Role of manual compression time and bed rest duration on the occurrence of femoral bleeding complications after sheath retrieval following 4Fr left-sided cardiac catheterization.

To shorten hospital stay or to allow ambulatory procedures, 4Fr catheters for left-sided cardiac catheterization can be used. These latter parameters may also be influenced by compression time and bed rest duration. The role of these parameters was assessed by prospectively including 130 consecutive patients who underwent 4Fr femoral diagnostic procedures. The patients were randomized into two groups: group 1 consisted of 70 patients undergoing 5-minute compression and group 2 consisted of 60 patients with 15-minute compression. In each group, a second randomization was applied to determine the bed rest duration (2-4 hours). More group 1 patients experienced immediate bleeding following manual compression than group 2 patients (12 [17%] vs 3 [5%], P < 0.03, respectively). Compared to group 2, a slight but nonsignificant increase in the total number of hematomas was observed in group 1 (31 vs 22%, NS). No difference existed in terms of local large hematomas at 24 hours (7% in each group) or in terms of benign > or = 10 cm diffuse subcutaneous ecchymosis at 7-day follow-up (13 [19%] group 1 patients vs 8 [13%] group 2 patients, NS). However, persistence of diffuse subcutaneous ecchymosis at 7-day follow-up appeared to be related to the history of immediate bleeding following manual compression in both groups (group 1: 5/13 vs 7/57 patients [P < 0.04] and group 2: 3/8 vs 0/52 patients [P < 0.002]). In conclusion, 4Fr femoral left-sided cardiac catheterization is safe and could be performed as an ambulatory procedure. However, it requires 15-minute duration of manual compression associated with 2-hour bed rest to decrease local bleeding complications.

Role of the etiology of cardiomyopathies on exercise capacity and oxygen consumption in patients with severe congestive heart failure.

Peak oxygen consumption is of great importance for the decision of heart transplantation in congestive heart failure. Moreover, the level of exercise capacity seems to depend on the etiology of congestive heart failure. This study compared 14 heart failure patients with idiopathic dilated cardiomyopathy (group 1) to 14 heart failure patients with cardiomyopathy due to ischemic heart disease (group 2), matched for sex (13 male, one female in each group), age +/-10 years, left ventricular ejection fraction +/-5% and pulmonary artery mean pressure +/-5 mm Hg, to assess exercise capacity and oxygen consumption independently of the age, sex and the level of left ventricular dysfunction. Right ventricular function was also assessed. No difference existed in terms of right ventricular parameters. Maximal exercise parameters were significantly higher in group 1 than in group 2. Peak oxygen consumption was statistically higher in group 1 than in group 2. In the whole population, a significant correlation was found between peak oxygen consumption and right ventricular ejection fraction (r=0. 44, P<0.02) but not between peak oxygen consumption and left ventricular ejection fraction. For similar levels of left ventricular dysfunction, exercise capacity and oxygen consumption appear to be better in idiopathic dilated cardiomyopathy than in ischemic cardiomyopathy, thereby suggesting that functional tolerance of left ventricular dysfunction might depend on the etiology of severe congestive heart failure.

Long-term outcome in patients treated by intracoronary stenting with ticlopidine and aspirin, and deleterious prognostic role of unstable angina pectoris.

Compared with stable clinical conditions, unstable angina carries an increased risk of immediate and delayed cardiac adverse events after balloon coronary angioplasty. The influence of stent use in reducing these differences remains unknown. We analyzed the early (30 days) and late outcome of a cohort of 459 consecutive patients who underwent stent placement with ticlopidine and aspirin as antithrombotic regimen according to the presence (group 1, n = 151) or absence (group 2, n = 308) of unstable angina at rest (Braunwald classes II and III). Group 1 patients were older and more likely to be current or former smokers. In group 2, prior myocardial infarction was more frequent. Procedural, in-hospital results, and early outcome were similar in the 2 groups. However, over the long term, the incidence of myocardial infarction (11% vs 6%, p <0.04), target lesion revascularization (19% vs 13%, p <0.04), or any revascularization (30% vs 20%, p <0.01) was significantly higher in group 1. Kaplan-Meier probabilities of survival without myocardial infarction (85% vs 91%, p <0.05), survival without revascularization of the target lesion (73% vs 83%, p <0.01), survival without any revascularization (65% vs 77%, p <0.006), and survival without any events (61% vs 73%, p <0.009) were significantly worse in group 1. In addition, Cox multivariate analysis showed that unstable angina at rest was an independent predictor of target lesion revascularization, of survival without any revascularization, and without any events. Thus, unstable angina at rest remains an adverse prognostic indicator in patients treated with intracoronary stents, particularly with regard to subsequent requirement of revascularization procedures and event-free survival.

[Changes in velocity of left ventricular filling measured by color M-mode during dobutamine stress echocardiography]. / Evolution de la vitesse de propagation du flux de remplissage ventriculaire gauche mesurée en TM couleur au cours de l'échocardiographie de stress à la dobutamine.

Myocardial ischaemia affects left ventricular relaxation. The velocity of propagation of rapid left ventricular filling flow (VPF, cm/s) measured by colour M-mode is strongly correlated with the haemodynamic constant of left ventricular relaxation (Tau). The authors compared the changes in VPF during stress echocardiography with Dobutamine in a control group of non-coronary patients (Group 1, N = 12) and a group of coronary patients (Group 2, N = 29). Coronary angiography was performed in all patients. The basal VPF were similar in both groups (Group 1: 68.3 +/- 22.7 cm/s vs Group 2: 66.2 +/- 23.1 cm/s, NS). The VPF at the peak of dobutamine infusion were significantly different from the values observed under basal conditions in Group 1 (105.1 +/- 25.0 cm/s, p < 0.001) whereas this difference was not significant in Group 2 (67.4 +/- 19.3 cm/s, NS). There were significant differences between the two groups for peak values (p < 0.001) and for percentage variation of VPF (peak-basal value/basal value) with respect to the basal values (Group 1: 63 +/- 43% vs Group 2: 9 +/- 39%, p < 0.01). A percentage variation of VPF < 25% (Group 1: 3/12 patients and Group 2: 23/29 patients) allows detection of coronary artery disease with a sensitivity of 79% and a specificity of 75%. During Dobutamine infusion, the velocity of propagation of left ventricular filling flow increases less in coronary patients than in non-coronary patients. The study of this quantitative parameter of left ventricular relaxation seems to be a valuable tool for detecting the presence of coronary artery disease during stress echocardiography.

[Long-term follow up of 115 patients with ischemic heart disease and ventricular flutter induced by programmed ventricular stimulation in the absence of ventricular arrhythmia]. / Suivi à long terme de 115 patients atteints de cardiopathie ischémique avec flutter ventriculaire déclenché lors d'une stimulation ventriculaire programmée en l'absence de trouble du rythme ventriculaire soutenu spontané documenté.

The clinical significance of rapid monomorphic ventricular tachycardia (VT) (> 270 beats/min), also called ventricular flutter, remains controversial in patients without documented spontaneous sustained VT. The aim of this study was to evaluate the outcome of 115 patients with ischaemic heart disease, aged 58 +/- 10 years, without spontaneous ventricular arrhythmias, but who had inducible ventricular flutter during programmed ventricular stimulation. The patients underwent stimulation to evaluate the prognosis after myocardial infarction or to investigate a malaise with or without loss of consciousness. Sustained ventricular flutter was the only inducible arrhythmia in all patients. The mean left ventricular ejection fraction (LVEF) was 42 +/- 14%. During an average follow-up period of 66 +/- 43 months, 31 deaths, including 27 of cardiac causes, were observed. The 1, 5, and 11 year survival of the whole population was 94, 79 and 64% respectively. In univariate analysis, anterior wall myocardial infarction, a low LVEF, the presence of non-sustained ventricular tachycardia (NSVT) on 24 hour Holter monitoring and Class III antiarrhythmic treatment, were poor prognostic factors (p 0.05). In multivariate analysis, the only independent predictive factors of mortality were low LVEF (p = 0.006), the presence of NSVT on Holter monitoring (p = 0.003) and the absence of betablocker therapy (p = 0.015). Medical therapy with betablockers or the implantation of an automatic defibrillator may be indicated in these patients at higher risk.

[Evaluation of high amplification ECG and the study of sinus variability in the detection of patients at risk of sudden death]. / Evaluation de l'ECG à haute amplification et de l'étude de la variabilité sinusale pour le dépistage des patients à risque de mort subite.

In order to define the best strategy of prognostic evaluation in relation to patients in heart failure, 415 patients with impaired left ventricular function (ejection fraction < 40%) were prospectively included, between June 1993 and 1996, in a study comparing the respective value of high amplification ECG and Holter analysis of sinus variability, 308 patients in sinus rhythm and narrow QRS complexes were included. The patients were distributed into 4 groups according to the presence or absence of late potentials and altered sinus variability (group I with 2 normal examinations, group II with late potentials and normal variability, group III without late potentials, but with altered variability and group IV with 2 abnormal examinations). The sudden and overall mortality was significantly greater in groups III (28 and 11%) and IV (28 and 9%) than in group I (7 and 3%) and II (11 and 2%). The presence of potential was unable to identify patients at risk of ventricular tachycardia and sudden death. In another 60 patients with complete branch block, the prognosis was also correlated with the alteration of sinus variability. In conclusion, high amplification ECG correctly evaluated the prognosis of subjects in heart failure. However, analysis of sinus variability should be systematically proposed to detect subjects at high risk of mortality, whether the subject has large or narrow QRS complexes.

[Influence of time (4 years) on the results of programmed ventricular stimulation]. / Influence du temps (4 ans) sur les résultats de la stimulation ventriculaire programmée.

The reproducibility of programmed ventricular stimulation has been previously demonstrated for periods of a few hours to several months. It has not been studied over longer intervals. The aim of this study was to assess the reproducibility of the method at long-term (> 2 years). Forty-six patients with underlying cardiac disease underwent two programmed ventricular stimulations in the absence of antiarrhythmic treatment at intervals of 2 to 6 years (mean 4 years). None of the patients had myocardial infarction or cardiac surgery during this period. The protocol was identical: up to 3 extra-stimuli were delivered in the two right ventricular sites over 3 cycles. Twenty-eight patients had inducible sustained monomorphic ventricular tachycardia during the first investigation (Group I): the investigation was negative in the remaining 18 patients (Group II). During the second investigation, 26 of the 28 patients in Group I had inducible ventricular tachycardia, the rate of which decreased from 206 +/- 50 bpm to 196 +/- 54 bpm. The induced ventricular tachycardia was slower in 15 patients and faster in 5 patients. The mode of induction was different in 12 cases. In Group II, 4 patients (22%) had inducible sustained ventricular tachycardia at the second investigation. The authors conclude that the reproducibility of programmed ventricular stimulation remains good in the long-term in subjects within inducible tachycardia, demonstrating the stability of the arrhythmogenic substrate; the frequency of this tachycardia is generally slower. In subjects with an abnormal initial investigation who became symptomatic, it may be useful to repeat programmed ventricular stimulation.

[Reproducibility of heart rate variability in the chronic phase of myocardial infarction]. / Reproductibilité de la variabilité de la fréquence cardiaque à distance de la phase aiguë de l'infarctus du myocarde.

Evaluation of heart rate variability is a common method of assessing autonomic nervous system function and its effects on heart rate in different conditions. The reproducibility of the technique is not known in the chronic phase of myocardial infarction. The aim of this study was therefore to assess the reproducibility of the measurement in 54 subjects who were clinically stable with no change in treatment at a distance from acute or semi-recent (> 2 years) myocardial infarction, after an interval of one month. The temporal and spectral analysis of heart rate variability included measurement of the standard deviation of the normal RR intervals (SDNN), on the mean heart rate, the percentage of RR intervals greater than 50 ms than the adjacent interval (pNN50), the coefficient of variability (CV), the square root of the differences between successive RR intervals (rMSSD), the power of low frequencies (LF) and high frequencies (HF) and of the fractional spectral power (LF/HF). No significant changes in these parameters were observed. Analysis of individual variations showed that the heart rate was the most stable parameter: for evaluation of vagal tone, the rMSSD showed less variability than the pNN50 and HF. The presence of cardiac disease did not influence these results. The authors conclude that parameters of evaluation of heart rate variability in temporal and spectral analysis are globally reproducible in stable subjects. However, individual values may change from one measurement to another. Nevertheless, abnormal variability is constantly observed at the second investigation and, similarly, normal variability also remains unchanged. These individual variations suggest that, for the demonstration of change in these parameters of variability with treatment, large population groups must be studied.

Increased atrial vulnerability in arrhythmogenic right ventricular disease.

Supraventricular tachyarrhythmias (SVTA) may occur in patients with the arrhythmogenic right ventricular dysplasia (ARVD). The purpose of the study was to evaluate the incidence of SVTA in 47 patients with ARVD proved by right ventricular angiography. Thirty-three men and 14 women, aged 21 to 72 years (mean 44 +/- 18) were admitted for nonsustained or sustained ventricular tachycardia. Eight patients had a history of spontaneous SVTA several years before ventricular tachycardia occurrence. Protocol of the study consisted of programmed atrial stimulation with one and two extrastimuli delivered during sinus rhythm and two driven rhythms (600 and 400 msec), programmed ventricular stimulation with up to three extrastimuli and was performed in the control state and after infusion of isoproterenol. The results of programmed atrial stimulation were compared with those obtained in 36 asymptomatic subjects without heart disease and with a mean age of 50 +/- 18 years (control group). Sustained SVTA (> 1 minute) was induced in seven of eight patients with spontaneous SVTA, in 27 (69%) of those with ARVD, who did not have spontaneous SVTA, and in two control subjects (5.5%) (p < 0.001). SVTA was inducible in the control state, but ventricular tachycardia induction required isoproterenol in 11 of 27 patients. Two patients without SVTA history but with inducible SVTA developed later spontaneous SVTA. ARVD was associated with a significantly higher incidence of inducible SVTA than in a control population. Supraventricular tachycardias may precede ventricular tachycardias. This association argues for a diffuse myocardial disorder in ARVD.

[Can 1/1 atrial flutter be foreseen by class I anti-arrhythmics?]. / Peut-on prévoir le flutter 1/1 sous antiarythmiques de classe I?

1/1 atrial tachycardia or "quinidine" flutter under class I antiarrhythmic drugs is a serious complication of these agents which, unfortunately, cannot be anticipated. The aim of this study was to review the cases of 11 patients who had suffered this complication of class I antiarrhythmic therapy to see if it could have been prevented. All drugs of this class were included. The 11 subjects were aged 57 to 78: 7 had no apparent underlying cardiac disease and the others had valvular (n = 1), hypertensive (n = 1) and ischaemic (n = 2) heart disease. They were treated for episodes of paroxysmal atrial fibrillation or tachycardia. In the absence of treatment, 7 patients had a short PR interval on the ECG (PR between 0.11 and 0.14 s). In the other 4, the PR interval was normal (0.16 to 0.20 s), but the P wave was widened with appearances of left atrial hypertrophy or an intra-atrial conduction defect. High amplification ECG performed in 3 patients showed continuity of atrial and ventricular depolarisation. Atrial stimulation showed excellent nodal conduction with a Wenckebach point of 200/min. The authors conclude that a short PR interval is predisposing factor to 1/1 atrial tachycardia with class I antiarrhythmics. High amplification ECG which allows identification of the end of the P wave with respect to the QRS complex could help identify subjects at risk when the P wave is widened and that, consequently, the PR interval appears to be normal.

Clinical and bacteriological characteristics of infective endocarditis in the elderly.

OBJECTIVE: To determine the clinical and bacteriological features of infective endocarditis in the elderly. DESIGN: Prospective case series. SETTING: A university hospital that is both a referral and a primary care centre. PATIENTS: 114 consecutive patients treated for infective endocarditis from November 1990 to December 1993: 25 were > 70 years of age (group 1) and 89 were < 70 years old (group 2). RESULTS: Location of infective endocarditis, clinical signs, and symptoms were similar in the two groups, except for a lower occurrence of embolic episodes in the elderly (group 1:8%, group 2: 28%; P < 0.04). A higher rate of infective endocarditis on intracardiac prosthetic devices was noted in group 1 (group 1: 52%, group 2: 25%; P < 0.05). The distribution of causative micro-organisms showed a higher proportion of bacteria from the gastrointestinal tract in the elderly (group D streptococci and enterococci: 48% in group 1 v 20% in group 2) and the presumed portal of entry was more often digestive (group 1: 50%, group 2: 17%; P = 0.01). Elderly patients were less often operated on (group 1: 24%, group 2: 43%; P = 0.07) and their mortality rate was higher (group 1: 28%, group 2: 13%; P = 0.08). CONCLUSIONS: Infective endocarditis in patients over 70 often occurs in those with intracardiac prosthetic devices and is more often due to bacteria from the gastrointestinal tract. Its prognosis appears to be worse than in younger subjects.

The signal-averaged electrocardiogram is of limited value in patients with bundle branch block and dilated cardiomyopathy in predicting inducible ventricular tachycardia or death.

An abnormal signal-averaged electrocardiogram (SAECG) has predictive value for arrhythmic events in patients with idiopathic dilated cardiomyopathy and a normal conduction. The purpose of this study was to investigate whether the presence of a complete bundle branch block (BBB) affects prognostic information of the SAECG. We prospectively obtained SAECGs in 128 patients with idiopathic dilated cardiomyopathy. Forty-three of them had BBB and 85 had a normal QRS duration. According to their clinical history and results of ventricular programmed stimulation, patients were divided into 4 groups: (1) group IA with BBB and ventricular tachycardia (VT) (n = 18); (2) group IB with BBB but without VT (n = 25); (3) group IIA without BBB but with VT (n = 40); (4) group IIB without BBB and without VT (n = 45). Patients were compared with 129 patients without heart disease and without VT. Fifty-seven of them had BBB (group III) and 72 had normal conduction (group IV). The filtered QRS duration was longer in group IB than in group III (175 +/- 21 vs 149 +/- 16 ms, p <0.001), and in group IIB than in group IV (111 +/- 19 vs 96 +/- 12 ms, p <0.05). QRS duration was similar in groups IA and IB (176 +/- 24 vs 175 +/- 21 ms) but longer in group IIA than in group IIB (131 +/- 24 vs 111 +/- 19 ms, p <0.001). The low-amplitude signal duration (LAS) and the root-mean-square voltage (RMS) of the last 40 ms of the filtered QRS did not differ between groups IB and III and IA and IB. LAS and RMS were, respectively, longer (44 +/- 20 vs 31 +/- 13 ms, p <0.01) and lower (21 +/- 20 vs 43 +/- 33 microV, p <0.001) in groups IIA and IIB. In groups IA and IB the combination of 2 of the 3 available criteria: QRS duration >170 ms, RMS <20 microV, LAS >45 ms lead up to the best overall statistical result, with a sensitivity and specificity of 78% and 56%, respectively. In groups IIA and IIB, using conventional late potential criteria, the sensitivity and specificity of the SAECG for VT detection were 65% and 73%, respectively. The risk of sudden death was not predicted by the SAECG, and total cardiac mortality was only dependent on left ventricular ejection fraction. In conclusion, QRS duration was prolonged in all of the patients with a dilated cardiomyopathy compared with those without heart disease. BBB did not change the sensitivity but decreased the specificity of the SAECG to predict any VT risk in dilated cardiomyopathy. The risk of sudden death and total cardiac mortality could not be predicted by the SAECG.

[Analysis of heart rate variability before and at the moment of cardiac death]. / Analyse de la variabilité sinusale avant et au moment du décès de cause cardiaque.

The study of heart rate variability is a new means of assessing autonomic nervous system function and the risks of cardiac and sudden death in patients with advandec cardiac disease. The aim of this study was to analyse changes in heart rate variability in the hours preceding cardiac death and just before its occurrence. Seventeen subjects aged 78.5 +/- 10 years, with advanced cardiac disease responsible for a reduction of left ventricular ejection fraction below 40%, died during Holter ECG recording. Ten died of ventricular fibrillation, 5 of bradycardia and 2 of non-rhythmic causes. General analysis of heart rate variability showed a decrease in all but 1 patient, the average standard deviation of normal RR intervals in subjects in sinus rhythm being 53 +/- 14 msec and the fractioned spectral power (low frequency/high frequency power) being 1 +/- .07. The change in heart rate variability did not allow prediction of the mechanism of death: the mean heart rate only increased before death in 3 of the patients with an ischaemic component in the hours before death, the indices of vagal tone were very low in the majority of patients and, just before death, a disequilibrium between the spectral powers with a sudden increase in LF/HF ratio of 10 of the 17 patients, irrespective of the cause of death, appeared. In conclusion, a decrease in heart rate variability was observed in all cases but did not predict the mechanism of death. Just before death occurred, some patients, especially those with acute ischaemia, showed a sudden change in the indices of heart rate variability indicating a terminal vaso-sympathetic disequilibrium.

[Long-term reproducibility of programmed atrial stimulation]. / Reproductibilité à long-terme de la stimulation auriculaire programmée.

Programmed atrial stimulation is a technique increasingly used to assess different pathologies but the reproducibility of the results is totally unknown. The aim of this study was to determine its reproducibility. Two electrophysiological studies were undertaken without antiarrhythmic therapy in an interval of one to three months (average 18 months) in 48 patients. The programmed atrial stimulation used 1 and 2 extrastimuli delivered in sinus rhythm and then three paced rhythms (sinus cycle -10%, 600 ms, 400 ms). Twenty-one patients had documented atrial arrhythmias (atrial fibrillation n = 13, flutter n = 3 or tachycardia n = 5) (group 1) and the 27 other patients had no spontaneous arrhythmias (group II). In group I, clinical tachycardial was reproduced in 18 patients during the initial stimulation procedure. During the second investigation, 17 remained inducible and in the 3 in whom stimulation was negative, it remained so in 2 of the cases. The reproducibility was therefore 90%. In group II, 12 patients had inducible sustained (for over 1 minute) tachycardia during the first procedure (44%) but this only remained inducible in 6 patients. In the other 15 subjects, stimulation was negative during the first procedure but 7 of them had inducible tachycardial during the second procedure. The reproducibility of the technique was therefore only of 52%. The authors conclude that the reproducibility of programmed atrial stimulation in patients with documented spontaneous paroxysmal arrhythmias is excellent. However, the reproducibility is mediocre in subjects without spontaneous arrhythmias and the induction of tachycardial in this group of patients should be interpreted with caution given the variability of the response to programmed atrial stimulation.

Bradycardia-induced polymorphic ventricular tachycardia after radiofrequency catheter modification of atrioventricular junction.

We report the case of a 59-year-old man with a dilated nonischemic cardiomyopathy who had chronic rapid atrial fibrillation despite several therapies. Radiofrequency modification of the atrioventricular (AV) junction slowed the mean ventricular rate from 120 beats per minute (bpm) to 60 bpm. Five hours after the procedure and during the following 1 week, despite ventricular pacing at 90 bpm, the patient developed nonsustained or sustained polymorphic ventricular tachycardias. Finally, pacing at 90 bpm was successfully used in this patient. In conclusion, patients who have undergone modification of AV conduction may be at high risk of life-threatening ventricular arrhythmias in the first week following the procedure.

[Prognostic value of serial electrophysiological tests in inducible sustained ventricular tachyarrhythmias]. / Intérêt pronostique des explorations électrophysiologiques sériées dans les tachyarythmies ventriculaires soutenues inductibles.

The authors report the results of a study evaluating serial electrophysiological tests on a series of 166 patients with inducible sustained ventricular tachyarrhythmia. The initial electrophysiological investigation was indicated because of sustained ventricular arrhythmias documented in 95 patients or suspected in 71 symptomatic patients. Serial tests allowed identification of a protective antiarrhythmic treatment (non-inducible ventricular tachycardia) in 74 responding patients (44.6%) (group R) after 1.3 +/- 0.5 therapeutic trials versus 1.8 +/- 0.8 inconclusive trials in 92 non responding patients (group NR). Multivariate analysis demonstrated the absence of any underlying ischaemic heart disease (p < 0.01) and the presence of spontaneous ventricular fibrillation (p < 0.01) as independent predictive factors of success during serial testing. A follow-up of 43 +/- 29 months was available for 151 patients (91%). kaplan-Meier survival curves showed a better long-term prognosis for group R with survival rates of 97%, 87% and 70% at 1.3 and 6 years, respectively, versus 83%, 68% and 45% for group NR. Two variables were considered on multivariate analysis to be predictive factors of survival: left ventricular ejection fraction (p < 0.001) and response to serial electrophysiological tests (p < 0.02). Therapeutic ventricular pacing therefore remains a reliable method to select patients whose prognosis is improved with antiarrhythmic treatment after induction of sustained ventricular arrhythmia.

[Should protocol of programmed ventricular stimulation be adapted to each patient? ]. / Le protocole de stimulation ventriculaire programmée doit-il être adapté a chaque malade?

The authors report the case of a 56 year old patient in whom the mechanisms of a wide QRS complex tachycardia recorded on an intensive care monitor could not be determined. The patient also had episodes of atrial flutter with left bundle branch block. Programmed ventricular stimulation with 3 extrastimuli triggered a non-specific ventricular flutter. One week later, the patient was resuscitated from a cardiac arrest which was undocumented. It was therefore important to elucidate the mechanism of the initial tachycardia. A second session of programmed ventricular stimulation was undertaken. As the use of 2 extrastimuli triggered runs of unsustained polymorphic ventricular tachycardia, the classical protocol was stopped. An infusion of low-dose isoproterenol was used to repeat programmed stimulation with a single extrastimulus. This protocol triggered sustained monomorphic ventricular tachycardia at 240/min. The diagnosis of ventricular tachycardia could therefore be continued.

[Myocarditis of pseudo-infarctoid onset]. / Les myocardites à début pseudo-infarctoïde.

The authors report two cases of myocarditis in young individuals in whom clinical and electrocardiographic findings during the acute phase could have led to an erroneous diagnosis of myocardial infarction. The problem in such cases is that of a differential diagnosis with infarction with normal coronary arteries. Few clinical or paraclinical arguments are of diagnostic value, endomyocardial biopsy remaining the reference investigation. Proof of viral infection is not always obtained. It is often the retrospective argument of "complete return to normal" which supports the clinical impression. This usual benign outcome is not always the case, since cases of cardiogenic shock have been reported. The dual nature of the pathogenesis ("myositis" and/or "vasculitis" with thrombus and actual MI) is stressed.