Diagnostic value of electrocardiographic (resting and 24-h Holter) monitoring in comparison with NT-proBNP in the differential diagnosis of patients with cardiogenic and neurogenic syncope

BackgroundSyncope is a cause of 1–6% of hospitalizations. Both European and American syncope guidelines recommend a 12-lead ECG as part of the evaluation of all patients with unexplained loss of consciousness.ObjectivesThe aim of this study was the assessment of the significance of ECG, Holter ECG and the concentration of NT-proBNP that would be useful in the differentiation of patients with cardiac and reflex syncope.MethodsWe investigated 100 patients (56 men), aged 18–77 years with reflex or cardiac syncope over the last 3 years. The following factors were investigated: age, sex, systolic and diastolic blood pressure, the presence of cardiovascular disease. Moreover, we assessed basic resting ECG parameters and 24-h Holter ECG parameters, and NT-proBNP concentration in the differential diagnosis of syncope.ResultsPatients with reflex syncope were younger compared to patients with cardiac syncope (44.4 ± 16.5 vs. 60.8 ± 12.6; p < 0.001). A pathologic resting 12-lead ECG was present more frequently in the group with a cardiogenic type of syncope – 12 (24%) vs. 8 (16%). 24-h Holter ECG monitoring showed no statistically significant difference between minimal, mean and maximal heart rates in the analyzed groups. However, statistically significant differences were observed in the occurrence of ventricular and supraventricular arrhythmias between the investigated groups. Patients with cardiac syncope had significantly higher concentrations of NT-proBNP compared to patients with reflex syncope (448.7 ± 212.2 vs. 68.2 ± 64.1; p < 0.0001).ConclusionsElevated NT-proBNP concentration is present in patients with a cardiogenic mechanism of syncope, despite the fact that a resting ECG is inconclusive.