[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.

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.

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.

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.

The effect of P wave indices on new onset atrial fibrillation after trans-catheter aortic valve replacement.

OBJECTIVES: Data is scarce regarding the relation between P wave indices and new onset atrial fibrillation (NOAF) after trans-catheter aortic valve replacement (TAVR). AIMS: The present study aimed to find out certain characteristics of P wave that may predict NOAF after TAVR procedure. METHOD: Patients with severe calcific aortic stenosis who had undergone TAVR procedure between 2013 and 2019 in two centers were investigated. P wave abnormalities that have been resumed to reflect impaired atrial conduction; partial and advanced inter atrial block (IAB), P-wave terminal force in lead V1, P wave dispersion, reduced amplitude of P- wave in lead I, P wave peak time in D2 and V1 were evaluated on pre- procedural 12 derivation surface electrocardiography (ECG). The relationship between these parameters and incidence of NOAF during index hospitalization was evaluated. RESULTS: A total of 227 consecutive patients (median age 79 [74-83]; 134 [59%] female) were included in the study. NOAF occurred in 46 (20.3%) patients. P wave duration, P wave dispersion, number of patients with partial and advanced IAB, left atrium diameter, STS score were higher in NOAF patients. Use of general anesthesia and history of prior open heart surgery were also more frequent in NOAF group. In multivariable logistic regression analysis; advanced IAB (OR 6.413 [2.555-16.095] p < 0.01), P wave dispersion (OR 3.544 [1.431-8.780] p = 0.006) and use of general anesthesia (OR 2.736 [1.225-6.109] p = 0.014) were independent predictors of NOAF. CONCLUSION: Among P wave abnormalities evaluated on pre-procedural 12-derivation surface ECG, advanced IAB and P wave dispersion may predict NOAF after TAVR procedure.

Electrocardiographic Ccharacteristics of metastatic cardiac tumors presenting with ST-segment elevation.

INTRODUCTION: ST segment elevation (STE) in the standard 12­lead surface electrocardiography (ECG) is a well-known finding in patients with metastatic cardiac tumors. It is important to identify the specific characteristics of STE among those patients to prevent unnecessary aggressive treatments. In the present study, we aimed to demonstrate the ECG characteristics of patients with metastatic cardiac tumors who has STE. MATERIAL AND METHODS: Medical literature was searched from Pubmed database with key words "metastatic cardiac tumors" or "cardiac tumors" and "ST segment elevation" or "ST elevation". In addition, remaining articles were explored using the references of case reports which were obtained during former screening (snowball procedure). RESULTS: Thirty six of 46 case reports were included and ECG characteristics of each case were evaluated. Convex- shaped STE was observed in all patients and it showed a specific coronary territory in 35 of 36 patients (97.2%). Pathologic Q wave and/or loss of R wave progression were observed in only one patient. T wave inversion following STE was detected in 34 patients (94.4%). STE evolution was absent in 32 of 36 patients while the information regarding STE evolution were not provided in the remaining cases. CONCLUSION: STE due to tumor invasion has certain characteristics which could help clinicians in the differential diagnosis.

The role of Beta-1 receptor gene polymorphism in Beta-Blocker therapy for vasovagal syncope.

BACKGROUND: Vasovagal syncope (VVS) is a common clinical condition involving genetic background. The role of beta-blockers in the treatment is controversial. OBJECTIVE: The aim of this study was to investigate the effect of beta-1 gene polymorphism on beta-blocker therapy in patients with VVS. METHODS: We included 123 patients who were diagnosed with VVS after the tilttable test. We searched for the polymorphism Arg389Gly (rs1801253) in the beta-1 adrenoceptor gene. RESULTS: Overall, 64 patients (52%) had Arg389Arg with Arg389Arg genotype were more frequent compared with patients having Arg389Gly genotype (total syncopal episodes [TSE], 7.9 ± 3.7 vs. 6.4 ± 3.0; p = 0.012). TSE in patients with Arg389Arg genotype decreased significantly after 18 months of beta-blocker treatment (7.9 ± 3.7 vs. 3.0 ± 1.4, p < 0.001). After 18 months of beta-blocker treatment, patients with Arg389Arg genotype had significantly fewer syncopal episodes than patients with Arg389Gly genotype (3.0 ± 1.4 vs. 6.8 ± 3.2, p < 0.001). CONCLUSIONS: Results of beta-blocker therapy in patients with Arg389Arg genotype suggest that VVS pathophysiology is a multifactorial condition, with genetic, psychological, and environmental components, and therefore, treatment selection can be based on gene polymorphism.

Catheter-induced premature ventricular complexes (PVCs) may aid in the determination of optimal timing for clinical PVC ablation.

BACKGROUND: The aim of the present study is to evaluate whether catheter-induced premature ventricular complexes (PVCs) produced at the presumptive ablation site may aid in the identification of the optimal timing of the earliest local activation for the successful ablation of clinical PVCs. METHODS: Sixty-three consecutive patients (35 males, age: 53.5 ± 14.4 years) without any exclusion criteria who had undergone PVC ablation between 1 July 2018 and 1 July 2019 constituted our study population. The time interval between the beginning of the EGM and the beginning of the QRS of each catheter-induced PVC (Cath EGM-ECG) and the time interval between the beginning of the EGM of clinical PVCs at the earliest site and the beginning of the QRS of clinical PVCs (PVC earliest EGM-ECG) were noted for each patient. The value of Cath EGM-ECG as a reference for procedural success of ablation was evaluated by examining the relationship between Cath EGM-ECG and PVC earliest EGM-ECG. RESULTS: Fifty-two patients had successful ablation, and 43 of them (82.7%) had PVC earliest EGM-ECG values greater than or equal to Cath EGM-ECG. Eleven patients had procedural failure, and all of them had PVC earliest EGM-ECG values lower than Cath EGM-ECG. A PVC earliest EGM-ECG value -1.5 ms greater than Cath EGM-ECG predicted successful ablation with a sensitivity of 90.4% and a specificity of 100.0% in the general patient population. CONCLUSION: Cath EGM-ECG seems to serve as a reliable guide for finding the optimal timing of the earliest site for successful PVC ablation.

Could fragmented QRS predict mortality in aortic stenosis patients after transcatheter aortic valve replacement?

BACKGROUND: Fragmented QRS evaluated in 12-derivation electrocardiography has widely been accepted as a sign of myocardial fibrosis. The prognostic value of that marker has been demonstrated, particularly, in cardiac diseases that accompany myocardial scar and fibrosis. Myocardial fibrosis is also an issue in patients with aortic stenosis. In this study, we wanted to determine whether fragmented QRS could predict all-cause mortality in aortic stenosis patients after transcatheter aortic valve replacement (TAVR). METHOD: In this study, we evaluated a total of 116 eligible patients on whom we performed TAVR between 2014 and 2018. Patients' demographic and clinical findings, echocardiography results, in-hospital and 30-day mortality, long-term survival statuses were noted. Patient's ECGs before the procedure were evaluated in regard to the occurrence of fragmented QRS. Predictors of mortality were evaluated using univariable and multivariable Cox regression analysis. RESULTS: The study population consisted of 116 patients of median age 79 (IQR 75-83), 64 females (55.2%). Mortality occurred in 27 (23%) patients; median follow-up time was 319 (IQR 122-719) days. Fragmented QRS was observed in 44 out of 116 (37.9%) patients. The presence of a fragmented QRS (HR = 2.178, 95% CI 0.999-4.847, p = 0.050), a history of stroke (HR = 3.463, 95% CI 1.276-9.398, p = 0.015), and the creatinine levels at admission (HR = 2.198, 95% CI 1.068-4.520, p = 0.030) were associated with the long-term mortality in multivariable Cox regression analysis. CONCLUSION: Like in the case of the other diseases associated with myocardial fibrosis, fragmented QRS could also predict mortality in aortic stenosis patients after TAVR procedure.

The relationship between grade of ischemia, success of reperfusion, and type of thrombolytic regimen.

BACKGROUND: This study was aimed to determine whether the grade of ischemia can predict the success of reperfusion in patients treated with thrombolytic therapy (TT) for ST elevation myocardial infarction (STEMI). MATERIAL AND METHODS: We enrolled 229 consecutive patients with diagnosis of STEMI and receiving TT. Patients were divided into 2 groups--grade 2 ischemia (GI2) and grade 3 ischemia (GI3)--according to initial electrocardiogram (ECG). As TT, fibrin-specific (tissue plasminogen activator (t-PA)) or non-fibrin-specific (streptokinase (SKZ)) regimens were used. Successful reperfusion was defined as >50% resolution of the maximal ST segment on 90-min ECG. We tried to evaluate whether the grade of ischemia could predict the success of reperfusion and if there were any differences in terms of successful reperfusion between different thrombolytic regimens. RESULTS: The successful reperfusion rate was significantly higher in GI2 than GI3 (82.4% vs. 64.4% respectively, p=0.002). The success rate was lowest at anterior GI3 (55.8%). Although there was no significant difference between thrombolytic regimens in all groups (p=0.77), t-Pa was superior to SKZ in anterior GI3 (63,6% vs. 30%, p=0.061). In addition, in multivariate analysis, GI and infarct localization were found as independent predictors for successful reperfusion with TT (p=0.006 and p=0.042, respectively). CONCLUSIONS: In the current study, we found that GI2 is an independent predictor for successful reperfusion in STEMI treated with TT. Fibrin specific regime should be preferred in anterior GI3.

Positive blood pressure response may predict the recovery of renal function after transcatheter aortic valve implantation.

OBJECTIVE: Transcatheter aortic valve implantation (TAVI) may ameliorate renal function and increase blood pressure (BP). We aimed to investigate the association between increased BP and improved renal function (IRF) after TAVI. METHODS: A total of 176 patients who had undergone TAVI were evaluated retrospectively. BP records that were taken 24 h before and 72 h after TAVI were reviewed. Pre-procedural, post-procedural 48 h, and the first month estimated glomerular filtration rate (eGFR) levels were noted. IRF was accepted as a ≥ 10% increase in eGFR. The predictors of acute kidney injury (AKI) development at 48 h and IRF at 1 month were investigated. The association between mortality and BP response was assessed. RESULTS: A total of 157 patients were included in this study after exclusion as defined in the methodology. Mean age was 78.1 ±â€…7,1 and 51.6% were female. AKI occurred in 25.5% of patients and baseline eGFR and male gender were found as independent predictors for AKI development. IRF was observed in 16% at 48 h and 31.8% of patients at 1-month follow-up. Positive BP response was seen in 42% of patients. Pre-procedural chronic kidney disease, positive BP response, and an early increase in eGFR emerged as independent predictors of IRF at the first month. The patients with positive BP response were found to have decreased mortality at 710 days follow-up. CONCLUSION: Positive BP response after TAVI is related to improved survival and renal functions. The beneficial effect of TAVI on renal function may be precisely evaluated at 1st month rather than 48 h.

Is dynamic change in mean platelet volume related with composite endpoint development after transcatheter aortic valve replacement?

Aortic valve stenosis (AS) is the most common valvular disease, and surgical or transcatheter aortic valve replacement (TAVR) are the treatment options. Diminish in platelet production or dysfunction may occur due to shear stress, advanced age, and other coexisting diseases in AS patients. Bleeding is one of the complications of TAVR and associated with increased mortality. MPV (mean platelet volume) indicates platelet's thrombogenic activity. Overproduction or consumption of platelets in various cardiac conditions may affect MPV values. We aimed to investigate the pre and postprocedure MPV percentage change (MPV-PC) and its association with post-TAVR short-term complications. A total of 204 patients who underwent TAVR with a diagnosis of severe symptomatic AS were included. The mean age was 78.66 ±â€Š6.45 years, and 49.5% of patients were women. Two groups generated according to composite end point (CEP) development: CEP(+) and CEP(-).110 patients(53.9%) formed CEP(+) group. Although baseline MPV and platelet levels were similar between groups, MPV was increased ( P  < 0.001) and platelet was decreased ( P  < 0.001) significantly following the procedure when compared to baseline. MPV-PC was significantly higher in the VARC type 2-4 bleeding ( P   =  0.036) and major vascular, access-related, or cardiac structural complication groups ( P   =  0.048) when CEP subgroups were analyzed individually. Regression analysis revealed that diabetes mellitus [ P   =  0.044, ß: 1.806 odds ratio (95% confidence interval): 1.016-3.21] and MPV-PC [ P   =  0.007,ß: 1.044 odds ratio (95% confidence interval): 1.012-1.077] as independent predictors of CEP development at 1 month after TAVR. The MPV increase following TAVR may be an indicator of adverse outcomes following TAVR procedure within 1-month.

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.

The effect of paclitaxel plus carboplatin chemotherapy on subclinical cardiotoxicity in patients with non-small cell lung cancer: A speckle tracking echocardiography-based study.

BACKGROUND: Although chemotherapy-induced cardiotoxicity is an emerging problem, limited information is available on the effects of chemotherapy on left ventricular (LV) mechanical functions in patients with non-small cell lung cancer (NSCLC). OBJECTIVE: We aimed to explore chemotherapy-induced alterations in cardiac mechanical functions in patients with NSCLC using speckle tracking echocardiography (STE). METHODS: Seventy-one patients with NSCLC and 34 age and sex matched control subjects were consecutively included. Based on their good performance status (Eastern Cooperative Oncology Group performance status), 39 patients were treated with paclitaxel plus carboplatin (PC) regimen and 32 patients were treated with vinorelbine plus cisplatin (VC) regimen. All patients and controls underwent conventional two-dimensional echocardiography and STE at baseline to assess their LV functions. The echocardiographic examinations of NSCLC patients were repeated after the chemotherapy regimens. RESULTS: None of the NSCLC patients developed any signs or symptoms of clinical heart failure during or after the chemotherapy. There were not any significant differences in LV ejection fraction between NSCLC patients and controls before and after chemotherapy. There were not any significant differences in baseline LV global longitudinal strain (GLS), radial strain (RS), and circumferential strain (CS) between NSCLC patients and controls. However, all LV GLS, RS and CS significantly decreased in patients treated with the PC regimen resulting in a significant difference compared to both VC group and controls while no significant decreases were observed in strain measures in VC group. CONCLUSION: Paclitaxel plus carboplatin, but not VC, may induce subclinical cardiotoxicity in patients with NSCLC, which may be detected by STE.

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.

Fluoroscopy time and scattered radiation during electrophysiology procedures: analysis of one-year data of a laboratory providing electrophysiology training.

OBJECTIVES: Patients and medical staff expose to significant radiation during electro-physiological (EP) procedures. There are few data regarding the leading factors of longer fluoroscopy time and higher scattered radiation in a laboratory giving EP training during those interventions. MATERIAL AND METHODS: The patients' recordings that underwent EP procedure in a single centre arrhythmia unit from February 2019 to January 2020 were examined. Prospectively collected data regarding procedure duration, fluoroscopy time and total air kerma, demographic characteristics of the patients, type of procedure, success of ablation and the use of electro anatomic mapping were retrospectively evaluated. Predictors of total air kerma were analysed with linear regression analysis. RESULTS: Study population consisted of 437 patients with a median age of 47 (39-56); 184 (42.1%) were male. Median fluoroscopy time was 768 (420-1320) seconds and median cumulative air kerma was 369 (191-750) mGy. Fluoroscopy time and cumulative air kerma were significantly lower in diagnostic EP studies compared to other procedures. There was no difference in terms of total air kerma between the procedures other than the diagnostic EP study. In multivariable linear regression analysis; body surface area, fluoroscopy time, not using the electro-anatomical mapping, unsuccessful ablation and atrial flutter ablation were predictors of total air kerma in EP studies performed by trainees. CONCLUSION: Scattered radiation during EP procedures performed by in-training operators is related with some factors. Awareness about those may help to effort reducing the harmful effect of ionising radiation.

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.

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.