Recurrence Of Syncope Research Articles

885 The bradycardia-hypotension reaction during head-up tilt test: clinical and hemodynamic characteristics related to blood pressure and heart rate behavior during the early stage of the test

There was no correlation between delayed increase of aldosterone and NTG provocation during HUT. The delayed increase of aldosterone observed in 22% of all patients was related to syncope recurrence during follow-up, but not to the phase of tilt in which syncope occurred. Conclusions: 1. The delayed increase of aldosterone concentration during HUT-induced syncope is a risk factor of syncope recurrence during follow-up. 2. The delayed increase of aldosterone could be the marker of disturbed activation of RAA system predisposing the patients to vasovagal syncope.

883 The lack of significant activation of RAA system during tilt-induced VVS is a risk factor for syncope recurrence during follow-up

883 The lack of significant activation of RAA system during tilt-induced VVS is a risk factor for syncope recurrence during follow-up

733 Vasovagal syncope: prognostic factors for syncope recurrences

733 Vasovagal syncope: prognostic factors for syncope recurrences

883 The lack of significant activation of RAA system during tilt-induced VVS is a risk factor for syncope recurrence during follow-up

883 The lack of significant activation of RAA system during tilt-induced VVS is a risk factor for syncope recurrence during follow-up

733 Vasovagal syncope: prognostic factors for syncope recurrences

value from Mann-Whitney test. Standard deviation of the normal-to-normal beat interval averages calculated over 5 minutes (SDANN) and lowfrequency power (LF% n.u.) were significantly lower in ARVD patients than in healthy controls; there were no differences in measures of parasympathetic activity. There were no significant differences in QTc duration between groups. However, QT variability was increased and QT/RR slopes were steeper in ARVD patients than in controls. Conclusions: Young ARVD patients show decreased heart rate variability, increased QT variability, and signs of abnormal QT adaptation that might contribute to an increased risk of arrhythmic events.

Apport du test à l'adénosine-5′-triphosphate (ATP) dans l'évaluation diagnostique et l'approche thérapeutique des syncopes d'origine indéterminée (vasovagale ou neurocardiogénique)

The prevalence of syncope increases in elderly population. An inappropriate reflex reaction of the autonomous nervous system in specific circumstances is responsible for symptoms in more than 50% of cases. These neurocardiogenic or vasovagal syncopes are due to a vasoplegia or to a cardio-inhibitory reflex or to the association of both mechanisms. Reproducing the symptoms may contribute to identify the responsible mechanism of syncope; this objective is partly reached by the head-up tilt test — a provocative test —, which reproduces symptoms in about half of the cases, mainly by provoking a severe vasodilation with fall of blood pressure. On the opposite, the ATP test (20 mg i.v. bolus) — a descriptive test — provokes a strong cardio-inhibitory reflex independent from external factors like body position but it must be undertaken in a calm environment for preventing any anticipative sympathetic reaction. The test is considered positive if ATP produces a cardiac pause longer than 10 seconds and related symptoms are not taken into account for assessing the final result. ATP test positivity increases with age and with the presence of cardiac diseases. Permanent dual chamber pacing at 70 bpm has been shown to reduce significantly the syncope recurrences in patients with positive ATP test and to have no influence on patients with a negative test. The use of ATP test should be extended to all syncope screening. Its positivity identifies a group of patients in whom the mechanism of the syncope is susceptible to be improved by a permanent dual chamber pacing.

The usage and diagnostic yield of the implantable loop-recorder in detection of the mechanism of syncope and in guiding effective antiarrhythmic therapy in older people

To evaluate the usage and diagnostic yield of the implantable loop-recorder (ILR) in detection of the mechanism of syncope and in guiding therapy in patients aged >/=65 years and comparing them with those <65 years. This was a two-hospital, observational, prospective study in consecutive patients with unexplained syncope who underwent an ILR implantation. Between November 1997 and December 2002, a total of 2052 patients with syncope were evaluated (local population of 590,000 inhabitants). The diagnosis remained unexplained in 371 (18%). Of these, 103 patients (5% of the total, 28% of those with unexplained syncope) received an ILR. There were 70 (76%) patients aged >/=65 years and 25 (24%) <65 years. ILR implantation was 110 and 9 per million inhabitants per year, respectively. During a mean follow-up of 14+/-10 months, syncope was recorded in 52 patients. Compared with younger patients those older had a 2.7 higher syncope recurrence rate (56% vs 32%, P=0.03); arrhythmias were 3.1 times more likely to be responsible for syncope (44% vs 20%, P=0.03). More patients >/=65 years finally received ILR-guided therapy (42% vs 20%, P=0.04). Among the 29 patients (25 of those >/=65 years) who received specific antiarrhythmic therapy, only one (3%), had recurrence of syncope during the subsequent follow-up of 40+/-18 months. In patients referred for investigation of unexplained syncope, the older subjects are more likely to have an indication for ILR implantation than those younger, ILR has a higher diagnostic value, an arrhythmia is more likely to be detected and successfully treated.

Implantable loop recorder for the evaluation of unexplained syncope: diagmostic contribution of the automatic and of manual activation of the device

Aim Our experience with implantable loop recorder (ILR) for patients (pts) with unexplained syncope is reported, focusing on the relative diagnostic contribution of the manual and the automatic activation of the device. Methods According to the European Society of Cardiology Guidelines on Syncope, an ILR was reserved to: a) pts with structural heart disease and syncope unexplained after a complete diagnostic workup; b) pts without heart disease but with recurrent, severe syncope. Pts implanted with an ILR underwent elective controls every four months; further, urgent controls were planned in the case of syncope recurrence. Results Between 15/11/02 and 22/11/04, 14 pts (M/F 4/9, age 77±9, 8 with heart disease) were implanted with an ILR. After a 7±7 months follow-up, 25 elective and 5 urgent controls were performed. Among the 5 pts with syncope recurrence, only 2 were able to manually activate the device, and in both cases a bradyarrhythmia was detected. In further 2 pts the mechanism of syncope was detected by the automatic activation of the device corresponding to the spontaneous symptoms. During the elective controls further 239 automatic activations were detected, but none of these was diagnostic. Conclusions The findings from ILR were useful only in the case of symptom recurrence during the monitoring period, while the automatic activation in absence of symptoms was totally useless. Nevertheless, this latter function of the device was clinically relevant given the low patients' ability to manually activate the device after a spontaneous clinical event.

Vasovagal syncope: Prognostic factors for syncope recurrences

Vasovagal syncope: Prognostic factors for syncope recurrences

Effect of Syncope-Related Traumatic Injuries on the Diagnostic Evaluation and Syncope Recurrence of Patients With Syncope and Apparently Normal Hearts

The aims of this study were to assess the frequency of traumatic injuries in patients with syncope and apparently normal hearts and their influence on the diagnostic evaluation and recurrence of syncope. Patients presenting with syncope before head-up tilt testing frequently had a history of syncope-related injuries. Syncope-related injuries seemed to be random: they was not related to patients' histories, including the number of previous syncopal attacks, and they had no predictive value for the outcome of head-up tilt testing or for the recurrence of syncope during 1-year follow-up.

Pacemakers in patients with familial dysautonomia

Familial dysautonomia (FD) is a genetic disease associated with a high incidence of sudden death. If fatal bradyarrhythmia is an etiological factor then the incidence of sudden death should decrease after pacemaker placement. Retrospective review of 596 registered FD patients revealed that 22 FD patients (3.7%) had pacemakers placed between December 1984 and June 2003. Clinical and electrocardiographic indications for placement and demographic data were assessed for 20 of the 22 patients (10 males, 10 females, ages 4 to 48 years). Two patients were excluded because of insufficient data. Prior to pacemaker placement, presenting symptoms were syncope and cardiac arrest, 16/20 (80%) and 6/20 (30 %), respectively. Asystole was the most frequent electrocardiographic finding and was documented in 17/20 patients (85 %). Other electrocardiographic abnormalities included bradycardia, AV block, prolonged QTc and prolonged JTc. The average duration of pacemaker utilization was 5.7 years (range 5 months to 14.5 years). Complications included infection (1 patient) and wire migration (2 patients). In the one patient with infection, the pacemaker was permanently removed. This patient then experienced multiple syncopal episodes and death. There were 7 other deaths. Three deaths occurred suddenly without preceding events, and 4 patients had non-cardiac causes of death. None of these 7 deceased patients had recurrence of syncope after pacemaker placement. In the 12 surviving patients, 6 had recurrence of syncope but none had cardiac arrest. Pacemaker placement may protect FD patients from fatal bradyarrhythmia and may decrease the incidence of syncope. However, data are limited and prospective analysis is needed.

Nitrate-stimulated tilt testing enhances the predictive value of the tilt test on the risk of recurrence in patients with suspected vasovagal syncope

Objective — Nitrate-stimulated tilt testing may be used to diagnose vasovagal syncope and to guide therapy. However, to date the predictive value of the test is undetermined.This study analyses the risk of recurrence of syncope in vasovagal patients on the basis of a nitrate-stimulated tilt result and other clinical factors.Methods and results — We used a combined passive and nitrate-stimulated tilt protocol. One year after the test a questionnaire, asking about recurrence of syncope and other demographic factors, was sent to 131 patients. Passive tilting was found not to be a useful predictor; recurrence rates after a positive and negative test were 26% and 30%, respectively, and non-significant. With the addition of sublingual nitrates the test became a significant predictor; recurrence rates were 34 (34%) with a positive and 4 (13%) with a negative tilt test (p = 0.031). Univariate analysis of the clinical factors revealed that gender and pre-test symptomatology were significant predictors of recurrence. Multivariate analysis revealed no additional relationships.Conclusion — In patients with suspected vasovagal syncope, a positive tilt test with sublingual nitrates together with the clinical factors gender and symptomatology, are predictors for recurrence of syncope during one year of follow-up.Without specific therapy the prognosis of vasovagal syncope is good.

Effectiveness of fludrocortisone and salt in preventing syncope recurrence in children: A double-blind, placebo-controlled, randomized trial

We sought to evaluate the effectiveness of salt and fludrocortisone versus placebo in the prevention of syncope recurrence in children. Intravascular volume expansion with fludrocortisone and salt has been reported to be effective in the treatment of syncope in children. However, no pediatric placebo-controlled data are available on the effectiveness of this mode of therapy. Thirty-three children with syncope or severe presyncope were randomized in a double-blinded fashion to receive either fludrocortisone 0.1 mg/day and salt 1 g/day or placebo two capsules per day for one year. All children had a positive tilt test before enrollment. Thirty-two children (20 female) had follow-up. Their age was (mean +/- SD) 13.9 +/- 2.5 years. The number of syncopal episodes before therapy was 4.4 +/- 4.8. Therapy was continued for 176 +/- 117 days, and follow-up including time after discontinuation of medications was 1.2 +/- 0.8 years. The demographics were similar in the 18 children treated with fludrocortisone and salt compared with the 14 children on placebo. Data for up to one year of randomization were included in analyses. Symptoms recurred in 10 of 18 children on fludrocortisone and salt and in 5 of 14 children on placebo (p < 0.04). Children on placebo had no symptoms until they discontinued their study medications. These data, coupled with the reported comparable effect of many medications used in the treatment of syncope, raise the potential of a significant placebo effect with pharmacologic therapy.

Prognostic Value of Head‐Up Tilt Test with Intravenous Beta‐Blocker Administration in Assessing the Efficacy of Therapy in Patients with Vasovagal Syncope

Although beta-blockers are frequently used in order to prevent the recurrence of vasovagal syncope, the efficacy of this treatment is difficult to determine. To determine if the result of a tilt test with an intravenously administered beta-blocker can predict the long-term efficacy of beta-blockade. The study group consisted of 62 patients (29 females, mean age 32.8 +/- 12.3 years and 33 males, mean age 35.9 +/- 18.2 years) with at least two syncopal episodes during 6 months preceding the positive tilt test. After the baseline tilt test, propranolol (0.1 mg/kg BW) was administered intravenously and the tilt test was repeated. Beta-blockade was considered effective if the subsequent tilt test proved negative (complete efficacy) or if the time until the occurrence of syncope at the subsequent tilt test was longer compared to the baseline test (partial efficacy). All the patients were put on continuous propranolol treatment and were followed up for a period of 1 year or until the time when syncope recurred. Intravenously administered propranolol prevented (n = 33) or delayed (n = 18) the occurrence of syncope at the tilt test in 51 patients (82%), while it was found ineffective in the remaining 11 patients (18%). During the 8.6 +/- 6.7 months (range 1-14) of the follow-up period, the syncope recurred in 20 patients (32%), with 13 patients (25%) in the group where intravenously administered propranolol proved effective versus 7 patients (64%) for whom intravenously administered propranolol did not prevent syncope during the tilt test (P < 0.015). The survival analysis with respect to the recurrence of syncope revealed a significant correlation between the results of the tilt test with intravenously administered propranolol and the efficacy of the long-term beta-blocker therapy (P < 0.003). There were no significant differences with respect to the predictive value of the tilt test with propranolol between the patients showing complete and partial propranolol efficacy (ns), while significant differences were observed between these two groups on one hand and the patients in whom intravenously administered propranolol was found ineffective on the other (P < 0.04 and P < 0.002, respectively). Intravenous propranolol prevents tilt-induced syncope in a significant percentage of patients. The results of the tilt tests combined with the administration of propranolol predict the efficacy of a continuous propranolol treatment. Both complete and partial propranolol efficacy at tilt test can successfully identify those patients who will benefit from continuous beta blockade.

Detection of asymptomatic arrhythmias in unexplained syncope

Abstract Background Although electrocardiographic monitoring during syncope is the most unambiguous method of diagnosing or excluding an arrhythmia, it requires recurrence of syncope with potential morbidity. We hypothesized that long-term monitoring of patients with syncope would yield significant asymptomatic abnormalities that might preclude waiting for recurrence of actual syncope. Methods Sixty patients (age, 67±16 years; 27 men) with recurrent unexplained syncope, aged ≥30 years, with a left ventricular ejection fraction ≥35% and negative results on conventional monitoring were enrolled in a prospective study involving long-term automatic arrhythmia detection monitoring with an implantable loop recorder. Pre-specified significant asymptomatic arrhythmias were a pause >5 seconds, 3° atrioventricular block >10 seconds, heart rate (HR) 10 seconds while awake, wide complex tachycardia >10 beats, and narrow complex tachycardia >180 beats/min for >30 beats. Borderline asymptomatic arrhythmias included 3- to 5-second pauses, HR 10 seconds while asleep, and nonsustained wide complex tachycardia or narrow complex tachycardia. Results Recurrent symptoms developed in 30 patients during the 1-year follow-up period (47%), with arrhythmias detected in 14 patients (23%). Pre-specified significant asymptomatic arrhythmias developed in 9 patients (15%), with bradycardia in 7 patients who underwent pacemaker implantation. Twenty patients (33%) had borderline asymptomatic arrhythmias. Five of these patients (25%) went on to have more pronounced diagnostic arrhythmias of the same mechanism during further follow-up, including pauses of 6 to 17 seconds duration in 3 patients. Conclusion Long-term monitoring of patients with unexplained syncope with automatic arrhythmia detection demonstrated that significant asymptomatic arrhythmias were seen more frequently than anticipated, leading to a change in patient treatment. Automatic arrhythmia detection provides incremental diagnostic usefulness in long-term monitoring of patients with syncope.

Closed loop stimulation in prevention of vasovagal syncope. Inotropy controlled pacing in vasovagal syncope (INVASY): a multicentre randomized, single blind, controlled study

To determine whether dual-chamber rate-adaptive Closed Loop Stimulation (CLS) could prevent recurrence of Vasovagal Syncope (VVS). During VVS, an increase in myocardial contractility associated with a reduction of ventricular filling produces an increase in baroreceptor afferent flow and a consequent decrease in the heart rate. The CLS algorithm is a form of rate-adaptive pacing, which responds to myocardial contraction dynamics, by measuring variations in right ventricular intracardiac impedance: during an incipient VVS it could increase paced heart rate and avoid bradycardia, arterial hypotension and syncope. Fifty patients (27 males, mean age 59+/-18 year) with severe and recurrent vasovagal syncope and positive Head Up Tilt Test (HUTT) with cardioinhibition, received a CLS pacemaker (INOS2, Biotronik GmbH Co., Germany). The primary end point was recurrence of two VVSs during a minimum of 1 year of follow-up. Randomization between DDD-CLS and DDI mode (40 bpm) pacing was performed only during the first stage of the study (first year): 9/26 randomized to DDI mode (control group) and 17/26 in DDD-CLS mode. All the 24 patients recruited in the second stage of the study (second year) were programmed in DDD-CLS mode. Of the nine patients randomized to the DDI mode, seven had recurrences of syncope during the first year. At the end of the first year the nine patients were reprogrammed to the CLS mode and no syncope occurred after reprogramming. The 41 patients programmed to CLS had a mean follow-up of 19+/-4 months: none reported VVS, only four (10%) reported occasional presyncope and their quality of life greatly improved. Positive HUTT at the end of the first year failed to predict the clinical response to CLS pacing. The study demonstrates the effectiveness of CLS pacing in preventing cardioinhibitory VVS. A possible placebo effect of pacemaker implantation occurred in 22% of patients.

The management of patients with carotid sinus syndrome: is pacing the answer?

Carotid sinus syndrome (CSS) is an under recognized cause of recurrent unexplained syncope and potentially of recurrent falls in the elderly. The mechanisms that lead to syncope in patients with CSS remain debated. However, evidence for both peripheral and central alterations have been recently reported. The diagnosis of CSS is challenging and a high clinical suspicion is usually needed to make the diagnosis. Clinical presentation may be typical and characterized by a clear association between accidental manipulation of the carotid sinus and the presentation of syncope. On the other hand, recurrent unexplained syncope and unexplained falls may be the clinical presentation of patients with CSS without a specific trigger. Carotid sinus hypersensitivity documented by carotid sinus massage (CSM) may be the only finding indicating the possibility of CSS as the cause of syncope. In older patients with recurrent unexplained syncope and a negative diagnostic work-up, carotid sinus massage both in the supine and upright positions is recommended. CSS may present primarily as a cardioinhibitory response or a true vasodepressor response. Therapy should address any underlying pathology if present, and be directed to either prevent cardioinhibition, vasodepression or both alterations. A variety of medical therapies have been used with unclear effects. No appropriately designed controlled clinical trials have been performed comparing pacing with medical therapy. Nonetheless, available information indicates that pacing may have a strong beneficial effect and prevents recurrence of syncope in patients with CSS. The present paper critically reviews the latest insights in the pathophysiology, diagnosis and management of CSS.

Response to treatment during medium-term follow-up in a series of patients with neurocardiogenic syncope

Syncope is a common symptom that has different recurrence ratios. We hypothesized that an individualized treatment regimen including pharmacologic and nonpharmacologic measures considering kind of neurocardiogenic syncope (NCS) and basal characteristics of each patient could allow optimized therapy to avoid recurrences. We conducted a prospective study to evaluate performance of diverse accepted treatments for NCS. Each patient received specific treatment including general measures such as an increase in salt and water intake, tilt training, specific pharmacologic treatment according to head-up tilt table test (HUTT) result, and patient basal blood pressure and heart rate measurements. We followed a group of 127 patients during a main period of 20.8 +/- 9 months (range, 6-38 months). Mean age was 47.8 +/- 19.2 years and 66.9% were females. We had six (4.7%) patients with recurrence of symptoms 4 +/- 0.9 months after diagnostic HUTT. Medications used were atenolol in 20 patients, pindolol in 17, dysopiramide in 50, and fluoxetine in 25. Two patients received fludrocortisone. Tilt training was not indicated initially for patients with recurrences but was indicated later; to date, these patients have not experienced further episodes. Increase in water and salt intake, as well as tilt training, showed great value in prevention of syncope recurrences in this specific set of patients. Pharmacologic treatment has an important role, but there is no single medication associated with significant improvement in symptom control.

Reproducibility of tilt-table test result in patients with malignant neurocardiogenic syncope.

The indication for permanent pacemaker remains controversial in malignant neurocardiogenic syncope. A highly reproducible prolonged pause during a repeat head-up tilt-table testing may identify a subgroup of neurally mediated syncope with a prominent and consistent cardioinhibitory component. Seven patients (3 females) with a mean age of 30 years (23-44 years) were diagnosed to have malignant neurocardiogenic -syncope; all are classified according to the Vasovagal Syncope International Study as 2B type, with observed sinus pauses ranged from 3 s to 26 s of which only 1 demonstrated a reproducible sinus pause. No recurrence of syncope was clinically observed in patients during the follow-up period. Of 6 patients treated non--pharmacologically, one required a beta-blocker and none required a permanent pacemaker. Prolonged asystole manifest during head-up tilt-table testing is a poorly reproducible phenomenon and permanent pacemaker implantation in malignant neurocardiogenic syncope should not be a first line therapy.

Detection of asymptomatic arrhythmias in unexplained syncope

Background Although electrocardiographic monitoring during syncope is the most unambiguous method of diagnosing or excluding an arrhythmia, it requires recurrence of syncope with potential morbidity. We hypothesized that long-term monitoring of patients with syncope would yield significant asymptomatic abnormalities that might preclude waiting for recurrence of actual syncope. Methods Sixty patients (age, 67±16 years; 27 men) with recurrent unexplained syncope, aged ≥30 years, with a left ventricular ejection fraction ≥35% and negative results on conventional monitoring were enrolled in a prospective study involving long-term automatic arrhythmia detection monitoring with an implantable loop recorder. Pre-specified significant asymptomatic arrhythmias were a pause >5 seconds, 3° atrioventricular block >10 seconds, heart rate (HR) <30 beats/min for >10 seconds while awake, wide complex tachycardia >10 beats, and narrow complex tachycardia >180 beats/min for >30 beats. Borderline asymptomatic arrhythmias included 3- to 5-second pauses, HR <30 beats/min for <10 seconds while awake, HR <30 beats/min for >10 seconds while asleep, and nonsustained wide complex tachycardia or narrow complex tachycardia. Results Recurrent symptoms developed in 30 patients during the 1-year follow-up period (47%), with arrhythmias detected in 14 patients (23%). Pre-specified significant asymptomatic arrhythmias developed in 9 patients (15%), with bradycardia in 7 patients who underwent pacemaker implantation. Twenty patients (33%) had borderline asymptomatic arrhythmias. Five of these patients (25%) went on to have more pronounced diagnostic arrhythmias of the same mechanism during further follow-up, including pauses of 6 to 17 seconds duration in 3 patients. Conclusion Long-term monitoring of patients with unexplained syncope with automatic arrhythmia detection demonstrated that significant asymptomatic arrhythmias were seen more frequently than anticipated, leading to a change in patient treatment. Automatic arrhythmia detection provides incremental diagnostic usefulness in long-term monitoring of patients with syncope.