Biomedical subjects
F Solti
Publications and source records attributed to F Solti.
The effect of Cavinton on impulse formation and impulse conduction of the heart.
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Ultrastructural and electrophysiologic changes of experimental acute cardiac lymphostasis.
Experimental impairment of cardia lymph flow in dogs produced histologic and electrophysiologic changes in the heart. Interstitial edema, lipid swelling of myofibrils, dilatation of lymph vessels, and fibrinoid degeneration of small coronary arteries occurred in and near the sinus node and the atrioventricular conduction system. On electrical stimulation of the heart, significant shortening of the atrial and ventricular effective refractory periods, increases in the sinus node recovery time and in the atrioventricular conduction time, and ventricular extrasystoles and ventricular fibrillation were observed. Many of these EKG changes are similar to those observed in sick sinus syndrome in man. An attempt was made to create dynamic lymphatic insufficiency by rapid electrical stimulation of the heart. EKG abnormalities observed in these cases could be prevented by intravenous injection of calcium dobesilate.
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.
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.
Effect of the Ca2+ chelators EDTA and EGTA on sinoatrial-node activity and heart irritability.
The effect of the Ca-chelators EDTA and EGTA on sinoatrial activity and heart irritability was studied in dog experiments by perfusing the artery supplying the sinoatrial node. Beside the usual ECG recordings left and right atrial and left and right ventricular epicardial electrograms, His-bundle electrogram and the early activity of the sinoatrial node were recorded. In addition action potentials were recorded from the left auricle and right ventricle of the dog hearts. Local application around the sinoatrial and atrio-ventricular nodes of EDTA and EGTA caused sinus bradycardia and later sinus arrest within 1 min after introduction of the drugs. For substitution of the sinus rhythm junctional (seldom lower atrial) escape rhythm developed. One to two minutes later it was followed by atrial premature beats and even later atrial flutter and fibrillation could be recorded. In one third of the cases atrial fibrillation was followed by secondary ventricular fibrillation. Atrio-ventricular impulse conduction was prolonged in the av node by EDTA and EGTA. Atrial action potentials and the slow (Ca dependent) ventricular action potentials were depressed by EDTA and EGTA.
Lymphatic cardiomyopathy: cardiac lymphostasis in the pathogenesis of arrhythmias.
Artificial lymphatic cardiomyopathy was produced in 30 dogs by ligating the regional lymph nodes and the efferent collecting lymph trunks of the heart. In the development of cardiac lymphostasis the appearance of arrhythmias and conduction disturbances was revealed by repeated ECG recordings. The arrhythmic condition of the heart increased and pacemaker function of the sinus node deteriorated in lymphatic cardiomyopathy. Cardiac lymphostasis could be detected during open heart surgical procedure and in long lasting tachycardiac attacks. It is probable that the cardiac lymphostasis has a role in the pathogenesis of some arrhythmias.
Limb circulation after deep venous thrombosis.
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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.
Limb circulation in varicosity of various types.
Regulation of limb circulation was studied by the use of the venous isotope dilution technique in 35 patients with leg varicosities. The circulatory parameters of 54 patients with normal limb circulation served as control. The various types of varicosity revealed characteristic circulatory patterns. (i) In the cases of congenital, "juvenile", varicosity limb blood flow is high, the limb AV-O2 difference is very slight and limb O2 uptake is normal. (ii) In secondary varicosity consecutive to thrombophlebitis the limb (total) blood flow is slightly reduced, the limb AV-O2 difference is smaller than normal and O2 uptake by the extremital tissues is diminished. (iii) In non-congenital, primary varicosity, i.e. in the most common form, limb blood flow is normal, the limb vascular resistance is slightly increased. The possibilities of the production of an AV shunt and the clinical implications of the circulatory changes accompanying the various types of varicosity are discussed.
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.
[The effect of Cavinton on heart conduction].
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The effect of cardiac lymphostasis on the microcirculation of the heart: effect of cardiac lymphoedema on the development of an arteriovenous shunt circulation.
The effect of cardiac lymphostasis on the microcirculation of the heart was studied in 18 dogs. By ligation of the main lymph trunks and regional lymph nodes of the heart, cardiac lymphoedema--lymphogenic cardiomyopathy--was induced in 9 dogs, while 9 served as control animals. For microcirculatory investigations: 1) gelatin Indian ink injection, 2 benzidine reaction, 3) PVC injection corrosion preparation was applied. Characteristic changes were demonstrated in the microcirculation and capillary circulation of the heart in cardiac lymphostasis. In some capillaries-mainly where the interstitial oedema exists--the capillary circulation decreased: inhomogeneously vessel-free spots were formed in the heart. Around the vessel-free capillaries, elongated capillaries were found including very dilated pre- and post-capillary vessel sections. Arteriovenous shunts can be revealed in the heart in consequence of lymphoedema. The pathogenesis of the microcirculatory circulation changes caused by cardiac lymphostasis was discussed.
[Ultrastructural changes in the aorta following damage to the transport through the vessel wall].
Be the ligature of lymphatic vessels lymphostasis has been produced and the consequences of it in the myocardium were studied. Lymphatics of the myocardium in lymphostasis were compared with those in the normal one. It was found that the space between lymphatics and myocardial fibers filled mainly with connective tissue due to accumulation of oedema fluid enlarges and the collagen fibers disintegrate. At the same time accumulation of fluid and dilatation of lymphatics takes also place. Pinocytotic activity of endothelial cells increases. Due to oedema vacuolization of myocardial cells occurs. Disturbance of the capillary circulation leads to swelling of endothelial cells and narrowing the capillary lumen. This lies on the basis of hypoxia and fatty degeneration of the myocardium. The coronary vessels have also shown alterations. In the subendothelial space accumulation of plasma constituents, in the smooth muscle cells of the vessel wall oedema was found. Thus, lymphostasis in the myocardium results in significant alterations.
[Mechanism of the development of lymphogenic cardiomyopathy as revealed by electron microscopy].
Lymphostasis in the aortic wall has been produced experimentally. It has been proved that the disturbance of the lymph circulation results in changes of the aortic wall e.g. oedematic transformation of muscle cells, demarcation of parts of them, formation of ghost bodies and eventually total necrosis of muscle cells. The necrosis of muscle cells usually is followed by proliferation and development of sclerosis.
[Ultrastructural studies on the mechanism of lymphogenic cardiopathy].
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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.
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.