Stepwise evaluation of syncope: A prospective population-based controlled study

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.

Vascular Causes of Syncope: An Emergency Medicine Review

BACKGROUND

Syncope is a common emergency department (ED) complaint, accounting for 2% of visits annually. A wide variety of etiologies can result in syncope, and vascular causes may be deadly.

OBJECTIVE

This review evaluates vascular causes of syncope and their evaluation and management in the ED.

DISCUSSION

Syncope is defined by a brief loss of consciousness with loss of postural tone and complete, spontaneous recovery without medical intervention. Causes include cardiac, vasovagal, orthostatic, neurologic, medication-related, and idiopathic, and most cases of syncope will not receive a specific diagnosis pertaining to the cause. Emergency physicians are most concerned with life-threatening causes such as dysrhythmia and obstruction, and electrocardiogram is a primary means of evaluation. However, vascular etiologies can result in patient morbidity and mortality. These conditions include pulmonary embolism, subclavian steal, aortic dissection, cerebrovascular disease, intracerebral hemorrhage, carotid/vertebral dissection, and abdominal aortic aneurysm. A focused history and physical examination can assist emergency physicians in determining the need for further testing and management.

CONCLUSIONS

Syncope is common and may be the result of a deadly condition. The emergency physician, through history and physical examination, can determine the need for further evaluation and resuscitation of these patients, with consideration of vascular etiologies of syncope.

The Cost-Effective Evaluation of Syncope

Syncope is a common clinical problem that carries a high socioeconomic burden. A structured approach in the evaluation of syncope with special emphasis on a detailed history, comprehensive physical examination that includes orthostatic vital signs, and an electrocardiogram, proves to be the most cost-effective approach. The need for additional testing and hospital admission should be based on the results of the initial evaluation and use of risk-stratification tools that help identify those syncope patients at highest risk for poor outcomes.

Opportunities for Emergency Medical Services (EMS) Care of Syncope

Introduction Emergency Medical Service (EMS) systems are vital in the identification, assessment, and treatment of trauma, stroke, myocardial infarction, and sepsis patients, improving early recognition, resuscitation, and transport. Emergency Medical Service personnel provide similar care for patients with syncope. The role of EMS in the management of patients with syncope has not been reported. Hypothesis/Objective The objective of this study was to describe the management of out-of-hospital syncope by prehospital providers in an urban EMS system.

METHODS

This was a retrospective cohort study of consecutively enrolled patients over 18 years of age, over a two-year period, who presented by EMS with syncope, or near-syncope, to a tertiary care emergency department (ED). Demographics included comorbidities, history, and physical exam findings documented by prehospital providers, as well as the interventions provided. Data were collected from standardized patient care records for descriptive analysis.

RESULTS

Of the 723 patients presenting with syncope to the ED, 284 (39.3%) were transported by EMS. Compared to non-EMS patients, those who arrived by ambulance were older (mean age 65 [SD = 18.5] years versus 61 [SD = 19.2] years; P = .019). There were no statistically significant differences in cardiovascular comorbidities (hypertension, coronary artery disease, diabetes mellitus, stroke, or congestive heart failure) between EMS and non-EMS patients. The most common chief complaints were fainting (50.0%) and dizziness (44.7%). The most common intervention provided was cardiac monitoring (55.6%), followed by administration of normal saline infusion (50.5%), oxygen (41.9%), blood glucose check (41.5%), and electrocardiogram (EKG; 40.5%).

CONCLUSION

Emergency Medical Service personnel transport more than one-third of patients presenting to the ED with syncope. Documentation of key elements of the history (witnesses, prodrome, predisposing factors, and post-event symptoms) and physical examination were not recorded consistently. Long BJ , Serrano LA , Cabanas JG , Bellolio MF . Opportunities for Emergency Medical Services (EMS) care of syncope. Prehosp Disaster Med. 2016;31(4):349-352.

Implantable Loop Recorder – A Good Opportunity to Diagnose Unexplained Syncope

Implantable loop recorder (ILR) is a method in cardiology, which is used for the diagnosis of unexplained syncope in patients who were not treated successfully using standard methods. Implantable loop recorder is a diagnostic device that is surgically implanted under the skin of the chest area. This device does not have the endovenous implantation of electrodes; instead, electrodes are attached to the machine housing. The device records the heart rhythm continuously, up to 14 months, and stores data outside the activator whenever symptoms appear, or by the automatic activation of the predefined program for bradycardia, asystole, and tachycardia. The aim of this paper was to describe the method for the detection of cardiac syncope with the use of implantable loop recorder.

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.

Usefulness of patient's history and non-invasive electrocardiographic parameters in prediction of ajmaline test results in patients with suspected Brugada syndrome

INTRODUCTION

The aim of the work was to assess the usefulness of patient's history and non-invasive electrocardiographic parameters in the prediction of ajmaline test results in patients with suspected Brugada syndrome.

MATERIAL AND METHODS

The study involved a group of 59 patients (37 men) at average age of 31.6 ±12.2 years with suspected concealed form of Brugada syndrome. Pharmacological provocation with intravenous ajmaline administration was performed. The patients were divided into two groups depending on ajmaline test results. Individual and total predictive value for ajmaline test was based on the analysis of medical anamnesis and non-invasive electrocardiographic examination.

RESULTS

The analysis carried out within the work indicated a special predictive value of 2 parameters which constituted the study inclusion criteria - family history of Brugada syndrome (28.6% vs. 3.8%; p = 0.0477) and occurrence of saddleback electrocardiographic changes in ECG curve (42.9% vs. 0.0%; p = 0.0002). Non-invasive electrocardiographic parameters which showed significant predictive value for ajmaline test were as follows: dispersion of QTc interval (prior to the provocation test 54.43 ±24.77 ms vs. 32.70 ±12.98 ms; p = 0.0005 and during daytime activity 46.81 ±27.16 ms vs. 32.07 ±13.19 ms; p = 0.0198), corrected QT intervals, Tpeak-Tend intervals in particular leads, QTpeak intervals, dispersion of Tpeak-Tend interval assessed from precordial leads (V1-V6) (42.86 ±13.80 ms vs. 26.54 ±11.70 ms; p = 0.001) and J-point elevation in V2 and V3 leads.

CONCLUSIONS

Both interview and non-invasive electrocardiographic parameters which reflect cardiomyocyte repolarization disorders are of high predictive value in anticipating ajmaline pharmacological provocation results in patients with suspected Brugada syndrome.

Yield of diagnostic tests in evaluating syncopal episodes in older patients

BACKGROUND

Syncopal episodes are common among older adults; etiologies range from benign to life threatening. We determined the frequency, yield, and costs of tests obtained to evaluate older persons with syncope. We also calculated the cost per test yield and determined whether the San Francisco syncope rule (SFSR) improved test yield.

METHODS

Review of 2106 consecutive patients 65 years or older admitted following a syncopal episode.

RESULTS

Electrocardiograms (in 99% of admissions), telemetry (in 95%), cardiac enzyme tests (in 95%), and head computed tomographic (CT) scans (in 63%) were the most frequently obtained tests. Results from cardiac enzymes tests, CT scans, echocardiography, carotid ultrasonography, and electroencephalography all affected diagnosis or management in less than 5% of cases and helped determine the etiology of syncope less than 2% of the time. Postural blood pressure (BP) recording, performed in only 38% of episodes, had the highest yield with respect to affecting diagnosis (18%-26%) or management (25%-30%) and determining etiology of the syncopal episode (15%-21%). The cost per test affecting diagnosis or management was highest for electroencephalography ($32 973), CT scans ($24 881), and cardiac enzymes test ($22 397) and lowest for postural BP recording ($17-$20). The yields and costs for cardiac tests were better among patients meeting, vs those not meeting, the SFSR. For example, the cost per cardiac enzymes test affecting diagnosis or management was $10 331 in those meeting, vs $111 518 in those not meeting, the SFSR.

CONCLUSIONS

Many unnecessary tests are obtained to evaluate syncope. Selecting tests based on history and examination and prioritizing less expensive and higher yield tests would ensure a more informed and cost-effective approach to evaluating older patients with syncope.

Response to intravenous ajmaline: a retrospective analysis of 677 ajmaline challenges

AIMS

The diagnostic type I ECG in Brugada syndrome (BS) is often concealed and fluctuates between the diagnostic and non-diagnostic pattern. Challenge with intravenous ajmaline is used to unmask the diagnostic Brugada ECG. The aim of this study was to evaluate the safety of the test and to identify predictors for the response to an intravenous ajmaline challenge.

METHODS AND RESULTS

In four tertiary referral centres, 677 consecutive patients underwent an intravenous ajmaline challenge for diagnosis or exclusion of BS in accordance with the recommendations of the Brugada consensus conferences. Two hundred and sixty-two ajmaline challenges (39%) were positive. Male gender, familial BS, sudden cardiac arrest (SCA), first-degree AV-block, basal saddleback type ECG, and basal right bundle branch block were identified as predictors for a positive ajmaline challenge. A predictor for negative ajmaline test was the absence of ST-segment elevation at baseline. Six of 12 patients who had experienced SCA, and five of 25 patients with a familial sudden death exhibited a positive response to ajmaline. Only one patient (0.15%) developed sustained ventricular tachyarrhythmias (ventricular fibrillation) during ajmaline challenge, which was terminated by a single external defibrillator shock.

CONCLUSION

Ajmaline challenge is a safe procedure to unmask the electrocardiographic pattern of BS. Electrocardiographic and clinical parameters were identified to predict patients' response to ajmaline. The results of this study guide the clinician in which setting an ajmaline challenge is an appropriate diagnostic step.

Symptoms during ATP-test under pacing: impact on syncope recurrence and prediction from the ATP-test without pacing

Syncope recurrence in patients with positive ATP-test who underwent permanent pacemaker implantation is suspected to be related to vagal vasodilatation. We studied symptoms during ATP-test in 38 temporary paced patients. Among patients with positive ATP-test who underwent permanent pacemaker implantation (N = 14), the only one patient who recurred during follow-up was symptomatic during the initial paced ATP-test. Symptoms during paced ATP-test were well predicted by a higher blood pressure (BP) drop during standard ATP-test (i.e. without pacing) (Area under ROC curves > 0.70 for all BP parameters except for relative diastolic BP drop). Moreover, BP drop during standard and paced ATP-test were significantly correlated (all p ≤ 0.03). Thus, a higher BP drop measured during ATP-test without pacing might help identify patients who would experience recurrences due to vasodilatation under permanent pacing.

Hyperoxic chemoreflex sensitivity is impaired in patients with neurocardiogenic syncope

BACKGROUND

During the development of neurocardiogenic syncope (NCS) postural dependant venous blood pooling sets off a cascade of autonomic reflexes. This causes an initial rise in sympathetic tone, which is followed by an overshoot parasympathetic activation resulting in systemic vasodilatation and/or sinus bradycardia. However, other factors like associated hyperventilation or changes in blood gas content may also contribute to syncope. Hyperoxic cardiac chemoreflex sensitivity (CHRS) is an autonomic functional test that describes the heart rate decrease in response to increases in blood oxygen content. The purpose of this study was to investigate whether CHRS is altered in NCS.

METHODS AND RESULTS

CHRS was compared in 16 NCS patients (49+/-4 yr old) vs. 16 age and gender matched controls (53+/-2 yr old). NCS was verified by clinical syncope and positive head-up tilt testing. The hyperoxic CHRS was measured by determination of the venous partial pressure of oxygen and heart rate before and after 5 min of pure oxygen inhalation. The difference of the R-R intervals before and after oxygen inhalation divided by the difference in the oxygen pressures were calculated as hyperoxic chemoreflex sensitivity [ms/mm Hg]. CHRS in the control group was 7.1+/-1.1 ms/mm Hg. By contrast, CHRS in NCS patients was significantly lower (2.8+/-1.0 ms/mm Hg; p<0.05).

CONCLUSION

Neurocardiogenic syncope is associated with decreased hyperoxic cardiac chemoreflex sensitivity possibly reflecting impaired deactivation of arterial chemoreceptors. The clinical and pathophysiologic importance of chemosensor function in neurocardiogenic syncope needs to be investigated in more detail.

Influence of age and gender on the occurrence and presentation of reflex syncope

BACKGROUND

The clinical history is the cornerstone of diagnosing patients with transient loss of consciousness (TLOC). Reflex syncope is the most common cause of TLOC in patients across all ages. Knowledge of the variation in incidence and clinical features of reflex syncope by age and gender provides important background information to acquire an accurate diagnosis.

METHODS

In a cohort of 503 patients presenting with TLOC we established a final diagnosis after systematic evaluation and two years of follow-up. The occurrence of prodromal signs, symptoms, and triggers in patients with reflex syncope was analyzed by both age (< 40 yrs, 40-59 yrs and > or = 60 years) and gender.

RESULTS

Reflex syncope was the most frequently obtained diagnosis (60.2%) in patients of all ages presenting with TLOC. Its occurrence was higher in patients under 40 years (73.4%), than above 60 years of age (45.3%). Pallor (79.9%), dizziness (73.4%), and diaphoresis (63.0%) were the most frequently reported prodromal signs and symptoms. Most triggers and prodromal signs and symptoms were more common in patients under 40 years of age and in women.

CONCLUSIONS

Reflex syncope is nearly twice as common in patients under 40 years of age than in patients aged 60 years or above. Typical signs and symptoms of reflex syncope are more common in younger patients and in women. Therefore, age and gender provide important diagnostic information and can help to decide whether additional testing is necessary.

Blood pressure drop and symptoms during ATP-test under pacing

We studied systolic blood pressure (SBP) behavior and symptoms during ATP-test in temporary paced patients. SBP drop during ATP-test is only partially prevented by pacing. During DDD paced ATP-test, SBP minimum was lower in symptomatic patients. Considering the role of endogenous adenosine in neurally-mediated syncope (NMS), our results are concurrent with a SBP fall resulting in NMS recurrence under permanent pacing.