Detection of hypotension in patients with syncope: combined tilt test and ambulatory blood pressure monitoring strategy in clinical practice

Abstract Both ambulatory blood pressure monitoring (ABPM) and Tilt Test (TT) (a provocation method), can identify the hypotensive component that predisposes to syncope. Objective 1)To establish a) the prevalence of confirmed hypotension (CHp) with both methods; b) the concordance between them. Methods Patients (pts) ≥18 years with syncope for whom it was decided to perform a TT were included. TT was performed for 45 min at 75 degrees. On a different day, within 15 days, an ABPM was performed (≥70 % adequate readings). Criteria: CHp: In TT: TT(+) or detection of systolic blood pressure (SBP) ≤ 100 mmHg during the study resulting from a drop from baseline; in ABPM: SBP ≤ 100 mmHg resulting from a drop ≥ 20 mmHg from the previous one. Only the awake periods were considered. Results 61 pts (age= 62.5±16.8, female= 39 (64%); antihypertensive medications= 35 pts (57%); Cardiovascular history, except isolated hypertension= 29 pts (47%). The reported number of episodes was 4±4.4 (median=2). Syncope was post-prandial in 25 pts (41%) and probable reflex by the description in 28 pts (46%). CHp during syncope was confirmed in 25 pts during TT and in 1 pt during ABPM. Positive responses to TT were: vasodepressor in 14 pts, mixed in 10 pts and disautonomic pattern in 1 pt. Average 24 h in ABPM was above 135 mmHg in 10 pts (16%). Seventy-nine per cent of the population (48 pts) presented ≥ 2 falls ≥20 mmHg of SBP during the waking period. SBP ≤ 100 mmHg constituted ≥ 20% of awake measurements in 10 pts (16%). A post-prandial fall in SBT ≥ 20 mmHg was detected in 24 patients (39%). Of these, in 8 (13%), the achieved SBP was ≤ 100 mmHg. Table 1 shows the prevalence for CHp with both methods. Table 2 shows the concordance between TT and ABPM. CHp was detected by TT or ABPM in 48 pts, i.e 79% of the population. Both studies were concordant in 32 pts (52%) (Cohen's kappa coefficient: 0.04). CHp was identified in 28% of pts only by TT and in 20% only by ABPM. Conclusion CHp was detected in ¾ of this population using a combined TT and ABPM strategy. They were complementary not only to establish a diagnostic suspicion, but also to guide the therapeutic management of these patients.CHp PrevalenceTT and ABPM Concordance