Near-infrared spectroscopy in evaluation of cerebral oxygenation during vasovagal syncope.

Near-infrared spectroscopy (NIRS) offers a non-invasive, real-time monitoring of cerebral oxygenation. This method is based on the oxygenation and the light wavelength dependent absorption of near-infrared light by tissue chromophores, e.g. oxyhaemoglobin and deoxyhaemoglobin. The objective of the present study was the application of NIRS for evaluation of the brain function during vasovagal syncope (VVS). The VVS is a clinical syndrome affecting ca 3.5% of the population and for which the widely used diagnostic examination in this disease entity is the head-up tilt table test (HUT). In this study 69 patients with a history of VVS were examined using HUT. In 42 patients VVS was provoked. Results of the examination have shown that the changes in cerebral oxygenation measured by the NIRS technique are distinctly visible before the syncope. A gradual decrease of oxyhaemoglobin followed by its sudden drop was observed in all the VVS patients. Changes in the oxyhaemoglobin concentration measured by NIRS were observed on average 3.3 min before the syncope. They preceded the presyncope symptoms about 1.3 min (p < 0.005), the blood pressure and heart rate drop 2.2 min (p < 0.0001) and the arterial blood saturation 2.6 min (p < 0.00001).

Laser Doppler method in evaluation of vasovagal syncope induced by tilt table test.

The laser Doppler flowmetry offers a new noninvasive, real-time technique for monitoring of the blood perfusion in living tissue. In spite of some instrumental problems, e.g. relative calibration and unknown sampling measurement depth, this method has already been used in clinical examination. The purpose of presented study was the application of the laser Doppler method in evaluation of the vasovagal syncope induced in the tilt-table test. Twelve patients with the history of syncopal episodes were examined using the head-up tilt-table test. In the some condition three normal subjects were also examined as the reference. Results of examination have showed that the changes measured by laser Doppler method are clearly visible during the pre-syncope and syncope period. These changes in perfusion precede the subjective clinical symptoms as well as decrease in the blood pressure, blood oxygen saturation and heart rate.

[Difficulties with pharmacologic treatment of a patient with atrioventricular nodal reentrant tachycardia]. / Trudnosci w leczeniu farmakologicznym u chorej z nawrotnym czestoskurczem wezlowym.

A case history of a 38 year old teacher with AVNRT is described. She had been treated for 11 years with 11 antiarrhythmic drugs in various combinations. No treatment prevented recurrence of arrhythmia. During long term treatment with class IA, IC, II, III and IV antiarrhythmic drugs, various side effects occurred. There was also suspicion of proarrhythmic effect, especially of prajmaline. Some of the drugs terminated tachycardia while administered intravenously. But often deep hypotonia, heart automatism disturbances and even asystole occurred, MAS syndrome occurred 5 times. The patient was referred to our laboratory to perform percutaneous radiofrequency ablation of the slow pathway. The procedure was performed without any complications. Efficacy of the ablation was proved by electrophysiologic study before and after intravenous atropine administration. During the 11 months follow-up the patient had no tachycardia. She is on no antiarrhythmic medication and continues her normal activity.

[Selective catheter ablation of the slow pathway in a patient with recurrent atrioventricular nodal reentrant tachycardia]. / Wybiórcza ablacja drogi wolnego przewodzenia usunela napady nawrotnego czestoskurczu wezlowego.

The case of a 35 year-old patient with recurrent, sustained atrioventricular nodal reentry tachycardia (AVNRT)--type slow/fast--refractory to group IA, IC, II, IV antiarrhythmic agents is presented. The maximum rate of the tachycardia was 280/min. During the antiarrhythmic treatment with group IA, IC and IV agents the tachycardia rate was 230/min. The effective refractory period (ERP) of the slow pathway was 200 ms in antegrade direction. ERP of the fast pathway was 260 ms in antegrade and 210 ms in retrograde direction. Ablation of the slow pathway was performed with radiofrequency energy (device HAT 200 S manufactured by Osypka GMBH, catheter Cereblate No 6). The total ablation time was 96 s, maximal temperature of the effective ablation time was 51 centrigrades. Total energy delivered was 2316 J. The ablation caused neither atrioventricular conduction block nor any damage to the heart structure other than the slow conduction pathway. After the ablation there are no evidence of conduction through the slow pathway. Conduction in anterograde and retrograde direction occurs through the fast pathway. No AVNRT were observed. After ablation the patient has no antiarrhythmic treatment.

[Electrical ablation with high frequency (radiofrequency) in patients with recurrent atrioventricular nodal reentrant tachycardia--introductory information]. / Ablacja pradem wysokiej czestotliwosci (radiofrequency) u chorych z nawrotnym czestoskurczem wezlowym--doniesienie wstepne.

In 10 patients (pts) with atrioventricular nodal reentrant tachycardia type slow/fast (AVNRT) refractory to the antiarrhythmic treatment, radiofrequency current catheter ablation was performed. Adult pts (mean age 31 years) suffered from paroxysms of AVNRT for 2 to 18 years (mean 8 years). Episodes of arrhythmia recurred from 2-3 times a week to 1 for several months during antiarrhythmic therapy. The mean rate of the tachycardia was 243/min. 3 pts had syncope and 5 fainted during the tachycardia. In 2 females mitral valve prolapse was diagnosed. Programmed stimulation of the right atrium on the basic rate 130/min revealed ERP of the slow pathway mean 238 ms and ERP of the fast one mean 346 ms. The tachycardia has been induced with right atrium stimulation--most often programmed or burst stimulation--200 and 220/min, sometimes with incremental pacing. Successful radiofrequency energy ablation was performed in all 10 pts. Average number of the impulses for one pt was 7.7 (from 1 to 18 impulses). The total average time of the ablation was 216 s. The temperature of effective ablation was average 65 centigrade. The effect of the ablation was evaluated during repeated electrophysiological study before and after intravenous injection of atropine. Ablation was considered successful when no tachycardia was induced. P-R interval did not change and no episodes of AVNRT was observed in the 1-3 months follow-up. No complications were observed during the ablation and after the procedure, especially no thromboembolism was noticed. The echocardiographic evaluation revealed no damage to the heart structure. The pts receive no antiarrhythmic treatment and they are systematically controlled.

[Selective ablation of slow conduction pathway in a patient with atrioventricular nodal reentrant tachycardia]. / Celowana ablacja drogi o wolnym przewodzeniu u chorej z nawrotnym czestoskurczem wezlowym.

In a 42-year female with paroxysmal atrioventricular nodal reentrant tachycardia of the type I (slow/fast) verapamil did not prevent it. Verapamil injections terminated tachycardia but marked hypotonia followed. Electrophysiologic study revealed dual conduction pathway within the atrioventricular node that made the substrate for reentrant tachycardia. An effective refractory period od the slow conduction pathway in antegrade direction was less than 220 msec. An effective refractory period of the fast pathway in antegrade and retrograde directions was 300 msec. Radiofrequency current ablation was performed at the site of slow pathway morphology electrogram recording. A single application of the radiofrequency current that lasted 40 sec. producing the maximum 60C successively ablated the slow pathway. Follow-up electrophysiologic study before and after atropine administration proved the success of this procedure. No other heart structures were damaged. A 4-month follow-up period did not show tachycardia.

[Multi-electrode mapping from thoracic surface in patients with Wolff-Parkinson-White syndrome]. / Wieloelektrodowy mapping z powierzchni klatki piersiowej u chorych z zespolem Wolff-Parkinson-White'a.

Body surface potentials mapping is a new method of heart electric phenomena visualisation. Attempts of accessory conduction pathways localisation in 9 patients with overt and in 1 with concealed WPW syndrome are presented. In 4 pts the preexcitation with QRS complex > 120 ms was clearly seen, in next 4 individuals that symptom was less evident and in one case the retrograde conduction through the accessory pathway was hardly noticed. The isopotential maps allowed precise localisation of the accessory pathways ventricular insertion in all patients with QRS > 120 ms and in one with QRS < 120 ms. After successful dissection of accessory pathways, isopotential maps became normal. In patients with slight signs of preexcitation, noninvasive (transesophageal) or invasive atrial stimulation could improve the visibility of accessory pathways localisation.

[Consequences of late diagnosis and long-term conservative treatment of patients with congenital heart defects]. / Konsekwencje póznych rozpoznan oraz wieloletniego zachowawczego leczenia chorych z wrodzonymi wadami serca.

Of adult patients of the Cardiac Defects Clinic, National Institute of Cardiology (in Warsaw) we can distinguish several groups of patients with congenital heart defects among which those who were diagnosed after the age of 18 or those who despite of early and correct diagnosis, not underwent surgery on the childhood due to many reasons. In this paper we analyzed the group of 218 patients treated in our clinic between 1981-1987; 103 women aged 13-64 (mean-32 years) and 115 men aged 15-58 (mean-28 years). We classified congenital heart defects into 6 group: ASD, VSD, Tetralogy of Fallot, Persistent Ductus Arteriosus, Coarctation of Aorta and others (19.2%). We classified the range of health care before admission to our Department into the following categories: cardiosurgery (palliative or total correction); no therapy after congenital heart defects diagnosis; medical treatment after diagnosis; admission to our clinic immediately after the diagnosis of a heart defect. We compared that range of health care with qualifications of our Institute-(1. qualification for operation, 2. contraindication for operation, 3. operation unnecessary as the defect is not significant). We conclude basing on our results that, late diagnosis of a congenital heart defect does not finally effect on cardiosurgery possibilities. the majority of patients with C.H.D. have been waiting for many years for a specialist diagnosis and optimal therapeutic decision. long term conservative therapy of the patients with C.H.D. significantly reduces the changes of surgical correction.