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Which Hemodynamic Parameter Predicts Nitroglycerin‐Potentiated Head‐Up Tilt Test Response?
Author(s) -
RUSSO VINCENZO,
PAPA ANDREA ANTONIO,
CIARDIELLO CARMINE,
RAGO ANNA,
PROIETTI RICCARDO,
CALABRÒ PAOLO,
RUSSO MARIA GIOVANNA,
NIGRO GERARDO
Publication year - 2015
Publication title -
pacing and clinical electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.686
H-Index - 101
eISSN - 1540-8159
pISSN - 0147-8389
DOI - 10.1111/pace.12593
Subject(s) - medicine , hemodynamics , blood pressure , heart rate , stroke volume , anesthesia , cardiology , vascular resistance , haemodynamic response , diastole , population , cardiac output , environmental health
Background The aim of our study was to identify the early hemodynamic predictors of head‐up tilt test (HUTT) outcome in healthy patients with recurrent unexplained syncope. Methods and Results The study involved 95 patients (mean age 38 ± 15; 42 male) who were referred for the evaluation of the syncopal episodes from October 2012 to May 2013. According to the nitroglycerin‐potentiated diagnostic tilt test response, the study population was divided into two groups: HUTT+ Group (61 patients, mean age 37 ± 10; 27 male) and HUTT– Group (34 patients, mean age 38 ± 11; 15 male) with no tilt‐induced syncope. Finger arterial blood pressure (BP) was recorded during tilt testing. Left ventricular stroke volume (SV), cardiac output (CO), and total peripheral resistance (TPR) were computed from the pressure pulsations. After nitroglycerin administration, the HUTT+ Group showed a significant increase in heart rate (92.0 ± 7.3 beats/min vs 68.9 ± 8.7 beats/min, P < 0.0001), with well‐maintained systolic BP (111.6 ± 14.1 mm Hg vs 108.8 ± 11.5 mm Hg; P = 0.332) and diastolic BP (66.1 ± 8.5 mm Hg vs 63.1 ± 6.9 mm Hg; P = 0.0913); a significant decrease in SV (53.9 ± 8.0 mL vs 78.6 ± 8.2 mL; P < 0.0001) and CO (4.0 ± 0.5 L/min vs 5.8 ± 1.0 L/min; P < 0.001), and a significant increase in TPR (1.3 ± 0.3 U vs 0.9 ± 0.2 U, P < 0.0011). We tested three hemodynamic parameters (SV, CO, and TPR) as predictors of positive tilt test response with receiver‐operating characteristic curve analysis. Conclusions Our results show that, 2 minutes after nitroglycerin administration, a statistically significant decrease of SV values (<67 mL) strongly predicts (area under the curve, 0.985; P < 0.0001) the HUTT‐positive response in healthy patients with recurrent unexplained syncope.