[Ablation of supraventricular tachydysrhythmias with direct and radiofrequency current]. / Skúsenosti s abláciou supraventrikulárnych tachydysrytmií jednosmerným a rádiofrekvencným prúdom.

Ablation therapy of tachycardias refractory to pharmaceutical preparations is considered in recent years the method of choice. In the submitted paper the authors give an account of 12 years experience with ablation treatment of supraventricular tachycardias. The group comprises 23 patients, who were subjected to ablation therapy by radiofrequency current (RF) on account of relapsing supraventricular dysrhythmias, resistant to medicamentous treatment (between May 1994 and February 1996). The mean age of the patients was 60.4 +/- 9.2 years. The historical control group is formed by 13 patients who were subjected to ablation of the AV junction by direct current (DC) between March 1984 and April 1994, their mean age being 68.4 +/- 10.4 years. After DC ablation the operation was successful in 8 cases (62%) where complete AV block was achieved, while it was partially successful in two cases where modification of the conductivity was achieved (15%) and it failed in three cases (23%). The levels of AST and CK enzymes at the investigated time intervals are significantly higher than in the RF method. During RF ablation the mean duration of successful ablation sequence was 36 s, the mean energy 1 042 +/- 726 J, the median number of sequences was 10.5. In ablation of the AV junction the success was 95%. In one of two patients who were subjected to ablation of arterial flutter a relapse of tachycardia was recorded after an interval of 24 hours. Subsequently complete ablation of the AV junction was performed. In a female patient with atrioventricular reciprocal tachycardia due to a latent accessory pathway in the area of the free left ventricular wall temporarily tachycardia could not be induced, however, after discharge from hospital the paroxysms of supraventricular tachycardia with a substantially lower frequency reappeared. Comparison of the two methods does not suggest a significant difference of their effectiveness, the RF method causes, however, less extensive myocardial damage.

[Rapid continuous stimulation of the atrium (overdrive) in the treatment of refractory supraventricular tachycardia]. / Rýchla kontinuálna stimulácia predsiení (overdrive) v liecbe refraktérnych supraventrikulárnych tachykardií.

In 71 patients, divided into four groups by the type of supraventricular tachycardia (SVT) during electrophysiological examination, 918 stimulations were implemented by the method of rapid continuous stimulation of the atria (overdrive) in order to interfere with a SVT paroxysm. In addition to characteristics of tachycardia the authors evaluated parameters of overdrive stimulation, i.e. the duration of the stimulation cycle (CL STIM), the ratio CL STIM/CL SVT, the number of stimuli required to terminate tachycardia (N STIM) and their mutual relations. In the group of atrioventricular reciprocal tachycardias (WPW, n = 17) the effectiveness was 50.4%, CL SVT 334 +/- 43 ms, the ratio CL STIM/CL SVT 78.3 +/- 12%, the median of N STIM 14 +/- 6. In the group of AV nodal tachycardias (AVNR, n = 26) the effectiveness is 53.1%, CL SVT 356 +/- 70 ms, CL STIM/CL SVT 77 +/- 8.6%. In the group of atrial tachycardias (AT, n = 5) the effectiveness was 62.3%, CL SVT 348 +/- 24 ms, CL STIM/CL SVT 73.7 +/- 7.5%, N STIM 6 +/- 4. In the group of atrial flutter (AFL, n = 23) the effectiveness was 9.2%, CL SVT 226 +/- 29 ms, CL STIM/CL SVT 84.5 +/- 8.2%, N STIM 22.5 +/- 9. The effectiveness of overdrive stimulation in AFL is significantly lower than in other groups of SVT. The regression correlation in the entire group of tachycardias for calculation of a suitable duration of CL STIM--0.855 x CL SVT--28 (ms), the median number of stimuli N STIM 14 +/- 7.(ABSTRACT TRUNCATED AT 250 WORDS)

[Experience with permanent cardiac pacemakers in the East Slovakian Region 1978-1987]. / Skúsenosti s trvalou kardiostimuláciou vo Východoslovenskom kraji v rokoch 1978 az 1987.

The authors present a group of patients where in the course of the 10-year period of 1978-1987 a permanent pacemaker was implanted. 587 primary implantations were made and 327 exchanges of cardiac pacemakers. The mean age in the group of primary implantations was 70.4 +/- 10.3 years, in the group of exchanges 70.4 +/- 10.6 years. n 98.8% pacemakers VVI and VOO made in Czechoslovakia were implanted. Indications for primary implantation were in 64% atrioventricular block (AV) grade III, in 11% AV block grade II, in 22% disease of the sinoatrial node and in 4% other dysrhytmias. The age category above 60 years accounts for 85.5% in the group of primary implantations. A positive feature is the low incidence of complications of surgical and technical nature. An unfavourable feature is that almost all implanted devices were the simplest single electrode systems where the frequency cannot be adapted and where other parameters cannot be changed.

[Does the left atrial dimension predict the short-term effect of electric cardioversion?]. / Predpovedá rozmer l'avej predsiene krátkodobý efekt elektrickej kardioverzie?

The authors evaluate in their retrospective investigation the influence of the left atrium, assessed by echocardiography, on the short-term effect of electric cardioversion in auricular fibrillation. The group comprises 44 patients divided into four groups: ischaemic heart disease, cardiomyopathy and specific myocardial affection, mitral stenosis and idiopathic fibrillation. The authors did not find a significant difference between the left atrial diameter in patients with successful electric cardioversion (ECV) (44.4 +/- 8.2 mm) and patients with not successful ECV (43.4 +/- 6.7 mm). The authors did not prove the influence of age and aetiology of fibrillation on the effect of ECV. The size of the left atrium alone does not possess a significant predictive value when estimating the short-term effect of ECV.