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Biomedical subjects

R Slama

Publications and source records attributed to R Slama.

At least 91 records · Page 5Linked to original sources

[Double fulguration of the bundles of His and Kent for recurrent tachycardia in Wolff-Parkinson-White syndrome].

A 59 year old patient with a left postero-septal Kent bundle had daily attacks of reciprocating tachycardia resistant to anti-arrhythmic therapy and was referred for catheter ablation. Kent bundle activity was recorded in the proximal part of the coronary sinus. An endocavitary electric shock delivered at this site suppressed conduction through the Kent bundle for several minutes. Catheter ablation of the His bundle (2 X 200 joules) was then attempted suppressing anterograde conduction for 2 days, after which conduction was reestablished and the reciprocating tachycardia recurred. A second session of catheter ablation was carried out and 2 X 200 joules shocks were delivered in the coronary sinus and 4 to the Bundle of His. Complete anterograde and retrograde atrioventricular block was obtained. Two weeks later, the patient recovered anterograde conduction through the accessory pathway. Retrograde conduction through the Kent bundle was decremental, RP' lengthening with increasing heart rate. Conduction was detected in the His bundle but was insufficient to give rise to reciprocating rhythm. After one year's follow-up the patient was asymptomatic without treatment. Catheter ablation of physiological or accessory conduction pathways provides a valuable alternative to surgical treatment of pre-excitation pathways in the WPW syndrome resistant to medical therapy.

Bundle of His↗

[Mechanisms determining sudden death. A cooperative study of 69 cases recorded using the Holter method].

A cooperative study involving 23 centres enabled review of 69 cases of sudden death occurring less than one hour after onset of symptoms recorded by the Holter method and not related to recent, clinically documented myocardial infarction or to class IV cardiac failure. The 15 cases of asystole (22 p. cent) were observed in elderly patients (73.3 +/- 2.7 years) whose known ischaemic heart disease (12/15) was confirmed in 10 cases as the direct cause by the preceding acute ST changes. In 2 cases, death resulted from AV block presumed to be iatrogenic. The 13 episodes of torsades de point (19 p. cent) occurred mainly in younger women (58.8 +/- 6 years) without apparent cardiac disease (8 cases) and were provoked by a Group IA antiarrhythmic drug (7 cases) or by hypokalemia (3 cases). Apart from 1 case of congenital long QT syndrome, slowing of the sinus rhythm was observed (78.3 +/- 2.6 to 60.2 +/- 2.7 bpm, p less than 0.001) in the 3 hours preceding these episodes, and ventricular bigeminy with a long coupling interval was recorded in the lasts seconds before the torsades. The 41 (59 p. cent) cases of ventricular fibrillation (VF) were observed in men aged 64.9 +/- 2 years with coronary artery disease (39/41). However signs of acute ischaemia were only found in 5 cases. The VF was primary in 8 cases and secondary to ventricular tachycardia (VT in 33 cases). An acceleration of the cardiac rhythm (83.3 +/- 3.4 to 90 +/- 4.1 bpm, p less than 0.01) was recorded in the hour preceding VF and other arrhythmias were common: atrial tachycardia (4 cases), atrial extrasystoles (4 cases), a new type of ventricular extrasystoles (VES). The VF and VT were preceded by a long cycle in 17 cases. The first complex was different from previous VES in 10 cases and identical to the previous VES in 16 cases; in 4 cases this feature could not be identified and in 11 cases there were no premonitory VES. The coupling interval of the initial VES was shorter than that of the most premature preceding VES (368 +/- 13 ms vs 442 +/- 19 ms, p less than 0.001), especially in primary VF (335 +/- 9 ms, N = 8) compared to polymorphic VT (360 +/- 12 ms, N = 11) or monomorphic VT (384 +/- 18 ms N = 22).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

[Peroperative echocardiography in cardiac surgery].

Echocardiography is not only useful for pre-operative evaluation of cardiac lesions and to control the quality of some surgical procedures; used peroperatively, it contributes to our knowledge of cardiac function at different stages of the operation. It has taught us that the ischaemic cardiac arrest observed in cardiopulmonary bypass results in reduction of left ventricular compliance and that this can be prevented by potassium-induced cardioplegia. It has also shown that immediately after cardiac valve replacement, the left ventricular "pump" function is reduced in aortic and mitral regurgitation and increased in stenosis. In addition, it has provided evidence that closure of the pericardium and sternum is accompanied with a fall in left ventricular compliance and with disturbances in haemodynamics. The few post-operative studies reported have shown that end-expiratory positive pressure reduces the size of both right and left ventricular cavities. Per--and post--operative studies of left ventricular regional kinetics have not yet been carried out, but this seems to be a good field of application for trans-oesophageal echocardiography.

Cardiac Surgical Procedures↗

Relationships between single-vessel coronary artery obstructions and wall motion dysfunction analyzed by four computer-based methods.

We analyzed regional wall motion in 238 patients by using cineangiograms recorded in the 30 degrees right anterior oblique projection. The sample was divided into three groups: a normal group (n = 71), a group with isolated obstruction of the left anterior descending coronary artery and previous anterior myocardial infarction (n = 85), and a group with isolated obstruction of the right coronary artery and previous inferior myocardial infarction (n = 82). Both anterior and inferior groups also had motion abnormality within the corresponding anterior or inferior wall as judged by the qualitative analysis of cineangiograms. Four quantitative methods were compared: a long axis method and a center of mass method using internal reference systems, a method derived from the Stanford model and an area-based method using external reference systems. Normal regional values were determined from the normal group to evaluate the specificity and sensitivity of the methods. The area-based method was the most sensitive in the anterior infarction group, whereas the center of mass method was the most sensitive in the inferior infarction group. We conclude that there is no evidence that any method, among those tested, is superior to others for every expected location of wall motion abnormality.

Adult↗

Logic and empiricism in the selection of antiarrhythmic agents. The role of drug combinations.

Advances in investigative techniques of cardiac arrhythmias through invasive procedures (clinical electrophysiology) or through ambulatory electrocardiographic monitoring provide a better understanding of the mechanism responsible for these disturbances and a better assessment of therapeutic efficacy. Yet, it cannot be inferred that the selection of antiarrhythmic agents is orientated in all cases by logical reasoning. Too many factors are unknown, especially those regarding the spontaneous mechanism of initiation of clinical arrhythmias. Patient management very often remains mainly empirical. The problem becomes even more complex when dealing with arrhythmias resistant to single-agent therapy. Drug combinations are then used, often successfully, particularly those combining membrane-stabilising agents with amiodarone or beta-adrenergic blocking agents or combining amiodarone with verapamil. Explanations of the efficacy of these combinations at reduced doses become less certain, but it is more important to achieve efficacy than to understand its mechanism, which does not always amount to a simple increase in plasma drug levels. When attempting to determine the reasons behind the theoretically logical selection of an antiarrhythmic agent, it appears that, in spite of advances in electrophysiology and pharmacology, the logic of this selection owes more to chance than to reason. The problem becomes further complicated when drug combinations are to be used which, in clinical practice, are often the therapeutic solution in difficult cases. Advances made in recent years bring up the question of knowing whether or not logic is near to replacing empiricism.

Anti-Arrhythmia Agents↗

[Anti-arrhythmic effect of amiodarone in the 24 hours following a single oral loading dose. Clinical and pharmacological study].

This study demonstrated the rapid antiarrhythmic effects of oral amiodarone (Am). A single 30 mg/kg dose was given to 67 patients, 18 with supraventricular arrhythmias (atrial extrasystoles: 11 cases, reciprocating tachycardia: 4 cases, intraatrial reentrant tachycardia: 2 cases, paroxysmal atrial fibrillation, AF: 1 case). Eighteen patients had permanent AF. Thirty-one patients had ventricular arrhythmias (ventricular extrasystoles, VES, isolated or in salvos: 22 cases, and ventricular tachycardia, VT: 19 cases). The effect on atrial extrasystoles was significant 4 to 13 hours after AM and maximal (-98% +/- 3.6%) at 7.7 +/- 1 hours. They recurred in 3 cases at the 18th hour. No significant effects were observed on the other supraventricular tachycardias. The effect on the atrioventricular node (AVN) assessed by the ventricular response to permanent AF, was significant after the 3rd hour and maximal ( = 38 +/- 6 bpm) at the 7th hour. The reduction in the frequency of VES was significant from the 5th to the 19th hour of treatment. Control of VT was obtained in 5 cases between the 3rd and 8th hours. The treatment was well tolerated as no side effects were reported. The plasma concentration (PC) of amiodarone (54 patients) and of N-desethylamiodarone (NDA) (36 patients) were measured; the maximal values were 2.53 +/- 1.5 mg/l for Am and 0.22 +/- 0.1 mg/l for NDA. A 60% decrease in the number of VES was observed with PC of Am of 1.90 +/- 0.3 mg/l and a 20% reduction in the ventricular response to AF at PC of Am of 1.50 +/- 0.33 mg/l.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗

[Block of the atrioventricular trunk: diagnosis of the site by Holter monitoring].

Twelve patients with intrahisian AV block, confirmed later by electrophysiological investigations had Holter recordings showing the block (paroxysmal in 11 cases, permanent in 1 case). The diagnosis of the site of the block was made before endocavitary investigation in all cases on the following criteria: narrow QRS complexes in 10 out of 11 paroxysmal blocks (1 with phase III LBBB) with a sudden transition from 1/1 to 2/1 conduction. Only 3 patients had rare sequences of lower degree, Mobitz II block. Only 3 patients had 2 or more consecutive blocked P waves. The role of sinus tachycardia (block in phase III) was demonstrated in 10 out of 11 cases. The block was found on the first 24 hour Holter recording in all but 1 patient. This contrasts with paroxysmal trifascicular block: out of 46 patients recruited during the same period, only 4 had Holter recordings showing the block and this was not reproducible. The 12th patient had permanent AV block with wide QRS complexes and narrow sinus captures in the supernormal period in the morning. The sudden transition from 1/1 to 2/1 conduction in phase III is characteristic of intrahisian block and distinguishes it from intranodal AV block. All patients were improved by VDD mode pacing.

Aged↗

[Coronary angiography and coronary bypass in patients over 70 (valvular disease excluded). Indications and results].

Between 1982 and 1984, 30 patients aged 70 or over underwent coronary angiography for isolated coronary artery disease, complicated in 8 cases by an infarct and uncontrolled by major medical treatment, including triple therapy on 28 mmHg (range 5-30 mmHg). Coronary angiography was performed under intravenous trinitrin in 9 cases, under intra-aortic balloon pumping in 1 case, without any serious complications. The majority of patients had triple vessel disease (18 cases) and stenosis of anterior interventricular (27 cases). The left main stem was diseased in 5 patients. Twenty-four patients, with an EF of over 0.40, underwent a coronary bypass with an average of 27 grafts/patients; 4 myocardial infarcts and 5 postoperative deaths were observed. Nineteen patients survived at medium term follow-up and had an excellent clinical result. Of the non operated patients, there was one early death and 3 patients remained severely incapacitated. In the absence of a major contra-indication to surgery, coronary angiography can be offered to patients over 70 years old in cases of severe coronary insufficiency, resistant to major medical treatment. Coronary bypass is justified by the spectacular functional improvement which it alone can bring about.

Age Factors↗

The potential role of the implantable defibrillator in malignant ventricular arrhythmias.

A malignant arrhythmia is one which threatens life and is difficult to predict, prevent or treat. Any arrhythmia which falls into this category is an indication for the implantable defibrillator. The simplicity of this statement is of course deceiving. Transthoracic defibrillation, which for 20 years has been the therapeutic standard, has provided us with the greatest insight and understanding of cardiac arrhythmias. In the long run, the same information will be acquired with the implanted defibrillator. However, technical, medical and economic factors are more complex and will not be resolved in the near future.

Arrhythmias, Cardiac↗

Comparison of geometrical models for evaluating left ventricular wall motion from cineangiograms.

Regional wall motion of the left ventricle (LV) has been analyzed from contrast ventriculograms by using 4 methods based on different geometrical frameworks. Two of them utilize moving internal reference systems, the center of mass (CMM) and the long axis (LAM) methods; the two other ones use fixed external reference systems, the area-based (ABM) and the Palo Alto (PAM) methods. The techniques were applied on a set of 81 patients: 42 were normal and composed the group I; 22 had a single vessel obstruction greater than 75% of the left anterior descending coronary artery (group II) with old necrosis or active ischemia of the LV anterior wall; 17 had a single vessel obstruction greater than 75% of the right coronary artery (group III) with old necrosis or active ischemia of the LV inferior wall. ABM and PAM showed the highest specificities and sensitivities on the studied sample. Therefore, we believe these two methods, of the techniques tested, are the best to quantitate wall motion from cineangiograms.

Cineangiography↗

[Mobitz type II suprahisian atrioventricular block : block in the subnodal-suprahisian (NH) zone?].

The electrophysiological properties of the atrioventricular node differ from those of the His bundle. Nodal conduction is always decremential; this is its principal physiological characteristic, and accounts for the fact that almost the only form of block found at this level is Wenckebach block. The His bundle is characterised by an all-or-nothing response and usually blocks in the Mobitz II mode. Wenckebach phenomena have been described in the His Purkinje system, but Mobitz II block has not been reported in the atrioventricular node. Similarly, phase IV paradoxical block is found in the His Purkinje system but has not been described in the atrioventricular node in the absence of vagal phenomena. In addition, the atrioventricular node is very sensitive to the influence of the autonomic nervous system, the His bundle much less so. The first patient had a normal resting electrocardiogram showing sinus rhythm; second degree atrioventricular block was observed when the atrial rhythm was increased by exercise, atropine or atrial pacing. His bundle recordings showed the block to be suprahisian; the blocked atrial potentials were not followed by a His potential, whilst the conducted atrial activity was followed by a normal His potential and a normal HV interval. However, this atrioventricular block was of the Mobitz II and not the expected Mobitz I type, conduction to the ventricles suddenly blocking (with a 3/2 or 2/1 response) when the atrial rate was increased, without obvious lengthening of the PR or AH intervals before the blocked atria.(ABSTRACT TRUNCATED AT 250 WORDS)

Electric Stimulation↗

[Surgical atrioventricular disconnection in Wolff-Parkinson-White syndrome].

Surgical atrioventricular disconnection is a possible means of treating patients with severe paroxysmal arrhythmias resistant to medical treatment due to the Wolff-Parkinson-White syndrome. Between 1971 and April 1982 we operated 50 patients (38 men and 12 women) with the WPW syndrome. Thirty seven patients were operated for arrhythmias (paroxysmal tachycardia) resistant to medical therapy or with a high risk of sudden death. Thirteen patients had associated cardiac disease with less severe arrhythmias (aortic valve disease: 6 cases; mitral and aortic valve disease: 3 cases; mitral valve disease: 3 cases, and atrial septal defect: 1 case). The causes of paroxysmal tachycardia were atrial fibrillation (13 cases), atrial flutter (2 cases), orthodromic reciprocating tachycardia (30 cases), with associated atrial fibrillation in 9 cases, and with associated atrial flutter in 4 cases. Antidromic reciprocating tachycardia was present in 2 cases. In 3 cases, the preexcitation was a chance finding. Electrophysiological studies performed before and after antiarrhythmic drug administration showed type A WPW (LV preexcitation) in 23 cases, and type B WPW (RV preexcitation) in 20 cases. The ECG was normal in the horizontal plane in 7 cases. The atrioventricular accessory pathway was permeable in both directions in 39 cases; in 9 cases the pathway was permeable only in the retrograde direction and in 2 cases it was permeable only in the anterograde direction. In 7 patients an atrio-hisian short circuit was demonstrated. The site of the accessory conduction pathway was located by epicardial mapping, the first surgical stage, in the left lateral region of the atrioventricular junction (28 cases), in the right lateral region (6 cases), in the posterior septal region (15 cases) (right sided in 4 cases, left sided in 11 cases), and in the anterior septal region (1 case). The accessory pathway (so-called Bundle of Kent) was interrupted by atrioventricular disconnection. Six patients died during surgery, mainly at the beginning of the series; the operative risk is now low (1 death in the last 34 cases: 2,95%). Complete interruption of the accessory pathway was obtained in 38 cases, 1 of which had to be reoperated. Three patients had an incomplete result due to partial interruption or the presence of a second accessory pathway. However, these patients no longer have severe arrhythmias. Surgical section failed in 3 cases, but the patients are now controlled by medical therapy.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗

[The implantable automatic defibrillator. Preventive treatment of sudden death caused by ventricular arrhythmia].

The material and implantation technique of the implantable defibrillator developed by M. Mirowski and used by the authors in 3 patients are described. Through lateral thoracotomy, 4 electrodes are installed, including one patch on the apex of the heart. In case of sustained ventricular arrhythmia the instrument delivers, after less than 30 seconds, a 25 joules shock increased to 30-35 joules if this fails. The results were very encouraging since conversion of severe ventricular arrhythmia was obtained in all 3 patients after the first shock. There was no false detection or inappropriate start. The limitations and indications of the technique are discussed and compared with other treatments of ventricular arrhythmia.

Arrhythmias, Cardiac↗