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Cardiovascular and hormonal responses in presyncopal state
Author(s) -
Grasser Erik Konrad,
Goswami Nandu,
Jantscher Andreas,
Rössler Andreas,
HinghoferSzalkay∗ Helmut
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.6.a949-c
Subject(s) - supine position , heart rate , medicine , blood pressure , pulse pressure , stroke volume , cardiology , mean arterial pressure , anesthesia
Purpose : To test the feasibility of a new cardiovascular (CV) test paradigm, we studied presyncopal CV responses in 15 males and one female. Methods and protocol : After 30min supine rest, graded LBNP (Lower Body Negative Pressure), with increasing intensity by 10mmHg every 3min, was added to 70° HUT (Head Up Tilt) until a presyncopal sign occured. Blood pressure (BP), heart rate (HR) and thoracic impedance (TI) were monitored on a beat to beat basis and total peripheral resistance index (TPRI) was calculated. Results : Mean standing time was 12.3 ± 1.2 min. HR increased 77% and stroke index decreased 47%. Systolic pressure dropped by 25%, diastolic pressure by 15% and mean arterial pressure by 19%. TI rose by 12%, TPRI decreased by 10% and pulse pressure by 38%. HR and BP variabilities decreased together with pulse pressure. Plasma volume decreased by 11% as expected. Norepinephrine increased by 80% while epinephrine remained unchanged. Conclusion : A combined HUT‐LBNP paradigm is useful to study CV regulation under severe stress conditions. Support for this study was provided by Medical University, Graz, and the Austrian Space Forum (OEWF).