Head-up tilt test diagnostic yield in syncope diagnosis

Definitive aetiology of unexplained syncope after cardiovascular autonomic tests in a tertiary syncope unit

AIMS

Syncope is a common condition with many possible causes, ranging from benign to life-threatening aetiologies. Establishing a diagnosis can be difficult, and specialized syncope units, using cardiovascular autonomic tests (CATs), including a head-up tilt test, can increase the diagnostic yield. However, up to one-fifth of examined patients have inconclusive CAT results. The aim of the present study was to investigate the predictive value of history, and clinical findings for unexplained syncope after CAT and characterize the group with negative results.

METHODS AND RESULTS

Consecutive syncope patients [n = 2663, 61% women, median age 52 (32-69) years] were evaluated and CAT explained aetiology of syncope in 79% of cases, whereas 21% remained unexplained. Predictors of negative CAT were older age at first syncope (+8% higher odds per 10-year increment, P = 0.042), higher supine heart rate (HR; +12% per 10 b.p.m.; P = 0.003), absence of prodromes (+48%; P < 0.001), hypertension (+45%; P = 0.003), diabetes (+82%; P < 0.001), heart failure (+98%; P = 0.014), and coronary artery disease (+51%; P = 0.027). Compared with vasovagal syncope, patients with negative CAT were older, reported more often the absence of prodromes, and had a higher burden of cardiovascular comorbidities.

CONCLUSION

A cardiovascular autonomic test established the cause of syncope in 79% of patients evaluated in a syncope unit. Syncope without prodromes and cardiovascular comorbidities were significant predictors of failure to reveal an aetiology from assessment by CAT. These are known risk factors for cardiac syncope and patients with inconclusive CAT warrant further investigation.

Long-term recurrences and mortality in patients with noncardiac syncope

INTRODUCTION AND OBJECTIVES

There are no in-depth studies of the long-term outcome of patients with syncope after exclusion of cardiac etiology. We therefore analyzed the long-term outcome of this population.

METHODS

For 147 months, we included all patients with syncope referred to our syncope unit after exclusion of a cardiac cause.

RESULTS

We included 589 consecutive patients. There were 313 (53.1%) women, and the median age was 52 [34-66] years. Of these, 405 (68.8%) were diagnosed with vasovagal syncope (VVS), 65 (11%) with orthostatic hypotension syncope (OHS), and 119 (20.2%) with syncope of unknown etiology (SUE). During a median follow-up of 52 [28-89] months, 220 (37.4%) had recurrences (21.7% ≥ 2 recurrences), and 39 died (6.6%). Syncope recurred in 41% of patients with VVS, 35.4% with OHS, and 25.2% with SUE (P=.006). In the Cox multivariate analysis, recurrence was correlated with age (P=.002), female sex (P <.0001), and the number of previous episodes (< 5 vs ≥ 5; P <.0001). Death occurred in 15 (3.5%) patients with VVS, 11 (16.9%) with OHS, and 13 (10.9%) with SUE (P=.001). In the multivariate analysis, death was associated with age (P=.0001), diabetes (P=.007), and diagnosis of OHS (P=.026) and SUE (P=.020).

CONCLUSIONS

In patients with noncardiac syncope, the recurrence rate after 52 months of follow-up was 37.4% and mortality was 6.6% per year. Recurrence was higher in patients with a neuromedial profile and mortality was higher in patients with a nonneuromedial profile.

The Relationship Between Unexplained Chest Pain in Children and Head-Up Tilt Test

BACKGROUND

To explore the relationship between unexplained chest pain in children and head-up tilt test (HUTT).

MATERIALS AND METHODS

A total of 825 children with the main symptom of unexplained chest pain were admitted to the Specialist Outpatient Clinic of Children's Cardiovascular Disease from October 2000 to November 2021 at The Second Xiangya Hospital, Central South University. Among them, 473 were male and 352 were female, with a mean age of 10.61 ± 2.21 years. The control group included 58 cases, comprising 35 males and 23 females, with a mean age of 10.26 ± 2.66 years. The detailed history, physical examinations, conventional 12-lead electrocardiogram, chest X-ray, echocardiography, myocardial enzymes, electroencephalogram, and blood series were all examined. Disorders of the chest wall, lung, heart, mediastinum, and esophageal reflux, as well as drug effects, were ruled out. All the children underwent HUTT. Demographic description, univariate analysis, and multivariate logistic regression analysis were used to explore the possible linear or non-linear relationships between the children's unexplained chest pain and HUTT.

RESULTS

Among the 825 chest pain cases, 301 (36.48%) were HUTT positive and 524 (63.52%) were HUTT negative. HUTT-positive patients were older than HUTT-negative patients (11.04 ± 2.03 vs. 10.34 ± 2.31 years, P < 0.001). The logistic regression results showed that each year of age increased the probability of being HUTT positive by 17.90% (P < 0.000), and females were 91.30% more likely to be HUTT positive than males (P < 0.000).

CONCLUSION

Clinically unexplained chest pain in children is mainly caused by unbalanced autonomic nervous function. HUTT can help clear the cause of unexplained chest pain.

Etiology, risk factors, and prognosis of patients with syncope: A single-center analysis

OBJECTIVE

To investigate the main causes, risk factors, and prognosis of patients hospitalized with syncope.

METHODS

The patients admitted due to syncope were included. We analyzed the etiology, risk factors, and prognosis of patients with an average follow-up of 15.3 months.

RESULTS

High-risk factors for cardiogenic syncope included age ≥60, male, hypertension, palpitation, troponin T-positive, abnormal ECG, CHD history, and syncope-related trauma. Mortality rate was 4.6%, recurrence rate of syncope was 10.5%, and the rehospitalization rate was 8.5%. Univariate analysis showed that prognosis of syncope was related to age ≥60 years old, hypertension, positive troponin T, abnormal electrocardiogram, and coronary heart disease (p < .05). Multivariate Cox proportional hazard analysis showed that age ≥60 years old (p = .021) and high-sensitivity troponin-positive (p = .024) were strongly related to the prognosis of syncope. Kaplan-Meier curve showed statistical difference in the survival rate between the groups divided by age ≥60 years (p = .028), hs-TnT-positive (p < .001), abnormal ECG (p = .027), and history of CHD (p = .020).

CONCLUSION

High-risk factors for cardiogenic syncope included age ≥60, male, hypertension, palpitation, troponin T-positive, abnormal ECG, CHD family history, and syncope-related trauma. Age, hypertension, troponin T-positive, abnormal ECG, and CHD history were associated with the prognosis of syncope.