactive Protein-to-Albumin Ratio With the Presence and Progression of Abdominal Aortic Aneurysm.

Aortic dilatation due to inflammation may lead to an increase in C-reactive protein (CRP) levels. We investigated the possible relationship between CRP-to-albumin ratio (CAR) and presence and progression of abdominal aortic aneurysms (AAAs). The study included 150 patients previously diagnosed with AAA (diameter 40-54 mm) and 100 normal controls. Clinical and laboratory parameters and maximal cross-sectional AAA diameters (measured by computed tomography angiography) were obtained from all participants at baseline assessment as well as after 1 year for those with an AAA. The patients with AAA had significantly higher serum CAR compared with controls at baseline (P < .001). Increased serum CAR was found to be an independent predictor of the presence of AAA (odds ratio: 3.162, 95% CI: 1.690-5.126, P = .001) after multivariate logistic regression analysis. There was a significant increase in aortic diameter and CAR after 1 year in the patients with AAA (P < .001; P = .003); a significant correlation was found between changes in the diameter of AAAs and CAR (r = 0.414; P = .005). Serum CAR may be useful as an inflammatory biomarker for the presence and progression of AAA.

Acute effect of outflow tract premature ventricular complex ablation on QT dispersion, Tp-e interval and Tp-e/QT ratio.

BACKGROUND: There is limited data regarding the effect of idiopathic premature ventricular complexes (PVC) on myocardial repolarisation. Most of PVC's originate from right and left ventricular outflow tracts (RVOT and LVOT). AIM: The aim of this study is to evaluate the acute effect of outflow tract PVC ablation on electrocardiographic repolarisation markers. METHODS: A total of 180 patients (49.2 ± 13.6 years, 74 male) without any exclusion criteria who had undergone outflow tract PVC ablation between 1 January 2015 and 1 November 2018 constituted our study population. Electrocardiographic recordings that had been obtained before and after ablation procedure on the same day were retrospectively evaluated for the QTc dispersion, Tp-e interval, Tp-e/QT ratio and Tp-e/QTc ratio. Significance of difference between pre- and postablation values was tested. RESULTS: There was no significant difference regarding QTc dispersion between pre- and post-ablation state (36.5 ± 20.9 vs. 35.3 ± 16.4 ms, p: NS). However, Tp-e and Tp-e/QT values in all lateral precordial derivations were observed to decrease significantly after PVC ablation (in the respective order on derivation V5: 104.0 ± 21.6 ms vs. 91.1 ± 14.8 ms, p<.001 and 0.26 ± 0.05 vs. 0.23 ± 0.04, p<.001). CONCLUSIONS: Based on these observations, it may be suggested that frequent outflow tract PVC's increase transmural dispersion of repolarisation and this effect is attenuated by catheter ablation in the acute phase. Results of further prospective studies are required for evaluation of the long term effects of PVC ablation on myocardial repolarisation.

Transvenous extraction of pacemaker leads via femoral approach using a gooseneck snare.

BACKGROUND: The growing problem of endocardial lead infections and lead malfunctions has increased interest in percutaneous lead-removal technology. Transvenous lead extraction (TLE) via simple manual traction (SMT) is the first-line therapy. When SMT is not successful, TLE from the femoral vein using a gooseneck snare (GS) with a radiofrequency ablation catheter (RFAC) may be an alternative option. The aim of our study was to evaluate the success rate of transvenous extraction of chronically implanted leads via the femoral approach using a GS with RFCA in cases of failure with SMT. METHODS: The study included 94 consecutive patients who were referred for lead extraction due to pocket erosion and infection (71 patients) and to lead malfunction (23 patients). Initially, SMT was attempted for all patients. If SMT was not successful, patients underwent TLE using a GS with RFAC. RESULTS: Leads were extracted successfully with SMT in 34 patients (54 leads), while 60 patients (83 leads) underwent TLE using a GS with RFAC. The mean indwelling time of the leads was longer in the femoral approach with GS (87.5 ± 37.9 vs. 31.3 ± 25.8 months; p < 0.001). The procedural success rate was 96.7% in the femoral approach with GS. A preceding implantation lead duration of >51 months predicted an unsuccessful SMT necessitating alternative TLE using a GS with RFAC with 86% sensitivity and 78% specificity (p < 0.001). CONCLUSION: Transvenous lead extraction via the femoral approach using GS with RFAC may be an alternative approach to SMT with a high success rate, especially when the indwelling time of the leads is long.

Dynamic thiol/disulphide homeostasis in patients with hypertrophic cardiomyopathy.

BACKGROUND: In addition to the genetic complexity of hypertrophic cardiomyopathy (HCM), there must be other disease-modifying factors that contribute to its highly variable clinical and phenotypic expression. The authors aimed to investigate serum thiol/disulphide homeostasis as a proxy for oxidative stress using a novel automated assay in patients with HCM. METHODS: This cross-sectional study was conducted on 119 patients with HCM and 52 without HCM. The methods used to measure dynamic thiol/disulphide homeostasis as calorimetric and duplex quantities were developed in 2014. RESULTS: Median serum native thiol levels were significantly lower in patients with HCM than in those without (312.5 µmol/L [285-370 µmol/L] vs 421 µmol/L [349-469.5 µmol/L]; p < 0.001). Serum total thiol levels and disulphide levels were considerably lower than those in the control group ([844.68 ± 195.99 µmol/L vs 1158.92 ± 243.97 µmol/L; p < 0.001], [259.13 ± 65.66 µmol/L vs 375.02 ± 79.99 µmol/L; p < 0.001], respectively). Serum disulphide/native thiol ratios and disulphide/total thiol ratios were significantly lower in HCM patients than in controls (0.80 ± 0.09 vs 0.92 ± 0.05; p < 0.001 and 0.31 [0.30-0.32] vs 0.32 [0.32-0.33]; p < 0.001). Finally, reduced thiol ratios were higher and oxidized thiol ratios were significantly lower in patients with HCM than in controls. CONCLUSIONS: Despite the fact that antioxidant capacity was impaired, the extracellular environment remained in a reducing state by keeping serum disulphide/native thiol ratios low. Therefore, the authors speculate that HCM may behave similarly to tumours with respect to serum thiol-disulphide levels.