Clinical aspects and diagnostic relevance of neuroautonomic evaluation in patients with unexplained falls.

OBJECTIVE: To evaluate the diagnostic relevance of neuroautonomic evaluation in patients with unexplained falls compared to those with a syncope etiologically unexplained after initial evaluation. METHODS: It is an observational study, comparing 298 patients with unexplained fall with 989 patients with unexplained syncope. Each patient underwent supine and upright blood pressure measurement, tilt testing (TT) and carotid sinus massage (CSM). RESULTS: Patients with unexplained falls were older (75.3 ± 11.1 vs. 63.2 ± 19.2 years, p < 0.001), were more frequently hypertensive (66.1 vs. 47.2 %, p < 0.001) and more frequently prescribed antihypertensive drugs (62.4 vs. 48.7 %, p < 0.001) or benzodiazepines (15.7 vs. 10.6 %, p = 0.01), and in a greater proportion they experienced major traumatic injuries (77.5 vs. 29.6 %, p < 0.001) as a consequence of falls. The TT was less frequently positive in patients with unexplained falls (36 vs. 51.3 %, p < 0.001), whereas a Carotid Sinus Syndrome as suggested by CSM had a similar prevalence in the two groups (14.3 vs. 10.5 %, p = 0.074). Overall, either TT or CSM were positive in 61 % of patients with unexplained falls, and in 64 % of those with syncope (p = 0.346). After matching by age 298 patients with falls (75.3 ± 11.1 years) and 298 patients with unexplained syncope (75.4 ± 11.1 years), we found that the positivity prevalence of TT and CSM were similar in the two groups. CONCLUSIONS: The positivity prevalence of TT and CSM in patients with unexplained falls compared to patients with unexplained syncope is similar. Given its high diagnostic relevance, the neuroautonomic evaluation should be routinely performed in older patients with unexplained falls.

Poor diagnostic performance of tilt testing in hypertensive patients with unexplained syncope.

Syncope is a common condition. Tilt testing with sublingual nitroglycerin (TT-TNT) provides a test with good specificity and positivity rate in young and old patients. Its use in hypertensive patients with unexplained syncope has not been validated. The aims of this study were to evaluate the positivity rate, specificity and tolerability of TT-TNT in hypertensive patients with unexplained syncope. Five hundred and ten subjects (mean age 55 years) were enrolled, 388 patients with unexplained syncope (73 hypertensive and 315 normotensive) and 122 controls (59 hypertensive and 63 normotensive). All subjects underwent TT-TNT. The responses were classified as positive, negative or exaggerated (aspecific). In hypertensive patients, the usual hypotensive therapy was taken on the day of the test. In hypertensive controls, the positive responses were higher than in normotensives (19% vs 6%, P<0.001). The overall specificity was 81% in hypertensives and 94% in normotensives. The positivity rate was significantly lower in hypertensives (55% vs 72%, P<0.03). There was no significant difference between young patients and patients >65 years. TT was well tolerated, and no serious side effects occurred. TT potentiated with TNT has a lower positivity rate and specificity in hypertensive than in normotensive patients with syncope.