Pseudo-Hypertension in the Elderly: Still Hazy, After All These Years*

COMMENTARY Pseudo-hypertension in the elderly: still hazy, after all these years*

JD Spence Departments of Clinical Neurological Sciences Internal Medicine, and Pharmacology and Toxicology, University of Western Ontario, Canada

Keywords: pseudohypertension; blood pressure measurement; elderly (*with apologies to Simon and Garfunkel)

The study reported in a recent issue of the Journal of and 12 Osler-negative (OM−) patients matched for Human Hypertension by Wright and Looney1 raises age and sex, they found no significant difference important issues about the difficulty of obtaining between the two groups; the over-estimation of dias- accurate measurements of blood pressure (BP), parti- tolic pressure by the cuff was 18.4 + 15.7 in the OM+, cularly in the elderly. How common is pseudohy- and 12 + 5.8 mm Hg in the OM−. They found, as did pertension, and how can it be reliably detected short we4 and Messerli et al,2 that there was a good corre- of doing intra-arterial BP measurements? It is inter- lation between the pulse wave velocity and the mag- esting that these issues remain unresolved, after 20 nitude of cuff artifact. years. Lewis et al5 did intra-arterial pressures in 15 nor- They studied Osler’s manoeuver, the sign of cuff motensives and 21 hypertensive elderly patients artifact due to arterial stiffness described by Mes- (age 65–89; mean age was 79 for the normotensives serli et al2 and so named because Osler, in his 1892 and 76 for the hypertensive group). They found cuff text, indicated that he mistrusted the BP reading in diastolic pressure more than 10 mm Hg higher than patients with stiff arteries, in whom the radial artery intra-arterial pressure in 10 cases, but Osler’s test was still palpable even though the cuff had been was negative in the pseudohypertensive patients, inflated above the systolic pressure. Messerli et al while systolic pressures were lower by cuff than the called patients with that finding ‘Osler manoeuver intra-arterial level in four patients that were OM+. + positive’ (OM ), and found discrepancies between Oliner et al6 measured intra-arterial pressures in the cuff and intra-arterial diastolic pressure in such 19 patients in whom at least two observers agreed on patients, ranging from 10 to 54 mm Hg. In the cohort the presence of a positive Osler’s manoeuver (OM+). of patients being screened for SHEP (the Systolic They reported that mean arterial pressure was у10 Hypertension in the Elderly Program) studied by mm Hg higher by cuff in two cases, and у10 mm Hg Wright and Looney, 243 of 3387 patients (7.2%) + lower by cuff in three cases, and concluded that the were OM . They suggest that Osler’s manoeuver Osler manoeuver was not useful. However, it is could be used to identify patients with pseudohy- important that the patients they studied, though pertension. appropriate in age (age 56–93, mean 76 ± 10 years), It is important to recognise, however, that the did not for the most part have diastolic hyperten- Osler manoeuver is not a reliable indicator of the sion: the systolic pressures averaged 187 ± 28 by presence of pseudohypertension. A number of stud- cuff, and 201 ± 28 by intra-arterial measurement; ies have shown that the two cannot be equated, and diastolic pressures were 87 ± 12 by cuff and 81 + 14 that the sign is not reliably detected by different by direct measurement. Seven of the cases had a cuff observers. pressure at least 10 mm Hg higher than the intra- Belmin et al3 found among 205 consecuttive eld- ± arterial pressure, which would often be reported as erly (age 84 6.2 years) in-patients of a French geri- pseudohypertension, but they concluded that atric hospital that 12 (5.8%) were OM+; however, + because the mean arterial pressure was less than 10 when they did intra-arterial pressures in the 12 OM mm Hg different by cuff and direct measurements, pseudohypertension was not present. These reports and others betray a misunderstand- Correspondence: Dr David Spence, Stroke Prevention & Athero- ing of this issue. Pseudohypertension is essentially sclerosis Research Centre, Siebens-Drake Bldg., Robarts Research a diastolic phenomenon; in fact the systolic pressure Institute, 1400 Western Rd, London, ON, Canada N6G 2V2 Received 19 March 1997; revised 15 May 1997; accepted 19 is usually underestimated by cuff measurements in May 1997 patients with stiff arteries, as discussed below. Pseudo-hypertension in the elderly: still hazy, after all these years JD Spence 622 BP measurement by the cuff method is frequently and a 5 mm false elevation of the diastolic pressure inaccurate. London and London,7 among others, by the cuff. In those healthy ambulatory elderly vol- showed that the cuff method of BP measurement is unteers, therefore, there was less discrepancy subject to great error, depending on interobserver between intra-arterial and cuff pressures, than had variability and the decision to choose muffling ver- been observed in patients selected because of a sus- sus disappearance of Korotkoff sounds; they found pected discrepancy. In that study, we also examined that commonly the error in measurement was 30 the relationship between arterial stiffness as mm Hg. reflected in pulse wave velocity, and extent of cuff The first descriptions of pseudo-hypertension due artifact: a significant though not very strong corre- to arterial stiffness were three single case reports of lation was observed. pseudohypertension from 1974 to 1978, attributed These findings were validated by Messerli et al,2 to ‘pipe stem brachial arteries’, in patients that had who also found a correlation between pulse wave very high diastolic cuff pressures that were shown velocity and the magnitude of cuff artifact. to be false by intra-arterial pressure recording, usu- The correct identification of patients with pseudo- ally as a part of anaesthetic monitoring for general hypertension can be important. Misidentification of surgery.8–10 normotensive patients as hypertensive can lead to We began the first systematic study of the problem excessive lowering of BP, which may account for the in 1977, in patients whose BP readings by cuff were observations of Jackson et al,16 and their suggestion at odds with the clinical findings:11,12 we studied that treatment of hypertension in the enderly may patients that had a diastolic pressure greater than be dangerous. Unfortunately, measurement of intra- 100 mm Hg, without any evidence of end organ dis- arterial pressure is somewhat difficult and carries a ease. Thus, the patients had apparent hypertension, slight risk, and is not available in the physician’s but with normal optic fundi, normal renal function office. For that reason, identification of pseudohy- and no evidence of left ventricular hypertrophy on pertension without intra-arterial measurements has a chest X-ray or electrocardiogram. been attempted in a number of ways. The findings had in fact been predicted by Sacks et al,13 whose studies in simulated arteries showed Is there a way to evaluate that a doubling of arterial thickness would cause a pseudohypertension short of intra- false elevation of the diastolic pressure by 30 mm Hg. arterial pressure measurement? In these patients we found a significant discrep- Recently, Miller et al17 reported that the Accutracker ancy between the intra-arterial pressure and the cuff II ambulatory recorder measured systolic pressure pressure, particularly in patients above age 60. In 5.6 mm Hg lower, and diastolic pressure 6.3 mm Hg the older age group, half the patients had a signifi- lower than pressures measured with a standard mer- cant (30 mm Hg or more) elevation of the cuff dias- cury sphygmomanometer. Similarly, Hla et al18 tolic pressure, compared to the intra-arterial dias- reported better correspondence between intra- tolic pressure. We defined pseudohypertension as a arterial pressures and pressures measured by an diastolic cuff pressure Ͼ100 mm Hg, with an intra- automated Infrasonde device, compared with press- arterial pressure Ͻ90 mm Hg, since in the days ures measured by random zero sphygmomanometer. before SHEP, those pressures were thresholds that These studies, as well as our experience in heal- would change the patients’ treatment. thy elderly subjects,4 and our finding15 that an auto- Subsequently, others have defined pseudohyper- mated digital device using an oscillometric method tension as a false elevation of the pressure by cuff more accurately predicted increased left ventricular measurement of 10 mm Hg or more; that way of mass over 2 years of untreated borderline hyperten- looking at things is problematic because systolic and sion than did random zero pressures, all suggest that diastolic pressures, somewhat surprisingly, have in the elderly, pressures may be more accurately errors in cuff measure that are usually opposite in measured by automated oscillometric devices than sign or direction; the systolic pressure is usually fal- by auscultation. sely reduced by the cuff. It may make more sense to Another observation that may be helpful in cases refer to the magnitude of cuff artifact, rather than to of suspected pseudohypertension is that the mean rely on thresholds for diagnosis of ‘hypertension’. arterial pressure calculated from the cuff pressure Subsequently, a number of studies were done in (MAP = diastolic + [(systolic − diastolic)/3]) is usu- which elderly individuals had intra-arterial press- ally quite close to the intra-arterial measurement, ures, which did not appear to differ significantly since the cuff artifact causes under-estimation of the from cuff pressure.14 However, in those studies, the systolic and over-estimation of the diastolic press- patients were not selected because of any discrep- ure, and the errors tend to cancel out.4 That ancy between the cuff pressure and the clinical fin- phenomenon may be responsible for the approach dings; they were simply elderly individuals that had described by Lewis et al5 and Oliner et al,6 in which intra-arterial pressures compared with cuff press- mean arterial pressures were used to define pseudo- ures. hypertension. That issue was addressed further by us15 in a Two new approaches to sorting out this problem study of the difference between intra-arterial press- have been reported. One is to measure closing pressure and cuff pressure in 55 healthy elderly volun- ure of the artery. This is done by observing the teers. In that study, the average cuff artifact was an brachial artery with ultrasound during compression 8 mm false reduction of systolic pressure by the cuff, by a BP cuff; normal arteries close spontaneously Pseudo-hypertension in the elderly: still hazy, after all these years JD Spence 623 when the proximal artery is occluded with a cuff; in 5 Lewis RR, Evans PJ, McNabb WR, Padayachee TS. those cases in which the artery below the cuff Comparison of indirect and direct blood pressure remains open, the pressure required to collapse the measurement with Osler’s manoeuver in elderly artery with an additional water cuff has been called hypertensive patients. J Hum Hypertens 1994; 8: the ‘closing pressure’ by Colgan et al.19,20 They 879–885. 6 Oliner CM, Elliot WJ, Gretler DD, Murphy MB. Low believe that the closing pressure closely mirrors the predictive value of positive Osler manoeuver for difference between intra-arterial and cuff pressures, diagnosing pseudohypertension. J Hum Hypertens and may be a substitute for intra-arterial measure- 1993; 7: 65–70. ments. 7 London WB, London RE. Comparison of indirect press- Another approach is to measure the BP in the ure measurements (Korotkoff) with simultaneous finger, where there is apparently not enough athero- direct brachial artery pressure distal to the cuff. Adv sclerosis or arteriosclerosis to cause a cuff artifact.21 Int Med 1967; 13: 127–142. 8 Taguchi JT, Suwangoal P. Pipe-stem brachial arteries. A cause of pseudohypertension. JAMA 1974; 288: 733. How common is pseudohypertension? 9 Wallace CT, Carpenter FA, Evins CS, Mahaffey JE. Acute pseudohypertensive crisis. Anaesthesiology Pseudohypertension is a problem in some elderly 1975; 43: 588–589. patients with stiff arteries. Its prevalence is still 10 Sprague DH, Kim DI. Pseudohypertension due to Mon- 22 keberg’s arteriosclerosis. Anesth Analg 1978; 57: unclear; I have estimated that the problem occurs 588–589. in approximately 4% of patients in a busy Hyperten- 11 Spence JD, Sibbald WJ, Cape RD. Pseudohypertension sion Clinic, and half of elderly patients with dias- in the elderly. Clin Sci Mol Med 1978; 55 (Suppl 4): tolic pressure Ͼ100 mm Hg but no end-organ dis- 399s–402s. ease. Belmin et al3 found that 5.8% of elderly 12 Spence JD, Sibbald WJ, Cape RD. Direct, indirect and geriatric in-patients were OM+, and Wright and mean blood pressures in hypertensive patients: the Looney1 found that 7.2% of patients screened for problem of cuff artefact due to arterial wall stiffness SHEP at their centre were OM+; however, not all and a partial solution. Clin Invest Med 1980; 2: 165– those patients will have pseudohypertension. 173. Osler’s manoeuver may be used to raise clinical 13 Sacks AH, Raman KR, Burnell JA (1963) A study of auscultatory blood pressure in simulated arteries. in suspicion of a large cuff artifact, but further evalu- Symposium on Biorheology 215–230. ation is required to establish the true BP level; new 14 O’Callaghan W, Fitzgerald DJ, O’Malley K, O’Brien E. approaches to sorting this out are ultrasound deter- Accuracy of indirect blood pressure measurement in mination of arterial closing pressure, and BP the elderly. Br Med J 1983; 286: 1545–1546. measurement with a finger cuff. The diagnosis 15 Spence JD et al. Prospective study of ambulatory moni- should be suspected in elderly patients with resist- toring and echocardiography in borderline hyperten- ant high diastolic pressures and no end-organ dis- sion. Clin Invest Med 1991; 14(3): 241–250. ease, who complain of light-headedness when the 16 Jackson G, Pierscianowski TA, Mahon W, Condon J. BP is treated to levels that do not explain the symp- Inappropriate antihypertensive therapy in the elderly. toms. Lancet 1976; ii: 1317–1318. 17 Miller ST, Elam JT, Graney MJ, Applegate WB. Dis- I recommend changing the term to ‘Diastolic crepancies in recording systolic blood pressure of eld- Pseudohypertension’, as patients with isolated sys- erly persons by ambulatory blood pressure monitor. 23 tolic hypertension should be treated in any case, Am J Hypertens 1992; 5: 16–21. and the cuff seldom underestimates systolic press- 18 Hla KM, Vokaty KA, Fessner JR. Observer error in sys- ure. tolic blood pressure measurement in the elderly. Arch Int Med 146: 2373–2376. 19 Colgan MP et al. The importance of B-mode imaging References in Pseudohypertension. J Vasc Technol 1992; 16: 292–294. 1 Wright JC, Looney SW. Prevalence of Positive Osler’s 20 MacMahon M et al. Arterial closing pressure correlates Manoeuver in 3387 persons screened for the Systolic with diastolic pseudohypertension in the elderly. J Hypertension in the Elderly Program (SHEP). J Hum Gerontol 1995; 50A: M56–M58. Hypertens 1997; 11: 285–289. 21 Anzal M, Palmer AJ, Starr J, Bulpitt CJ. The prevalence 2 Messerli FH, Ventura HO, Amodeo C. Osler’s of pseudohypertension in the elderly. J Hum Hypert- maneuver and pseudohypertension. N Engl J Med ens 1996; 10: 409–411. 1985; 312: 1548–1551. 22 Spence JD. Pseudohypertension. In: Laragh JH, 3 Belmin J et al. Osler’s maneuver: absence of usefulness Brenner BM (eds). Hypertension: Pathophysiology, for the detection of pseudohypertension in an elderly Diagnosis and Management. Raven Press: New York, population. Am J Med 1995; 98: 42–49. 1990, pp 1407–1414. 4 Finnegan TP, Spence JD, Wong DG, Wells GA. Blood 23 Reeves RA, Fodor JG, Patterson C, Spence JD. Report pressure measurement in the elderly: Correlation of of the Canadian Hypertension Society Consensus Con- arterial stiffness with difference between intra-arterial ference: 4. Hypertension in the elderly. Can Med Assoc and cuff pressures. J Hypertens 1985; 3: 231–235. J 1993; 148: 815–820.