Does atrioventricular reentry tachycardia (AVRT) or atrioventricular nodal reentry tachycardia (AVNRT) in children affect their cognitive and emotional development?

The current study sought to assess cognitive and emotional functions among children and adolescents with atrioventricular reentry tachycardia (AVRT) and atrioventricular nodal reentry tachycardia (AVNRT). 113 patients (62 girls and 51 boys ages, 9-18 years) scheduled for radiofrequency ablation due to AVRT or AVNRT underwent neuropsychologic examination. The study excluded patients who had experienced cardiac arrest, congenital heart defects, neurologic disorders, or other diseases affecting cognitive or emotional development. Standardized tests for examining verbal and visual memory as well as visual-spatial functioning were performed. For patients exhibiting deficits in two or more tests, a diagnosis of "cognitive deficits" was determined. Levels of anxiety were tested using the State-Trait Anxiety Inventory. Cognitive deficits were found in 47.8 % of the patients. The age at first arrhythmia attack was related to memory dysfunction. The mean age at which the first symptoms occurred was significantly lower for patients with deficits (8.3 years) than for patients who had no deficit (10.2 years) (t = 2.15; p = 0.03). Boys exhibited a significantly higher level of trait anxiety than girls (t = 3.42; p = 0.0009). A significant negative correlation was found between anxiety and the age at appearance of the first symptoms (r = -0.26; p = 0.005). These findings led us to conclude that cognitive and emotional developments can be negatively affected by AVNRT and AVRT, particularly if tachycardia appears early in life.

Atrial fibrillation in patients with Wolff-Parkinson-White syndrome: role of pulmonary veins.

AIM: We aimed to characterize electrophysiological properties of pulmonary veins (PVs) in patients with Wolff-Parkinson-White (WPW) syndrome and atrial fibrillation (AF), and to compare them to those in patients with WPW without AF. METHODS AND RESULTS: A total of 31 patients (mean age 40 ± 15 years, 23 males) with WPW were recruited: 16 patients with (AF group) and 15 without (controls) a history of AF. The basic electrophysiological (EPS) and echocardiographic data were not different between the 2 groups. Effective refractory periods (ERPs) of PVs were significantly shorter in the AF group compared to controls: left superior (LS) PV ERP 185±29 versus 230 ± 24 ms, P = 0.001; left inferior PV ERP 198 ± 25 versus 219 ± 26 ms, P = 0.04; right superior (RS) PV ERP 207 ± 25 versus 236 ± 19 ms, P = 0.001; right inferior PV ERP 208 ± 30 versus 240 ± 19 ms, P = 0.003. Maximal veno-atrial conduction delay (i.e., the maximal prolongation of interval from stimulus delivered at PV ostia to proximal coronary sinus after extrastimulus compared to the basic drive cycle) was longer in the AF group when pacing from LSPV (69.3 ± 37.9 vs 32.6 ± 16.1 ms, P = 0.01) and RSPV (74.1 ± 25.9 vs 50.2 ± 26.5 ms, P = 0.04). During EPS, AF was induced more often in the AF group (n = 7) compared to controls (n = 1; P = 0.04). Follow-up revealed that AF recurred in 3 patients in the AF group and none of the controls. CONCLUSION: Patients with WPW syndrome and AF have shorter ERPs of PVs and greater maximal veno-atrial conduction delay compared to patients with WPW without AF. These findings suggest a potential role of PVs in the development of AF in patients with WPW.

Recurrence of RVOT PVCs with a marked shift of its exit point. Gradual elimination of arrhythmogenic focus by multisite approach.

We present a case of recurrent outflow tract arrhythmia despite repeated ablations. Premature ventricular contractions (PVCs) morphology suggested a right-sided focus. However, electrograms preceding PVCs were recorded from the right and left outflow tracts, distal coronary sinus, and right sinus of Valsalva. Arrhythmia was eliminated after radiofrequency (RF) applications delivered from different sites. We conclude that, in patients with recurrent outflow tract PVCs, mapping all the sites mentioned above may be necessary to find the earliest activation site and carry out successful ablation. In some patients, RF applications from multiple sites may be necessary to completely eliminate arrhythmia.

Simultaneous Entrainment Response Assessment at Multiple Sites.

BACKGROUND: The entrainment response, defined as the difference between the postpacing interval and the tachycardia cycle length (TCL) recorded from a mapping catheter, allows to track down the components of the tachycardia loop. OBJECTIVES: The aim of this study was to evaluate if the postpacing interval measured simultaneously from multiple sites that are remote from the pacing site (PPIR) could be clinically useful in mapping re-entrant circuits. METHODS: Ninety-two episodes of entrainment response in 29 patients with different macro-re-entrant tachycardias were evaluated using a standardized entrainment protocol. The spatial distribution of different values of PPIR-TCL in a simulation and a computational model of an entrained re-entrant tachycardia was also analyzed. RESULTS: The PPIR exceeded TCL by more than 20 milliseconds only if both pacing and recording sites were outside the tachycardia circuit. The PPIR-TCL at in-circuit sites was always ≤20 milliseconds. Sites with negative PPIR-TCL values were found either outside or inside the tachycardia circuit. CONCLUSIONS: Assessment of entrainment response from catheters remote from the pacing site may enhance spatial mapping of the tachycardia circuit. The PPIR-TCL above 20 milliseconds has an excellent positive predictive value in identifying sites outside the tachycardia circuit.

Ablation of severe drug-resistant tachyarrhythmia during pregnancy.

AIMS: The goal of this study was to describe mapping and ablation of severe arrhythmias during pregnancy, with minimum or no X-ray exposure. Treatment of tachyarrhythmia in pregnancy is a clinical problem. Pharmacotherapy entails a risk of adverse effects and is unsuccessful in some patients. Radiofrequency ablation has been performed rarely, because of fetal X-ray exposure and potential maternal and fetus complications. GROUP AND METHOD: Mapping and ablation was performed in 9 women (age 24-34 years) at 12-38th week of pregnancy. Three had permanent junctional reciprocating tachycardia, and 2 had incessant atrial tachycardia. Four of them had left ventricular ejection fraction < or =45%. One patient had atrioventricular nodal reciprocating tachycardia requiring cardioversion. Three patients had Wolff-Parkinson-White syndrome. Two of them had atrial fibrillation with ventricular rate 300 bpm and 1 had atrioventricular tachycardia 300 bpm. Fetal echocardiography was performed before and after the procedure. RESULTS: Three women had an electroanatomic map and ablation done without X-ray exposure. The mean fluoroscopy time in the whole group was 42 +/- 37 seconds. The mean procedure time was 56 +/- 18 minutes. After the procedure, all women and fetuses were in good condition. After a mean period of 43 +/- 23 months follow up (FU), all patients were free of arrhythmia without complications related to ablation either in the mothers or children. CONCLUSION: Ablation can be performed safely with no or minimal radiation exposure during pregnancy. In the setting of malignant, drug-resistant arrhythmia, ablation may be considered a therapeutic option in selected cases.

Relationship between cycle length of typical atrial flutter and double potential interval after achievement of complete isthmus block.

BACKGROUND: There is some disagreement concerning the minimal value of the interval between components of double potentials (DPs interval) that allows distinguishing complete and incomplete block in the cavotricuspid isthmus (CTI). OBJECTIVES: To assess clinical utility of the relationship between atrial flutter cycle length (AFL CL) and the DPs interval. METHODS: Ablation of the CTI was performed in 87 patients during AFL (245 ± 40 ms). Subsequently, DPs were recorded during proximal coronary sinus pacing at sites close to a gap in the ablation line and after achievement of complete isthmus block. RESULTS: We noted strong correlation between AFL CL and the DPs interval after achievement of isthmus block (r = 0.73). The mean DPs interval was 95.3 ± 18.3 ms (range 60-136 ms) and 123.3 ± 24.3 ms (range 87-211 ms) during incomplete and complete isthmus block, respectively (P < 0.001). When expressed as a percentage of AFL CL, this interval was 35.7 ± 3.5% AFL CL (range 28-40.2%) and 50.4 ± 6.9% AFL CL (range 39-72%) during incomplete and complete isthmus block, respectively (P < 0.001). A cutoff value of 40% of AFL CL identified CTI block with 96.7% sensitivity and 100% specificity. CONCLUSIONS: The interval between DPs after achievement of block in the CTI correlates with AFL CL. The DPs interval expressed as a percentage of AFL CL allows better distinguishing between complete and incomplete isthmus block compared to standard method based on milliseconds. The DPs interval below 40% of AFL CL indicates sites close to a gap in the ablation line.

Predictors of successful defibrillation threshold test during CRT-D implantation.

BACKGROUND: The assessment of defibrillation energy requirement (DER) is a standard practice during cardioverter-defibrillator (ICD) implantation. It is recommended to assure that the energy at least 10 J below the maximal energy deliverable by the implanted device successfully converts the induced ventricular fibrillation (VF). The cardiac resynchronisation therapy with defibrillator (CRT-D) recipients are at increased risk of developing serious complications due to repeated VF induction. AIM: To define the prevalence of high DER among CRT-D recipients and to determine the factors which allow to obtain defibrillation safety margin. METHODS: We examined all patients who underwent CRT-D implantation between June 2006 and June 2009 in our institution. The verification of the DER required at least one termination of the induced VF with the energy at least 10 J below the maximal energy deliverable by the implanted device. RESULTS: The CRT-D was implanted in 65 patients. The first defibrillation test was successful in 57 (88%) patients. In the remaining 8 patients (12%), the defibrillation test was unsuccessful. These patients required system revision: reprogramming shocking polarity (2), reversing polarity and adjusting waveform (3), lead repositioning (1) and adding a subcutaneous lead (2). The use of high output devices (maximal energy > 30 J) and dual-coil leads was associated with a significantly (p < 0.05) lower rate of high DER, although high DER occurred in one patient implanted with the high output device. There was a correlation between the probability of successful defibrillation and renal function. It was less likely to obtain successful defibrillation safety margin in patients with creatinine > 175 micromol/L. During the follow up, ventricular tachyarrhythmia detected in the VF detection zone occurred in 13 (20%) patients, including two patients, who required system modification during implantation. In both cases, VF was terminated by the first defibrillation with the maximal energy of the implanted devices. CONCLUSIONS: High DER occurred in a significant number of CRT-D recipients. There is a correlation between high DER and impaired renal function. The use of high output devices significantly decreases the number of patients who required system modification in order to obtain an adequate defibrillation safety margin.

[Parahisian atrial tachycardia or atrioventricular nodal reentrant tachycardia with tendon of Todaro breakthrough?]. / Czestoskurcz przedsionkowy z okolicy peczka Hisa czy czestoskurcz wezlowy z prezepustem przez sciegno Todara?

We present a case of a 61 year-old woman with tachycardia originating close to the His bundle where radiofrequency (RF) ablation may bear potential risk of atrioventricular (AV) block. In this case report we discuss the possibility of a AV nodal reciprocating tachycardia with tendon of Todaro breakthrough. Patient was safely and effectively treated with RF catheter ablation.

[Ortodromic atrio-ventricular reentrant tachycardia with functional left bundle branch block morphology - differential diagnosis of wide complex tachycardia based on case report]. / Czestoskurcz przedsionkowo−komorowyortodromowy z czynnosciowym blokiemlewej odnogi peczka Hisa ­ róznicowaniemechanizmów czestoskurczu z szerokimizespolami QRS na podstawie opisu przypadku.

We present a case of 18 year-old man, without structural heart disease, who suffered from regular and irregular palpitations. ECG was normal during sinus rhythm, and showed LBBB morphology during tachycardia (220/min). Programmable pacing from CS induced sustained atrial fibrillation with normal and wide QRS (LBBB-like, RBBB-like) and minimal RR interval 270 ms. We found and ablate concealed left free wall accessory pathway. During 1-year observation patient stayed asymptomatic.

[Radiofrequency ablation of ventricular arrhythmia from the non-coronary cusp]. / Ablacja pradem o wysokiej czestotliwosci podloza komorowych zaburzen rytmu serca z niewiencowej zatoki valsalvy.

There is a close anatomical relationship between the non-coronary aortic cusp (NCC) and sites where His bundle (HB) is recorded in the right ventricle (RV). We describe a patient with frequent premature ventricular beats originating near HB. Arrhythmia was successfully ablated from the NCC although local electrogram preceded QRS in NCC and His area. When RV mapping reveals an earliest ventricular activation in the HB region, mapping in the right coronary cusp and NCC should be done to identify the area of arrhythmia origin.

Clinical validation and comparison of alternative methods for evaluation of entrainment mapping.

INTRODUCTION: Measuring the postpacing interval (PPI) and correcting for the tachycardia cycle length (TCL) is an important entrainment response (ER). However, it may be impossible to measure PPI due to electrical noise on the mapping catheter. To overcome this problem, 2 alternative methods for the assessment of ER have been proposed: N+1 difference (N+1 DIFF) and PPIR method. PPI-TCL difference (PPI-TCL) correlates very well with ER assessed by new methods, but the agreement with PPI-TCL was established only in relation to PPIR method. Moreover, it is not known which of these methods is superior in the assessment of ER. METHODS: We analyzed 155 episodes of ER in 21 patients with heterogeneous reentrant arrhythmias. ER was estimated by PPI-TCL and by both alternative methods. Agreement between methods was assessed by means of the Bland-Altman test, kappa coefficient (kappa), and correlation coefficient (r). Finally, a mathematical comparison of the alternative methods was performed. RESULTS: The agreement between PPI-TCL and alternative methods was very good. For N+1 DIFF the mean difference was -1.86 +/- 7.31 ms; kappa = 0.9; r = 0.98; for PPIR method the mean difference was -1.46 +/- 7.65 ms; kappa = 0.92; r = 0.99. Agreement between both alternative methods was also very high: the mean difference of 0.5 +/- 6.6 ms; kappa = 0.89; r = 0.99. The analysis of the equations used for calculation of ER by these methods revealed that essentially they were mathematically equivalent. CONCLUSION: Each of the alternative methods may be used for evaluation of ER when PPI-TCL cannot be assessed directly. Results obtained by both alternative methods are comparable.

Subacute cardiac perforations associated with active fixation leads.

AIMS: Having several recently published reports on increased rate of cardiac perforation with some lead models as background, we assess the relation between cardiac perforations and models of leads used. METHODS AND RESULTS: All pacing and defibrillation leads implantations between 1 January 2007 and 31 March 2008 were analysed retrospectively. There were 2247 leads implanted in 1419 patients aged 67.6 +/- 14.1, 1200 (53%) active and 1047 (47%) passive fixation leads. Cardiac perforation occurred in eight patients (0.5%). The number of perforations does not differ significantly between the pacemaker and implantable cardioverter defibrillator implantations (five and three cases, respectively, P = 0.13). All perforations were associated with the active fixation leads implantation (8 vs. 0, P < 0.01). Only four models of leads were associated with perforations, but the risk of their use was not statistically significantly increased, when compared with other active fixation leads placed in the adequate position. CONCLUSIONS: The incidence of cardiac perforation related to pacing and defibrillation leads is low. The use of active fixation leads is associated with an increased risk of cardiac perforation. We did not find any correlation between the perforation rate and any particular model of the implanted lead.

[Ventricular bigeminy as a cause of CRT inefficacy and inappropriate cardioverter-defibrillator intervention]. / Bigeminia komorowa jako przyczyna nieskutecznosci terapii resynchronizujacej i nieadekwatnych interwencji kardiowertera-defibrylatora.

Double counting of ventricular beats is not only one of the cause of an inappropriate detection of ventricular arrhythmias but a reason of lost of resynchronisation therapy. Sensing disturbances often creates the need for reprogramming of the device or additional pharmacotherapy and procedures. We present a case of 76-year-old man with CRT-D and inappropriate detection and intervention due to ventricular bigeminy. Fortunately, change of device program, potassium and magnesium supplementation was successful, without necessity of RF ablation of the ventricular ectopic beats.

[Incessant septal tachycardia eliminated by RF applications from right and left atrium]. / Aplikacje z obu stron przegrody usuwaja ustawiczny czestoskurcz przedsionkowy.

We present a case of a 29-year-old woman who suffered from incessant atrial tachycardia (AT) leading to tachycardia-induced cardiomyopathy. Based on classical mapping of the right and left atria the focus of AT was localised in the inter-atrial septum area. The RF applications from the right atrium stopped AT for some seconds. Applications from the left atrium terminated AT definitively. The patient has been free from symptoms of arrhythmia and heart failure for seven years.

[Sixty four-slice computed tomography unmasked unexpected source of atrial arrythmias--a case report]. / Wielorzedowa spiralna tomografia komputerowa ujawnia nieoczekiwane zródlo przedsionkowych zaburzen rytmu - opis przypadku.

We describe a 23-year-old man with drug refractory, left atrial arrhythmias (paroxysmal atrial tachycardia, runs, pairs and single extra beats) in the area of remnant of left upper pulmonary vein ostium (in fact, this vein). The superior drained into vena innominata/vena cava superior. The patient underwent three unsuccessful catheter ablations in another center. Computed tomography scan of left atrium and pulmonary veins revealed this rare congenital anomaly. This information was crucial to perform successful ablation in the area of remnant and distinguish left atrial appendage from the remnant area. During 6 month follow-up the patient remained free of arrhythmia.

Outcomes of a single centre registry of patients with ischaemic heart disease, qualified for an RF ablation of ventricular arrhythmia after ICD intervention.

BACKGROUND AND AIM: Reduction of ICD interventions improves the quality of life and possibly reduces mortality. Ablation reduces ICD interventions in patients with ablatable arrhythmia, but its effectiveness needs to be proven for patients with coronary artery disease (CAD) regardless of the type of arrhythmia. Our study was designed to address this issue, but it had to be terminated due to recruitment problems. The reasons for early termination are described in this paper. METHODS: Patients with CAD and implanted ICD, who within the past three months survived an episode of VT/VF, were selected for this study. Patients were to be randomised for ablation or pharmacotherapy. A group of 209 patients was screened between June and December of 2007. RESULTS: Out of 209 patients, 39 (18.7%) had appropriate ICD therapy during the last three months and were potentially eligible for the trial. Out of 39 patients, 34 could not be randomised, due to the presence of exclusion criteria (n-25) or consent refusal (n-9). Previous ablation (n-10), left ventricular thrombus (n-3) or presence of mitral or aortic artificial valve (n-3) were the most frequent exclusion criteria. During follow-up of 12 months one patient required ablation due to frequent ICD discharges. From the five randomised patients, two were randomised to ablation and three to the pharmacotherapy arm. CONCLUSIONS: 1. Ablation might not be suitable as a routine treatment for all patients with ICD interventions, as a significant group prefers not to undergo RF ablation as a routine treatment or there are contraindications for the ablation. 2. There are obstacles in prospective and randomised evaluation of the role of ablation in patients with CAD and ICD interventions, which are related both to patients' medical conditions and to patients' will. These limitations should be taken into account when designing further studies.

[Next cardioversion or RF ablation in professional driver with recurrent typical atrial flutter and MAS syndromes]. / Nastepna elektrowersja czy ablacja RF podloza typowego trzepotania przedsionków u zawodowego kierowcy z napadami MAS.

We describe a 42-year-old professional driver with hypertension, obesity and recurrent episodes of highly symptomatic typical atrial flutter. Despite chronic sotalol treatment, 1:1 AV conduction with RBBB-morphology was observed. After excluding of thrombus in the heart chambers, the 'urgent' and successful RF ablation was performed.

Technical and practical aspects of remote monitoring of implantable cardioverter-defibrillator patients in Poland - preliminary results.

BACKGROUND: The aim of remote monitoring of implantable cardioverter-defibrillators (ICD) is to increase the patient's safety by early detection of technical or medical malfunctions and decrease the number of follow-up visits. AIM: To evaluate the feasibility and reliability of internet-based home monitoring of ICD recipients in Poland. METHODS: Twenty-seven patients with ICD with remote monitoring options were evaluated; 20 (74%) patients had a single chamber ICD, 6 (22%) patients had a dual chamber ICD and one had an ICD with a resynchronisation therapy option. Medical and technical events reported by the remote monitoring system as well as interruptions in monitoring longer than 14 days were analysed. RESULTS: The patients were followed for 12.7 +/- 10.5 months. Two of them died because of heart failure (6 and 13 months after ICD implantation, respectively). The remote monitoring system reported medical events in 13 (48%) patients. In total, we received 32 event reports (from 1 to 19 per patient, mean 2.6) which were generated due to the detection of ventricular tachycardia (VT) (17 events in 9 patients), ventricular fibrillation (VF) (9 episodes in 6 patients), ineffective defibrillation with the maximal energy (5 reports in 3 patients) and supraventricular tachycardia in the VT detection window (1). Two patients had more than 3 VT/VF episodes during 24 h. There were no reports on technical abnormalities of the ICD system. Interruptions in home monitoring longer than 14 days occurred in 5 (18.5%) patients and lasted 2 to 14 weeks (mean 2.8 +/- 7.1). The longest break was caused by the patient's stay abroad. The remaining interruptions were caused by: journeys (5 episodes), hospitalisations (4), and a temporary stay in a place without sufficient GSM coverage (3). During the follow-up period there were no interruptions in monitoring caused by transmitter or ICD failure. All data received by the home monitoring system were confirmed during the follow-up visits. CONCLUSION: Remote monitoring of ICD recipients in Poland does not present technical difficulties and enables early detection of serious events in ICD patients.

Predictors of the atrial fibrillation occurrence in patients with Wolff-Parkinson-White syndrome.

BACKGROUND: Atrial fibrillation (AF) in WPW syndrome occurs earlier and is more common than in the general population. AIM: To evaluate the predisposing factors for the first episode of AF in patients with WPW. METHODS: We analysed data on 930 patients (510 males, 420 females) with WPW treated in our centre during 1988-2007. AF was diagnosed in 236 patients (25% - 161 males, 75 females, aged 36 +/- 15 years). The AF group was divided into two subgroups - patients with AF and atrio-ventricular reentrant tachycardia (AVRT), and patients with AF only. The analysis included subjects' age and gender, the presence of AVRT, the number and properties of accessory pathways, left ventricular ejection fraction (LVEF) and concomitant cardiovascular diseases. RESULTS: The groups did not differ in terms of concomitant diseases and LVEF. In the whole group of patients with AF, arrhythmia occurred earlier in men than in women (34 +/- 14 vs. 40 +/- 15 years of age, p = 0.013). In the subgroup with AF and AVRT, AF was documented earlier compared to patients with AF only (34 +/- 15 vs. 41 +/- 15 years of age, p = 0.0072). AVRT was more common in patients with AF compared to those without AF (69 vs. 53%, p < 0.001). In the whole group of 930 patients, AF was observed more often in patients with overt pre-excitation compared to concealed WPW (29 vs. 12%, p < 0.001). CONCLUSIONS: In patients with WPW syndrome, AF occurs earlier in patients with AVRT compared to patients with AF and without documented AVRT, earlier in men compared to women, and is more common in patients with overt WPW.

[Pseudo atypical atrial flutter or atrial tachycardia dependent on complex substrate in a patient with univentricular heart after palliative operations - mapping and ablation]. / Rzekomo atypowe trzepotanie przedsionków czy czestoskurcz przedsionkowy zalezny od zlozonego podloza u chorej z sercem jednokomorowym po operacjach paliatywnych - opis ablacji.

We describe a case of persistent atrial tachycardia/flutter in a 19-year old female with corrected transposition of great arteries (ccTGA) and dual inlet left ventricle (DILV), treated with surgical palliative operations. The arrhythmia became persistent and symptomatic with dyspnea and severe cyanosis. During the EP study, the right atrial isthmus-dependent reentry was identified. In electroanatomical maps large areas of low voltage and electrical silence were localised. Due to these areas of slow conduction the isthmus dependent arrhythmia had long CL. Linear RF applications closed the isthmus, resulting in flutter termination. During 3 months of follow-up the patient remained free of arrhythmia.