Hyperventilation and amplified blood pressure response: is there a link?
Based on prior studies, the hypothesis that hyperventilation (HV) may have a pressor effect and play a causal role in hypertension has been suggested. The objective of this study was to correlate HV with blood pressure (BP)-change during a postural challenge. Consecutive subjects referred for evaluation of syncope, dizziness, chronic fatigue syndrome (CFS), fibromyalgia, or non-CFS fatigue were assessed with a 10-min supine 30-min head-up tilt test combined with capnography. We selected for analysis the records of patients aged 17-70 years, not taking vasoactive medications, having sitting systolic BP (SBP) < 140 mmHg, sitting diastolic BP (DBP) < 90 mmHg, and who completed 30 min of tilt. HV was diagnosed when end-tidal pressure of CO2 < 30 mmHg was recorded consecutively for > or = 10 min. Postural hypertension (PHT) was diagnosed when DBP on tilt > or = 90 mmHg was recorded consecutively for > or = 10 min. DBP-change was computed as (median DBP on tilt) -(median DBP supine). PHT and DBP-change were correlated with HV. A total of 320 patient charts were reviewed. PHT was present in 30 cases. The mean DBP-change in patients with PHT was +9.9 mmHg (s.d. 5.8), with three patients manifesting HV. Of the remaining 290 patients, 56 had HV, their mean DBP-change was -0.3 mmHg (s.d. 7.2). The other 234 patients without HV had a mean DBP-change +0.95 mmHg (s.d. 5.7), comparable to the DBP-change in patients with HV. In, conclusion, posturally induced HV was not associated with an increase in BP, nor was PHT associated with HV, except in a small minority of cases.
Naschitz
J E
JE
Department of Internal Medicine A, Bnai-Zion Medical Center, Haifa, Israel. Naschitz@tx.technion.ac.il
Mussafia-Priselac
R
R
Peck
E R
ER
Peck
S
S
Naftali
N
N
Storch
S
S
Slobodin
G
G
Elias
N
N
Rosner
I
I
D000293:Adolescent; D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000502:physiology*; D019296:Capnography; D002245:Carbon Dioxide / Q000378:metabolism; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006973:Hypertension / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D006985:Hyperventilation / Q000150:complications* / Q000175:diagnosis / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011187:Posture / Q000502:physiology; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012720:Severity of Illness Index; D018667:Tilt-Table Test
D002245:Carbon Dioxide