Predictive models of syncope causes in an outpatient clinic

Clinical history in the diagnosis of the cardiac syncope–the predictive scoring system

BACKGROUND

Cardiac syncope represents clinical situation with serious prognosis. The aim of the present study was to develop the diagnostic scoring system based on the clinical history allowing to distinguish between cardiac and noncardiac syncope.

METHODS

Clinical history was obtained in the form of the structured questionnaire in 60 patients with cardiac syncope (mean age 70 ± 10 years, 33 men) an in 140 patients with noncardiac syncope (mean age 45 ± 20 years, 44 men). Multivariate regression analysis identified seven variables that were included in the final regression model.

RESULTS

The age above 55 years, presence of structural heart disease, syncope in supine position, absence of prodromal symptoms, and chest pain before syncope were predictive of cardiac syncope. Predictors of noncardiac syncope were recovery duration of more than 1 minute and syncope occurring immediately after standing up. A diagnostic point score was derived from the regression coefficients. The sum of the points identified patients with cardiac syncope if the diagnostic point score was ≤2. Diagnostic performance of the score was assessed on the validation group of 67 patients with syncope (21 patients with cardiac syncope and 46 patients with noncardiac syncope). Sensitivity was 81%, specificity 84.8%, positive predictive value 70.8%, and negative predictive value 90.7%.

CONCLUSION

Predictive model based on parameters form clinical history of the patients may help to distinguish between cardiac and other causes of syncope.

Long-term follow-up of patients with syncope evaluated by head-up tilt test

BACKGROUND

Clinicians may be tempted to consider a positive head-up tilt test (HUTT) an unfavorable prognostic indicator. We investigated whether results of routine HUTT predict long-term recurrence of syncope.

METHODS

We analyzed syncope recurrence at long-term among 107 patients (mean age 51 +/- 20 years) receiving HUTT for diagnostic evaluation of unexplained/suspected neurocardiogenic syncope in our Institute.

RESULTS

HUTT was positive in 76 patients (vasodepressive response, n = 58; cardioinhibitory, n = 5; mixed, n = 13). During a median follow-up of 113 months (range, 7-161), 34 (32%) patients experienced recurrence (24 [32%] with positive HUTT during 110 months (7-159); 10 [32%] with negative HUTT during 120 [22-161] months). Actuarial freedom from recurrence at 10 years did not significantly differ for patients with positive/negative test results (after passive/active phases) or with different positive response patterns (vasodepressive, cardioinhibitory, mixed). By contrast, history of >4 syncopes in the 12 months preceding HUTT stratified risk of recurrence, irrespective of HUTT positivity/negativity. At Cox proportional hazards analysis, history of >4 syncopes in the 12 months preceding HUTT was the single independent risk factor for recurrence both in the overall study population (HR, 1.7; 95% CI, 1.07-2.69) and within the subset of patients who tested positive (HR, 1.83; 95% CI, 1.07-3.17).

CONCLUSIONS

This long-term follow-up study reinforces the concept that a positive HUTT should not be considered an unfavorable prognostic indicator; frequency of recent occurrences may be a more valid predictor.

The diagnostic protocol in children and adolescents with syncope: a multi-centre prospective study

AIM

The appropriate diagnostic protocol for children with syncope has not been well established. A diagnostic protocol was developed and prospectively implemented to improve the diagnostic performance of paediatricians.

METHODS

The study population included 474 consecutive patients (range 6-17 years) presenting with a syncopal spell in one of the five participating hospitals of China. In step 1, all patients underwent initial evaluation for history, physical examination, standing test and standard electrocardiography (ECG). In step 2, priority was given to cardiographic tests for possibly cardiogenic syncope, or electroencephalographic examination and brain imaging for suspected neurological syncope, or psychiatric tests for suspected psychiatric syncope. Patients with unexplained syncope underwent head-up tilt testing (HUT).

RESULTS

The initial evaluation gave a definite diagnosis in 59 (12.4%) and possible diagnosis in 54 of the 474 patients. Further testing gave a definite diagnosis for 326 patients (69.7%). After the entire diagnostic protocol, definite diagnosis was established in 385 patients (81.1%). Autonomic-mediated reflex syncope (AMS) accounted for 73.0% of cases. The average cost of diagnostic results per patient was RMB 1030.24 +/- 150.09 ($118.42 +/- 17.25).

CONCLUSION

The use of a simplified diagnostic protocol for children and adolescents with syncope improves diagnostic yield.

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.

Syncope: experience at a tertiary care hospital in Karachi, Pakistan

Introduction

Our aim was to determine the characteristics of patients presenting with syncope at a tertiary care hospital in Karachi, Pakistan.

Methods

A review of medical records was conducted retrospectively at the Department of Medicine, Aga Khan University Hospital, Karachi. Patients aged 16 and above, admitted from January 2000 to December 2005 with the diagnosis of syncope made by the attending physician were included.

Results

A total of 269 patients were included (75% males, mean age: 57.4 years). Neurogenic (vasovagal) syncope was the most common cause (47%), followed by cardiogenic syncope (18%) and orthostatic syncope (9%). A total of 24% were discharged undiagnosed. Twenty patients (7.4%) did not have any prodrome. Common prodromal symptoms included dizziness (61%), sweating (25%), palpitations (19%), nausea/vomiting (19%) and visual symptoms (17%). The distribution of symptoms according to cause of syncope revealed only breathlessness to be significantly associated with cardiogenic syncope (p = 0.002). Most patients with cardiogenic syncope were aged above 40 (98%, p < 0.001), had coronary artery disease (72%, p < 0.001) and abnormal electrocardiogram at presentation (92%, p < 0.001).

Conclusion

Despite differences in burden of diseases, our findings were similar to those of published syncope literature. Further studies are needed to develop a protocol to expedite the evaluation and limit the work-up and admission in low-risk patients.

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.

Ictal bradycardia and asystole: an uncommon cause of syncope

We report on two patients with recurrent syncope secondary to ictal bradyarrhythmias, triggered by partial epileptic seizures with atypical, stereotyped auras. Ictal bradyarrhythmias are potentially lethal, and likely originate from the involvement of limbic autonomic regions. The appropriate treatment is double-headed, including an antiepileptic drug and the implantation of a pacemaker.