http://doi.org/ 10.33698/NRF0085 -Harmeet Kaur Kang, G Rachel Andrews, S. Ramamoorthy
Abstract : Background: Hill’s sign is described as an indicator of severity of aortic insufficiency. But there has been considerable difference of opinion in the literature regarding the reliability of Hill’s sign. Aim of the study is to evaluate the clinical value of Hill’s sign in severe aortic-regurgitation. Objectives: I) to determine the difference in systolic blood pressures between the arm & the leg recordings using sphygmomanometer cuff & intra arterial measurements in patients with severe AR.2) to correlate cuff pressures with intra-arterial pressures.Methods: A prospective observational design was used. The study included 25 patients diagnosed as severe AR at All India Institute of Medical Sciences, New Delhi. At the time of catheterization, cuff pressures were measured in the arm & the thigh with a mercury sphygmomanometer using 12cm and 19cm cuffs. Systolic pressure and diastolic pressures (both phase IV and phase V) were recorded. Intra-arterial pressures were measured in the axillary & femoral arteries.Results: Hill’s sign was present in all subjects only when both arm and thigh pressures were recorded with the 12cm cuff. It was present only in a minority of subjects (3 of 30, 10%) when the thigh pressure was recorded with the appropriate cuff(l9cm). Hill’s sign was not evident on intra-arterial pressure measurement in any subject (mean difference: 4.366±2.93 mmHg). Conclusions: Hill’s sign is not applicable to intra-arterial pressure measurements. In a majority of patients, its presence appears to be related to the use of an inappropriately smaller cuff for lower limb measurements.
Key words :
Hill’s sign, aortic regurgitation, aortic insufficiency, intra-arterial pressure sphygmomanometer.
Correspondence at :
Harmeet Kaur Kang
W/o Dr. Tejinderpal Singh, Lecturer,
University School of Business,Panjab University Chandigarh E-mail: hkkang@rediffmail.com
Introduction
Aor tic regurgitation is a potentially serious cardiac abnormality. Rheumatic heart disease is usually the underlying cause of aortic regurgitation in countries with a high prevalence of rheumatic fever. The world Health Organization estimates that more than 12 million people are affected by rheumatic fever or rheumatic heart disease. Children and young adults mainly account for more than 40,000 deaths annually. Most cases of rheumatic heart disease affect mitral valve but aortic & tricuspid valve involvement also occur.
Patients with aortic regurgitation require careful clinical monitoring to identify the optimal time for surgical intervention. Endocarditis prophylaxis may be indicated for the patients who are undergoing various procedures I. The use of non-invasive cardiac testing such as echocardiography has increased in recent years. It is estimated that 2% of general population undergoes non- invasive cardiac diagnostic evaluation annually2. If a careful clinical examination can exclude the presence of aortic regurgitation, then there would be no need with fur ther cardiac evaluation.
Aortic insufficiency was first clearly described by Cooper in 1705 and the associated collapsing pulse by Vieussens in 17153. After Corrigan’s classical clinicopathological correlation was presented in 18233, with the advent of modern sphygmomanometry in 1896, attention was turned to physical findings in this disease and it was recognized that the characteristic features are low diastolic pressure, increased systolic pressure, and wide pulse pressure. In addition, Hill and associates reported finding a consistently higher systolic pressure in the leg than in the arm in patients with aortic regurgitation, but not in normal subjects (Hill sign) 4,5 Since then Hill’s sign (an exaggerated difference in the systolic ar terial pressure between upper and lower limbs) is described as an indicator of the severity of aor tic insufficiency.
There has been considerable difference of opinion in the literature regarding the reliability of Hill’s sign. Some studies have shown that Hill’s sign is a useful indicator of aortic insufficiency, 6,7 but others have shown that there is no difference in systolic blood pressure in arms & legs in aortic regurgitation; hence Hill’s sign should not be used as an indicator of aortic regurgitation. 8,9. It was felt impor tant to determine the validity and reliability of Hill’s sign as an indicator of aortic regurgitation. Hence a study was planned with an aim to evaluate the clinical value of Hill’s sign in the assessment of aortic regurgitation.
Objectives of the Study
- To determine whether there is any difference in the systolic blood pressure of the arm and leg recorded by sphygmomanometer cuff in patients with aortic
- To compare the above difference with intra-arterial pressures recorded during cardiac
- To correlate the systolic and diastolic pressures obtained by cuff occlusion with the Intra-ar terial pressure
Materials & Methods
Study was done by quantitative study approach. Prospective non- experimental observational design was used. Setting was Cardiac catheterization laboratory of All India Institute of Medical Sciences Hospital, New Delhi. A total of 30 patients diagnosed with severe aortic insufficiency were included in the study. Patients diagnosed to have severe aortic insufficiency based on one or more of the following features and undergoing cardiac catheterization i.e. (i) High pitched decrescendo diastolic murmur, attributed to aortic insufficiency with peripheral signs of aortic insufficiency such as collapsing pulse, wide pulse pressure with low diastolic pressure, Pistol shots and Duroziez murmur.
(ii) Left ventricular enlargement and severe aortic insufficiency on Echocardiography were included. Informed consent was taken from all the patients about being the participant of the study. The patients with peripheral vascular disease, those having contraindications to cardiac catheterization and the patients having complications during cardiac catheterization precluding detailed, time consuming recording of intra ar terial pressures were excluded from the study.
Data Collection Tools
For noninvasive BP measurement a Standard mercury sphygmomanometer was used to take blood pressure readings in the arm and leg. Cuff size of atleast 40% of limb circumference was used i.e. for arm – l2-cm. width and for thigh – 19-cm. width. For intra-arterial BP measurement a 6F or 7F ar terial sheath, a 6 or 7 F ludkin’s right coronary ar tery catheter & a standard transducer were used. Reliability of sphygmomanometer was checked. The sample size taken for Interrater reliabiiity was 95.
The blood pressure was checked on 95 subjects according to the standard procedure by two observers. Pearson’s correlation coefficient was 0.998 for systolic blood pressure and 0.989 for diastolic blood pressure. Correlation coefficient for systolic and diastolic blood pressure was significant at the 0.0 I level.
Data Collection Procedure Cuff pressure recording: 10,11 Patient was placed in the supine position and extremities placed comfortably in a natural position. For measurement of leg pressure, the patient was made prone if necessary. Measurements were taken after at least 5 min. of rest. Noises etc. were avoided. Constrictive clothing were removed and the level of mercury was adjusted at zero level. Left arm blood pressure was taken by palpating the brachial artery & appropriately sized cuff was placed on subjects’ arm with the tubing directly over the brachial artery. Left leg blood pressure was taken by placing the appropriately sized cuff on the thigh. The popliteal artery was palpated and systolic and diastolic blood pressure was checked.
Appearance of the first sound was used to define the systolic blood pressure and the disappearance / as well as the muffling of the sounds was used to define the diastolic blood pressure. Blood pressure was measured three times or more until the variability in readings was less than 10mmHg. Systolic and diastolic blood pressure of arm & leg were recorded.
For intra-arterial BP measurement: Cardiac catheterization – as performed by experienced cardiologist under local anesthesia from the right groin following aseptic and antiseptic precautions. Femoral artery was cannulated with 6F or 7F arterial sheath. An end hole catheter such as Judkin’s right coronary artery catheter used to record intra-ar terial pressures using a standard transducer prior to per forming any angiograms. Intra-arterial pressures (systolic, diastolic and mean) were recorded from the right axillary and right femoral arteries. Near simultaneous measurements of arm and leg pressures with the sphygmomanometer cuff were also obtained whenever possible.
Ethical clearance was obtained from the ethics committee of the institution. Informed consent from all subjects was taken. Confidentiality of information of subjects was maintained
Results
The study included 30 subjects diagnosed with severe aortic regurgitation. The demographic characteristics of group are given in Table 1. The average age of the participants was 37.96 ±12.25 yrs, ranged between 16.00 – 66.00 years. The average height and weight of par ticipants were 163.2±9.4 cm and 55.53±1O.57Kg respectively the upper arm circumference ranged between 26.00 – 33.00 cm, average 29.13±2.37cm whereas the thigh circumference ranged between 38.00 – 50.00 an average 45.70±3.04 cm.
Table II depicts that on physical examination collapsing pulse, cardiomegally and early diastolic murmur were present in all the 30 subjects, whereas Traub’s sign was present in 60% subjects (18 out of30 subjects). Widened pulse pressure was also present in all the subjects in 4 (13%) subjects: the pulse pressure ranged between 40 – 60 mm Hg. and in 26 (87%) subjects pulse pressure was> 60 mm Hg.
Table III depicts that out of 30 subjects, etiology of AR was RHD (Rheumatic Heart Disease) in 29 subjects & only one patient had CHD (Congenital Heart Disease).
Table IV depicts that mean difference between arm and leg pressure was 55.43±30.0 mm Hg when 12 cm cuff was used for both arm and leg, whereas the mean difference between arm and leg blood pressure was 10.01±6.87 mmHg when 12 cm cuff was used for arm and 19 cm cuff was used for thigh. So it shows that the mean difference between arm and leg pressure was very less when appropriate 19 cm cuff was used for leg.
Whereas mean difference between axillary and femoral ar tery pressure (intra- arterially) was negligible ( 4.366±2.93 mm Hg.) Table V depicts that Hill’s sign was present in all subjects only when both arm and thigh pressures were recorded with inappropriate cuff. It was present only in a minority of subjects (3 of 30, 10%) when the thigh pressure was recorded with the appropriate cuff. Hill’s sign was not evident on intra-arterial pressure measurement in any subject.
Table – I : Demographic characteristics of sample N-30
| Variable | Range | Mean ±S.D |
| Age | 16.00 – 66.0 (yrs) | 37.96±12.55 yrs. |
| Height | 149.00 – ]80.00 (cm) | 163.2±9.4cm |
| Weight | 30.00 – 76.00 (kg) | 55.53± 10.57Kg |
| Upper arm circumference | 26.00 – 33.00 (cm) | 29.13± 2.37cm |
| Thigh circumference | 38.00 – 50.00 (cm) | 45.70±3.04cm |
Table – II : Physical Examination N=30
| Variable | Number | Percentage | |
| Collapsing pulse | 30 | 1OO | |
| Cardiomegaly . | 30 | 100 | |
| Traube’s sign | 18 | 60 | |
| Widened pulse pressure | |||
| 4 | 13 | ||
| 40 – 60 mm Hg | |||
| > 60 mm Hg | 26 | 87 | |
| Early diastolic murmur | 30 | 100 |
Table – III : Diagnosis & Associated lesions
| Variable | Number | Percentage |
| Diagnosis
– RHD |
30 |
100 |
| Associated Lesion
Mild As CO A Mild MR Moderate MR Severe MR Mild MS Severe MS Non – Sever MR, Mild MS |
2 1 4 2 3 1 12 |
(6.7) (3.3) (13.3) (6.7) (10.0) (3.3) (40.0) |
Table – IV : Mean Difference in Arm & Leg Systolic Pressures N=30
| Variable | Mean differnce |
| Mean difference between arm pressure (12 cm cuff) & leg pressure (12 cm cuff) | 55.43±30.0 mmHg |
| Mean difference between arm pressure (12 cm cuff) & leg pressure (19 cm cuff) | 10.01 ±6.87mmHg |
| Mean difference between axillary artery & femoral artery pressures (intra-arterial) | 4.366±2.93 mmHg |
Table – V : Presence of Hill’s sign N=30
| Hill’s sign | Positive | Negative |
| With appropriate cuff | 03 | 27 |
| With inappropriate cuff | 30 | – |
| With Intra arterial measurement | – | 30 |
Discussion
The present study indicates that in aortic insufficiency, intra-arterially there is as such no difference in systolic pressures between upper & lower limb. The same findings were shown by Pascarelli et al 8 & they concluded, “Hill’s sign does not appear to be related to intra-arterial pressures”. Kurtyl M et al 9 (1997) concluded that Hill’s sign is an ar tifact of sphygmomanometeric lower limb pressure measurement.
In present study, intra-ar terial measurements were taken from axillary artery for upper limb & femoral artery for lower limb. In five patients diagnosed with severe AR, both brachial & axillary artery pressures were taken & compared. It was found that brachial & axillary ar tery pressures were vir tually same. Therefore axillary artery pressures were measured and compared with brachial cuff occlusion pressures in present study.
In this study, non-invasive measurements in leg were measured with 12cm as well as 19 cm cuff at popliteal artery. And appropriateness of cuff was decided according to limb circumference and it was found that Hill’s sign was absent in majority of subjects with the use of appropriate cuff size. In the earlier studies appropriateness of cuff for limb has not been shown to be taken into account.
Kotte et al12 used standard 12cm & 151/ 2 cm cuff size for femoral cuff pressures & found that femoral wide cuff pressures were consistently too high, especially for the systolic, but also for diastolic. These differences were greatly exaggerated by the use of narrow cuff. And concluded that the difference between the blood pressure in the arm & leg in patients with aortic regurgitation is not so marked as is generally believed because the cuff, wide or narrow, does not allow true measurements of femoral pressures.Therefore it is probable that no diagnostic value should be attributed to this sign.
Frank et al 7 used 19cm cuff for leg for all subjects did not mention limb circumference and found that that popliteal-brachial systolic pressure gradient correlated well with aortic valvulography & effected diagnostically useful separation between grades of severity of aortic insufficiency. In present study three subjects had Hill’s sign present with appropriate as well as inappropriate cuff size but intra-arterially Hill’s sign was absent. That might be because the compression of particular ar tery may alter resonance of proximal & distal arterial system, resulting in a change in contour & amplitude of the pressure pulse proximal to the cuff.
Strong points of the present study are the use of both appropriate & inappropriate cuff size for lower limb pressure measurement and larger sample size as compared to earlier studies. Further, the cuff pressures and intra- ar terial pressures were measured simultaneously.
It is concluded from the findings that that Hill’s sign is not applicable to intra-arterial pressures, as intra-ar terially there is no exaggerated difference in upper & lower limb systolic pressures. It is an ar tifact of sphygmomanometeric lower limb pressure measurement. Hill’s sign is largely the result of the use of inappropriate small size of cuff in the lower limb. With the use of appropriate sized cuff, Hill’ sign is absent in most of the patients with severe AR.
Therefore, Hill’s sign has no physiological basis. hence it is recommended that use of inappropriate size cuff can be avoided to minimize the error in blood pressure measurements. As it is clear from the present study that Hill’s sign does not have any physiological basis, it will help in proper nursing diagnosis & plan the nursing interventions appropriately. further the study can be replicated on the larger sample size to generalize the study results.
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