PubMed Health⌕ Search

Biomedical subjects

H Pürerfellner

Publications and source records attributed to H Pürerfellner.

11 recordsLinked to original sources
PubMed2006

Short- and long-term experience in pulmonary vein segmental ostial ablation for paroxysmal atrial fibrillation.

INTRODUCTION: Segmental ostial pulmonary vein isolation (PVI) is considered a potentially curative therapeutic approach in the treatment of paroxysmal atrial fibrillation (PAF). There is only limited data available on the long-term effect of this procedure. METHODS: Patients (Pts) underwent a regular clinical follow up visit at 3, 6 and 24 months after PVI. Clinical success was classified as complete (i.e. no arrhythmia recurrences, no antiarrhythmic drug), partial (i.e. no/only few recurrences, on drug) or as a failure (no benefit). The clinical responder rate (CRR) was determined by combining complete and partial success. RESULTS: 117 patients (96 male, 21 female), aged 51+/-11 years (range 25 to 73) underwent a total of 166 procedures (1.4/patient) in 2-4 pulmonary veins (PV). 115 patients (98%) had AF, 2 patients presented with regular PV atrial tachycardia. ,109/115 patients. exhibited PAF as the primary arrhythmia (versus persistent AF). A total of 113 patients with PVI in the years 2001 to 2003 were evaluated for their CRR after 6 (3) months. A single intervention was carried out in 63 patients (55.8%), two interventions were performed in 45 patients (39.8%) and three interventions in 5 patients (4.4%). The clinical response demonstrated a complete success of 52% (59 patients), a partial success of 26% (29 patients) and a failure rate of 22% (25 patients), leading to a CRR of 78% (88 patients). Ostial PVI in all 4 PVs exhibited a tendency towards higher curative success rates (54% versus 44% in patients with 3 PVs ablated for the 6 month follow up). Long-term clinical outcome was evaluated in 39 patients with an ablation attempt at 3 PVs only (excluding the right inferior PV in our early experience) and a mean clinical follow up of 21+/-6 months. At this point in time the success rate was 41% (complete, 16 patients) and 21% (partial, 8 patients), respectively, adding up to a CRR of 62% (24 patients). In total, 20 patients (17.1%) had either a single or 2 (3 patients, 2.6%) complications independent of the number of procedures performed with PV stenosis as the leading cause (7.7%). CONCLUSION: The CRR of patients with medical refractory PAF in our patient cohort is 78% at the 6 month follow up. PV stenosis is the main cause for procedure-related complications. Ablation of all 4 PV exhibits a tendency towards higher complete success rates despite equal CRR. Calculation of the clinical response after a mid- to long-term follow of 21+/-6 months in those patients with an ostial PVI in only 3 pulmonary veins (sparing the right inferior PV) shows a further reduction to 62%, exclusively caused by a drop in patients with a former partial success. To evaluate the long-term clinical benefit of segmental ostial PVI in comparison with other ablation techniques, more extended follow up periods are mandatory, including a larger study cohort and a detailed description of procedural parameters.

Journal Article↗
PubMed2004

Recent developments in cardiovascular drug therapy: treatment of atrial arrhythmias with new class III drugs and beyond.

Despite recent advances in non-pharmacologic approaches antiarrhythmic drugs still play a dominant role in the treatment of cardiac arrhythmias. Large randomized controlled clinical trials have pointed out the importance of a proper benefit to risk evaluation in various patient subsets. This led to a continuous decline in the use of sodium channel blockers due to their possible proarrhythmic effects particularly in patients with reduced left ventricular function and ischemic heart disease. On the contrary, beta-blockers and more complex class III compounds such as sotalol and amiodarone have been prescribed increasingly. However, side effects commonly observed boosted the development of agents with simpler ion channel-blockade and less adverse reactions. In this review newer so-called "pure" class III agents will be discussed. Their common mechanism of action is an antifibrillatory effect both on the atrial and ventricular level. Clinically, they are used in the chemical cardioversion and the prevention of atrial fibrillation or atrial flutter as well as for the maintenance of sinus rhythm after its successful restoration. This report contains a detailed analysis of the pharmacokinetics, results of clinical studies and implications regarding the use in daily practice for three distinct compounds: ibutilide, dofetilide and azimilide. As efficacy is still limited their current and future role in hybrid therapies combining drug therapy with alternative treatment modalities (catheter ablation, pacemakers and implantable cardioverter defibrillators) is discussed. In addition, an outlook for a future drug design implementing changes in electrically remodeled atrial tissue will be given.

Anti-Arrhythmia Agents↗
PubMed2000

Transvenous left ventricular lead implantation with the EASYTRAK lead system: the European experience.

Several independent studies suggest that resynchronization therapy--achieved by left- or biventricular pacing--improves hemodynamics in heart failure patients with interventricular conduction disturbances. Delivery of this new therapy in an effective and minimally invasive manner presents technical challenges, as transvenous access to the left ventricle is required. Since 1999, a novel over-the-wire approach combining standard pacing lead and angioplasty technology has been evaluated in several European countries. This new left ventricular lead, the EASYTRAK system (Guidant, St. Paul, MN), has been clinically evaluated in 2 phases. The first phase was a clinical investigation to obtain the CE-mark (i.e. European Commission approval). The second phase, which started immediately after the CE-mark was obtained, consisted of a postmarket surveillance called the European registry. This article reports on the results of the pre-CE-mark clinical investigation and the preliminary results of the European registry (first 150 patients). During the pre-CE-mark clinical investigation of the EASYTRAK system, lead performance was assessed in 36 successfully implanted patients. The patients had indications for VVI-pacing, symptoms of heart failure and significant left ventricular dysfunction. The left ventricular lead was implanted in conjunction with a conventional right ventricular lead and a new heart failure device (CONTAK TR, Guidant, Brussels, Belgium). Lead measurements (threshold, sensing, and impedance) were performed at implant and subsequent follow-ups. The stimulation thresholds at 0.5 msec impulse width were acceptable, although (as expected) slightly higher than with standard right ventricular pacing leads: 1.39 +/- 1.15 V at implant, 1.72 +/- 1.26 V at predischarge, 1.54 +/- 0.88 V at 2 weeks, 1.38 +/- 0.80 V at 6 weeks, and 1.24 +/- 0.73 V at 12 weeks. R-wave and impedance measurements were stable over time. A revision of the EASYTRAK lead was required in 3 patients. No perforations were observed. During the second phase of the European registry, 150 implants were attempted in 63 centers from November 1999 to January 2000. The EASYTRAK was implanted with a pulse generator offering, in addition to resynchronization therapy, either tachycardia monitoring (CONTAK TR) or implantable cardioverter defibrillator therapy (CONTAK CD), depending on the patient indication. Over half of the centers involved had not previously implanted the EASYTRAK system. Total implant success rate was 83% (135/150), skin-to-skin duration of the implant was 169 +/- 81 minutes (range, 53-480 minutes), with a clear learning curve. Once the coronary sinus was found, the implant success rate was 92%. One lead dislodgment and 2 cases of phrenic nerve stimulation were reported. We conclude that the new EASYTRAK lead design for transvenous left ventricular lead implantation seems to be a suitable and safe tool for delivering resynchronization therapy to heart failure patients.

Aged↗
PubMed2000

[Pacemaker in therapy of heart failure--biventricular stimulation].

The management of congestive heart failure remains a therapeutic challenge despite recent advances in drug therapy, including ACE inhibitors, beta blockade and spironolacton treatment. Patients affected with the disease still have a restricted quality of life and a poor prognosis in the long run. Epidemiologically, the incidence and prevalence are increasing due to improved survival from both coronary artery disease and arterial hypertension. A subgroup of patients presents with marked prolongation of the QRS-complex in the surface ECG, mostly with a left bundle branch block pattern. This acts as a marker for interventricular conduction abnormality and specifically indicates a reduced left ventricular systolic function. Biventricular pacing tries to resynchronize the abnormal activation pattern by actively influencing diastolic filling and systolic function. The mechanisms involved are supposed to be restoration of left ventricular septal mechanical synchrony, reduction in presystolic mitral regurgitation and optimization of diastolic function with the maximization of diastolic filling time. In this article the current role and future directions of biventricular pacing are discussed.

Animals↗
PubMed1998

[Subpectoral venous approach in implantable cardioverter defibrillator systems (ICD)].

Lead complications may have fatal consequences for ICD patients. Lead fractures have been reported to occur a long time after subclavian puncture during ICD-implantation. Damage can also be caused by the patient manipulating subcutaneous lead segments. In this report we describe a simple implantation technique which avoids the risks related to subcutaneous lead position and transmuscular subclavian vein puncture. In 16 patients, after preparation of the site of the device, we chose the subpectoral venous approach for the implantation of the leads from the ICD. Available approaches are the pectoral vein, the subpectoral section of the cephalic vein or a puncture of the subclavian vein which is fully visible from that size. Once the pectoral muscle has been sutured, the entire system is protected behind it. Apart from an early postoperative lead dislocation, no complications were observed in association with the operating technique within a mean follow-up period of 10.7 +/- 6.7 (SD) months. The advantages of this technique are as follows: There is no transmuscular subclavian puncture or exposure of the deltoideopectoral groove. The entire ICD system is situated under the pectoralis major muscle. Subcutaneous lead positions with the potential complications mentioned above can thus be avoided. The fact that a more complex technique and therefore a slightly lengthier operating time is required and that this technique is not particularly suitable for local anaesthesia may be regarded as disadvantages. Due to the small number of cases and the short follow-up period, a final conclusion on the application of this technique is not possible to date.

Adult↗
PubMed1998

Absence of significant changes in heart rate variability after slow pathway ablation of AV nodal reentrant tachycardia by using serial Holter recordings.

BACKGROUND: Persistent inappropriate sinus tachycardia may evolve as a complication after radiofrequency (RF) fast pathway ablation of atrioventricular nodal reentrant tachycardia (AVNRT). Parasympathetic denervation may serve as one of the possible mechanisms. We performed a study to show the prevalence of this phenomenon in RF ablation of the slow pathway. METHODS AND RESULTS: Thirty-three patients (25 women, 8 men) aged 53 +/- 16 years were investigated. A median of 3 pulses was used to selectively modify or ablate the slow pathway and render AVNRT noninducible. Heart rate (HR) and different indexes in the time and frequency domain of heart rate variability were evaluated in serial 24-hour Holter recordings. Data were obtained 1 day, 1 month, and 3 months after the procedure and compared with preablation values. Despite a trend of increasing HR and decreasing heart rate variability within the first month after RF ablation, no significant changes were detected. CONCLUSIONS: RF ablation of the slow pathway in AVNRT does not change parameters of HR and heart rate variability significantly by means of serial 24-hour Holter recordings.

Adult↗
PubMed1995

[High frequency catheter ablation in AV-nodal reentry tachycardia: clinical significance of slow pathway potentials and junctional tachycardia].

During slow pathway-ablation of AV nodal reentrant tachycardia (AVNRT) with a mean cycle length of 355 +/- 70 ms the clinical significance of slow pathway electrograms (SP-EGM) and junctional tachycardias (JT) was evaluated in 39 patients (9 male, 30 female; mean age 57 +/- 15 years). After two patients were excluded from further investigation because of inadvertent procedural complete heart block, typical SP-EGM were recorded in 30/37 patients (81%) before successful RF administration in the posteroseptal portion of the right atrium. Signals were recorded 61 +/- 22 and 34 +/- 24 ms after atrial activation in the His bundle and proximal coronary sinus catheter, respectively. Additionally, timing was noted 15 +/- 10 ms before the His spike; the duration of SP-EGM was 27 +/- 7 ms, and the A/V relation of the SP-EGM was calculated as 0.59 +/- 0.51 in the ablation bipole. JT was observed in 24/37 patients (78%), with a mean cycle length of 511 +/- 92 ms. The first tachycardia beat appeared initially 4.1 +/- 3.8 s after delivery of the successful RF administration and lasted 18 +/- 8 s. In 14/37 patients (38%) either SP-EGM or JT was missing; in one patient neither of these two was recorded despite successful ablative therapy. The success rate, defined by noninducibility of AVNRT, was 95% (35/37). In 11% (4/37) AVNRT recurred during a mean follow-up of 5 +/- 4 months. In summary, SP-EGM and JT were recorded reproducibly and proved to be a useful tool as electrographic mapping approach of slow pathway ablation in AVNRT.

Adult↗
PubMed1994

Successful radiofrequency ablation of adenosine-sensitive right ventricular outflow tract tachycardia.

We report on a patient without evidence of structural heart disease who presented with adenosine-sensitive sustained ventricular tachycardia with left bundle branch block and right axis QRS morphology. Endocardial catheter mapping revealed the origin of ventricular tachycardia to be located in the right ventricular outflow tract, where the earliest endocardial activation during ventricular tachycardia was registered 30-40 ms prior to onset of QRS complex in the surface ECG. Pace-mapping provided no additional information; we found a good match between 12 lead surface ECGs registered during spontaneous episodes of ventricular tachycardia and those recorded during pacing in a relatively large area in the right ventricular outflow tract. The 10th application of radiofrequency current abolished ventricular tachycardia temporarily, but it recurred within 30 min. After the 28th radiofrequency current delivery ventricular tachycardia was permanently abolished.

Adenosine↗
PubMed1991

Plasma propafenone concentration in the evaluation of anti-arrhythmic efficacy.

The anti-arrhythmic drug efficacy of oral propafenone therapy (300 mg to 900 mg per day) was studied in relation to propafenone and hydroxy-propafenone plasma concentrations in 70 outpatients (46 males, 24 females, mean age 57 +/- 12 years) followed up for 24 +/- 32 months. On average 1.7 plasma concentration measurements were performed per patient. The arrhythmias were effectively controlled in 32 patients, but in another 32 patients propafenone therapy was ineffective; in six patients the evaluation was unclear. The therapy was effective in 66% of patients with ventricular premature beats, in 50% with complex ventricular arrhythmias, in 40% with ventricular tachycardia and in 20% with supraventricular tachycardia. Fifty per cent of patients with coronary heart disease and electrical disease, but only 20% with dilated cardiomyopathy and Wolff-Parkinson-White syndrome were effectively treated. Measurement of peak plasma propafenone levels performed 4.5 +/- 2 h after oral drug administration revealed no statistically significant dose-plasma concentration relation. Optimal propafenone drug efficacy was documented at propafenone plasma concentrations ranging from 0.20 to 0.60 micrograms/ml (63% of patients considered as effectively treated). There was a trend to decrease propafenone efficacy at plasma concentrations below 0.20 micrograms/ml and above 0.60 micrograms/ml. Analysis of hydroxypropafenone identified four patients as poor metabolizers with unusually high propafenone and low hydroxypropafenone plasma concentrations; only one of these four patients showed drug efficacy. Monitoring of propafenone and hydroxypropafenone plasma concentrations was a practical procedure to assess patient's compliance, to identify poor metabolizers and to guide anti-arrhythmic drug therapy.

Adult↗