Franciszek Walczak

Ablation of severe drug-resistant tachyarrhythmia during pregnancy

Ablation of 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.

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.

Dilated cardiomyopathy in children: Clinical course and prognosis

SummaryThe clinical profile of 19 patients with dilated cardiomyopathy ages 2–18 years (mean 13.4±4 years) was reviewed to detect any factors that might be predictive for their survival. Follow-up ranged from 5 to 105 months (mean 39±33 months). Routine treatment consisted of digitalis and diuretics: 14 patients received antiarrhythmics, 6 received vasodilators, and 12 were managed with immunosuppression. There were 12 survivors and 7 nonsurvivors: The 1-year mortality was 21.2% and the 2-year mortality 35.8%. All deaths were within first 2 years. Of the 12 patients who survived 2 years, a significant improvement was noticed in 9. In 3 patients tachycardia-induced cardiomyopathy was diagnosed, and abolition of supraventricular tachycardia was followed by improvement and regression of cardiomegaly. Endomyocardial boopsy was performed in 16 patients. Four with a histologic diagnosis of active myocarditis survived, and in 3 of them a considerable improvement was noticed. Of the 12 patients with nonspecific histologic findings, 6 died (p<0.05). There were no significant differences between survivors and nonsurvivors for any of the following parameters: incidence of severe heart failure (NYHA class III–IV) and severe ventricular arrhythmias (Lown class III–V), relative heart volume, echocardiographic left ventricular diastolic diameter and shortening fraction, and the hemodynamic parameters of cardiac index, left ventricular ejection fraction, left ventricular end-diastolic pressure, and left ventricular end-diastolic volume index.

Long-term cognitive outcome in teenage survivors of arrhythmic cardiac arrest

BACKGROUND Sudden cardiac arrest (SCA) can be the first sign of ventricular arrhythmia in teenagers. Neurocognitive problems are common after successful resuscitation. We studied cognitive function in teenage survivors of SCA, including emotional status and coping ability. METHOD Ten SCA survivors, aged 11-19 years, had neuropsychological tests within a few weeks of resuscitation. Awareness status, orientation, episodic and semantic memory, basic auditory-visual functions, praxis and speech, short-term memory, ability to learn new verbal and visual material were assessed. These tests were repeated at about 6 months. RESULTS Eight patients had an initial assessment; one boy remained in a coma and one was making simple emotional contact, revealing intensified mixed aphasia and dyskinesia. Six patients had severe disturbances of memory, motor functions and praxis. After 6 months, four patients had no neurocognitive disturbance. Four patients had memory impairment making school education difficult. Two patients were totally dependent on caregivers. Because of the absence of symptoms before SCA, and amnesia relating to the SCA episodes, patients had problems accepting their heart problems and limitations resulting from it. CONCLUSION Teenagers surviving SCA have significant neurcognitive and psychological problems. They need psychological care and guidance in understanding their condition.

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.

Histological Examination of the Topography of the Atrioventricular Nodal Artery within the Triangle of Koch

The treatment of choice in patients with drug‐resistant atrioventricular nodal reentry tachycardia is radiofrequency fast or slow pathway ablation. Ablation of the reentrant circuit in the region of the His bundle, when approached from the anterior‐superior region (fast pathway), can result in complete AV block. This is less likely if the posterior‐inferior (in the region of coronary sinus ostium) approach is used (slow pathway ablation). The possibility that radiofrequency energy may damage the vascular sjdpply to the AV node must be considered. In order to confirm this hypothesis observation was conducted on the autopsy material of 50 human hearts (20F, 30M) from 18 to 81 years of age. Specimens were taken containing the triangle of Koch (the apex‐ right fibrous trigone, the base‐ coronary sinus ostium). These histological blocks were sectioned in the frontal plane and stained using Massons method. Kochs triangle was divided in the sagittal plane into 3 parts: inferior (between the base and the attachment of the tricuspid valve), central (between the base and the apex of the right fibrous trigone) and superior (between this trigone and the tendon of Todaro). It was observed that the AVN artery at the coronary sinus ostium level (the base of the triangle of Koch) was positioned in 68% in the central and in 32% in the inferior part of Kochs triangle. The AVN artery in the central part was removed from the endocardium 1mm (18%), 2mm (42%), 3mm (22%), 4mm (18%). In the inferior part imm (26%), 2mm (37%), 3mm (37%). No statistically significant relationship was observed between those groups. Conclusions: 1) in 20% of examined hearts the AVN artery lay just beneath the endocardium near the coronary sinus ostium 2) there is a risk of the AVN artery coagulation during radiofrequency ablation m the slow pathway region.

Ventricular fibrillation risk factors in over one thousand patients with accessory pathways

BACKGROUND Published data concerning risk factors of VF in WPW patients are inconsistent or contradictory. METHODS AND RESULTS We included 1007 patient (pts) (mean age 35 years; 45% female) with an accessory pathway (AP) referred for non pharmacological treatment. Group 1 consisted of 56 pts (42M, aged 34 ± 15 yrs) with an AP and documented VF and Group 2-951 pts (513M, aged 35 ± 15 yrs) with an AP and without VF. Univariate predictors of VF were: overt pre-excitation, male gender, multiple AP, large AP. Multivariate predictors were: overt pre-excitation, male gender and MAP. The mean shortest pre-excited RR interval during AF was significantly shorter in Group 1: 205 ± 27 vs. 243 ± 64, P=0.019. VF as an end point of the first arrhythmia episode (AVRT or AF) was observed in 20 pts (15M, 5F). Primary VF (no documented arrhythmia prior to aborted SCD) occurred in 16 pts (13M, 3F). The mean age of primary VF pts was significantly lower than of pts with history of AVRT or AVRT and/or AF (24.5 vs. 36.5 vs. 38 yrs., P<0.005 and P=0.002, respectively). Age at VF occurrence shows a bi-modal distribution with peak occurrences in the 2-nd/3-rd and 5-th decades. CONCLUSION In patients with an accessory pathway, overt pre-excitation, male gender and multiple AP constitute independent risk factors of VF episodes. Young patients in the 2-nd/3-rd and older patients in the 5-th decade might be at higher risk of VF occurrence.

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

AF in WPW Syndrome. 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.

Idiopathic ventricular arrhythmia in children and adolescents: early effectiveness of radiofrequency current ablation

BACKGROUND AND AIM The aim of the study was to evaluate early effectiveness of radiofrequency (RF) current ablation for idiopathic ventricular arrhythmia (iVA) in children and to identify factors affecting treatment results. METHODS Among over 600 children, 30 ablation procedures were performed for iVA. Patient age ranged from 2.0 to 17.9 years (mean 14.7 ± 3.1). We analysed arrhythmia recurrences at 24 h and the effect of patient age, arrhythmia location, type of anaesthesia, and the presence of spontaneous arrhythmia during the procedure on the treatment results. RESULTS Sixteen (53%) children had right ventricular (RV) arrhythmia, including RV outflow tract arrhythmia in 9 of them (56%). In 14 (47%) children, arrhythmia was located in the left ventricle (LV), including LV outflow tract in 2 children, and the posterior fascicle in 4 children. The procedure was effective in 13 (81%) children in the RV arrhythmia group and in 11 (78%) children in the LV arrhythmia group, including all children with fascicular tachycardia. The only variable that affected the treatment results was the presence of spontaneous arrhythmia during the procedure (p = 0.012). No procedural complications were noted. CONCLUSIONS RF current ablation of iVA is a safe procedure with high early effectiveness. The only variable that affected the treatment results was the presence of spontaneous arrhythmia during the procedure.

Safety of nerve conduction studies in patients with implantable cardioverter–defibrillators

OBJECTIVE A patient with an implantable cardioverter-defibrillator (ICD) may suffer from neuromuscular disorders and may need to undergo a nerve conduction study (NCS). However, a NCS may be a source of electromagnetic interference (EMI). The aim of the present study was to investigate whether the interference from NCS used in a standardised test protocol affects ICD function. METHODS Twenty patients (19 males; mean age of 59.8±9.9 years) with implantable ICDs (eight with integrated and 12 with true bipolar leads), treated with amiodarone and with symptoms suggesting neuropathy were included. NCS were conducted using repetitive stimulation with frequency of 2 Hz and single, rectangular pulses of intensity up to 100 mA. Stimulation was performed in standard sites including proximal sites in the arm. RESULTS The impulses generated NCS were not detected by the ICD, irrespective of the site, rate or stimulus intensity. CONCLUSIONS Standardised test protocol for an NCS is safe in patients with an ICD regardless of the leads type. SIGNIFICANCE Current guidelines which limitate the NCS in patients with ICD may be the subject of revision.