Recognizing Cardiac Syncope in Patients Presenting to the Emergency Department with Trauma

Patient characteristics and diagnostic tests associated with syncopal falls: A Southwestern surgical congress multicenter study

BACKGROUND

Patients suspected of syncope frequently undergo laboratory and imaging studies to determine the etiology of the syncope. Variability exists in these workups across institutions. The purpose of this study was to evaluate the utilization and diagnostic yield of these workups and the patient characteristics associated with syncopal falls.

METHODS

A multi-institutional retrospective review was performed on adult patients admitted after a fall between 1/2017-12/2018. Syncopal falls were compared to non-syncopal falls.

RESULTS

4478 patients were included. There were 795 (18%) patients with a syncopal fall. Electrocardiogram, troponin, echocardiogram, CT angiography (CTA), and carotid ultrasound were more frequently tested in syncope patients compared to non-syncope patients. Syncope patients had higher rates of positive telemetry/Holter monitoring, CTAs, and electroencephalograms.

CONCLUSION

Patients who sustain syncopal falls frequently undergo diagnostic testing without a higher yield to determine the etiology of syncope.

Syncope workup: Greater yield in select trauma population

BACKGROUND

There is great variation in practice regarding the assessment of trauma patients who present with syncope. The purpose of this study was to determine the yield of screening studies (electrocardiogram, echocardiogram, and carotid duplex) and define characteristics to identify groups that may benefit from these investigations.

METHODS

We conducted a retrospective cohort study of all trauma patients from 2003 to 2015 who received a carotid duplex as part of a syncope evaluation at our urban Level 1 Trauma Center. Demographics, clinical findings as well as interventions undertaken (ie: placement of defibrillators/pacemakers) as a result of the syncope evaluation were collected. Data analysis was performed with STATA 14 and relationships between comorbidities, positive findings and interventions were assessed. Significance was assumed for p < 0.05.

RESULTS

736 trauma patients were included in the study. The most common mechanism of injury was fall (592, 82%). A history of congestive heart failure (CHF) and/or coronary artery disease (CAD) and age ≥ 65 were significantly associated with abnormal ECG and ECHO findings, but not with severe carotid stenosis. Elevated Injury Severity Scale (ISS) was significantly associated with an abnormal ECHO on both univariate and multivariate analysis. An abnormal ECG was predictive of an abnormal ECHO (p = 0.02). Ten patients (1.4%) underwent placement of a defibrillator and/or pacemaker, all of whom reported having CHF. Only 11 patients (1.7%) had severe carotid stenosis (>70%) requiring intervention.

CONCLUSION

The screening studies used in a syncope evaluation have low yield in the general trauma population. Carotid duplex should not be routinely performed. Cardiac evaluation should be tailored to individuals with cardiac comorbidities, older age and elevated ISS. An ECG should be used as initial screening in this patient cohort.

Presence and extent of cardiac computed tomography angiography defined coronary artery disease in patients presenting with syncope

Background

In syncope patients, presence of coronary artery disease (CAD) is associated with poor prognosis. However, data concerning CAD prevalence in syncope patients without known cardiovascular disease are lacking. Therefore, the aim of this study was to investigate presence and extent of CAD in syncope patients.

Methods

We included 142 consecutive patients presenting with syncope at the outpatient cardiology clinic who underwent coronary computed tomography (CT) angiography. Syncope type was ascertained by two reviewers, blinded for coronary CT angiography results. Of the patients, 49 had cardiac syncope (arrhythmia or structural cardiopulmonary disease) and 93 had non-cardiac syncope (reflex [neurally-mediated], orthostatic or of unknown cause). Cardiac syncope patients were compared with matched stable chest pain patients regarding age, gender, smoking status, diabetes mellitus type 2 and systolic blood pressure.

Results

Distribution of CAD presence and extent in cardiac and non-cardiac syncope patients was as follows: 72% versus 48% any CAD; 31% versus 26% mild, 8% versus 14% moderate and 33% versus 7% severe CAD.

Compared with non-cardiac syncope, patients with cardiac syncope had a significantly higher CAD presence and extent (p = 0.001). Coronary calcium score, segment involvement and stenosis score were also higher in cardiac syncope patients (p-values ≤0.004). Compared to the chest pain control group, patients with cardiac syncope showed a higher, however, non-significant, prevalence of any CAD (72% versus 63%) and severe CAD (33% versus 19%).

Conclusion

Patients with cardiac syncope show a high presence and extent of CAD in contrast to non-cardiac syncope patients. These results suggest that CAD may play an important role in the occurrence of cardiac syncope.

Electronic supplementary material

The online version of this article (doi: 10.1007/s12471-017-0970-7) contains supplementary material, which is available to authorized users.

Time- and frequency-domain analysis of beat to beat P-wave duration, PR interval and RR interval can predict asystole as form of syncope during head-up tilt

To seek possible differences in short-period temporal RR interval, P-wave and PR interval dispersion and spectral coherence in patients with a head-up tilt test positive for vasovagal syncope with or without prolonged asystole, severe symptoms and at high risk of trauma. We retrospectively reviewed 5 min ECG and blood pressure recordings obtained at baseline, at rest and during head-up tilt in 40 patients diagnosed as having recurrent vasovagal syncope confirmed at a head-up tilt test. We analysed autoregressive spectral power for all the ECG-derived variables, focusing on temporal P-wave and PR interval dispersion indexes as well as their spectral coherence calculated on the same 5 min recordings at rest and during tilt. ECG recordings obtained during tilt before syncope showed significantly lower P  →  PR spectral coherence and higher RR standard deviations in patients with tilt-induced asystole than in those without (0.567  ±  0.097 versus 0.670  ±  0.127, p: 0.010 and 84  ±  36 versus 46  ±  22 ms², p  <  0.0001). Differences in the RR standard deviations persisted also on the last hundred beats (_-100) (113  ±  54 versus 34  ±  17 ms², p  <  0.0001). Multiple regression analysis identified a significantly negative association between the maximum RR intervals and P  →  PR coherence at rest (β:  -0.3, p  <  0.05) and positive association with RR_-100 standard deviation during tilt-induced syncope (β: 0.621, p  <  0.001). P  →  PR spectral coherence could be used to assess the risk of prolonged asystole in patients with tilt-induced vasovagal syncope as well as as a possible surrogate for tilt-testing during these patients' follow-up.

Transient loss of consciousness assessment in a University Hospital: From diagnosis to prognosis

Background

Transient loss of consciousness (TLoC) is a symptom that has several differential etiologic diagnosis, causes significant morbidity and mortality with impact on quality of life.

Objective

The purpose of this study was to access the diagnosis and prognosis of these patients admitted in a Portuguese University Hospital.

Methods

The study included 125 patients with TLoC admitted in the emergency room and then admitted to the hospital during the year 2013. Patients were contacted by phone for follow-up evaluations, during the 18 months from the date of admission.

Results

Cardiogenic syncope was the most common etiology of TLoC (39.2%). The 18-month overall mortality was 11.2%, however this was higher in patients with unexplained TLoC, with an 18-month mortality of 27.8% (p = 0.031); It was found that half of patients who died, did so in the first month from admission date; 20% of patients had recurrent episodes of TLoC (mean number of 5.6 episodes), with a higher percentage of recurrence occurring in patients with reflex syncope (35.3%; p = 0.023). 60% of patients with recurrent episodes suffered accidents and/or injuries, and 20% of recurrence patients gave up driving (p = 0.019).

Conclusion

The results obtained highlight the burden of TLoC in terms of morbidity and mortality, similar results to those previously published, except for the prevalence of the etiology, cause of death and recurrence's etiology of TLoC. This study emphasizes the significant implications that TLoC leads on morbidity and mortality being essential its accurate diagnosis.

Estimating negative likelihood ratio confidence when test sensitivity is 100%: A bootstrapping approach

Objectives Assessing high-sensitivity tests for mortal illness is crucial in emergency and critical care medicine. Estimating the 95% confidence interval (CI) of the likelihood ratio (LR) can be challenging when sample sensitivity is 100%. We aimed to develop, compare, and automate a bootstrapping method to estimate the negative LR CI when sample sensitivity is 100%. Methods The lowest population sensitivity that is most likely to yield sample sensitivity 100% is located using the binomial distribution. Random binomial samples generated using this population sensitivity are then used in the LR bootstrap. A free R program, "bootLR," automates the process. Extensive simulations were performed to determine how often the LR bootstrap and comparator method 95% CIs cover the true population negative LR value. Finally, the 95% CI was compared for theoretical sample sizes and sensitivities approaching and including 100% using: (1) a technique of individual extremes, (2) SAS software based on the technique of Gart and Nam, (3) the Score CI (as implemented in the StatXact, SAS, and R PropCI package), and (4) the bootstrapping technique. Results The bootstrapping approach demonstrates appropriate coverage of the nominal 95% CI over a spectrum of populations and sample sizes. Considering a study of sample size 200 with 100 patients with disease, and specificity 60%, the lowest population sensitivity with median sample sensitivity 100% is 99.31%. When all 100 patients with disease test positive, the negative LR 95% CIs are: individual extremes technique (0,0.073), StatXact (0,0.064), SAS Score method (0,0.057), R PropCI (0,0.062), and bootstrap (0,0.048). Similar trends were observed for other sample sizes. Conclusions When study samples demonstrate 100% sensitivity, available methods may yield inappropriately wide negative LR CIs. An alternative bootstrapping approach and accompanying free open-source R package were developed to yield realistic estimates easily. This methodology and implementation are applicable to other binomial proportions with homogeneous responses.

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.