Search PubMed⌕ Search

Biomedical subjects

E Czakó

Publications and source records attributed to E Czakó.

At least 19 recordsLinked to original sources
PubMed1986

The acute effect of ajmaline on ventricular arrhythmia after cardiac surgery.

The acute effect of ajmaline was investigated in the treatment of postoperative ventricular arrhythmias. Ajmaline (Glurytmal--Giulini Pharma GMBH) was applied intravenously in 15 patients suffering from ventricular premature beats (Lown II--IV/b), tachycardia and/or ventricular fibrillation after open heart surgery. Ajmaline infusion produced in 40% of the cases a total suppression and in 100% a significant improvement of malignant ventricular arrhythmia. In patients with recurrent and resistant ventricular tachycardia, ajmaline proved effective even when other antiarrhythmic drugs had failed. It was shown to be effective in reducing ventricular premature contractions and recurrent ventricular tachycardia after heart surgery, without haemodynamic side effects. Because of recurrent ventricular premature beats in 11 patients after acute ajmaline administration further oral application of prajmalium bitartarate (Neo-Gilurytmal) was necessary. The maintenance of these patients on oral ajmaline treatment seemed important.

Adolescent↗
PubMed1986

Electrophysiological characteristics of lorcainide, a new antiarrhythmic drug.

The electrophysiological characteristics and the antiarrhythmic indication areas of lorcainide were studied by using electrophysiological investigations and clinical studies in patients suffering from sustained arrhythmias. According to the data of the arrhythmia analyses (30 patients) the most important electrophysiological effects of lorcainide are: increase of the effective refractory period of the atria and ventricles; prolongation of the conduction time in the His bundle; prolongation of the refractory period and conduction of the accessory pathways. In the course of clinical studies (55 patients) lorcainide proved to be very effective in treating ventricular arrhythmias and preventing or disrupting ventricular tachyarrhythmic attacks. Lorcainide has a very promising antiarrhythmic effect in the suppression of tachyarrhythmias with accessory pathway conduction, too.

Adolescent↗
PubMed1985

Recording of sinus node electrogram: its technique, electrophysiological and clinical importance.

The electric sign of sinus node activity, the sinus node electrogram, was recorded in animal experiments and in 22 patients. In humans the electric sign of the sinus node precedes the atrial activation by 60 msec on the average. Atrial impulse conduction time is somewhat longer than the sinoauricular one. Canine sinus node electrogram is very similar to that recorded in humans but sinoauricular impulse conduction is somewhat quicker in dogs. The pathological importance of the sinus node electrogram is discussed.

Adult↗
PubMed1984

Autonomic sinus node dysfunction and its treatment.

The clinical, electrocardiographic, pharmacologic, electrophysiologic and Holter monitoring findings are described in four patients with autonomic sinus node dysfunction and one patient with autonomic binodal disease. All showed cerebral symptoms, and had attacks of dizziness, weakness, near-syncope or syncope. After a pharmacologic autonomic blockade with propranolol and atropine, all patients had normal intrinsic heart rates. Electrophysiological studies revealed normal corrected intrinsic node recovery time (less than or equal to 240 msec) a gradual return to the basic cycle length in the secondary postpacing cycles after autonomic blockade, and no intrinsic paroxysmal atrioventricular block. Continuous ECG monitoring (1-3 X 24 hours) revealed severe sinus bradycardia, SA-block, severe sinus arrest, cardiac standstill, atrial fibrillation and in two patients associated AV-block. Autonomic blockade with electrophysiological studies exclude the intrinsic involvement of the sinoatrial and atrioventricular node. Holter monitoring is the best method for assessing the autonomic neurovegetative component of dysrhythmias. Therapy regarding isolated autonomic sinus node dysfunction depended on the pathomechanisms of rhythm disorders: two patients received permanent pacemakers, antiarrhythmic drugs were applied in the case of two patients, and etiological treatment in the case of one. During the follow-up, all patients became symptom-free.

Adult↗
PubMed1984

The effect of adenosine on impulse formation and propagation in the heart. Electrophysiologic studies and clinical implications.

The effect of adenosine on impulse formation and conduction in the heart was studied in 20 dogs by the sinus node artery perfusion technique. Electrophysiologic studies were performed by using His electrograms and epicardial electrograms of the atria and left ventricle. This action potential was recorded in the hearts of 10 dogs. After adenosine administration, there first developed bradycardia, then sinus arrest. Instead of sinus rhythm, there appeared a junctional escape rhythm. Atrial extrasystoles could be also regularly detected. Impulse conduction slowed down in the AV node. Similar changes could be observed after local administration of verapamil. Adenosine decreased the resting membrane potential and the maximum rate of depolarisation in atrial tissue preparations. Experimental data support the assumption that slow Ca++ channels are involved in the bradycardiac effect of adenosine.

Adenosine↗
PubMed1984

The electrophysiological peculiarities of childhood tachyarrhythmias.

Electrophysiological analysis of 20 patients in child or adolescent age affected by paroxysmal tachycardia has been performed. In 16 cases the tachycardia was supraventricular and in 4 cases it was ventricular. Evaluation of the electrophysiological parameters revealed certain characteristics of childhood tachyarrhythmias, viz. (1) adequate sinus node function, absence of sinus dysfunction, (2) absence of brachycardia, (3) acceleration of anterograde and retrograde atrioventricular impulse conduction systems.

Adolescent↗
PubMed1983

Effect of reconstructive surgery on the blood flow in the extremities. Early and late results.

The effect of vascular reconstruction on limb blood flow was studied in 20 patients with arterial disease in the lower extremity. Blood flow was determined with isotope dilution technique, ankle systolic pressure was estimated with the aid of Doppler ultrasounds. Circulation was studied prior to the operation (i); immediately afterwards (ii); 2-4 months later (iii); and 12-20 months later (iv). In obliterative limb arterial disease blood flow had remarkably slowed down with high vascular resistance in the limb. After surgery blood flow reached almost normal level and vascular resistance in the extremity also decreased to normal. Both the O2 uptake by the extremital tissues and systolic perfusion pressure in the ankle increased after the operation. At a later phase of the postoperative period blood flow in the limb slightly decreased but even after a year it was greatly improved and vascular resistance was much less as compared to the state before reconstructive vascular surgery.

Adult↗
PubMed1982

Refractory supraventricular reentry tachycardia treated by radiofrequency atrial pacemaker.

The authors report on a case of drug-resistant supraventricular tachycardia with frequent and long-lasting paroxysmal attacks. Electrophysiologic study revealed that the supraventricular tachycardia was based on a reentry circuit. The attack was regularly induced by premature delay 340-400 ms atrial stimulation and it could always be terminated by rapid atrial stimulation within 1-2 seconds. Atrioventricular 2:1 block occurred with very rapid atrial stimulation of greater than 190/min. The patient received a radiofrequency atrial pacemaker, and at the first sign of a tachyarrhythmia he switched on the instrument for 1-2 sec, and the attack was promptly terminated.

Adult↗
PubMed1982

Electric sign of the activity of the sinus node in the dog heart.

The possibility of local recording of the electrical activity of the sinus node was investigated on 22 dogs. Using a small unipolar electrode positioned at the proximity of the sinus node and applying a 2-4-fold electric amplification, an early, slow and low-amplitude wave could be recorded 20-40 ms before the P wave. This early wave gradually decreased when the electrode was moved away from the sinus node and finally fused into the local P wave. Temporary arrest of sinus node activity by injection of adenosine into the sinus node artery, electrical stimulation of the vagal nerve by infiltration with phenol of the sinus node region made the local P wave to disappear. Similarly, no early action before the P wave could be seen if the sinus node was driven electrically. The early wave recorded in the proximity of the sinus node represents the depolarization of the sinus node, and it is suitable to study the pacemaker activity of the sinus node together with sinoauricular conduction.

Action Potentials↗
PubMed1982

Increased susceptibility of the heart to arrhythmia in response to QT-prolongation associated with unhomogeneous repolarization: further data concerning the pathomechanism of arrhythmias associated with long QT-syndrome.

The pathomechanism of arrhythmias consecutive to a prolonged electrical systole --the long QT syndrome--was studied by local hypothermia in the heart. Local increase in the QT-interval (long QT with unhomogeneous repolarisation) was induced at a circumscribed area of the right ventricle by perfusion of the mid- and end-sections of the right coronary with cooled blood. The effect of local prolongation of QT on the arrhythmic susceptibility of the heart was studied by means of programmed electrical stimulation. Induced local hypothermia of the heart was found to increase the QT-interval of the ECG-tracings, also if QT had been corrected for heart rate. The local ECG tracings showed a considerable increase of the QT-interval at the selected right ventricular area under the effect of induced hypothermia but in relation to QT (ERP/QT) it diminished. The long QT in association with an unhomogeneous repolarization went hand in hand with an increased irritability of the heart. Early ventricular impulses were found to elicit extrasystolic runs, ventricular tachycardia or ventricular fibrillation. The results indicate that the cause of tachyarrhythmias consecutive to the long QT-syndrome may be ascribed to the inhomogeneity of repolarization on the one hand, and to the shortness of ERP in relation to the QT-duration on the other.

Animals↗
PubMed1980

Electrophysiological characteristics of tobanum, a new beta receptor blocking agent.

The electrophysiological properties of Tobanum (a new beta receptor blocking drug) were studied in 14 patients by the aid of His electrography and programmable electrical stimulation of the heart. On the effect of Tobanum (0,9 mg by slow i.v. injection), three characteristic changes could be detected: 1. The impulse conduction in AV node slowed down markedly. 2. The heart frequency decreased. 3. The effective refractory period of the atrium significantly increased. Tobanum seems to be a very effective antiarrhythmic drug for the treatment of supraventricular tachycardias.

Adolescent↗
PubMed1980

Adams-Stokes attacks associated with carotid sinus syncope. Pathogenesis and therapy of the carotid sinus syncopes.

The pathophysiology and therapy of the carotid sinus syncope were studied by means of electrophysiological investigations and clinical observations in 84 patients suffering from carotid sinus syncope. The most important data and conclusions of the study are the following: 1. The most frequent cause of the carotid sinus syncope (Adams-Stokes) attack is the sinus arrest and a sinus block. 2 degrees-3 degrees av block can be observed less frequent in the course of syncope attack. 2. In a patient suffering from carotid sinus syncopes, disorders of impulse formation and impulse conduction of the heart are frequent. First of all, the association of the sick sinus syndrome and the carotid sinus syncope can be often detected. 3. It is not rare at all that the carotid sinus syncope occurs with extracranial obliterative disorders. Transitory cerebral ischaemic attack frequently develops on the stimulation of the carotid sinus area. 4. The drug -- atropine -- therapy of the carotid sinus syncope is usually insufficient. Generally, pacemaker implantation is the adequate treatment. Late results are very good after pacemaker implantation.

Adams-Stokes Syndrome↗
PubMed1980

Hypertension secondary to bradycardia: blood pressure regulation under the effect of impaired cerebral blood flow and bradycardia.

Ninety-two patients of advanced age were studied in whom arterial hypertension was associated with chronic bradycardia, the cessation of bradycardia after pacemaker implantation was followed by a significant fall or permanent normalization of the high blood pressure. In three cases cerebral blood flow was found low, but it increased when the heart rate was normalized on pacing. In order to check the results obtained in humans, cerebral blood supply was restricted by carotids ligation, in some animals the vertebral artery of one side was also ligated. During obstruction of cerebral blood flow, bradycardia induced by av block or vagal stimulation was followed by an increase in arterial blood pressure. It is suggested that disturbances of cerebral blood flow associated with bradycardia have a decisive part in the pathogenesis of hypertension in old age.

Aged↗