DISTINCT CLINICAL FEATURES AND ORTHOSTATIC TEST CHARACTERISTICS OF DELAYED VS. CLASSIC ORTHOSTATIC HYPOTENSION

초록

Objective: Delayed orthostatic hypotension (OH) is a milder form of classic OH, but its clinical features and diagnostic differences are unclear. This study compared clinical characteristics and head-up tilt test (HUT) findings between classic and delayed OH. Design and method: The study included 390 patients who underwent a HUT and completed a detailed symptom questionnaire survey (23 items). Patients were classified as Classic-OH group (drop in systolic blood pressure (BP) of above 20 in normotension or above 30mmHg in patients with supine hypertension 1-3min) and Delayed-OH group (same BP drop after 3-45min). Based on the cardiac cycle, OH patterns were subcategorized into isolated systolic, isolated diastolic, or combined OH. HUT involved BP measurement after 5 minutes of supine rest and every minute for 45 minutes at 60° tilt. Results: 306 patients (78.5%) were diagnosed with OH (Classic-OH vs DelayedOH, 61.8% vs 38.2%) and females had a higher proportion (61.6%). In the HUT, diagnoses of classic-OH were made at 1min/2min/3min in 69.3%/23.3%/7.4% of cases, 3-5min/6-10min/11-15min/16-20min/over 20min in Delayed-OH, 27.7%/35.3%/18.5%/13.4%/5.1%). Classic-OH patients were older (56.6 ± 17.8 vs. 50.9 ± 18.5, p = 0.007) and more likely to have hypertension (44.1% vs. 29.1%, p = 0.008). Combined OH was more frequent in Classic-OH (38.1% vs. 23.1%, p = 0.01). Heart rate increases at the time of diagnosis were greater in Delayed-OH (10.62 ± 8.46 vs. 7.29 ± 6.54bpm, p = 0.001). Most patients (78.1%) had no symptoms at diagnosis. On symptom surveys, patients reported an average of 7.9 ± 4.1 symptoms; dizziness (74.5%) and fatigue (68%) were most common, while Classic-OH patients reported more general weakness (64.6% vs. 50.0%), insomnia (38.6% vs. 27.4%), and abdominal bloating (22.8% vs. 13.7%). Presyncope was a higher tendency in Classic-OH (44.4% vs. 34.2%, p = 0.076). Conclusions: Accurate OH diagnosis requires detailed history-taking and continuous BP monitoring every minute for up to 20 minutes during HUT, as ClassicOH and Delayed-OH differ in clinical features and diagnostic timing. Traditional bedside tests which measure BP at 1 and 3 minutes are insufficient for precise diagnosis.