Pharmacological testing in the diagnosis of arrhythmias.

Pharmacological testing has several indications in the diagnosis of arrhythmia. It is used for the diagnosis of bradycardia-related syncope either during non invasive tests as adenosine triphosphate (ATP) for the diagnosis of vasovagal syncope, but also for the diagnosis of sick sinus syndrome or isoproterenol infusion during the head up tilt test to induce a vasovagal syncope or during electrophysiological study to look for infrahisian AV block or organic sick sinus syndrome after injection of Ajmaline or to know if sick sinus syndrome or suprahisian AV block are reversible after atropine and are vagal-related. It is used for the diagnosis of supraventricular and ventricular tachycardia; isoproterenol is largely used generally during electrophysiological study. The infusion of isoproterenol is required in exercise-related arrhythmias, in arrhythmogenic right ventricular cardiomyopathy, in idiopathic ventricular tachycardia and in idiopathic dilated cardiomyopathy. ATP can be used to induce a vagal-related atrial fibrillation and may help to differentiate a reentry through accessory pathway or AV nodal re-entrant tachycardia. It is used for the detection and the evaluation of prognosis of some diseases at risk of sudden death. Isoproterenol infusion is required in the preexcitation syndrome to look for the shortening of accessory refractory period. Ajmaline or flecaïnide injection is mandatory in the family of a patient with a Brugada syndrome to detect the disease.

The management of arrhythmic sincope.

Arrhythmic syncope explains 5% to 20% of the causes of syncope and its incidence increases with age. In patients with arrhythmic syncope, a poor prognosis can be expected if syncope is misdiagnosed, particularly when arrhythmias occur in a patient with advanced heart disease. Arrhythmic causes are due either to bradycardia (diagnosed by surface electrocardiography, 24-hour Holter monitoring and electrophysiologic study in patients with bundle-branch block) or to supraventricular or ventricular tachycardia (diagnosed by electrophysiologic study and/or long-term event recording). Arrhythmic syncope can be easily prevented with antiarrhythmic drugs or, more frequently, with non-medical treatments such as radiofrequency ablation of tachycardia, and pacemaker or defibrillator implantation.

[Relationships between age and accessory pathway location in Wolff-Parkinson-White syndrome]. / Rapports entre l'âge et l'incidence d'une voie accessoire atrioventriculaire de localisation antéroseptale dans le syndrome Wolff-Parkinson-White.

BACKGROUND: Radiofrequency ablation of atrioventricular accessory pathway (AP) which is currently used, remains associated with a risk of complete AV block in the case of anteroseptal (AS) location and its indication remains debatable. The purpose of the study was to evaluate the frequency of AS location in Wolff-Parkinson-White syndrome (WPW) and the clinical and electrophysiological data of these patients. METHODS: Electrophysiologic study (EPS) was performed in 503 pts aged from six to 85 years (35+/-17), 297 men, 206 women, recruited for a patent WPW syndrome. The location of AP was determined on a 12 lead ECG during atrial pacing at maximal preexcitation according to classical criteria. The location was confirmed at EPS. Eleven pts were excluded because the location remained not clearly defined. EPS was indicated for suspected or documented tachycardias (n=264), syncope (n=68) or was systematic in asymptomatic patients (n=171). RESULTS: AS AP location was identified in 34 patients aged eight to 48 years (7%). Their mean age was younger than the age of remaining population (25+/-13 versus 36+/-17, p<0.001). According to the age, the prevalence of AS location was significantly higher in children and adolescents (14%) than after 40 years (3%) (p<0.01). There was no AS location among 108 patients aged more than 50 years. The maximal rate conducted over AP was lower in patients with AS location than in other locations either in control state (174+/-60 per minute versus 197+/-63 per minute) (p<0.01) or after isoproterenol (206+/-71 versus 248+/-69) (p<0.01). The number of induced reciprocating tachycardia (47% versus 57.5%), atrial fibrillation (15% versus 21%) and malign forms (12% versus 17%) did not differ significantly in patients with AS location and in other patients. Anterograde conduction disappeared spontaneously in three of six patients followed 8+/-1.5 years, and significantly increased in two other patients. CONCLUSIONS: AS AP location in WPW syndrome was more frequent in children than in adults. The maximal rate conducted over the AP was lower than in other locations. The incidence decreased after 40 years. AS AP location was never noted after 50 years in our population. This disappearance with age should be taken into account for the indications of AS AP ablation.

[Dilated cardiomyopathy and syncope: management]. / Cardiomyopathie dilatée et syncope: conduite à tenir.

Syncope occurring in patients with primary dilated cardiac disease has several causes: ventricular tachycardia (VT), a major severe cause of this diagnosis, occurring however only in one third of cases. The other causes are supraventricular tachycardia, bradycardia and vagal hyperactivity. The management depends on the etiology of syncope in one hand and the severity of the cardiac disease and other comorbidities in the other hand. In 2007, a patient with life expectancy exceeding one year, without irreducible heart failure but with a known and stable altered left ventricular ejection fraction (LVEF)<30%, will probably benefit of non-drug technology for the treatment of syncope (defibrillator with or without resynchronization), possibly in association with the treatment of another identified etiology, such as ablation or anti-arrhythmic treatment of a supraventricular tachycardia. In a patient with LVEF>30%, the electrophysiology exploration remains the most reliable recommended investigation for identifying the cause of syncope prior to discuss the implantation of a portable Holter device, indicated when the electrophysiology study is negative and syncope repeating.

[Bi-tachycardia and ischemic cardiopathy (following myocardial infarction)]. / Bitachycardies et cardiopathies d'origine ischémique (antécédent d'infarctus du myocarde).

OBJECTIVE: The association of supraventricular tachycardia (SVT) and ventricular tachycardia (VT) is not common. The aim of this study was to evaluate its incidence and possible predisposing factors in patients with a history of myocardial infarction (MI), in order to correct them. METHODS: Out of 359 patients consecutively recruited for spontaneous VT occurring at least one month after the acute phase of an MI, 33 were noted to have a possible association of SVT with VT. These patients underwent the following investigations: Holter recording, left ventricular ejection fraction (LVEF) measurement, and electrophysiological studies including programmed atrial and ventricular pacing. RESULTS: The LEVF was 37.5+/-11%. An SVT was induced in 21 patients and a VT in 31 patients. Following investigation, the presumed factor predisposing to the two tachycardias was considered to be initiation of an SVT associated with rapid nodal conduction to the ventricle (Wenckebach point 210+/-23/mn) in 12 patients, branch to branch re-entry in 4 patients, reversible rhythmic dilated cardiomyopathy in 4 patients, an ischemic factor in 8 patients, post-operative period in 1 subject, infundibular VT in 1 subject, and an undetermined mechanism in 3 patients. The specific treatment of each of the identified etiologies usually prevented the recurrence of VT with the exception of one patient who had further VT during defibrillator recording, independent of any SVT. CONCLUSION: The association of SVT with VT is rare because it was only noted in 9% of subjects who presented with spontaneous VT following myocardial infarction; This incidence is debatable, and could be an underestimate due to the fact that diagnosis is difficult. Several presumed predisposing factors are implicated and should be actively sought.

[Influence of age on the presumed cause of syncope in patients with the Wolff-Parkinson-White syndrome]. / Influence de l'âge sur la cause présumée des syncopes en cas de syndrome de Wolff-Parkinson-White.

The aim of this study was to assess the causes of syncope in patients with the Wolff-Parkinson-White syndrome (WPW) and to determine whether the age of the patients was a significant factor. Forty-seven patients with a WPW, aged 11 to 72 years, underwent electrophysiological study by the oesophageal approach because of an unexplained syncope. Nineteen patients were under 20 years of age (16 +/- 3 years: group I) and 28 were over 20 years of age (40 +/- 13 years: group II). Junctional tachycardia was induced in 8 patients of group I (42%) and in 13 of group II (46%) (NS); atrial fibrillation was induced in 8 patients of group I (42%) and in 9 of group II (35%) (NS). A potentially malignant form of WPW was identified in 8 patients of group I (42%) and in 11 of group II (39%) (NS); Syncope was directly attributed to the WPW in 14 patients of group I (74%) and in 19 of group II (78%), either after identification of a serious form or induction of junctional tachycardia (6 patients of group I and 8 of group II). The rest of the syncopal episodes had various causes. There were no deaths. The authors conclude that oesophageal electrophysiological investigations enable rapid identification of a high incidence of tachycardias probably responsible for syncope in WPW. The causes of syncope and incidence of potentially severe forms of WPW were not significantly influenced by the age of the patients.

[Mycotic coronary aneurysm with Escherichia coli sepsis: a case report]. / Anévrisme coronaire mycotique consécutif à une septicémie à Escherichia coli: à propos d'un cas.

We report the case of a patient who was admitted for acute coronary syndrom associated with fever originating from urinary tract. Coronary arteriography revealed a huge coronary aneurysm which ruptured a short time after diagnosis. After surgery, it was proven to be mycotic aneurysm related to Escherichia Coli sepsis.

[Significance of permanent atrial fibrillation in idiopathic dilated cardiomyopathy]. / Signification de la fibrillation auriculaire permanente dans la cardiomyopathie dilatée primitive.

UNLABELLED: The significance of atrial fibrillation (AF) in idiopathic dilated cardiomyopathy (IDCM) remains discussed. The purpose of the study was to evaluate the clinical significance of permanent atrial fibrillation in patients with IDCM. METHODS: Systematic noninvasive and invasive studies including Holter monitoring, measurement of left ventricular ejection fraction (LVEF), electrophysiological study and coronary angiography were performed in 323 patients with IDCM; all patients had a left ventricular ejection fraction (LVEF)<40%. The studies were indicated for spontaneous ventricular tachycardia (VT) in 69 patients, syncope in 103 patients and nonsustained VT on Holter monitoring in 151 asymptomatic patients. Sixty-five patients were in permanent AF (group I). Remaining patients were in sinus rhythm at the time of evaluation (group II). Programmed ventricular stimulation using up to 3 extrastimuli in control state and if necessary after isoproterenol was systematic. Patients were followed 3+/-2 years. RESULTS: Mean age was significantly older in group I (61+/-8 years) than in group II (52+/-12) (P<0.01). Syncope (31 vs 36%), spontaneous sustained VT (18 vs 23%); mean LVEF (28+/-9% vs 29+/-9%), VT induction (25 vs 35%) were similar in both groups. During the follow-up, there were no statistical differences between groups I and II concerning each event: sudden death occurred in 13 patients, 1.5% of group I patients and 5% of group II patients (NS); a death related to heart failure occurred 22 patients, 5% of group I patients and 7% of group II patients (NS); heart transplantation was performed in 13 patients, 8% of group I patients and 3% of group II patients (NS). CONCLUSIONS: An older age is the only significant clinical factor associated with the presence of a permanent atrial fibrillation in idiopathic dilated cardiomyopathy. The presence of permanent AF does not increase the induction of a sustained ventricular tachycardia and does not affect the general prognosis of IDCM.

Supraventricular tachyarrhythmia as a cause of sudden cardiac arrest.

INTRODUCTION: Supraventricular tachyarrhythmias (SVTA) are an accepted cause of cardiac arrest in patients with Wolff-Parkinson-White syndrome (WPW) and hypertrophic cardiomyopathy but their participation in other conditions is less well understood. The purpose of the study was to examine the role of SVTA in sudden cardiac arrest (SCA) by comprehensive evaluation of patients successfully resuscitated from SCA. METHODS: A total of 169 survivors of SCA in the absence of acute myocardial infarction underwent systematic evaluation that included echocardiography, Holter monitoring, coronary angiography and electrophysiological study (EPS) with additional testing in selected cases using provocative drug testing with isoproterenol, ajmaline or ergonovine. RESULTS: SVTA was found as the only possible cause or as the cause facilitating SCA in 29 patients: (1) 3 had a WPW syndrome related to accessory pathway with short refractory period; (2) for 12 patients, SVTA was the cause of cardiovascular collapse; heart disease (HD) was present in 11 cases, but disappeared in two of four with dilated cardiomyopathy after the restoration of sinus rhythm; (3) in 14 patients, SVTA degenerated either in a VF or ventricular tachycardia (VT); HD was present in 12 cases, but disappeared in one; two had no HD and recurrent similar arrhythmia was documented by cardiac defibrillator in one of them. SVTA induced coronary ischemia was the main cause of SCA. CONCLUSION: Rapid SVTA was a cause of SCA, either by cardiovascular collapse or by the degeneration in VT or VF. The complication generally occurred in patients with advanced HD or with rapid SVTA-induced cardiomyopathy and rarely in patients without HD. The incidence of SVTA as the only cause or the facilitating cause of SCAs is probably underestimated, because it is difficult to prove.

[Association of Wolff-Parkinson-White syndrome with isolated non-compaction of the left ventricle: a case report]. / Association du syndrome de Wolff-Parkinson-White a une non-compaction isolée du ventricule gauche. A propos d'un cas.

The Wolff-Parkinson-White syndrome (WPW) may be associated with a number of cardiac pathologies, especially congenital disease, in 7.5 to 17% of cases. The authors report a rare association of the WPW syndrome with two Kent bundles, right and left septal, with non-compaction of the left ventricle in a 52 year old man. This was a chance finding during systematic echocardiography after ablation, and confirmed by cardiac MRI. The patient was asymptomatic.