Characteristic features of patients with multiple accessory pathways.

Objective Only limited clinical and electrophysiological data concerning patients (pts) with multiple accessory pathways (MAP) in comparison to large control groups are available. The aim of our study was to analyse these data from the largest cohort of patients with multiple accessory pathways and a large control group. Method and results We analysed data from pts with MAP (group 1) and pts with a single accessory pathway (AP) (group 2) referred for radiofrequency catheter ablation (RFCA) at our tertiary centre. Group 1 consisted of 124 pts (M 62.10%, mean age 33.00 ± 5.26) with MAP and RFCA. Group 2 consisted of 376 pts (M 51.20%, mean age 35.87 ± 16.15) with a single accessory pathway and RF ablation. Group 1 exhibited a higher incidence of overt APs (P < 0.0001), Ebstein anomaly (P = 0.001), ventricular fibrillation (P = 0.012), antidromic atrioventricular re-entrant tachycardia (A AVRT) (P = 0.025) and male gender (P = 0.038). The mean age at the first documented atrioventricular re-entrant tachycardia (AVRT) episode was lower in pts with MAP than in pts with single APs: 16.79 ± 13.41 vs 20.84 ± 14.29, respectively (P = 0.001). Concealed accessory pathways (P < 0.0001) occurred more frequently in the control group. Group 1 had more right-lateral (P = 0.0001), mid-septal (P = 0.0001), left-posterior (P = 0.01), left-anterior (P = 0.013) and left-lateral localizations of AP (P < 0.037). Conclusions The MAP group included statistically significantly more men, Ebstein anomaly and overt APs. The mean age of the first episode of atrioventricular re-entrant tachycardia was lower in pts with MAP. Certain distribution patterns are apparent for single and MAP. Pts with MAP are at higher risk of VF and antidromic atrioventricular re-entrant tachycardia.

Radiofrequency catheter ablation of accessory pathways in patients with Ebstein's anomaly: At 8 years of follow-up.

BACKGROUND: Data regarding long-term follow-up of radiofrequency catheter ablation (RFCA) of accessory pathways (APs) in patients with Ebstein's anomaly (EA) are limited. The procedures are challenging due to multiple or wide APs. METHODS: Analysis was performed on clinical and periprocedural data of patients with EA referred to the centre in order to perform catheter ablation of AP. The group consisted of 22 patients (female 40.9%, mean age 33.6 ± 19.1 years). The follow-up utilized electrocardiogram and Holter monitoring. RESULTS: Twenty-two patients had 33 accessory pathways (8 patients had multiple APs, 11 patients broad AP). Twenty-nine different arrhythmias were ablated: 20 orthodromic atrioventricular reciprocating tachycardia (O-AVRT), 5 antidromic atrioventricular reciprocating tachycardia (A-AVRT), 3 slow/ fast atrioventricular nodal reentry tachycardia (s/f AVNRT) and 1 cavotricuspid-isthmus-dependent atrial flutter (CTI-AFL). In 3 (13.6%) patients multiple ablation targets for RFCA ablation were observed. The acute procedural success rate after the first RFCA performed was: 100% for AVNRT, 77.3% for APs and 50.0% for CTI-AFL ablation. Follow-up (mean 95.7 ± 49.8 months) was completed in 86.4% of patients. One patient had paroxysmal atrial fibrillation not targeted during ablation. One patient died due to heart failure 12 years after RFCA. Three patients who underwent RFCA of accessory pathways in the mid-1990s were lost in follow-up. CONCLUSIONS: Radiofrequency ablation in patients with EA is challenging but safe and have a high short-term as well as long-term success rate.

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.

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.

[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.

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.

[Wide QRS complex tachycardia in a patient after inferior myocardial infarction and CABG -- the role of electrophysiological study and RF ablation]. / Czestoskurcz z szerokimi zespolami QRS u pacjenta po zawale serca i pomostowaniu aortalno-wiencowym - rola badania elektrofizjologicznego i ablacji RF.

We present a case of 53-year-old patient who experienced paroxysms of wide QRS complex tachycardia at a rate of 150 bpm and LBBB morphology 6 years after inferior myocardial infarction and CABG. Anamnesis and morphology of tachycardia could suggest ventricular tachycardia. However during electrophysiological study we observed AVRT with LBBB and "regularly irregular" AVRT with normal QRS complex and changing entrance to the AV node (through slow and fast pathway). In this paper we present our approach and try to explain why the tachycardia using concealed bypass tract appeared so late in life.

[Spectrum of atrial arrhythmias from the right upper pulmonary vein--successful isolation of the arrhythmogenic focus by RF ablation of atriovenous breakthroughs--a case report]. / Zespól uporczywych arytmii z zyly plucnej górnej prawej w postaci licznych pobudzen przedwczesnych, rytmów imitujacych rytm zatokowy, patologicznej bradykardii oraz napadów czestoskurczu--rola ablacji wybiórczej.

We present a case of a 19-year-old patient with incessant arrhythmias originating from the right upper pulmonary vein (RUPV) presenting as frequent premature beats, automatic rhythms mimicking sinus rhythm (SR) and pulmonary vein tachycardias. Morphology of P' wave resembled sinus P wave due to relatively short distance of the ectopic focus from the sinus node. Occasionally, when discharges from the focus were relatively slow (800-500 ms) and regular it was mimicking sinus rhythm. Activation preceding P' wave during arrhythmia was recorded in RUPV as well as in superior vena cava. In this paper we discuss our approach that allowed localising the arrhythmogenic focus in the RUPV. After isolation of the RUPV sinus rhythm was restored with tachycardia at a cycle length of 320 ms continuing in the isolated vein.

[Application of spectral frequency analysis in atrial fibrillation mechanism assessment]. / Zastosowanie spektralnej analizy czestotliwosciowej do oceny podloza napadowego migotania przedsionków.

Recent studies have demonstrated spatio-temporal organisation in atrial fibrillation (AF), with a highest dominant frequencies (DF) at pulmonary veins ostia (PVo). We present a case of 58-year-old woman with AF evaluated by spectral frequency analysis. Simultaneous recordings at each veno-atrial junction and coronary sinus were obtained. Sequential fast Fourier transforms (FFT) of digitalized signals were performed. FFT profiles were analysed to determine DF. Low DF recorded at right inferior PVo suggested no contribution to AF process. Ablation of high DF PVo and low DF SVC with nonuniform anisotropic conduction resulted in AF termination and good clinical outcome in 1-year follow-up.

[Eleven-years long follow-up in a patient after myocardial infarction, with low ejection fraction and recurrent ventricular tachycardia. The role of implantable cardioverter defibrillator and selective ablation]. / Jedenastoletnia obserwacja pacjenta z przebytym rozleglym zawalem serca, niska frakcja wyrzucania oraz nawracajacymi czestoskurczami komorowymi. Rola kardiowertera-defibrylatora i wybiórczej ablacji.

The selective ablation of the recurrent ventricular tachycardia (VT) in a 75-year old patient after extensive inferior myocardial infarction (24 years ago), with low ejection fraction was performed. In 1995 the cardioverter-defibrillator was implanted due to recurrent, symptomatic VT. The coronary angiography in 1995 and in 2006 revealed the occlusion of the right coronary and the circumflex arteries. One year after implantation, he had electrical storm caused by proarrhythmic effect of amiodarone with prolongation of QT/QTc interval. During follow up episodes of VT (approximately 5/year) were successfully terminated by ATP and rarely by cardioversion. Recently, the patient was admitted to the hospital because of the very frequent (25/day) episodes of slow (500-560 ms), sustained ventricular tachycardia. The pharmacological treatment was unsuccessful. CARTO mapping and entrainment pacing revealed VT circuit around mitral annulus. A few applications at the paraseptal part of the mitral isthmus terminated VT, which was no longer inducible. During following days there were no VTs requiring ICD interventions.