[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.

Clinical implication of totally occluded infarct-related coronary artery in non-ST-segment elevation myocardial infarction: the TOTAL-NSTEMI study.

BACKGROUND: A subset ofpatients found to have total occlusion of the culprit artery (TOCA), present with non-ST-segment elevation myocardial infarction (NSTEMI) and elevated biomarkers. The aim of this study is to assess the effect of the TOCA in patients presenting with NSTEMI. METHODS: This multicenter observational study was retrospectively conducted between 2015 and 2019. Thrombolysis in myocardial infarction (TIMI) flow grades 0-1 was defined as the TOCA. The primary end point included a combination of all-cause death, myocardial infarction, target vessel revascularization, stent thrombosis, and stroke. RESULTS: Of 3272 patients, TIMI 0-1 flow in the culprit artery was present in 488 (14.9%) patients. TOCA was more likely to be of thrombotic origin (54.1% vs. 10.3%; P < 0.001) and visible collaterals (22.5% vs. 4.4%; P < 0.001). The rates of 30-day (14.3% vs. 7.2%; P < 0.001) and 2-year (25% vs. 19.1%; P = 0.003) primary end points were significantly higher in TOCA patients. Fatal arrhythmias were remarkably higher at 30-day (8.6% vs. 4%; P < 0.001) and 2-year (9% vs. 5.2%; P = 0.001) follow-ups. Mechanical complications were also higher in patients with TOCA at 30 days (0.8% vs. 0.2%; P = 0.013). Moreover, TOCA (OR, 1.379; P = 0.001) was one of the independent predictors of MACCE in NSTEMI patients. CONCLUSION: The current data suggest that patients with TOCA in the context of NSTEMI are at higher risk of MACCE, fatal arrhythmias, and mechanical complications.

The relationship between CHA2DS2VASc score and left ventricular apical thrombus formation in patients with acute anterior ST segment elevation myocardial infarction.

BACKGROUND: Left ventricular apical thrombus (LVAT) formation is a well-known complication of acute anterior myocardial infarction (AMI). The CHA2DS2VASc is a scoring system that has been used to estimate the risk of thromboembolism in patients with nonvalvular atrial fibrillation. This score has also been used for other clinical conditions. The aim of this study was to investigate the relationship between CHA2DS2VASc score and development of LVAT in patients with AMI. METHOD: The study population included 378 patients (mean age: 56.5 ± 12.3 years, male: 318) presenting with AMI between January 2016 and January 2020. Primary percutaneous coronary intervention procedure was performed in all patients. Initial echocardiogram was performed within 7 days of admission. All patients were evaluated with echocardiography at 3rd, 6th and 12th months. Patients were divided into two groups according to the presence of LVAT on echocardiography. RESULTS: The incidence of the LVAT was 8.5% (n = 32) during a mean follow-up time of 233.1 ± 66.7 days. The mean CHA2DS2VASc score was notably higher in patients with LVAT compared to patients in the control group (3.1 ± 1.9 vs. 1.9 ± 1.2, p < 0.001). In Cox regression analysis, high CHA2DS2VASc score, low left ventricular ejection fraction (LVEF) and the presence of LV apical akinesis/aneurysm were the independent predictors for LVAT formation. All of these parameters were associated with higher cumulative incidence of LVAT formation in Kaplan-Meier analyses (p < 0.001 for all). CONCLUSION: High CHA2DS2VASc score, low LVEF and the presence of LV apical akinesis/aneurysm may be used for LVAT risk prediction among patients presenting with AMI.

Predictors of pulmonary hypertension after atrial septal defect closure: Impact of atrial fibrillation.

Background: In this study, we aimed to evaluate the course of pulmonary artery systolic pressure, to identify factors associated with pulmonary arterial hypertension, and to determine the impact of atrial septal defect closure on clinical outcomes in long-term follow-up. Methods: Between March 2008 and August 2020, a total of 547 adult patients (193 males, 354 females; median age: 37 years; range, 27.5 to 47 years) with secundum atrial septal defect were retrospectively analyzed. Of these patients, 304 underwent percutaneous defect closure and 243 underwent isolated surgical repairs. Pulmonary arterial hypertension was defined as a noninvasively estimated pulmonary artery systolic pressure of ≥40 mmHg at the final follow-up after atrial septal defect closure. Factors associated with pulmonary arterial hypertension were analyzed. Results: Sixty-nine (12.6%) patients presented with pulmonary arterial hypertension at the final follow-up. A total of 35 (6.4%) patients had persistent atrial fibrillation before atrial septal defect closure, and 22 of these 35 patients had pulmonary arterial hypertension during long-term follow-up. Older age at the time of atrial septal defect closure (HR: 4.76; 95% CI: 2.68-8.44; p<0.001), the presence of persistent atrial fibrillation (HR: 2.18; 95% CI: 1.21-3.91; p=0.009), and greater right ventricular basal diameter (HR: 4.78; 95% CI: 2.57-8.84; p<0.001) were found to be associated with late pulmonary arterial hypertension. Conclusion: The presence of persistent atrial fibrillation may be used to predict patients at higher risk for pulmonary arterial hypertension after atrial septal defect closure.

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.

Electrophysiologic Changes and Their Effects on Ventricular Arrhythmias in Patients with Continuous-Flow Left Ventricular Assist Devices.

Ventricular arrhythmias (VAs) continue even after left ventricular assist device (LVAD) implantation. The effect of LVAD on VAs is controversial. We investigated electrophysiologic changes after LVAD and its effects on VAs development. A total of 107 implantable cardioverter-defibrillator (ICD) patients, with LVAD, were included in this study. Electrocardiographic parameters including QRS duration (between the beginning of the QRS complex and the end of the S wave), QT duration (between the first deflection of the QRS complex and the end of the T wave) corrected QT (QTc), QTc dispersion, fragmented QRS (F-QRS), and ICD recordings before, and post-LVAD first year were analyzed. All sustained VAs were classified as polymorphic ventricular tachycardia (PVT) or monomorphic VT (MVT). The QRS, QT, QTc durations, and QTc dispersion had decreased significantly after LVAD implantation (p < 0.001 for all). Also MVT increased significantly from 28.9% to 49.5% (p = 0.019) whereas PVT decreased from 27.1% to 4.67% (p = 0.04) compared to pre-LVAD period. A strong correlation was found between QT shortening and the decrease in PVT occurrence. Besides, the increase in the F-QRS after LVAD was associated with post-LVAD de nova MVT development. Finally, F-QRS before LVAD was found as an independent predictor of post-LVAD late VAs in multivariate analysis. Pre-existing or newly developed F-QRS was associated with post-LVAD late VAs, and it may be used to determine the risk of VAs after LVAD implantation.

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.

Anxiety Disorder Associated with the COVID-19 Pandemic Causes Deterioration of Blood Pressure Control in Primary Hypertensive Patients.

OBJECTIVE: The new coronavirus disease (COVID-19) has spread rapidly all over the world and caused anxiety disorders. Recent studies have also shown that the prevalence of depression and anxiety increased during the COVID-19 outbreak. We aimed to evaluate the anxiety and depression levels during the pandemic and identify the effect of pandemic-related stress on blood pressure (BP) control in primary hypertensive patients. METHOD: A total of 142 patients with primary hypertension (HT) who continued to use the same antihypertensive drugs before and during the pandemic were included in the study. Twenty-four -hour Ambulatory Blood Pressure Monitoring (ABPM) and the Hospital Anxiety and Depression Scale (HADS) questionnaire were applied to patients. We retrospectively reviewed 24-h ABPM records of the same patients for the year before the pandemic. RESULTS: Daytime, nighttime and 24 -hour-systolic blood pressure (SBP) levels as well as daytime, nighttime, and 24- hour-diastolic blood pressure (DBP) levels , were significantly elevated during the COVID-19 outbreak compared to the pre-pandemic period (p<0.001). Higher HADS-A scores (HADS-A ≥7) were significantly associated with much greater increase in BP compared to the patients with lower HADS-A scores. CONCLUSION: Psychological stress due to the COVID-19 outbreak led to worsening of the regulation of BP in controlled hypertensive patients whose antihypertensive treatments did not change.

The Predictive Role of a Novel Risk Index in Patients Undergoing Carotid Artery Stenting: Systemic Immune-Inflammation Index.

BACKGROUND: Inflammatory mechanisms play an important role in both atherosclerosis and stroke. There are several inflammatory peripheral blood count markers associated with carotid artery stenosis degree, symptomatic carotid artery lesions and carotid artery stent restenosis that reported in previous studies. However, the prognostic role of the blood cell counts and their ratios in predicting in-hospital and long-term outcomes in patients undergoing carotid artery stenting (CAS) has not been comprehensively investigated. Systemic immune-inflammation index (SII) proved its' efficiency in patients with solid tumors and its' role was rarely examined in cardiovascular disorders and stroke. The current study evaluated the effect of this novel risk index on in-hospital and long-term outcomes in a large patient population who underwent CAS. METHOD: A total of 732 patients with carotid artery stenosis who underwent CAS were enrolled to the study. SII was calculated using the following formula: neutrophil-to-lymphocyte ratio × total platelet count in the peripheral blood (per mm3) and the patients were stratified accordingly: T1, T2 and T3. In-hospital and 5-year outcomes were compared between the tertiles of SII. RESULTS: During the hospitalization, major stroke, ipsilateral stoke, myocardial infarction, death and major adverse cardiovascular events (MACE) rates were significantly higher in high SII level (T3) compared to SII levels (T1 and 2). In long-term outcomes, ipsilateral stroke, major stroke, transient ischemic attack, death, and MACE were significantly higher in the patients with higher SII level (T3). The 5-year Kaplan-Meier overall survival for T1, T2, and T3 were 97.5%, 96.7% and 86.0% respectively. In-hospital and 5-year regression analyses demonstrated that high SII was independently associated with MACE and mortality. CONCLUSION: SII was independently associated with in-hospital and long-term clinical outcomes in patients undergoing CAS. Immune and inflammation status, as assessed easily and quickly using SII, has a good discriminative value in these patients.

Crochetage sign may predict late atrial arrhythmias in patients with secundum atrial septal defect undergoing transcatheter closure.

BACKGROUND: Atrial arrhythmias are well-known complications of atrial septal defect (ASD), and associated with substantial morbidity. After ASD closure, right atrial and ventricular enlargement regresses, however, the risk of atrial arrhythmia development continues. In this study, we aimed to investigate the relationship between the Crochetage sign, which is a possible reflection of heterogeneous ventricular depolarization due to long-term hemodynamic overload, and the development of late atrial arrhythmia after ASD closure. METHODS: This retrospective study included a total of 314 patients (mean age: 39.5 (30-50) years; male: 115) who underwent percutaneous device closure for secundum ASD. The study population was divided into two groups according to the presence or absence of the Crochetage sign. The Crochetage sign was defined as an M-shaped or bifid pattern notch on the R wave in one or more inferior limb leads. Cox-regression analysis was performed to determine independent predictors of late atrial arrhythmia development. RESULT: Fifty-seven patients (18.1%) presented with late atrial arrhythmia. Of these 57 patients, 30 developed new-onset atrial fibrillation/atrial flutter (AF/AFL), and 27 patients with pre-procedure paroxysmal AF/AFL had a recurrence of AF/AFL during follow-up. History of paroxysmal AF/AFL before the procedure (HR: 4.78; 95% CI 2,52-9.05; p < 0.001), the presence of Crochetage sign (HR: 3.90; 95% CI 2.05-7.76; p < 0.001), and older age at the time of ASD closure (HR: 1.03; 95% CI 1.01-1.06; p = 0.002) were found as independent predictors for late atrial arrhythmia. CONCLUSION: The presence of Crochetage sign may be used to predict the risk of late atrial arrhythmia development after transcatheter ASD closure.

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.

The relationship between dual antiplatelet treatment (DAPT) score and saphenous venous grafts patency after coronary artery bypass grafting surgery.

BACKGROUND: Coronary artery bypass grafting (CABG) remains the gold standard treatment for mutivessel and left main coronary artery disease (CAD). Saphenous vein graft (SVG) patency is still a problem in CAD patients after CABG surgery. The Dual Antiplatelet Treatment (DAPT) score is a clinical prediction tool that predicts ischaemic and bleeding risk in CAD patients. The aim of this study is to investigate the relationship between DAPT score and SVG patency in CABG patients. METHOD: This retrospective study enrolled a total of 398 patients (68 female; mean age 65.8 ± 9.1 years) with a history of CABG surgery. The study population was divided into two subgroups according to SVG patency. The DAPT score was calculated for each patients and compared between the two groups. RESULTS: Coronary angiography revealed SVG disease in 212 patients and SVG patency in 186 patients. The rates of diabetes mellitus and hypertension, red cell distribution width values, DAPT Score, time interval after CABG and number of SVGs were significantly higher while LVEF was significantly lower in patients with SVG disease. The presence of diabetes mellitus, high DAPT score, long time interval after CABG and high number of SVGs were found to be independent predictors of SVG patency. DAPT score above 2.5 predicted SVG disease with a sensitivity of 77.1% and a specificity of 87.1% (AUC: 0.873; 95%CI: 0.823-0.924; p < 0.001). CONCLUSION: The DAPT score may provide useful information for SVG patency in CABG patients. Patients with high DAPT score should be followed up closely for SGV occlusion. DAPT score may be useful prior to CABG in determining the duration of dual anti-platelet therapy and in encouraging the use of arterial grafts with better patency.

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.

Presence of fragmented QRS is associated with left ventricular systolic dysfunction after surgery in patients with severe aortic regurgitation.

BACKGROUND AND AIM OF THE STUDY: Chronic severe aortic regurgitation (AR) is associated with progressive accumulation of interstitial fibrosis and disruption of myocardial structure. After aortic valve replacement (AVR), the negative remodeling process reverses, and left ventricular ejection fraction (LVEF) improves but not in all patients. In this study, we aimed to investigate the association of fragmented QRS (F-QRS), which is a possible marker of myocardial fibrosis, with postoperative left ventricular (LV) systolic dysfunction. METHODS: A total of 147 consecutive patients with AVR were included in this study. F-QRS was identified by the presence of various RSR' patterns (QRS duration <120 ms) such as additional R wave (R prime)or notching of the R or S wave in at least two consecutive leads. Patients were compared in two groups based on the presence or absence of F-QRS. A logistic regression model was used to determine independent predictors of postoperative LV systolic dysfunction (LVEF <50%). RESULTS: Patients with F-QRS were associated with poor recovery of LV systolic function after AVR compared to the patients without F-QRS, regardless of preoperative LVEF (p = .008). F-QRS was found to be an independent predictor of postoperative LV systolic dysfunction (LVEF <50%). Lower preoperative LVEF and increased LV end diastolic diameter index were also found as independent risk factors for postoperative LV systolic dysfunction. CONCLUSIONS: As a possible marker of myocardial fibrosis, F-QRS was associated with postoperative LV systolic dysfunction. Therefore, as a simple and convenient clinical parameter, F-QRS may be used to predict poor recovery of LVEF after AVR.

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.

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.