Association between Syncope and the 6-Month Incidence of Ischemic Stroke, Arrhythmia, Brain Tumor, Epilepsy, and Anxiety Disorder

OBJECTIVES

the aim of the present study is to investigate the associations between syncope and subsequent diagnoses of brain tumor, cardiac arrhythmia, stroke/transient ischemic attack (TIA), epilepsy, and anxiety disorder in a large outpatient population in Germany.

METHODS

This retrospective cohort study uses data from the Disease Analyzer database (IQVIA). Adults who received syncope diagnosis from one of 1284 general practices between January 2005 and December 2021 (index date) were included and matched (1:1) to individuals without syncope diagnosis using a propensity score based on age, sex, the number of consultations during the follow-up period (up to 6 months), and defined co-diagnoses documented within 12 months prior to and on the index date. Finally, associations between syncope and subsequent outcome diagnoses were investigated using multivariable logistic regression models.

RESULTS

Data related to 64,016 patients with and 64,016 patients without syncope (mean age 54.5 years, 56.5% female) were available. In total, 6.43% of syncope patients and 2.14% of non-syncope patients were diagnosed with one of the five outcome diagnoses within 6 months of the index date. There was a positive and significant association between syncope and incidences of ischemic stroke/TIA (OR = 2.83, 95% CI = 2.41-3.32), arrhythmia (OR = 3.81, 95% CI = 3.44-4.18), brain tumor (OR = 4.24, 95% CI = 2.50-7.19), epilepsy (OR = 5.52, 95% CI = 4.27-7.14), and anxiety disorder (OR = 1.99, 95% CI = 1.79-2.21).

CONCLUSIONS

Syncope is significantly associated with an increased risk of subsequent ischemic stroke/TIA, cardiac arrhythmia, brain tumor, epilepsy, and anxiety disorder. Nevertheless, the cumulative incidences for all five diagnoses are very low.

AV-node isolation as an alternative to AV-node ablation in patients undergoing pace & ablate strategy

INTRODUCTION

Atrioventricular (AV)-node ablation (AVNA) is a common therapy option for rate control strategy of permanent atrial fibrillation (AF). We hypothesized that isolation of the AV nodal isolation (AVNI) is associated with a more frequent preservation of an adequate escape rhythm compared to AVNA.

METHODS

This retrospective study included 20 patients with therapy-refractory AF being treated with AVNI and 40 historical AVNA-controls. In AVNI the AV-node region was mapped using a 3D mapping system. Ablation was performed around the previously mapped HIS-cloud regions isolating the atrium from the AV-node. In the AVNI group, ablation was performed with irrigated tip ablation catheter in all cases. The two approaches were compared regarding rate of escape rhythm, delta QRS, and procedural data.

RESULTS

The number of patients with adequate escape rhythm in AVNI was significantly superior to AVNA immediately postoperative (90% vs. 40%, p < 0.01) and during follow-up (77% vs. 36%, p < 0.05). The median change in QRS width was 0 ms in AVNI versus +26 ms in AVNA (p < 0.01). Thirty percent new bundle branch blocks in AVNA were observed compared to 0% in AVNI (p < 0.01). In the AVNI group, fluoroscopy time and total dose area product were significantly lower (p < 0.01).

CONCLUSION

The present study suggests that AV-node isolation using 3D navigation mapping system is a feasible and effective alternative to conventional AVNA. The precise application of radiofrequency lesions preserves a stable AV-junctional rhythm.

Syncope: Diagnostic Yield of Various Clinical Investigations

Objective: The present study was designed to evaluate the clinical profile of patients with syncope and the usefulness of various tests to reach a diagnosis of syncope and its etiology.

Methods: This was a cross-sectional, observational study that enrolled 90 consecutive patients (aged ≥ 12 years) who presented with syncope. Detailed information was obtained from each enrolled patient on history and physical examination. All patients underwent electrocardiography (ECG) and echocardiographic examination. Other specific tests were also performed based on the findings from medical history, physical examination, ECG, and echocardiography findings.

Results: Among 90 patients with syncope, 45% were males, and age distribution showed a bimodal distribution with two peaks. A total of 67% and 5% of patients had past history of syncope and injury due to syncope, respectively. Of the patients, 38% underwent Holter monitoring, 79 (87%) underwent head-up tilt table test (HUTT) test, 8% underwent treadmill test, 36% underwent CT/MRI of the brain, 25% underwent electroencephalography, 40% underwent carotid sinus massage, 7% underwent coronary angiography, 3% underwent electrophysiological study, and 3% of patients underwent carotid Doppler ultrasound. The commonly noted syncope was vasovagal/neutrally mediated syncope (68%). However, the etiology of syncope could not be determined in six (7%) patients.

Conclusion: This study concluded that the initial evaluation of patients with syncope should focus on history, physical examination, and ECG examination. Information obtained from such basic evaluations should be used to guide the selection of further high yield tests to reduce the cost of evaluation and for appropriate workup for the diagnosis of syncope.

Isolated very low QRS voltage in the frontal leads predicts recurrence of neurally mediated syncope

BACKGROUND

The study was prompted by our observation that some patients with neurally mediated syncope (NMS) have an isolated QRS complex, of very low voltage (≤0.3 mV cutoff), in 1 of the frontal leads on the 12-lead electrocardiogram.

OBJECTIVE

To prospectively evaluate whether the presence of isolated very low voltage (VLV) predicts recurrence of NMS.

METHODS

We included 205 patients (aged 50 ± 17 years) with a median of 3 syncopal episodes. Tilt testing was performed in all patients and was positive in 87 (42%). The patients were followed for a median of 14 months.

RESULTS

VLV in frontal leads was present in 92 patients (45%). During the follow-up period 60 patients experienced recurrence of syncope. The actuarial total syncope recurrence rate at 1 year was 32% (95% confidence interval [CI 23%-44%) in patients with isolated VLV in frontal plane leads, and 14% (95% CI 8%-24%) in patients without VLV (log-rank test P < .0001). The significant relationship between the presence of isolated VLV in the frontal leads and syncope recurrence was retained in Cox multivariate analysis that included the history of presyncope and syncope as well as the left ventricular end-diastolic diameter. The presence of isolated VLV in frontal leads was associated with a 3-fold increase of the risk of recurrent syncope.

CONCLUSIONS

Isolated very low QRS voltage in the frontal leads predicts recurrence of NMS independent of clinical factors that predict recurrence of syncope in such patients. This phenomenon may help generate new diagnostic tools and insights into the pathogenesis of NMS.

Diagnostic yield of device interrogation in the evaluation of syncope in an elderly population

BACKGROUND

Device interrogation has become a standard part of the syncope evaluation for patients admitted with permanent pacemakers (PPM) or implantable cardiac defibrillators (ICD), although few studies have shown interrogation yields clinically useful data. The purpose of this study is to determine the diagnostic yield of device interrogation as well as other commonly performed tests in the workup of unexplained syncope in patients with previously implanted PPMs or ICDs.

METHODS

We retrospectively reviewed records of 88 patients admitted to our medical center for syncope with previously implanted pacemakers between January 1, 2005 and January 1, 2015 using ICD-9 billing data.

RESULTS

Pacemaker interrogation demonstrated an arrhythmia as the cause for syncope in 4 patients (4%) and evidence of device failure secondary to perforation in 1 patient (1%). The cause of syncope was unknown in 34 patients (39%). Orthostatic hypotension was the most commonly identified cause of syncope (26%), followed by vasovagal syncope (13%), autonomic dysfunction (5%), ventricular arrhythmia (3%), atrial arrhythmia (2%), congestive heart failure (2%), stroke (2%), and other less common causes (8%). History was the most important determinant of syncope (36%), followed by orthostatic vital signs (14%), device interrogations (4%), head CT (2%), and transthoracic echocardiogram (1%).

CONCLUSIONS

Device interrogation is rarely useful for elucidating a cause of syncope without concerning physical exam, telemetry, or EKG findings. Interrogation may occasionally yield paroxysmal arrhythmias responsible for syncopal episode, but these rarely alter clinical outcomes. Interrogation appears to be more useful in patients with syncope after recent device placement.

Maintaining Accurate Long-Term Sensing Ability Despite Significant Size Reduction of Implantable Cardiac Monitors

BACKGROUND

The Reveal LINQ™ implantable cardiac monitor (ICM; Medtronic, Minneapolis, MN, USA) is obviously smaller than its precursor (the Reveal XT™), but little is known about its long-term safety. Here, we investigated the long-term R-wave sensing reliability of the Reveal LINQ™ ICM.

METHODS

We analyzed the sensing quality of the Reveal LINQ™ ICM over time between March 2014 and January 2015.

RESULTS

A total of 30 patients underwent Reveal LINQ™ implantation. The main reason for implantation was unexplained syncope (60%). We evaluated a total of 305.8 patient-months (median, 10.7 months) of R-wave sensing quality. A comparison of baseline and follow-up R-wave sensing values revealed no difference (0.401 mV ± 0.244 mV vs 0.447 mV ± 0.323 mV; P = 0.225).

CONCLUSIONS

The consistent detection of events is an important safety feature of an ICM and linked to secure R-wave sensing. Despite the noticeable size reduction, the Reveal LINQ™ ICM retains reliable sensing quality over time.

Headache of neurally mediated syncope

BACKGROUND

Neurally mediated syncope and migraine have a complex relationship.

AIM

The aim of this study was to investigate whether patients developing syncope in the laboratory would experience migraine.

METHODS

Thirty-one consecutive patients were evaluated for precipitation of headache during head-up tilt (HUT)-induced syncope (reduction of systolic blood pressure [SBP] >20 mmHg and prodromal symptoms with or without loss of consciousness). Autonomic functions were assessed using heart rate response to deep breathing (HRDB), Valsalva maneuver and HUT. Blood pressure and heart rate (via electrocardiography) were continuously monitored. Headache diagnosis was based on ICHD-3 criteria.

RESULTS

Eighteen patients (58%) experienced syncope without headache and 13 (42%) had syncope and headache (SH). No difference was observed in time of syncope onset, reduction in SBP, Valsalva ratio, HRDB or tachycardia during initial 10 minutes of HUT. Of the 13 SH patients, 11 (85%) had a past history of migraine. Two reported headache just before tilt, eight developed headache during tilt and three developed headache only after tilt. Headache resolved within 1-15 minutes in 10 out of 13 patients. No patient experienced migraine.

CONCLUSIONS

Syncope did not precipitate migraine. Headache during syncope may be due to cerebral hypoperfusion, and cerebral hyperperfusion may cause post-syncopal headache.

Ischaemic stroke or TIA in older subjects associated with impaired dynamic blood pressure control in the absence of severe large artery stenosis

BACKGROUND

older subjects may require higher baseline blood pressures to maintain cerebral perfusion. We investigated whether episodic hypotension is associated with tissue infarction in subjects with syncopal symptoms at stroke onset.

METHODS

over 30 months, all acute strokes/TIAs were prospectively screened for symptoms of syncope or presyncope at stroke onset. Subjects with severe large vessel stenosis were excluded, while cases were referred for syncope unit investigation. All underwent 1.5 T MRI acutely, and suspected borderzone infarctions (BZI) were confirmed through Matlab-derived perfusion software. Case-control comparison was derived from stroke controls with no prior syncope history.

RESULTS

thirty-eight of 772 stroke patients described presyncope or syncope at stroke onset and had patent large vessels (4.9% of all strokes). Median age was 72 years (IQR 21.4). Twenty-two patients (58%) were prescribed antihypertensive agents at symptom onset. Twenty-six (68.4%) reported focal neurology <24 h in duration. 63.2% (n = 24) of cases reported prior syncope history, compared with 33% (N = 103) of controls, P < 0.001. Cases exhibited greater orthostatic BP drop than controls, P < 0.05 Twenty-four patients were diagnosed with vasovagal syncope through head-up tilt symptom reproduction, 9 with orthostatic hypotension, 4 with cardiac syncope and 1 with carotid sinus syndrome. Nineteen (50%) patients had an acute infarct on MRI, 14 of these were in the arterial borderzone (73.6%). The BZI group were significantly older than the non-BZI group, 79.2 yrs versus 63.3 yrs, P = 0.002.

CONCLUSION

subjects reporting hypotensive symptoms at stroke onset have a higher prevalence of borderzone infarction, despite being normotensive or hypertensive at baseline.

Syncope in Patients with Organic Heart Disease

Patients with syncope and organic heart disease remain a small but important subset of those patients who experience transient loss of consciousness. These patients require thoughtful and complete evaluation in an attempt to better understand the mechanism of syncope and its relationship to the underlying disease, and to diagnose and treat both properly. The goal is to reduce the risk of further syncope, to improve long-term outcomes with respect to arrhythmic and total mortality, and to improve patients' quality of life.

[Diagnostics and treatment of syncope]

A transient loss of consciousness in the elderly is in most cases caused by syncope of cardiac origin. The underlying cause of syncope is of prognostic importance and should be clarified in every single case even if a definitive diagnosis can be established in only approximately two thirds of all cases. The definitive diagnosis is the key for appropriate therapeutic measures to prevent recurrences. Flowcharts can help to implement considerate and efficient stepwise diagnostic procedures. The most important diagnostic measures and treatment options according to medical evidence are presented.

Syncope

Syncope is common representing approximately 3% of ED visits and up to 6% of hospital admissions, with a cost close to 2 billion dollars per year. Diagnostic testing is often poorly sensitive and evaluations commonly lack a standardized approach. A mindful and systematic approach can increase sensitivity and improve diagnostic accuracy. A thorough history and physical exam is paramount, as conclusions drawn from the history and exam will guide further assessment. Developing a strategy for the first and, if necessary, subsequent tests will improve the accuracy of identifying the etiology of syncope and reduce cost. Although syncope has a favorable prognosis, identification of patients with structural heart disease is critical, as these patients are at greatest risk for mortality. Several risk scoring systems have been developed to help separate high risk from low risk patients.

Current investigation and management of patients with syncope: results of the European Heart Rhythm Association survey

The aim of this European Heart Rhythm Association (EHRA) survey was to provide an insight into the current practice of work-up and management of patients with syncope among members of the EHRA electrophysiology research network. Responses were received from 43 centres. The majority of respondents (74%) had no specific syncope unit and only 42% used a standardized assessment protocol or algorithm. Hospitalization rates varied from 10% to 25% (56% of the centres) to >50% (21% of the centres). The leading reasons for hospitalization were features suggesting arrhythmogenic syncope (85% of respondents), injury (80%), structural heart disease (73%), significant comorbidities (54%), and older age (41%). Most widely applied tests were electrocardiogram (ECG), echocardiography, and Holter monitoring followed by carotid sinus massage and neurological evaluation. An exercise test, tilt table test, electrophysiological study, and implantation of a loop recorder were performed only if there was a specific indication. The use of a tilt table test varied widely: 44% of respondents almost always performed it when neurally mediated syncope was suspected, whereas 37% did not perform it when there was a strong evidence for neurally mediated syncope. Physical manoeuvres were the most widely (93%) applied standard treatment for this syncope form. The results of this survey suggest that there are significant differences in the management of patients with syncope across Europe, specifically with respect to hospitalization rates and indications for tilt table testing in neurally mediated syncope. The majority of centres reported using ECG, echocardiography, and Holter monitoring as their main diagnostic tools in patients with syncope, whereas a smaller proportion of centres applied specific assessment algorithms. Physical manoeuvres were almost uniformely reported as the standard treatment for neurally mediated syncope.

Pathophysiology of neurally-mediated syncope

INTRODUCTION

Neurally-mediated syncope (NMS) is defined as a transient loss of consciousness due to an abrupt and intermittent drop in blood pressure (BP).

OBJECTIVES

This study describes the putative pathophysiological mechanisms giving rise to NMS, the role of baroreflex (BR), and the interaction of its main haemodynamic variables: heart rate (HR) and BP.

DEVELOPMENT

Episodic dysregulation affects control over the haemodynamic variables (HR and BP) mediated by baroreflex mechanisms. During active standing, individuals experience a profound transient drop in systolic BP due to the effect of gravity on the column of blood and probably also because of reflex vasodilation. Abnormalities in the BR in NMS could be due to a more profound drop in BP upon standing, or to delayed or incomplete vasoconstriction resulting from inhibited or delayed sympathetic activity.

CONCLUSIONS

Sympathetic hyperactivity is present in patients with NMS at rest and before syncope. During active standing or passive tilting, excessive tachycardia may be followed by bradycardia and profound hypotension. Recovery of systolic BP is delayed or incomplete.

P-wave voltage and peaking on electrocardiogram in patients undergoing head-up tilt testing for history of syncope

BACKGROUND

Only scanty data are available in the literature on P-wave (PW) morphology at ECG in patients with history of vasovagal syncope undergoing diagnostic functional testing. In this study, we evaluated resting and head-up tilt testing (HUTT) related changes in PW voltage (PWV) and duration (PVD) and their relationship with triggered syncope.

METHODS

55 patients, mean aged 41 ± 19 y (35 F), without patent heart disease or neuropathy, underwent potentiated HUTT according to the Italian protocol. Heart rate (HR), blood pressure (BP), PR-interval, PWV and PWD were measured at rest, 15 min from passive position (15-min) and after nitroglycerine (peak-HR). PW peaking (PWP) was calculated as percent increase in PWV than baseline values. Patients were divided into 2 groups based on tilt-positive (group-A) or negative (group-B) response.

RESULTS

20 patients (36%) entered the group-A, whereas 35 (64%) the group-B. Higher PWV was observed at baseline in group-A (0.147 ± 0.034 mV vs 0.114 ± 0.036 mV in group-B, p=0.001), with no differences in the remaining ECG measurements. BP was lower in group-A than in B, both at 15-min and peak-HR. HUTT-related PWP in lead II (the most significant among all inferior leads) was 31 ± 30% in group-A vs 95 ± 54% in group-B (p<0.0001) at 15-min, and 52 ± 44% vs 112±72% at peak-HR, respectively (p=0.002). 75% of patients with PWP ≤ 50% experienced HUTT-triggered syncope, vs 5% of those with PWP ≥ 100% (p<0.0001).

CONCLUSIONS

This study shows a potential relationship between HUTT-triggered syncope and low or absent PWP, suggesting a role for atrial chamber functional involvement in the mechanisms underlying the vasovagal syncope.

Recognizing life-threatening causes of syncope

While the overall prognosis of syncope is favorable, the identification of individuals with a potentially life-threatening cause is of paramount importance. Cardiac syncope is associated with an elevated risk of mortality, and includes both primary arrhythmic and obstructive etiologies. Identification of these individuals is contingent on careful clinical assessment and judicious use of diagnostic investigations. This article focuses on life-threatening causes of syncope and a diagnostic approach to facilitate their identification.

Patient selection for ambulatory cardiac monitoring in the Indian healthcare environment

Cardiovascular disease (CVD) in India comprises the bulk of non-communicable diseases, resulting in 2 million deaths per year. The incidence of CVD in India is estimated to be up to four times higher than in other countries. Though the quantification of the prevalence of rhythm disorders in India is not available, it can be inferred to be proportionately high. Identification and treatment of arrhythmia is limited by several socioeconomic factors including low health insurance penetration, limited reimbursement and high out-of-pocket expenditures. Thus, there exists a need in India to (1) select an appropriate tool that is both high yielding and cost effective and (2) employ a suitable patient selection method. This paper focuses on these two aspects for cardiac arrhythmia diagnosis using ambulatory monitoring technology, while keeping in mind the dynamics of the Indian healthcare setting.