Electrocardiographic algorithms to guide a management strategy of idiopathic outflow tract ventricular arrhythmias

The current guidelines of the European Society of Cardiology outlined electrocardiographic (ECG) differentiation of the site of origin (SoO) in patients with idiopathic ventricular arrhythmias (IVAs). The aim of this study was to compare 3 ECG algorithms for differentiating the SoO and to determine their diagnostic value for the management of outflow tract IVA. We analyzed 202 patients (mean age [SD]: 45 [16.7] years; 133 women [66%]) with IVAs with the inferior axis (130 premature ventricular contractions or ventricular tachycardias from the right ventricular outflow tract [RVOT]; 72, from the left ventricular outflow tract [LVOT]), who underwent successful radiofrequency catheter ablation (RFCA) using the 3‑dimensional electroanatomical system. The ECGs before ablation were analyzed using custom‑developed software. Automated measurements were performed for the 3 algorithms: 1) novel transitional zone (TZ) index, 2) $V_{2}S/V_{3}R$, and 3) $V_{2}$ transition ratio. The results were compared with the SoO of acutely successful RFCA. The $V_{2}S/V_{3}R$ algorithm predicted the left‑sided SoO with a sensitivity and specificity close to 90%. The TZ index showed higher sensitivity (93%) with lower specificity (85%). In the subgroup with the transition zone in lead V3 (n = 44, 15 from the LVOT) the sensitivity and specificity of the V2– transition‑ratio algorithm were 100% and 45%, respectively. The combined TZ index+$V_{2}S/V_{3}R$ algorithm (LVOT was considered only when both algorithms suggested the LVOT SoO) can increase the specificity of the LVOT SoO prediction to 98% with a sensitivity of 88%. The combined TZ‑index and $V_{2}S/V_{3}R$ algorithm allowed an accurate and simple identification of the SoO of IVA. A prospective study is needed to determine the strategy for skipping the RVOT mapping in patients with LVOT arrhythmias indicated by the 2 combined algorithms

Long-term follow-up and comparison of techniques in radiofrequency ablation of ventricular arrhythmias originating from the aortic cusps (AVATAR Registry)

Introduction: Radiofrequency ablation (RFA) of outflow tract ventricular arrhythmia (VA) that originates from the aortic cusps can be challenging. Data on long-term efficacy and safety as well as optimal technique after aortic cusp ablation have not previously been reported. Objectives: This aim of the study was to determine the short- and long-term outcomes after RFA of aortic cusp VA, and to evaluate aortic valve injuries according to echocardiographic screening. Patients and methods: This was a prospective multicenter registry (AVATAR, Aortic Cusp Ventricular Arrhythmias: Long Term Safety and Outcome from a Multicenter Prospective Ablation Registry) study. A total of 103 patients at a mean age of 56 years (34–64) from the “Electra” Registry (2005–2017) undergoing RFA of aortic cusps VA were enrolled. The following 3 ablation techniques were used: zero-fluoroscopy (ZF; electroanatomical mapping [EAM] without fluoroscopy), EAM with fluoroscopy, and conventional fluoroscopy-based RFA. Data on clinical history, complications after RFA, echocardiography, and 24-hour Holter monitoring were collected. The follow-up was 12 months or longer. Results: There were no major acute cardiac complications after RFA. In one case, a vascular access complication required surgery. The median (interquartile range [IQR]) procedure time was 75 minutes (IQR, 58–95), median follow-up, 32 months (IQR, 12–70). Acute and long-term procedural success rates were 93% and 86%, respectively. The long-term RFA outcomes were observed in ZF technique (88%), EAM with fluoroscopy (86%), and conventional RFA (82%), without differences. During long-term follow-up, no abnormalities were found within the aortic root. Conclusions: Ablation of VA within the aortic cusps is safe and effective in long-term follow-up. The ZF approach is feasible, although it requires greater expertise and more imaging modalities

Validation of standard and new criteria for the differential diagnosis of narrow QRS tachycardia in children and adolescents

To establish an appropriate treatment strategy and determine if ablation is indicated for patients with narrow QRS complex supraventricular tachycardia (SVT), analysis of a standard 12-lead electrocardiogram (ECG) is required, which can differentiate between the 2 most common mechanisms underlying SVT: atrioventricular nodal reentry tachycardia (AVNRT) and orthodromic atrioventricular reentry tachycardia (OAVRT). Recently, new, highly accurate electrocardiographic criteria for the differential diagnosis of SVT in adults were proposed; however, those criteria have not yet been validated in a pediatric population. All ECGs were recorded during invasive electrophysiology study of pediatric patients (n = 212; age: 13.2 ± 3.5, range: 1–18; girls: 48%). We assessed the diagnostic value of the 2 new and 7 standard criteria for differentiating AVNRT from OAVRT in a pediatric population. Two of the standard criteria were found significantly more often in ECGs from the OAVRT group than from the AVNRT group (retrograde P waves [63% vs 11%, P < 0.001] and ST-segment depression in the II, III, aVF, V1–V6 leads [42% vs 27%; P < 0.05]), whereas 1 standard criterion was found significantly more often in ECGs from the AVNRT group than from the OAVRT group (pseudo r′ wave in V1 lead [39% vs 10%, P < 0.001]). The remaining 6 criteria did not reach statistical significance for differentiating SVT, and the accuracy of prediction did not exceed 70%. Based on these results, a multivariable decision rule to evaluate differential diagnosis of SVT was performed. These results indicate that both the standard and new electrocardiographic criteria for discriminating between AVNRT and OAVRT have lower diagnostic values in children and adolescents than in adults. A decision model based on 5 simple clinical and ECG parameters may predict a final diagnosis with better accuracy

Implantable cardioverter-defibrillators in patients with long QT syndrome: a multicentre study

Background: Implantable cardioverter-defibrillator (ICD) therapy has been proven effective in the prevention of sudden cardiac death, but data on outcomes of ICD therapy in the young and otherwise healthy patients with long QT syndrome (LQTS) are limited. Aim: We sought to collect data on appropriate and inappropriate ICD discharges, risk factors, and ICD-related complications. Methods: All LQTS patients implanted with an ICD in 14 centres were investigated. Demographic, clinical, and ICD therapy data were collected. Results: The study included 67 patients (88% female). Median age at ICD implantation was 31 years (12–77 years). ICD indication was based on resuscitated cardiac arrest in 46 patients, syncope in 18 patients, and malignant family history in three patients. During a median follow-up of 48 months, 39 (58%) patients received one or more ICD therapies. Time to first appropriate discharge was up to 55 months. Inappropriate therapies were triggered by fast sinus rhythm, atrial fibrillation, and T-wave oversensing. No predictors of inappropriate shocks were identified. Risk factors for appropriate ICD therapy were: (1) recurrent syncope despite b-blocker treatment before ICD implantation, (2) pacemaker therapy before ICD implantation, (3) single-chamber ICD, and (4) noncompliance to b-blockers. In 38 (57%) patients, at least one complication occurred. Conclusions: ICD therapy is effective in nearly half the patient population; however, the rates of early and late complica­tions are high. Although the number of unnecessary ICD shocks and reimplantation procedures may be lowered by modern programming and increased longevity of newer ICD generators, other adverse events are less likely to be reduced

Izolacja okrężna żył płucnych u chorego z napadowym migotaniem przedsionków przy użyciu systemu High Density Mesh Ablator (HDMA) - pierwsze polskie doświadczenie

We present a case of a 49 year-old man without structural heart disease who suffered from frequent episodes of atrial fibrillation. We performed pulmonary vein isolation using a new system High-Density Mesh Ablation. All four pulmonary veins were isolated and during an 8-month follow-up period no arrhythmia recurrences were noted. Kardiol Pol 2010; 68, 11: 1295-129

Duszność w zespole preekscytacji bez zaburzeń rytmu serca jako nowe kryterium oceny chorego kwalifikowanego do ablacji

Background: Patients with pre-excitation without arrhythmic symptoms are diagnosed as Wolff-Parkinson-White (WPW) pattern.Aim: To evaluate the efficacy of radiofrequency ablation (RFA) in patients with a WPW pattern and reported dyspnoea.Methods: Five patients (four adults and one adolescent, all female, age 33 ± 15 years) with a WPW pattern were referred due to dyspnoea and exercise intolerance. None had a history of paroxysmal syncope, pre-syncope, dizziness or palpitation. Before and after RFA, additional tests were used to exclude organic diseases of the pulmonary vessels, heart and lung, as well as bronchial hyperreactivity and metabolic diseases. Cardiopulmonary exercise test (CPET), echocardiography, time of forced expiration, baseline dyspnoea index (BDI), and transition dyspnoea index (TDI) were included into an objective evaluation of breath pattern.Results: In all investigated patients, no arrhythmia was inducible during the electrophysiology study. The time of forced expiration increased immediately after RFA from 15.8 ± 2.9 to 29.2 ± 4.4 s (p &lt; 0.001). The BDI score before RFA was 6.7 ± 1.9 and the TDI score after RFA showed a significant improvement: 8.0 ± 1.2 (p &lt; 0.05). CPET revealed significant improvement in cardiopulmonary capacity after RFA in all cases: peak oxygen consumption [mL/kg/min]: 31.1 ± 7 vs. 42.6 ± 9.6 (p = 0.014); peak exercise minute ventilation [L/min]: 60.0 ± 19.9 vs. 82.0 ± 27 (p = 0.006); peak exercise tidal volume [L]: 1.56 ± 0.25 vs. 2.04 ± 0.24 (p = 0.002); ratio dead space/tidal volume at the end of exercise: 28 ± 2.6 vs. 25 ± 2.3 (p = 0.005).Conclusions: Dyspnoea during sinus rhythm in women with pre-excitation may be considered to be an evaluation criterion before RFA. Wstęp: Pacjenci z rejestrowaną falą delta w standardowym EKG i bez wywiadu objawów arytmicznych są klasyfikowani jako chorzy z bezobjawową preekscytacją (WPW pattern or asymptomatic pre-excitation).Cel: Głównym celem badania było obiektywne pokazanie ustępowania objawów duszności u chorych z WPW po udanym zabiegu ablacji.Metody: Badaniem objęto 5 kobiet w wieku 35 ± 15 lat, z rozpoznanym zespołem preekscytacji i objawami duszności oraz obniżonej tolerancji wysiłku. Żadna z chorych nie miała nigdy rozpoznawanych zaburzeń rytmu serca, nigdy nie doświadczyła omdleń, nigdy nie odczuwała kołatań serca. Przed i po ablacji przeprowadzono badania obrazowe wykluczające chorobę serca, płuc, naczyń płucnych, wykluczono nadreaktywność oskrzeli i choroby metaboliczne. Ergospirometria, echokardiografia,czas natężonego wydechu, wskaźniki BDI (baseline dyspnea index) oraz TDI (transition dyspnea index) wykorzystano w celu obiektywnej oceny zgłaszanej duszności.Wyniki: Podczas badania elektrofizjologicznego u żadnej z pacjentek nie zaobserwowano zaburzeń rytmu serca, mimo że odczuwały duszność. Po udanej ablacji czas natężonego wydechu natychmiast się wydłużył z 15,8 ± 2,9 do 29,2 ± 4,4 s (p &lt; 0,001). Wskaźnik BDI przed ablacją wynosił 6,7 ± 1,9, natomiast wskaźnik TDI po ablacji istotnie się poprawił: 8,0 ± 1,2 (p &lt; 0,05). Ergospirometria wykazała znamienną poprawę wydolności sercowo-płucnej u wszystkich chorych: szczytowe pochłanianie tlenu [ml/kg/min]: 31,1 ± 7 vs. 42,6 ± 9,6 (p = 0,014); szczytowa wentylacja minutowa[l/min]: 60,0 ± 19,9 vs. 82,0 ± 27 (p = 0,006); szczytowa objętość oddechowa [l]: 1,56 ± 0,25 vs. 2,04 ± 0,24 (p = 0,002); wskaźnik przestrzeń martwa płuc/objętość oddechowa na szczycie wysiłku: 28 ± 2,6 vs. 25 ± 2,3 (p = 0,005).Wnioski: Duszność może być traktowana jako objaw zespołu preekscytacji i przy braku zaburzeń rytmu serca może stanowić dodatkowe kryterium oceny pacjenta przy kwalifikacji do zabiegu ablacji. Ergospirometria wydaje się badaniem przydatnym w diagnostyce duszności wynikającej z obecności dodatkowej drogi przewodzenia przedsionkowo-komorowego