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Congestive cardiac failure could be as important as cardiac arrhythmias in the natural history of arrhythmogenic right ventricular dysplasia. This can be related to the progressive replacement of myocardium by fat and fibrosis of the right ventricle. The left ventricle may also be involved by the same disease process. Moreover, inflammation can be superimposed on ARVD, resulting in a wide spectrum of clinical presentation which can mimick idiopathic dilated cardiomyopathy. Right ventricular cardiac failure has been controlled by anterior dynamic cardiomyoplasty.

Unlabelled: The effect of 50 Hz and 60 Hz (frequencies of current distribution) and 20 kHz to 50 kHz (frequencies of induction cooktop) magnetic interference on implanted pacemakers have been assessed with the present generation of device technology. Sixty patients implanted in 1998 and 1999 with dual chamber pacemakers from 9 different manufacturers were monitored with telemetry while passing through, and standing between a system of two coils. They generated a 50 Hz or a 60 Hz magnetic field at 50 microT. Then, patients used a cooktop at different power. The recordings were made with the standard setting of "medically correct" sensing parameters chosen for the patients. Then pacemakers were reprogrammed to the unipolar mode, with the highest atrial (A) and ventricular (V) sensitivity that did not induce muscular inhibition while moving. Between each exposure (50 Hz, 60 Hz or 20 kHz to 50 kHz), the pacemaker programmation was controlled. At the end of the tests, pacemakers will be reprogrammed with the standard setting. The medical observer being blind to the existence or not of the magnetic field. No pacemaker was influenced by the vicinity of the magnetic field at medically correct settings. At unipolar high sensitivity, no inhibition nor reprogramming was observed. Transient reversion to interference mode was observed in 6 cases, 3 transient acceleration due to atrial detection of the interference, and one T wave detection by the ventricular lead. All were observed with the 60 Hz, and only 3 with the 50 Hz magnetic field. One device (Biotronik) shifted out of its special program (hysteresis research) during the tests with the induction cooktop, but it maintained its standard program, and the event could not be repeated despite further testing., Conclusion: Actual pacemakers do not present any electromagnetic interference with 50 Hz and 60 Hz or induction cooktop frequency working. They are insensitive with medically correct settings. Unusual high sensitivity leads only to noise reversion mode, or transient ventricular tracking.

The IRM is formally contraindicated to the pacemaker and cardiac defibrillator wearers because of the risk of inhibition or inappropriate stimulations during the examination. However if the examination is essential, suitable programming of the apparatus and a constant monitoring of the heartbeat rate by a qualified doctor in cardiac stimulation must make it possible to avoid any accident.

Atrial flutter with 1/1 nodo-ventricular conduction is a classical complication of Vaughan-Williams's Class I antiarrhythmic drugs. The increase of the flutter cycle and weak action of the antiarrhythmic on the atrioventricular node leads to 1/1 conduction of atrial depolarisation to the ventricles. In view of their marked action on the atrioventricular node, this type of pro-arrhythmic effect is very unexpected with Class III antiarrhythmics. The authors report 7 cases of 1/1 atrial flutter with oral amiodarone observed between 1994 and 2001. The patients were 6 men and 1 woman with an average age of 58 +/- 14 years. Four of them had underlying cardiac disease; none were hyperthyroid. The initial arrhythmia was 2/1 atrial flutter (n = 4), 1/1 atrial flutter (n = 2) and atrial fibrillation (n = 1). Treatment was preventive with doses of 400 mg/day associated with carvedilol in one patient and 200 mg/day in another. The other five patients all received loading doses of 9200 +/- 2400 mg over 10 +/- 4 days. The symptoms were palpitations (n = 2) associated in one patient with hypotension, one syncope, one near syncope and one cardiogenic shock. The ventricular cycle of the 1/1 flutter was 287 +/- 33 ms. The QRS duration was 136 +/- 35 ms with ventricular tachycardia-like appearances in 3 cases. An adrenergic trigger factor was noted in 5 patients. One patient required emergency cardioversion. The authors discuss the physiopathology of 1/1 flutter and theoretical diagnostic methods are proposed. In conclusion, amiodarone does not always prevent the occurrence of 1/1 nodo-ventricular conduction in atrial flutter.

The authors report the case of a young man with idiopathic ventricular tachycardia occurring in bursts and arising from the pulmonary infundibulum. During follow-up, progressive, severe, dilated cardiomyopathy was observed. Radiofrequency ablation of the site of origin of this very active arrhythmia resulted in total regression of the cardiomyopathy. Contrary to generally accepted concepts, paroxystic ventricular tachycardia, usually qualified as benign, may be complicated by cardiomyopathy when the ventricular extrasystole is incessant and repetitive.

Non-coronary ST-segment elevation during right sided chest pain has been described in subjects with episodes of ventricular fibrillation at rest. This syndrome has been attributed to functional phenomena or to structural myocardial changes. A personal case has features belonging to two categories: ST-segment elevation observed before, during and after episodes of arrhythmia was compared to 11 previously recorded ECG recordings. Right ventricular dysplasia was shown by electrocardiography, electrophysiology and echocardiography. In addition, ST-segment elevation is classified in 3 categories: triangular and dome-shaped are the most commonly observed forms during the arrhythmias: the third form with "saddle"-shaped appearances has not been previously described and would seem to be a minor equivalent observed during intercritical periods. This form is found in 30% of clinically documented cases of arrhythmogenic right ventricular dysplasia.

Variations of temperature, impedance and power and the relationship between these three factors were studied in 20 patients during 351 applications of radiofrequency energy delivered by a generator with a regulated output power. The applications were divided into 3 groups according to the maximal temperature attained: group I (< 50 degrees C; n = 112), group II (50-60 degrees C; n = 100), and group III (60-70 degrees C; n = 139). Analysis of the total duration of time of applications (average +/- standard deviation) showed: the duration (seconds) was 23.9 +/- 11.9 seconds for group I, 36.1 +/- 18.7 seconds for group II and 45 +/- 23.6 seconds for group III. The time to attain maximal temperature was 6.8 +/- 9.6 seconds in group I, 11.7 +/- 12.7 in group II and 10 +/- 10.4 seconds in group III. The impedance remained under 200 omega in all applications, the target temperature being set at 70 degrees C. Analysis of the first three seconds of application: correlations coefficients between temperature and impedance were -0.08 (p < 0.001) in group I and -0.23 (p < 0.0001) in groups II and III. These coefficients were recalculated with respect to the average power delivered during the applications: < 40 watts (n = 79), r = -0.33; < 30 watts (n = 55), r = -0.41; < 20 watts (n = 33), r = 0.49 and < 10 watts (n = 15), r = -0.7 (p < 0.0001). The authors conclude that radiofrequency generators with thermal regulation allow early interruption of ineffective applications of radiofrequency and avoid increases in impedance. The poor correlations observed between increase in temperature (measured at the tip of the catheter) and the fall in impedance (related to tissue heating) for the first 3 groups, show that temperature alone is not a good indicator of contact. The improvement of the correlations for decreasing output power applications indicates better thermal transfer between the electrode and endocardium. Therefore a low power delivered in the first seconds at > 50 degrees C is to be interpreted as a marker of the quality of contact and a predictive factor of efficacy.

Radiofrequency energy was used for the ablation of chronic recurrent ventricular tachycardia (VT) in 58 patients who were divided into two groups: 44 cases with structural myocardial disease (36 men and 8 women: mean age 55 years; range: 14 to 85 years) with an average left ventricular ejection fraction of 38% (range: 15 to 80%): these patients had myocardial infarction (28 cases), arrhythmogenic right ventricular dysplasia (11 cases), idiopathic dilated cardiomyopathy (2 cases), operated congenital heart disease (2 cases) and operated valvular heart disease (1 case). The clinical success rate after the first session of radiofrequency ablation was 34%. When (according to our modified protocol of fulguration) 160 joule cathodal shocks were delivered to the same catheter previously used for RF ablation during the same session or secondarily (13 cases), the success rate increased to 76%. The average follow-up period of the 37 survivors was 16.7 months. The second group consists of 14 cases without structural myocardial disease (10 men and 4 women, mean age 41 years, range 14 to 69 years) with an average left ventricular ejection fraction of 61%. These patients had idiopathic ventricular tachycardia (10 cases) and verapamil-sensitive ventricular tachycardia (4 cases). The primary success of radiofrequency ablation alone was 43%. When combined with fulguration during the same of radiofrequency ablation alone was 43%. When combined fulguration during the same of at a later session, the success rate increased to 71.3%. The average follow-up period of the 13 survivors was 19 months (range 0.3 to 39 months). No significant difference was observed between the groups with or without structural myocardial disease after radiofrequency or fulguration ablation, not only with respect to global results but also after analysis of subgroups with, for example, post-infarction ventricular tachycardia or arrhythmogenic right ventricular dysplasia. However, clinical success was obtained after a single session of radiofrequency ablation alone in 8 of the 9 cases of incessant ventricular tachycardia in patients with structural myocardial disease.

The authors report 8 cases of regular tachycardia with wide QRS complexes during treatment with Vaughan-Williams class 1 antiarrhythmic drugs. These antiarrhythmics, prescribed to prevent atrial fibrillation (3 patients) and atrial flutter (5 patients), were flecainide in 4 cases, propafenone in 2 cases and cibenzoline and hydroquinidine respectively associated with digitoxine and propranolol. These wide complex tachycardias were regular atrial tachycardias with 1/1 conduction to the ventricle. The action of the drug, more pronounced on intra-atrial conduction velocities than on atrioventricular node refractoriness resulted in transformation of flutter at 300 cycles/min with 2/1 conduction and a ventricular rate of 150 cycles/min to atrial flutter at 210 cycles/min with 1/1 ventricular conduction. This acceleration of the ventricular rate was accompanied by widening of the QRS complex. Using the new ventricular tachycardia criteria recently published by Brugada resulted in a diagnostic error in 7 out of the 8 cases. The recording of a wide QRS complex tachycardia in a patient on class 1 antiarrhythmic therapy for an atrial arrhythmia should alert the physician to 1/1 atrial tachycardia despite morphological electrocardiographic criteria of ventricular tachycardia. The 1/1 atrial tachycardia may be poorly tolerated and require emergency treatment. The preventive association of a drug which slows conduction through the atrioventricular node is not always effective.

The authors propose a classification of the outcome of arrhythmogenic right ventricular dysplasia with reference to 4 selected cases with a follow-up period of over 9 years. In type I, the left ventricular ejection fraction is normal (EF > 50%) and the risk, exclusively arrhythmic, can be controlled by appropriate antiarrhythmic therapy. This is the commonest form of arrhythmogenic right ventricular dysplasia with different varieties according to the degree of dilatation of the right ventricle. In type II, there is a variable degree of left ventricular involvement (30 < EF < 50%) either by extension of a comparable disease process as observed in the right ventricle or by an isolated or superimposed phenomenon of myocarditis. This form is stable and may remain stable for many years providing the arrhythmias are correctly treated. In type III, progressive degradation of the myocardium is observed over a period of about 10 years with a clinical presentation comparable to that of certain arrhythmogenic dilated cardiomyopathies which are often hereditary. In this case, the patients have an arrhythmic risk associated with that of cardiac failure which becomes progressively irreversible. The histology shows interstitial fibrosis with biventricular lymphocytic infiltration suggesting an autoimmune phenomenon. Therefore, the classification of cases of arrhythmogenic right ventricular dysplasia depends on the potential evolutivity of the lesions. When the patient is seen in the early stages of the disease, the prognosis should be garded, especially in a hereditary form.

Three patients with typical histological signs of arrhythmogenic right ventricular dysplasia progressed to fulminating heart failure in 1 case and unexplained sudden death in the other two. There were signs of superacute myocarditis in the first case, previous healed pericarditis in the second and chronic myocarditis in the third case. These cases suggested the presence of an inflammatory process complicating the substrate of the dysplasia. Arrhythmogenic right ventricular dysplasia seems to be a developmental defect which is complicated in 50 to 70% of patients, according to a review of 74 cases reported in the literature, by a varying degree of myocarditis suggesting particular susceptibility of these patients to infection and explaining the presence of unusual amounts of fibrous tissue in some and the so called "progressive" nature of the disease in other patients.

Eighty-nine cases of ventricular tachycardia, resistant to antiarrhythmic therapy, were treated over a 10 year period by high energy D ablation (fulguration). This series included 37 cases of myocardial infarction with a mean ejection fraction of 30%. The mean follow-up period of the survivors was 61 months and clinical efficacy was 87.9%. Twenty-three cases of arrhythmogenic right ventricular dysplasia, aged 40 years, and with an ejection fraction of 57%, followed up for 71 months, had a clinical efficacy of 83%. Twelve patients had verapamil sensitive (fascicular) ventricular tachycardia. Their age was 30, their ejection fraction 65%, the follow-up period 55 months, and the clinical efficacy was 100%. Ten patients had primary dilated cardiomyopathy. Their age was 35, their ejection fraction 23%, the follow-up period of 38 months with a clinical efficacy of 80%. Four patients, aged 21, had operated congenital heart disease with an ejection fraction of 60%, a follow-up of 36 months and a clinical efficacy of 100%. Finally, 3 patients had idiopathic infundibular ventricular tachycardia. Their age was 36, the ejection fraction 62%, the follow-up period was 72 months and the clinical efficacy was 67%. Non lethal complications were observed in 16% of cases, mainly haemopericardium requiring pericardocentesis in 4.5% of cases. The operative mortality and in the month following ablation was 9.2%, observed mainly during the learning period. These results show that fulguration is not without risk, but in skilled hands, it gives remarkable results in the majority of cases.(ABSTRACT TRUNCATED AT 250 WORDS)

The indication for permanent pacing may be confirmed by a bradycardia counter in patients without ECG or Holter recording of the causal bradycardia. The algorithm was assessed in a multicenter register with the SORIN Theorema model. The activation of the device was programmed on a double hysteresis of 2 seconds with a programmable histogramme of detections and sensing and pacing counters. One hundred and forty five patients were recruited in 50 centers over 2 years: 89 men and 56 women aged 33 to 96 years (average 72 years), 87 of whom had no other obvious cardiac disease. One hundred and ten had typical syncopal episodes, 19 had atypical or minor syncopal attacks and 16 were asymptomatic, one with sinus node dysfunction and the others with pathological prolongation of the HV interval (> or = 70 ms) during endocavitary electrophysiological investigation. The mechanism of the bradycardia was considered to be infra-hisian in 62 patients who had HV intervals > or = 70 ms. This was also the probable mechanism in 20 others who had bundle branch block and typical syncope despite a HV interval < 70 ms and in 6 patients with bundle branch block and typical syncope who did not undergo electrophysiological investigation before implantation. Twenty one patients had sinus node dysfunction during electrophysiological investigation and 8 had a carotid sinus syndrome. The remaining 28 cases had transient syncope but no ECG changes or abnormality on electrophysiological investigation. Permanent pacing was proposed when an extracardiac origin of the syncope was excluded.(ABSTRACT TRUNCATED AT 250 WORDS)

Between 1983 and 1991, 86 cases of ventricular tachycardia (VT) resistant to antiarrhythmic therapy were treated by endocardious catheter fulguration: there were 21 cases of right ventricular dysplasia (RVD), 35 chronic myocardial infarctions (MI), 11 dilated cardiomyopathies (DCM), 10 bundle branch VT, 5 idiopathic septal VT, 3 operated Fallot procedures, 1 Ebstein's anomaly. There were 69 men and 17 women aged 14 to 76 years (average 45 +/- 18 years). The ejection fraction was under 30% in 37 cases. Forty-five VTs were permanent or recurred several times daily; 6 were inducible despite drug therapy and 35 patients had monthly recurrences. A total of 141 different forms of VT were treated in 133 procedures. One session was sufficient in 49 cases; 2 sessions were required in 29 cases; 3 sessions in 6 cases and 4 sessions in 2 cases. A total of 480 DC shocks were delivered with energies of 160 to 300 joules. The CPK-MB levels were 37 +/- 30 i.u./l. The following complications were observed: 7 perioperative deaths, 2 cardiac tamponades requiring surgical drainage, 1 permanent AV block, 5 reversible left ventricular failures. Follow up concerned 79 patients: 5 were followed up for less than 3 months with death occurring from cardiac failure which had been present before the ablation procedure without recurrence of VT. Seventy-four patients were followed up from 3 to 111 months (56 +/- 33 months). Thirty-two patients were without any antiarrhythmic therapy and had no recurrence of VT. Two of these patients developed a different form of VT 2 and 6 years after the catheter ablation.(ABSTRACT TRUNCATED AT 250 WORDS)

Sustained ventricular tachycardia in the absence of coronary artery disease is mainly observed in diffuse left ventricular cardiomyopathy especially dilated but sometimes hypertrophic, and in right sided cardiomyopathies such as ventricular dysplasia, more difficult to diagnose. More rarely, other localised abnormalities, mitral valve prolapse, cardiac tumour and idiopathic aneurysm, may give rise to this arrhythmia. Irrespective of the case, sustained ventricular tachycardia carries a poor prognosis during the most advanced stages of a myocardial disease. The therapeutic strategy remains the same as that of other cases of sustained ventricular tachycardia, drug therapy generally orientated by the results of programmed ventricular stimulation with the exception of Class I antiarrhythmics when the ejection fraction is under 30%, and non-pharmacological methods when drug therapy fails.

The authors report the first case of arrhythmogenic right ventricular dysplasia presenting with a sudden death due to primary ventricular fibrillation (ventricular fibrillation not preceded by ventricular tachycardia) recorded by the Holter method. The patient was a 56 year old man whose only complaint was near syncopal case is the fact that it is the first documented case of ventricular fibrillation revealing arrhythmogenic right ventricular dysplasia, the diagnosis of which was made at autopsy. In addition, the Holter recording showed the factors which triggered the arrhythmia: the "trigger" of 4 monomorphic ventricular extrasystoles during the minute preceding the ventricular fibrillation; the arrhythmogenic substrate giving rise to late ventricular potentials and, finally, the analysis of the R-R intervals suggesting a role of the sympathetic and parasympathetic nervous systems. Holter recordings could help identify subjects at high risk of severe ventricular arrhythmias.

Antiarrhythmic agents may be prescribed in the post-infarction period either as systematic therapy to prevent sudden death or as prophylactic treatment against recurrences of documented life-threatening arrhythmias. Systematic therapy or even the treatment of symptomatic ventricular extrasystoles by Class IC anti-arrhythmics is associated with an increased risk, especially in patients with a low risk of sudden death at the outset. Betablockers are effective on symptoms: they are not always effective on the arrhythmia but at least they do not aggravate the mortality of these patients. However, for high risk patients with post-infarction left ventricular dysfunction, betablockers are the only drugs which have a proven efficacy: they should therefore be prescribed, especially those whose efficacy has been demonstrated, at the same dosages as those used in clinical trials. Preventive treatment of sustained ventricular tachycardia should be chosen with respect to the patient's hemodynamic status. When the ejection fraction is under 40%, amiodarone and betablockers are the drugs of first intention, with controls of their efficacy by the inability to induce or the slowing of the tachycardia rhythm during endocavitary electrophysiological studies.

Doppler echocardiography was used to analyse transmitral blood flow in 23 patients undergoing DDD pacing under basal conditions at a pacing rate of 70/min. Changes in the atrioventricular delay led to changes in Doppler parameters corresponding to the different phases of ventricular filing. When the atrioventricular interval was increased, the maximum velocity, the velocity time integral and the duration of the E wave decreased and the maximum velocity, the velocity time integral and duration of the A wave increased. The atrial contribution to left ventricular filing increased by 15 to 46% (p less than 0.001). The changes of the Doppler parameters with respect to the duration of the atrioventricular interval varied according to the patient group studied. Patients without ventricular dilatation with or without hypertrophy had greater maximum velocities and velocity time integrals of the A wave than patients with left ventricular dilatation. However, for the same changes in atrioventricular delay, the A wave and atrial contribution to left ventricular filing were more variable in patients without left ventricular dilatation than those with left ventricular dilatation confirming the greater sensitivity of patients without left ventricular dilatation to the setting of the atrioventricular interval. These results confirm the great variability of transmitral flow with changes in atrioventricular delay. They illustrate the need for appropriate programming of the atrioventricular delay especially in patients in whom the mitral flow is most sensitive to this adjustment.

The roles of Holter monitoring and electrophysiological studies (EPS) in the evaluation of antiarrhythmic drugs for ventricular arrhythmias are to record their effects on ventricular extrasystoles (VES) and ventricular tachycardia (VT), and to search for undesirable rhythmological effects. The usual protocol is to perform baseline studies and then repeat them after a certain period of treatment using a number of modalities, comparison with placebo, control group, in acute or oral administration. Holter monitoring is an economical non-invasive method which carries no risk. Spontaneous arrhythmias of sufficient frequency to be recorded during the monitoring period can be studied. When applied to VES, it provides quantitative rather than qualitative information despite classifications such as Lown's. The results should be analysed taking spontaneous variations of the arrhythmia into consideration. Holter monitoring may also reveal proarrhythmic drug effects (bradycardia, torsades de pointe). However, there are no absolute criteria of efficacy except total suppression of VES, unexplainable by spontaneous variability. Holter antiarrhythmic studies require stable VES which creates a bias in the evaluation of results due to the special selection of patients. Electrophysiological studies are costly, invasive and uncomfortable but they are the only way of assessing paroxysmal VT apart from clinical follow-up. This method is only applicable to inducible VT, which is the commonest form. The investigating protocols are specific and reproducible: a tachycardia which is non-inducible does not recur in 90% of cases, which enables prediction of the antiarrhythmic effect.(ABSTRACT TRUNCATED AT 250 WORDS)

The increasing number of arrhythmogenic idiopathic cardiomyopathies with available histological studies by biopsy or peroperative sampling has prompted the need for data about the normal structure of the right ventricle. A retrospective study of right ventricular tissues was undertaken in 148 autopsies. The quantity of adipose tissue was scored 0 (only epicardial fat visible) to 4 (total replacement of the myocardium by adipose tissue). The topography of the adipocytes was also coded 0 to 4 according to the degree of intermyocytic penetration, irrespective of the total quantify of fat. The amount and extension of adipose tissue in the right ventricular wall was striking. Fifty called "normal" appearances with a myocytic wall of normal thickness and a separate layer of epicardial fat, were only present in 61 of the 148 cases. Adipocytes were present in variable numbers, often unexpectedly high in the majority of cases, with no relationship to the age or gender of the patient with frequent individualization of the myocardial bundles. These surprising findings in normal right ventricles should be born in mind when considering the diagnosis of arrhythmogenic right ventricular dysplasia (ARVD). The histopathological appearances of ARVD are very similar but also differ very significantly, at least in typical cases. The adipocytes are often present in large numbers but this is banal and non-specific. On the other hand, the bundles which penetrate the epicardial fat are usually fibro-muscular and not purely myocytic. In addition, arterioles suggesting segmental diversions are present within the fatty layer with non-specific inflammatory cells.(ABSTRACT TRUNCATED AT 250 WORDS)

The authors studied the value and limitations of Holter monitoring and electrophysiological investigation in the evaluation of treatment of sustained monomorphic ventricular tachycardia (VT). One hundred and twenty-four consecutive patients were included in the study from January 1981 to February 1988. The etiologies were chronic myocardial infarction (N = 54), dilated cardiomyopathy (N = 24), right ventricular dysplasia (N = 31), and idiopathic VT (N = 15). All the tachycardias could be induced during baseline electrophysiological investigations and presented as complex ventricular arrhythmias on the Holter recordings. The investigations were repeated after treatment which was maintained irrespective of the results, unless the tachycardia which was induced or recorded was over 130 cycles/min and/or poorly tolerated. Recurrence was defined as the recording of VT in the absence of a change of treatment and/or the occurrence of sudden death. The follow-up period averaged 29 +/- 21 months. The Kaplan-Meier method was used to study the prevalence of absence of recurrence and survival rates. We observed 28 recurrences of VT and there were 21 deaths. Eighty-five per cent of patients had normal Holter monitoring after treatment. The prevalence of absence of recurrence was 0.751 when the Holter was normal and 0.485 when an arrhythmia was recorded (p = 0.03). The sensitivity was 25 per cent and the specificity 88 per cent. The survival rates were 0.66 and 0.585 respectively (p = 0.008). Fifty-three per cent of patients remained inducible after treatment with a prevalence of absence of recurrence of 0.572. This value rose to 0.877 when VT could not be induced (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Arrhythmogenic right ventricular dysplasia has been described as a developmental malformation occurring during foetal life. This explains a number of familial cases of this condition where dysplasia was the result of a genetic abnormality transmitted in an autosomal dominant mode with incomplete penetrance. Histological data of peroperative or post-mortem specimens of 27 cases showed a large number of grape-like lymphoplasmocytic infiltrations. These appearances suggest an inflammatory origin of the disease, most probably related to an infective etiology. The authors suggest that in addition to the congenital form there may also be a possibility of acquiring arrhythmogenic right ventricular dysplasia after an episode of myocarditis.

The authors studied the influence on recurrence and mortality of induced ventricular arrhythmias during electrophysiological studies performed to assess the efficacy of treatment of sustained monomorphic ventricular tachycardia. One hundred and twenty-six consecutive patients investigated from 1981 to 1988 were included. The underlying pathology was chronic myocardial infarction (N = 56), dilated cardiomyopathy (N = 24), right ventricular dysplasia (N = 31) and there were 15 idiopathic cases. All these tachycardias could be induced during the control study. A second test was performed after instituting treatment. This was maintained whatever the result of the electrophysiological study except in patients in whom the tachycardia rate was over 130/mn and/or poorly tolerated. Recurrences were defined as the observation of tachycardia with the same morphology and/or the occurrence of sudden death. Follow-up averaged 29 +/- 21 months. The absence of recurrence and survival were assessed by the Kaplan-Meier method and Logrank's test. It was not possible to induce any arrhythmia after treatment in 52 patients (41%). The prevalence of absence of recurrence in this group was 0.863. If the induction of ventricular fibrillation, doublets or short runs of VT (N less than 6 with no recurrences) are included, the value increased to 0.877. These patients were considered to be non-inducible. The prevalence of absence of recurrence of arrhythmia in patients in whom it was possible to induce sustained ventricular tachycardia of the same morphology as the clinical arrhythmia was 0.512 (p = 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Ventricular pericardial cartography in sinus rhythm (SR) and during ventricular tachycardia (VT) in four cases of myocardial infarction has yielded additional information in the study of conduction disorders in myocardial ischaemia: 1. The significant slowing of activity in SR as well as in VT is demonstrated by this direct method. It is associated with a diminution in amplitude of the pericardial potentials in the zones affected by the ischaemia; 2. Cartography during VT accentuates or reveals disorders of conduction which are slight or latent in SR; 3. Disorders of intra-ventricular conduction are found to be related either to segmental blocks on the branches of the bundle of His, or as focal blocks (peri-infarct block) on the left side, whose nature can be shown up even during VT; 4. Secondary activation of the myocardial fiber found to be related either to segmental blocks on the bundle of His during VT is demonstrated.

Correlations between surface ECGs, epicardial mapping and histological data in 15 cases of arrhythmogenic right ventricular dysplasia (ARVD) provide information about the possible mechanism of intraventricular conduction defects in about one third of cases. Two cases in this series had complete right bundle branch block and 4 cases showed diffuse intraventricular conduction defects. The other cases had normal ECGs. The point of origin of the activation in 11 cases was situated in the left ventricle, even in 6 of the 9 cases with normal ECGs. The points of latest activation were located over the right ventricular free wall near the atrio-ventricular groove. However, in all cases but one, a normal right ventricular point of origin was observed, suggesting participation of the right bundle within a free wall showing delayed activation. This activation showed very irregular delayed propagation due to the zones of dysplasia. These results suggest that in ARVD, the mechanism of the conduction defects is not disease of the bundle branch itself but a distal block probably situated in the right ventricular wall. This hypothesis is supported by the histological appearances of the dysplastic zones.

We have studied a series of 330 Holter recordings (HR) (including 5 double observations) 189 men and 136 women, mean age 58,4 years Old. The analysis of this series shows that: --105 HR were performed on patients with focal ischemia attacks of suputed embolic origin; the HRT was positive in 35 patients (33 p. 100) with 25 supraventricular arrhythmias (SVA) 16 ventricular arrhythmias, associated in 9 cases, and 3 conduction blocks second degrees type 2. These arrhythmias are rare in patients under 40, increasing with age, and reaching 53 p. 100 in patients greater than 70 years. --86 HR were performed in ischemic heart disease (IHD): 52 HR for ST segment analysis, positive in 5 cases, and coexisting with chest pain in 4 cases; 34 HR for detecting arrhythmias in IHD, positive in 18 cases with 14 VA and 4 SVA. In 83 p. 100 the arrhythmias occur without IHD. They were positive in 70 cases, with 49 SVA, 34 VA, associated in 17 cases, and 4 blocks second degrees type 2. --10 cardiomyopathies were recorded; the HR was positive in 6, with 4 SVA, 3 VA associated in 1 case. --8 mitral valve prolapses were recorded with 5 VA and 1 SVA. In conclusion, the HR was positive in 45 p. 100 of the cases, and show especially the great incidence of asymptomatic VA in patients with IHD.

Unlabelled: Forty-four patients with ventricular tachycardias (VT) refractory to medical treatment underwent 73 sessions of endocavitary electrode catheter ablation. The clinical series included 16 cases of post-infarction VT, 14 cases of arrhythmogenic right ventricular dysplasia, 6 cases of dilated cardiomyopathy, 6 cases of idiopathic VT, 1 case of sequela of myocarditis and 1 case of VT consecutive to surgical repair of a congenital cardiopathy. Cardiomegaly was present in 30 patients, and 16 patients had an ejection fraction of less than 30 p. 100. None of the patients were receiving digitalis or class I antiarrhythmic drugs when ablation was performed. A total of 235 shocks of 100 to 320 J (mean 221 +/- 42 J) were delivered. 115 shocks (49 p. 100) were complicated by dysrhythmia and/or disorders of conduction; 29 shocks (12 p. 100) induced 13 ventricular fibrillations and 16 ventricular tachycardias. No relation was found between energy delivered, shock synchronization, haemodynamic status, heart cavity treated, underlying heart disease, CK MB levels and these arrhythmias. On the other hand, ablations performed while the patients were experiencing VT increased the risk of arrhythmia (p less than 0.02). 36 AV blocks, 21 left bundle branch blocks, 12 right bundle branch blocks and 11 sinus bradycardia were observed. With the exception of one right bundle branch block and one left posterior hemi-block, all blocks were transient., In Practice: (1) electrode catheter ablation may be complicated by disorders of cardiac rhythm or conduction in 50 p. 100 of the cases; (2) these disorders can easily be corrected by stimulation or defibrillation.(ABSTRACT TRUNCATED AT 250 WORDS)

In a population of 600 consecutive patients undergoing endocavitary electrophysiological study to assess nodal conduction, 40 had an atriohisian Wenckenbach point of over 200/mn. In 30 cases, vagal stimulation with ATP (10 to 40 mg IV) provoked an increase in atrioventricular conduction, with lengthening the AH interval by over 100 p. 100 or transient atrioventricular block. This increase allowed elimination of an accessory atriohisian pathway which could give similar high Wenckenbach points, but which do not show decremental conduction. In all our cases, the conduction passed through the artrioventricular node (AVN) whose response to rapid atrial stimulation was attenuated compared to normal. The parameter of this attenuated nodal response varied from case to case, but in general, the intervals were shorter than normal. The AH interval was less than 50 ms in 22 cases (N = 70 +/- 20 ms). The effective nodal refractory period was shorter than the functional atrial refractory period in 20 cases. The shortest atrial cycles transmitted 1/1 to the ventricles ranged from 230 to 300 ms (274 +/- 33 ms) (N = 375 +/- 40 ms). The functional structure of the AVN was studied by the lengthening of the AH interval with heart rate : 5 types were distinguished : 10 patients had progressive lengthening of AH interval greater than 100 ms (Type I) as in a normal AVN; 5 had progressive lengthening of AH interval of less than 50 ms (Type II), 5 had progressive lengthening of AH which then remained stable for a number of heart rates before lengthening again (Type III); 3 had an initial moderate lengthening of the AH interval which then became more rapid (Type IV) and 7 had no change in AH until 120/mn and then a progressive lengthening was observed (Type V). Two functional groups could also be identified depending on whether the lengthening was progressive, suggesting a single nodal pathway (Types I and II) or on whether differing increases were observed related to the atrial rate, suggesting two (Types IV and V) or even three (Type III) atrionodal or intranodal pathways with different refractory periods. Of these 30 patients, only 14 had documented supraventricular tachycardia, 13 being atrial fibrillation and the other a junctional tachycardia. Attenuated nodal behavior does not seem to be a direct cause of supraventricular arrhythmias but these arrhythmias were not tolerated as well because of the special properties of the atrioventricular node.

The natural history of disorders of conduction is imperfectly known. The presence of an HV interval of 70 milliseconds or more, which is regarded as pathological, usually results in pacemaker implantation. In this study the course of symptoms and disorders of conduction was investigated in 97 patients with an HV interval of 70 ms or more, and therefore equipped with a pacemaker, followed up for a mean period of 26.5 +/- 19.5 months. Among these 97 patients, 65 had presented with one or several syncopes, 14 had experienced feelings of faintness and 18 were asymptomatic. Among patients with symptoms, these totally disappeared in 63 and became milder in the remaining 12 patients. Complete and permanent AV block was observed in 11 patients. The actuarial incidence of complete permanent AV block was about 5 p. 100 per annum until 4 years. The only predictive parameter for such a course was the occurrence of a second degree type 2 or a third degree paroxysmal block prior to pacemaker implantation (significantly associated with the absence of symptoms).

Between October 1973 and December 1981, 31 symptomatic patients who underwent pacemaker therapy on the results of a positive Ajmaline test alone, showing infrahisian AV block, were followed up clinically and electrocardiographically. The mean follow up from the date of implantation was 30 months. Two groups of patients were identified according to the results of electrophysiological investigations and clinical and electrocardiographic follow-up: --group I: 13 patients with either infrahisian AV block or an HV interval greater than or equal to 120 ms after Ajmaline; --group II: 18 patients with an HV interval less than 120 ms after Ajmaline. During follow-up, the 5 AV blocks observed out of the 7 documented at inhibition of the pacemaker and the only two cases of deterioration of the intraventricular conduction during sinus rhythm occurred in Group I. The only discriminating variable between the two groups before the implantation of a pacemaker was the response to the Ajmaline test. The difference of the results of the electrical outcome between the two groups was statistically significant (p less than 0,03). During the same study period this critical value was observed in 49 other patients with a basal HV greater than or equal to 70 ms. In this group, 20 developed infrahisian AV block after Ajmaline, 26 had a HV interval greater than or equal to 120 ms and only 3 cases had HV intervals of 100 ms. These results suggest that a HV interval greater than or equal to 120 ms after Ajmaline has the same significance as infrahisian block produced by the drug.

Two patients, aged 52 and 55 years, were admitted to hospital for attacks of recurrent ventricular tachycardia for which preventive treatment was difficult. The crises were of one type, with left-sided delay. The findings on clinical examination, electrocardiography, haemodynamic and arteriographic investigation and at post-mortem were those of the parchment right ventricle syndrome of the adult. Electrophysiological investigation in the 2 cases indicated that a re-entry mechanism underlay the attacks of tachycardia. Late activation of the pulmonary infundibulum was responsible for a post-excitation potential on the surface and intra-cavitary leads. Mapping carried out during ventricular tachycardia in one case demonstrated the pathway for re-entry at the level of the pulmonary infundibulum.

Electrophysiological investigation and pericardial mapping have succeeded in isolating a particular type of ventricular tachycardia occurring in young subjects with no coronary artery disease who have dysplasia of the right ventricle. When these patients are no longer controlled by medical treatment, they may benefit from surgery. This condition is characterised by the presence of delayed potentials which appear after the end of ventricular depolarisation as recorded by épicardial mapping. This post-excitation phenomenom may also be demonstrated either by an intracavitary electrode or sometimes on an amplified ECG. This study describes a new method using the techniques of signal averaging and summation technique to demonstrate the delayed potential in the post-excitation syndrome. It is non-invasive, and seems to give better results than those obtained from intracavitary exploration.

A comparison between the epicardial siting of the zone of pre-excitation of the ventricle in Wolff-Parkinson-White syndrome and the ECG has allowed us to distinguish 6 topographical types, according to the orientation of the delta wave in the horizontal plane, and especially in the frontal plane which is often ignored: right anterior, left lateral, right of left anterior paraseptal, and right or left posterior paraseptal. The association of a heart defect with ventricular hypertrophy, or the coexistence of several associated accessory pathways prevents such correlation and makes it imperative to carry out intracavitary investigation and epicardial mapping to localise the accessory pathway if surgery is contemplated.

Right ventricular dysplasia (RVD) is characterised by fatty and fibrous infiltration of the right ventricular wall and usually presents clinically with ventricular arrhythmias. The aim of this study was to determine the morphological changes of RVD and establish diagnostic criteria applicable in cases with atypical clinical signs or electrocardiographic changes. The angiocardiographic data of 10 cases of RVD was reviewed. 8 cases were complicated by right ventricular arrhythmias. The other 2 cases were not arrhythmogenic but had highly suggestive ECG changes; there were no other causes of right ventricular disease. Selective right ventriculography was performed with the catheter positioned in the inflow tract distal to the moderator band. In the 8 cases without tricuspid regurgitation there was one constant finding: the presence of parietal fissuration with massive impregnation of the ventricle distal to the moderator band. Two signs were commonly observed; the stagnation of contrast in the inferior regions of the right ventricle during left ventricular opacification (6/8 cases); irregular opacification of the pulmonary infundibulum (5/8 cases); an infundibulor aneurysm was observed in 1 case. Biometrical data was normal in all 8 cases compared with a control group of 10 normal subjects: the right ventricular disease was segmental and not diffuse. It was associated with a moderate alteration of left ventricular function and with segmental abnormalities of wall motion in 2 cases. None of these signs were observed in the right ventriculographies of 7 cases of typical dilated cardiom-opathies. These 4 signs were not found in 2 cases with tricuspid regurgitation where changes were essentially limited to a dilatation of the right ventricular inflow tract.(ABSTRACT TRUNCATED AT 250 WORDS)

Programmed cardiac stimulation may be performed externally using implanted radiofrequency receiving capsules. Between 1979 and 1984, 44 patients underwent implantation of these devices, 12 with atrial leads for supraventricular tachycardias (8 orthodromic reciprocating tachycardias, 1 intranodal junctional tachycardia and 3 atrial tachycardias), and 32 with ventricular leads for ventricular tachycardias. In the first case the transmitter was given to the patients so that they could terminate the tachycardias themselves. In the second case, the transmitter was kept in the cardiology department. All patients were also prescribed prophylactic antiarrhythmic drugs. The radiofrequency method was effective in 11 out of 12 cases of supraventricular tachycardia with a follow-up period ranging from 24 to 65 months (average 45 +/- 11 months). In the ventricular tachycardia group, the device was used in 11 patients to terminate ventricular tachycardia and in all patients to evaluate the efficacy of the antiarrhythmic therapy by provocative programmed stimulation with a follow-up ranging from 2 to 81 month (average 24 +/- 20 months). This palliative therapeutic method has reduced the number of hospital admissions in these patients. The indications are relatively few because of the efficacy of currently available antiarrhythmic agents and the possibility of radical treatment of tachyarrhythmias by surgery or catheter ablation.

Sudden death is rare in athletes, and it is only in recent years that significant series were collected, making it possible to draw the cardiological profile of athletes who died suddenly at the peak of exertion or while recovering. A study of the literature, both medical and paramedical, has yielded 53 cases in which the most frequent causes of sudden death were hypertrophic cardiomyopathy (26 p. 100), (arrhythmogenic right ventricular disease (19 p. 100), congenital abnormalities of coronary arteries (11 p. 100) and coronary atheromatous lesions (9 p. 100), to which must be added various other causes. This study clearly demonstrates the hitherto unrecognized importance of arrhythmogenic right ventricular dysplasia-a condition which, as recent data suggest, is not solely due to a myocardial development disorder but also to an infective disease, an acute of chronic myocarditis. In subjects with this condition, new exploratory methods might detect the presence of an arrhythmogenic substrate during medical screening of athletes, but in any case these causes of sudden death suggest that a fast rhythm disorder was involved in several of these deaths. This disorder could be treated if the attendants were trained to carry out cardiorespiratory resuscitation procedures or if they had access to a defibrillator which should be available on every sports field.

The superior vena cava syndrome is an exceptionally rare complication of endocavitary cardiac pacing, asymptomatic venous thrombosis being much more common. Two cases wee observed as late complications of pacemaker implantation. In the first case the clinical signs regressed with the development of a collateral circulation under heparin therapy after failure of fibrinolytic drugs. In the second one, the severity of the superior vena cava syndrome and the poor quality of the collateral circulation led to the implantation of a Gore-Tex prosthesis. This surgical bypass led to a rapid and complete regression of the clinical signs. It would seem to be a valuable alternative when anticoagulant therapy fails.

Pacemaker implantation is seldom as a treatment of ventricular tachycardia after chronic myocardial infarction. In this new case, pacemaker implantation was successfull for over a year after partial surgery failure. A regular demand pacemaker with bipolar pervenous catheter inserted in the coronary sinus is to give atrial orthorhythmic pacing triggered by ventricular arrhythmias.