(1/3420) Frequency and long term follow up of valvar insufficiency caused by retrograde aortic radiofrequency catheter ablation procedures.

OBJECTIVE: To assess the frequency of valvar complications caused by left sided radiofrequency catheter ablation using the retrograde aortic technique. METHODS: 179 patients (118 male) with a mean (SD) age of 43 (17) years underwent 216 procedures at one centre. The target of the ablation was an accessory atrioventricular pathway in 144 patients, the atrioventricular junction in 29 patients, and a ventricular tachycardia in six patients. In 25 patients structural heart disease was identified before the procedure (ischaemic heart disease 10, cardiomyopathy nine, valvar three, other three). Echo/Doppler examinations were performed the day before the procedure and within 24 hours postablation; the investigations were all reviewed by the same investigator. Patients with identified valvar injury caused by the procedure were followed for 42 (7) months. RESULTS: Valvar injury caused by the ablation procedure was identified in four young (age 30 (8) years), otherwise healthy patients with left lateral atrioventricular accessory pathways. Mild mitral insufficiency with a central regurgitation jet was detected in two patients and remained unchanged at follow up. Mild aortic insufficiency was detected in another two patients. In one of these the regurgitation jet was central and remained unchanged at follow up. In one patient the regurgitation jet was located between the non-coronary and left cusps in relation to a loosely attached structure. Both the structure and the valvar regurgitation disappeared during follow up. No clinical complications occurred in any of the patients during follow up. CONCLUSION: In this study, the frequency of valvar complications after left sided radiofrequency catheter ablation using the retrograde aortic technique was 1.9%.  (+info)

(2/3420) AV reentrant and idiopathic ventricular double tachycardias: complicated interactions between two tachycardias.

An electrophysiological study was performed in a 61 year old man with Wolff- Parkinson-White (WPW) syndrome. At baseline, neither ventricular nor supraventricular tachycardias could be induced. During isoprenaline infusion, ventricular tachycardia originating from the right ventricular outflow tract (RVOT) with a cycle length of 280 ms was induced and subsequently atrioventricular reentrant tachycardia (AVRT) with a cycle length of 300 ms using an accessory pathway in the left free wall appeared. During these tachycardias, AVRT was entrained by ventricular tachycardia. The earliest ventricular activation site during the ventricular tachycardia was determined to be the RVOT site and a radiofrequency current at 30 W successfully ablated the ventricular tachycardia at this site. The left free wall accessory pathway was also successfully ablated during right ventricular pacing. The coexistence of WPW syndrome and cathecolamine sensitive ventricular tachycardia originating from the RVOT has rarely been reported. Furthermore, the tachycardias were triggered by previous tachycardias.  (+info)

(3/3420) Tachycardia induced tachycardia: case report of right ventricular outflow tract tachycardia and AV nodal reentrant tachycardia.

Tachycardia induced tachycardia, or so called double tachycardia, is rare. A 34 year old woman is described who had a history of syncope, frequent extrasystoles, and episodes of non-sustained ventricular tachycardia, perceived as palpitation, without syncope. At electrophysiological study, during infusion of isoprenaline, an episode of non-sustained ventricular tachycardia arising from the right ventricular outflow tract initiated sustained atrioventricular nodal reentrant tachycardia, thought to be the cause of the patient's syncope. Ablation of the right ventricular outflow tract focus abolished the ventricular ectopy; the slow AV nodal pathway was also ablated. The patient no longer has either syncope or palpitation.  (+info)

(4/3420) Clinical application of an integrated 3-phase mapping technique for localization of the site of origin of idiopathic ventricular tachycardia.

BACKGROUND: Radiofrequency (RF) catheter ablation provides curative treatment for idiopathic ventricular tachycardia (VT). METHODS AND RESULTS: Nineteen consecutive patients with an idiopathic VT underwent RF catheter ablation. An integrated 3-phase mapping approach was used, consisting of the successive application of online 62-lead body surface QRS integral mapping, directed regional paced body surface QRS integral mapping, and local activation sequence mapping. Mapping phase 1 was localization of the segment of VT origin by comparing the VT QRS integral map with a database of mean paced QRS integral maps. Mapping phase 2 was body surface pace mapping during sinus rhythm in the segment localized in phase 1 until the site at which the paced QRS integral map matched the VT QRS integral map was identified (ie, VT exit site). Mapping phase 3 was local activation sequence mapping at the circumscribed area identified in phase 2 to identify the site with the earliest local endocardial activation (ie, site of VT origin). This site became the ablation target. Ten VTs were ablated in the right ventricular outflow tract, 2 at the basal LV septum, and 7 at the midapical posterior left ventricle. A high long-term ablation success (mean follow-up duration, 14+/-9 months) was achieved in 17 of the 19 patients (89%) with a low number of RF pulses (mean, 3.3+/-2.2 pulses per patient). CONCLUSIONS: This prospective study shows that integrated 3-phase mapping for localization of the site of origin of idiopathic VT offers efficient and accurate localization of the target site for RF catheter ablation.  (+info)

(5/3420) LocaLisa: new technique for real-time 3-dimensional localization of regular intracardiac electrodes.

BACKGROUND: Estimation of the 3-dimensional (3D) position of ablation electrodes from fluoroscopic images is inadequate if a systematic lesion pattern is required in the treatment of complex arrhythmogenic substrates. METHODS AND RESULTS: We developed a new technique for online 3D localization of intracardiac electrodes. Regular catheter electrodes are used as sensors for a high-frequency transthoracic electrical field, which is applied via standard skin electrodes. We investigated localization accuracy within the right atrium, right ventricle, and left ventricle by comparing measured and true interelectrode distances of a decapolar catheter. Long-term stability was analyzed by localization of the most proximal His bundle before and after slow pathway ablation. Electrogram recordings were unaffected by the applied electrical field. Localization data from 3 catheter positions, widely distributed within the right atrium, right ventricle, or left ventricle, were analyzed in 10 patients per group. The relationship between measured and true electrode positions was highly linear, with an average correlation coefficient of 0.996, 0.997, and 0.999 for the right atrium, right ventricle, and left ventricle, respectively. Localization accuracy was better than 2 mm, with an additional scaling error of 8% to 14%. After 2 hours, localization of the proximal His bundle was reproducible within 1.4+/-1.1 mm. CONCLUSIONS: This new technique enables accurate and reproducible real-time localization of electrode positions in cardiac mapping and ablation procedures. Its application does not distort the quality of electrograms and can be applied to any electrode catheter.  (+info)

(6/3420) Atrioventricular nodal ablation and implantation of mode switching dual chamber pacemakers: effective treatment for drug refractory paroxysmal atrial fibrillation.

OBJECTIVE: To assess the effect of atrioventricular node ablation and implantation of a dual chamber, mode switching pacemaker on quality of life, exercise capacity, and left ventricular systolic function in patients with drug refractory paroxysmal atrial fibrillation. PATIENTS: 18 consecutive patients with drug refractory paroxysmal atrial fibrillation. METHODS: Quality of life was assessed before and after the procedure using the psychological general wellbeing index (PGWB), the McMaster health index (MHI), and a visual analogue scale for cardiac symptoms. Nine of the patients also underwent symptom limited exercise tests and echocardiography to assess left ventricular systolic function. RESULTS: The procedure allowed a reduction in antiarrhythmic drug treatment (p < 0.01). PGWB and symptom scores improved (p < 0.01) but the MHI score did not change. Left ventricular systolic function and exercise capacity were unchanged. CONCLUSIONS: Atrioventricular node ablation and implantation of a DDDR/MS pacemaker is effective treatment for refractory paroxysmal atrial fibrillation, producing improved quality of life while allowing a reduction in drug burden. The popularity of the treatment is justified, but further studies are needed to determine optimum timing of intervention.  (+info)

(7/3420) Predictors of atrial rhythm after atrioventricular node ablation for the treatment of paroxysmal atrial arrhythmias.

OBJECTIVE: To assess the natural history of the atrial rhythm of patients with paroxysmal atrial arrhythmias undergoing atrioventricular node ablation and permanent pacemaker implantation. DESIGN AND SETTING: A retrospective cohort study of consecutive patients identified from the pacemaker database and electrophysiology records of a tertiary referral hospital. PATIENTS: 62 consecutive patients with paroxysmal atrial arrhythmias undergoing atrioventricular node ablation and permanent pacemaker implantation between 1988 and July 1996. MAIN OUTCOME MEASURES: (1) Atrial rhythm on final follow up ECG, classified as either ordered (sinus rhythm or atrial pacing) or disordered (atrial fibrillation, atrial flutter or atrial tachycardia). (2) Chronic atrial fibrillation, defined as a disordered rhythm on two consecutive ECGs (or throughout a 24 hour Holter recording) with no ordered rhythm subsequently documented. RESULTS: Survival analysis showed that 75% of patients progressed to chronic atrial fibrillation by 2584 days (86 months). On multiple logistic regression analysis a history of electrical cardioversion, increasing patient age, and VVI pacing were associated with the development of chronic atrial fibrillation. A history of electrical cardioversion and increasing patient age were associated with a disordered atrial rhythm on the final follow up ECG. CONCLUSIONS: Patients with paroxysmal atrial arrhythmias are at high risk of developing chronic atrial fibrillation. A history of direct current cardioversion.  (+info)

(8/3420) Recovery pattern of left ventricular dysfunction following radiofrequency ablation of incessant supraventricular tachycardia in infants and children.

OBJECTIVE: To assess recovery pattern of left ventricular function secondary to incessant tachycardia after radiofrequency ablation in a group of infants and children. DESIGN AND SETTING: A combined prospective and retrospective echocardiographic study carried out in a tertiary paediatric cardiac centre. PATIENTS: Echocardiographic evaluation of left ventricular size and function in nine children with incessant tachycardia, before and after successful radiofrequency ablation. Age at ablation ranged from 2 months to 12.5 years (mean 4.1 years). Recovery of left ventricular function was analysed in relation to age at ablation (group I < 18 months, group II > 18 months). MAIN OUTCOME MEASURE: Ventricular recovery pattern. RESULTS: Seven of the nine children had left ventricular dysfunction; six of these also had left ventricular dilatation. All children with left ventricular dysfunction had normalisation of ejection fraction and fractional shortening; left ventricular dilatation also improved, but the improvement occurred after recovery of function. There was a shorter recovery time for left ventricular function in younger (group I) than in older children (group II) (mean (SD) 5.7 (7.2) months v 31.3 (5.2) (p < 0.002). CONCLUSIONS: Tachycardia induced cardiomyopathy is reversible following curative treatment with radiofrequency. Recovery of left ventricular systolic function precedes recovery of left ventricular dilatation. Time course to recovery is shorter in younger children.  (+info)