[Tachycardia-induced cardiomyopathy]. / Arytmogenna kardiomiopatia rozstrzeniowa.

Dilated cardiomyopathy induces circulatory insufficiency with poor prognosis. Persistent tachyarrhythmias may be the cause of this disease. At particular high risk for heart damage and insufficiency are young people and children. The group of most dangerous arrhythmias consist of: incessant tachycardia in patients with preexcitation syndrome and supraventricular tachyarrhythmias (atrial flutter and fibrillation, ectopic atrial tachycardia) with high rate of ventricles. The result of arrhythmias is dilatation of the heart and thinness of ventricular walls with hemodynamic disorders. The effective therapy of arrhythmias--ablation of the accessory pathway in patients with pre-excitation syndrome or reversion to sinus rhythm (pharmacological or electric cardioversion) in patients with atrial fibrillation and flutter, often leads to normalisation of heart ejection function and diameter. Therefore it exist important question: is dilated cardiomyopathy the cause or consequence of tachyarrhythmias? Causative antiarrhythmic therapy in these second cases gives a possibility to improve the prognosis in patients with such a disease.

[Atrial flutter: causes, electrophysiological characteristics, treatment with radiofrequency catheter ablation]. / Trzepotanie przedsionków--przyczyny, charakterystyka elektrofizjologiczna, leczenie za pomoca ablacji pradem o czestotliwosci radiowej.

Atrial flutter (TP) is one of the most common supraventricular tachyarrhythmias. Because of its influence on hemodynamics of the circulation, prolonged episode of paroxysmal TP can lead in as many as 1/3-1/2 patients to clinical signs of coronary insufficiency, decompensation of the circulatory system, or even such life-threatening states, like cardiac arrest. Patients with preexcitation syndrome, hyperthyroidism, as well as children, whose atrio-ventricular (AV) node can conduct in a 1:1 fashion, are in the group of particularly high risk of complications. Recurrent episodes of TP are also associated with frequent occurrence of thromboembolic events. Based on the electrocardiographic (ECG) pattern TP is divided into common type, with negative "sawtooth" in leads II, III, aVF, and uncommon type, which is characterised by other ECG morphologies. Experimental and clinical data have revealed, that common and some part of uncommon type are due to clockwise or counterclockwise reentry in the right atrium. These forms of TP can be treated with high success-rate with radiofrequency (CR) ablation. Because of difficulties in pharmacological conversion of the arrhythmia to the sinus rhythm and high frequency of recurrences, CR ablation seems to be a high effective method of treatment in patients with common and some forms of uncommon TP.

[Radiofrequency ablation of accessory pathway's atrial insertion site]. / Ablacja pradem o czestotliwosci radiowej ujscia przedsionkowego dodatkowych szlaków przewodzenia.

Brought into clinical practice in 80, method of radiofrequency catheter ablation (RFCA) enabled possibility of causative treatment in patients with preexcitation syndrome. RFCA may be performed utilizing various techniques, choice of one of them depends on experience and preference of the operator. Aim of the study was assessment of efficacy and safety of RFCA targeting accessory pathway's atrial insertion site with help of unipolar signals from ablation-catheter with regard to various localizations of accessory pathways. Material and method studied population consisted of consecutive 149 patients with symptomatic, drug-resistant WPW-syndrome, which were admitted to our Center for electrophysiologic study and RFCA. From the studied population two groups were subdivided: patients with left-sided (group I, n = 112) and right-sided (group II, n = 37) accessory pathway. Every patient underwent electrophysiological study with use of four diagnostic electrodes and after preexcitation was confirmed RFCA was undertaken. In case of left-sided accessory pathway transseptal puncture was performed. Analyzed parameters were: total duration, fluoroscopy-time, number of current-applications during RFCA, as well as success-rate, complications and recurrences after successful ablation. Patient in both groups did not differ significantly with respect to age and sex. Success-rate was insignificantly higher in gr.I (92.8%) than in gr.II (86.5%), as was RFCA-duration (136.4 min versus 123.6 min). We found significant differences in fluoroscopy-time, which was longer in gr.I (37.2 min versus 28.4 min, p < 0.05). Complications occurred in 1 patient in each group. RFCA aiming at accessory pathway's atrial insertion site with use of unipolar tracings from ablation-catheter is safe and effective method of treatment in WPW-patients.

[Radiofrequency catheter ablation of two accessory pathways in patients with WPW Syndrome]. / Ablacja pradem o czestotliwosci radiowej dwóch dróg dodatkowych u chorego z zespolem preekscytacji.

In 10-30% patients with WPW syndrome more than one accessory pathway in electrophysiology study is observed. These patients make a group of higher atrial fibrillation and coming next ventricle fibrillation risk. We present the 39 years old patient with symptomatic WPW syndrome, without preexcitation signs in ECG at rest. In medical history--palpitations was observed from childhood with one episode of atrial fibrillation with high ventricle response required cardioversion. Electrophysiology study: without preexcitation signs at rest, two ortodromic AV reentrant tachycardias were induced--200 and 166/min. Two accessory pathways were diagnosed, left lateral and left midseptal. Radiofrequency catheter ablation of both accessory pathways was made during tachycardia, first lateral, next septal. In six month follow-up the patient was asymptomatic.