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.

[Comparison of patients with paroxysmal junctional tachycardia and syncope with those without syncope]

INTRODUCTION

The purpose of the study was to determine the possible mechanisms of presyncope in patients who have paroxysmal junctional tachycardias (PJT) and a normal surface ECG between tachycardias.

METHODS

Among 419 patients consecutively recruited for PJT, aged from 10 to 88 years (47+/-19), 78 of them had presented at least one syncope; they had a normal ECG in sinus rhythm. Transesophageal programmed atrial stimulation was performed using one and two atrial extrastimuli delivered in control state and if necessary after infusion of 20-30 microg of isoproterenol; arterial blood pressure was monitored; vagal maneuvers and tilt test (n=25) were performed; echocardiogram was systematic.

RESULTS

Age, sex, method of induction, tachycardia mechanism and the mean heart rate in tachycardia were similar in patients with and without syncope. Syncope was related to a vagal reaction induced by the PJT in 31 patients, to a fast rate during PJT in 15 patients, to a sinus node dysfunction in six patients, to a coronary ischemia in five patients, to a tetany induced by PJT in three patients, to an advanced age in three patients, to multiple causes in three patients and remained unexplained in eight patients. Radiofrequency ablation of reentrant circuit, performed in 28 patients, suppressed syncope in 26 of them.

CONCLUSION

Presyncope or syncope occurred in 18% of patients who had a history of paroxysmal junctional tachycardia. Several mechanisms were implicated; the most frequent causes were coronary ischemia or sick sinus syndrome in old patients, vasovagal reaction or fast rate in tachycardia or tetany in patients of all ages.

Incomplete bundle-branch block and ST-segment elevation: syndrome associated with sustained monomorphic ventricular tachycardia in patients with apparently normal heart

This paper reports on three cases of patients with an apparently normal heart admitted for sustained monomorphic ventricular tachycardia. The only abnormal finding showed in the electrocardiogram (ECG) in sinus rhythm that exhibited an entity associated with incomplete right bundle-branch block and persistent ST-segment elevation. The ECG entity was variable and disappeared transiently. Spontaneous ventricular tachycardia in one patient was inducible by programmed stimulation. There was no underlying heart disease. The origin of the ventricular tachycardia in one patient was located by pace mapping in the left ventricle at the left ventricular basal septum. The follow-up (from 6 months up to 6 years) demonstrated a good prognosis. This particular ECG entity associated with monomorphic ventricular tachycardia could have been missed because of the variations in the ECG in sinus rhythm and was associated with a favorable prognosis.

[Relationships between age and accessory pathway location in Wolff-Parkinson-White syndrome]

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.

Wolff-Parkinson-White syndrome in the elderly: clinical and electrophysiological findings

BACKGROUND

Screening for Wolff-Parkinson-White (WPW) syndrome is recommended in children and young adults. The aim of this study was to evaluate the clinical and electrophysiological characteristics of patent WPW syndrome in subjects > or =60 years of age.

METHODS

Four-hundred and fifty-nine consecutive patients with WPW syndrome, aged 8-80 years, were recruited; 32 (7%) of these patients were > or =60 years of age. The clinical, electrophysiological and therapeutic data for these patients were evaluated.

RESULTS

Sixteen men and 16 women, aged 60-81 years (67+/-4.5), were admitted for resuscitated sudden death (1), rapid atrial fibrillation (4), syncope (4), or junctional tachycardia (13); 10 patients were asymptomatic (10). Left lateral bundles of Kent were detected more frequently in patients over 60 years (56%) than in those<60 years of age (40.5%). Reciprocal tachycardia was induced in 58% of subjects<60 years of age and 53% of those > or =60 years old (difference not significant); atrial fibrillation was more frequent in subjects > or =60 years of age (37.5% vs. 19%) (p<0.05). The incidence of malignant forms of WPW syndrome was identical in older and younger subjects. Ablation of the accessory pathway was indicated 18 times; effective ablation of a left bundle of Kent required a second intervention more often in patients > or =60 years of age (22% vs. 5%) (p<0.05).

CONCLUSION

WPW syndrome is not uncommon in subjects over 60 years of age (7%). Left lateral accessory pathways, that have similar conduction properties to those in much younger subjects, are common. Ablation of the bundle of Kent is often difficult but is indicated in symptomatic subjects or those with more serious forms of WPW syndrome.

[Bi-tachycardia and ischemic cardiopathy (following myocardial infarction)]

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.

[Dilated cardiomyopathy and syncope: management]

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.

Interest of non-invasive and semi-invasive testings in asymptomatic children with pre-excitation syndrome

AIMS

To determine the feasibility and the results of exercise testing (ET) and electrophysiological study (EPS) in outpatient asymptomatic children with a Wolff-Parkinson-White (WPW) syndrome.

METHODS AND RESULTS

Exercise testing and transesophageal EPS were performed in 55 outpatient asymptomatic children aged 6 to 19 years old (14 +/- 3) with WPW. Wolff-Parkinson-White persisted during maximal exercise. Isoproterenol was not required in five children younger than 10 years old, because they developed a catecholaminergic sinus tachycardia. Maximal rate conducted through accessory pathway (AP) was higher in children younger than 16 years old than in teenagers (P < 0.05). Atrioventricular re-entrant tachycardia (AVRT) was induced in six children; atrial fibrillation (AF) in 12 children. The induction of tachycardias and the dangerous forms (18%) were not influenced by age. After 5 +/- 1 years, one child, 12 year old with inducible rapid AF, had a sudden cardiac arrest; two children became symptomatic after ablation.

CONCLUSIONS

Transesophageal EPS was required to determine the prognosis of asymptomatic WPW in children. The maximal rate conducted in AP was higher in children younger than 16 years old than in teenagers; other data did not differ. AVRT was rare; 71% of children had no inducible arrhythmia and were authorized to resume physical activities.

[Significance of permanent atrial fibrillation in idiopathic dilated cardiomyopathy]

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.

[Cognitive impairment induced by digoxin intake in patients older than 65 years]

Cognitive impairment or clinical signs of dementia in an old patient who receives digoxin, should suggest a digitalis intoxication. Symptoms can be present although a normal digoxin serum concentration. It is recommended to stop the treatment to obtain a regression of dementia symptoms.

Experimental evaluation of a common susceptibility to motion sickness and vasovagal syncope in children

In children, vasovagal syncope (VVS) is the most common cause of syncope and motion sickness (MS) is also very frequent, with many symptoms of an autonomic nature. To study a possible relationship between VVS susceptibility and MS susceptibility in young patients, 21 children (10 boys, 11.3+/-2.6 years) with recurrent syncope or presyncope were explored with a questionnaire concerning their vasovagal symptoms, susceptibility to MS and familial history. A tilt-table test and a dynamic posturography with Equitest (Sensory Organisation Test (SOT), in six conditions) were performed. Children were divided into two groups: A with a positive tilt-table test and particular susceptibility to VVS (n=13/21, six boys) and B with negative tilt-table test. A control group of 30 healthy children (15 boys, 11.4+/-2.4 years) was studied for MS susceptibility and familial history. VVS susceptibility was related to MS susceptibility (MS susceptibility was 69.3% in Group A versus 12.5% in Group B (p=0.0237) and 16.7% in control group (p=0.0028)) and also to SOT scores which are related both to the role of vestibule in equilibrium and to MS susceptibility, with lower values in Group A than Group B (condition 5: 47.9+/-12.3% versus 66.0+/-13.8%, p=0.0189 and vestibular (ratio of conditions 5/1): 51.8+/-12.7% versus 71.3+/-13.5%, p=0.0147). Our study demonstrates, for the first time, a relationship between VVS susceptibility and MS susceptibility in a population of children with a particular susceptibility to VVS. This paradigm may prove useful in better understanding the mechanisms underlying the susceptibility to VVS and MS.

[Influence of age on the presumed cause of syncope in patients with the Wolff-Parkinson-White syndrome]

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.

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.

[Prevalence of sudden cardiac death during sports activities]

Sudden death during sport is a rare and unexpected event. It essentially affects young males, and a cardiomyopathy that had not been diagnosed during medical examinations is present in the majority of cases. In young subjects, there is generally hypertrophic cardiomyopathy or arhythmogenic right ventricular dysplasia. This is revealed during sporting activity, and sudden death is often the first symptom of the disease. Competitive sport increases the relative risk of sudden death to 2.5 compared to the risk in a non-sporting subject. The prevalence of sudden death during competitive sport is poorly understood. From the rare studies available, it could be estimated at 2.3/100,000 athletes per year. In Europe, it essentially occurs during football matches. However, the prevalence of sudden death during so-called 'recreational' sports is not precisely known. It could be much higher because these activities involve a larger number of people, and take place without supervision and usually without a medical examination beforehand. The participants are older, and coronary pathology is usually implicated.

[Respective interest of two techniques of electrophysiological study in patient without heart disease]

Electrophysiologic study (EPS) frequently is required to assess the prognosis of asymptomatic Wolff-Parkinson-White syndrome (WPW) or to prove the nature of no documented tachycardia. EPS usually is performed by intracardiac route and hospitalization is required. Similar data are given by an EPS performed by oesophageal route during a consultation. The purpose of the study was to evaluate the cost of both techniques in France. Transesophageal EPS was performed during a consultation in 100 patients with asymptomatic WPW syndrome and 100 patients with no heart disease, complaining of no documented tachycardias with abrupt beginning and end, suggesting a paroxysmal junctional re-entrant tachycardia (PJRT). The cost of transesophageal study including isoproterenol infusion is 127.75 euros. The cost of intracardiac EPS is at least 1460 euros, cost of hospitalization during only one day.

RESULTS

In patients with WPW syndrome, 15 had a potentially malignant form with the induction of a tachycardia conducted through the accessory pathway at a high rate (> 240/min in control state, > 300/min with isoproterenol); radiofrequency catheter ablation was indicated in a second time. In the group with no documented tachycardia, PJRT was induced in 30 patients and indication of ablation was discussed. In other 155 patients with either a benign form of WPW syndrome or with a tachycardia unrelated to a PJRT, hospitalization was not required; in these patients, intracardiac study performed during one day of hospitalization would have costed 226,300 Euros. The cost for the esophageal EPS and a similar diagnosis was 19,801 Euros, with a save money of 206,499 Euros. In 45 patients in whom hospitalization was indicated in a second time to perform catheter ablation of the arrhythmia, the cost related to esophageal EPS was 5749 Euros. In the total group, considering the final diagnosis and the need of hospitalization in 45 patients, the save money related to the use of esophageal EPS was 206,499 E-5749 E = 200,750 euros.

CONCLUSIONS

We should take into account the cost studies, when various techniques could be used for a similar diagnosis. There are important differences in the cost of diagnostic methods and it is easy to decrease this cost.

[Association of Wolff-Parkinson-White syndrome with isolated non-compaction of the left ventricle: a case report]

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.