- Email: [email protected]
Systemic hypertension and rheumatic mitral valve disease
Brit. J. Dis. Chest (i966) 6o, i48.
SYSTEMIC HYPERTENSION AND R H E U M A T I C MITRAL VALVE DISEASE BY G. M. DAVlFS Brompton Hospital, London s.w.3
WOOD (I950) found essential hypertension, defined as a blood pressure above i6o/xoo mm. Hg., in only 3 per cent. of his cases of mitral stenosis. A diastolic pressure above 12o mm. Hg. was recorded in only I per cent. Bechgaard (i 946) found that only I per cent. of patients with essential hypertension had mitral stenosis. Wood commented that "following valvotomy any tendency towards hypertension may become more evident". The frequency of this combination seemed worth re-examining. When, in the course of investigation, an unexpectedly high frequency was found, a possible association between systemic hypertension and systemic emboli and atrial fibrillation was sought. The Patients The records of patients with rheumatic valvular disease seen at Guy's Hospital between 1948 and 1961 were examined. The earliest record of mitral valvotomy performed at Guy's is dated 1948. As soon as surgery became available, records of history, signs, and opinion became more detailed, and follow-up of cases became better documented. Only about I per cent. of the records were discarded because of inadequate data. In each case, age, sex, date of operation, presence or absence of atrial fibrillation and of episodes of systemic emboli, and all records of blood pressure taken in the out-patients' departments were noted. As this is a retrospective study, based on routine hospital notes, further analysis was not felt justified. The diagnosis of systemic hypertension is notoriously difficult to establish. The most satisfactory criterion universally recorded is the level of the diastolic blood pressure as measured in the arm by sphygmomanometer cuff. This is subject to observer error, and in the presence of atrial fibrillation accurate measurement is very difficult. However, the teaching that the diastolic pressure is recorded as the sounds heard through the stethoscope become muffled has long been accepted at Guy's, and it is hoped that this led to consistency in recording, and that analysis of large numbers will reduce the influence of observer error. Other evidence of systemic hypertension, such as assessment of left ventricular hypertrophy by any criterion, including the electrocardiogram, is clearly not reliable in the presence of valvular disease. The presence of aortic valvular disease makes the peripheral blood pressure a most unreliable index of hypertension, and therefore all cases with evidence, or even suspicion, of aortic valve disease were excluded. Any patient who, on three consecutive readings taken on different visits, (Receivedfor publication, April 1966)
SYSTEMIC H Y P E R T E N S I O N
AND R H E U M A T I C M I T R A L VALVE DISEASE
I49
has a diastolic pressure of I oo mm. Hg. or above was arbitrarily called "hypertensive". All other cases were called "non-hypertensive". The systemic blood pressure is commonly found to be higher in hospital out-patients than in in-patients. Comparison was therefore made of the present series with that of Hamilton et al. (I954) , in which the blood pressure was recorded in hospital out-patients with no suspicion of heart disease. These patients were attending varicose-vein, skin, orthopzedic, fracture, and dental clinics: 1,2o 4 women and 827 men were included. In this series only a single record of blood pressure was taken in most cases, but in io6 women and 74 men a second reading was taken on another occasion. The diastolic blood pressure was found to have fallen in all pressure groups, and by as much as 9 mm. Hg. in women and 8-6 mm. Hg. in men with a pressure above ioo mm. Hg. on the first record. Therefore, the criteria adopted in the present series for calling a patient "hypertensive" will give a lower frequency than would be found by Hamilton's method. The age range of the two series was also compared. In the mitral series, the ages of the women ranged from 14 to 82, mean 42 years, standard deviation i o. 5 years. The ages of the men ranged from 16 to 72, mean 45"4 years, standard deviation 16"7 years. In the control series, the mean age of the women was 45"I years, standard deviation i6. 7 years; the mean age of the men was 42. 5 years, standard deviation x5"5 years. It was felt that the mean values were so close in the trial and the control groups that no age-correction was necessary. As valvotomy itself might reveal a hidden hypertension, the diastolic pressure before operation was compared with that afterwards in Ioo patients, both records being in the out-patients' department. As there was a mean fall of 2 mm. Hg. in pressure in the group as a whole, no further account is taken of the operation. Results Four hundred and twenty-eight women and I27 men were included in the series, a ratio of 3.37 to I. Seventy-nine of the women (I8. 5 per cent.) and 2I of the men (i6. 5 per cent.) were hypertensive. In Hamilton's series i5-2 per cent. of the women and 8.I per cent. of the men were hypertensive. Thus systemic hypertension may be more frequent in patients with mitral disease than would be expected. The differences are less significant in women (Table I). O f 104 women with evidence of both mitral disease and systemic emboli, 35 had hypertension (33.6 per cent.). O f 324 women without evidence of emboli, 44 had hypertension (I3.6 per cent.). Thus in women an association of hypertension with systemic emboli seems probable. In men the figures are less striking and not significant (Table II). A significant association between hypertension and atrial fibrillation in women is also shown, for 74 of 267 women with atrial fibrillation were hypertensive (27.8 per cent.), whereas only 5 of i6I without atrial fibrillation had hypertension (3.i per cent.). Again in men there was no significant association (see Table II).
15 °
DAVIES TABLE I . - - M I T R A L VALVE DISEASE AND SYSTEMIC HYPERTENSION
%
dVon-
Hypertensive
hypertensive
428
18"5
349
79
..
1,2o4
I5"2
I~O2I
I83
Mitral valve disease . .
I27
i6. 5
IO6
2I
Control
827
8.!
760
67
Total
Hypertensive
X2
P
Women M i t r a l valve disease Control
2"55
•2 o > P >
.io
Men
..
IO.6
.io>P>-ooi
TABLE II.--SYSTEMIC EMBOLI~ ATRIAL FIBRILLATION AND SYSTEMIC HYPERTENSION
Hypertension
No Hypertension
Emboli
. . . .
35
69
No emboli
. . . .
44
280
74
193
N o atrial fibrillation ..
5
156
Emboli
. . . .
9
29
No emboli
. . . .
12
77
I7
82
3
25
X~
P
21"1
< "OO1
40"5
< "00 I
Women A t r i a l fibrillation
••
2-0
-2o> P> .io
o.68
o'5>P>o'3
Men A t r i a l fibrillation N o atrial fibrillation
•.
Discussion Systemic hypertension seems to be associated with mitral valve disease. In women at least this appears to be related to systemic emboli and to atrial fibrillation. In men, where there is a clearer association between mitral valve disease and hypertension, these factors are not apparent. Subacute bacterial endocarditis is known to damage the kidneys and could be responsible for systemic hypertension. However, only 7 of the patients were known to have had endocarditis. Six were not hypertensive several years afterwards, but one developed hypertension ff years later. It appears most unlikely that subacute bacterial endocarditis could be important. There are two ways in which mitral valve disease could be related to systemic hypertension. First, Russell (I962) reported glomerulonephritis in 95 of 246 autopsies of patients with rheumatic heart disease (38.6 per cent.), and
SYSTEMIC H Y P E R T E N S I O N A N D R H E U M A T I C M I T R A L VALVE DISEASE
x5I
suggested that the rheumatic process and renal disease might be related. Secondly, emboli from a rheumatic heart may block small renal arterioles. Thus both ischremic renal disease and glomerulonephritis, either of which may cause hypertension, may be associated with rheumatic heart disease. Obeyesekere et al. (I965) studied 434 case records and I33 necropsy reports of patients with mitral valve disease. They found that systemic hypertension was commoner than in the population at large, but found no sex difference. They, too, found a close association between atrial fibrillation, renal infarction, and systemic hypertension. The significant association in women of mitral valve disease and systemic hypertension with systemic emboli, and with atrial fibrillation, where the chance of silent emboli is increased, seems to favour the hypothesis that it is renal infarction that causes the hypertension. However, failure to demonstrate a similar association in men, admittedly with small samples, calls for further study with larger numbers.
Summary and Conclusions Rheumatic mitral valve disease and systemic hypertension were found together more often than expected. In women but not in men, atrial fibrillation and episodes of systemic emboli were related to the increased frequency of hypertension. The association of hypertension with rheumatic heart disease may depend on the association of rheumatic heart disease with renal disease and that of renal disease with hypertension. ACKNOWLEDGEMENTS My thanks are due to Dr. Charles Baker for permission to study many of his patients, and to Dr. Lynne Reid for her helpful criticism. REFERENCES BEeHOAARD, P. (I946). Acta med. scan&, Supp., I72. HAMILTON,M., PmrmRiNC, G. W., FgASERRO~ERTS,J. A., & SOWRY, G. S. C. (1954). Glin. Sci., 13, I I. OBEYESEKERE, H. I., DULAKE,M., DEMERDASH, H., & HOLLISTER, R. (1965). Brit. med. 3 , 2, 44 I. PICKERXNG, G. ('963). Amer. o7. Med., 34, 7. RUSSELL, D. S. (I962). 3" din. Path., I5, 414 • WOOD, P. (I95o). Diseases of the Heart and Circulation. London : Eyre and Spottlswoode.
SYSTEMIC HYPERTENSION AND R H E U M A T I C MITRAL VALVE DISEASE BY G. M. DAVlFS Brompton Hospital, London s.w.3
WOOD (I950) found essential hypertension, defined as a blood pressure above i6o/xoo mm. Hg., in only 3 per cent. of his cases of mitral stenosis. A diastolic pressure above 12o mm. Hg. was recorded in only I per cent. Bechgaard (i 946) found that only I per cent. of patients with essential hypertension had mitral stenosis. Wood commented that "following valvotomy any tendency towards hypertension may become more evident". The frequency of this combination seemed worth re-examining. When, in the course of investigation, an unexpectedly high frequency was found, a possible association between systemic hypertension and systemic emboli and atrial fibrillation was sought. The Patients The records of patients with rheumatic valvular disease seen at Guy's Hospital between 1948 and 1961 were examined. The earliest record of mitral valvotomy performed at Guy's is dated 1948. As soon as surgery became available, records of history, signs, and opinion became more detailed, and follow-up of cases became better documented. Only about I per cent. of the records were discarded because of inadequate data. In each case, age, sex, date of operation, presence or absence of atrial fibrillation and of episodes of systemic emboli, and all records of blood pressure taken in the out-patients' departments were noted. As this is a retrospective study, based on routine hospital notes, further analysis was not felt justified. The diagnosis of systemic hypertension is notoriously difficult to establish. The most satisfactory criterion universally recorded is the level of the diastolic blood pressure as measured in the arm by sphygmomanometer cuff. This is subject to observer error, and in the presence of atrial fibrillation accurate measurement is very difficult. However, the teaching that the diastolic pressure is recorded as the sounds heard through the stethoscope become muffled has long been accepted at Guy's, and it is hoped that this led to consistency in recording, and that analysis of large numbers will reduce the influence of observer error. Other evidence of systemic hypertension, such as assessment of left ventricular hypertrophy by any criterion, including the electrocardiogram, is clearly not reliable in the presence of valvular disease. The presence of aortic valvular disease makes the peripheral blood pressure a most unreliable index of hypertension, and therefore all cases with evidence, or even suspicion, of aortic valve disease were excluded. Any patient who, on three consecutive readings taken on different visits, (Receivedfor publication, April 1966)
SYSTEMIC H Y P E R T E N S I O N
AND R H E U M A T I C M I T R A L VALVE DISEASE
I49
has a diastolic pressure of I oo mm. Hg. or above was arbitrarily called "hypertensive". All other cases were called "non-hypertensive". The systemic blood pressure is commonly found to be higher in hospital out-patients than in in-patients. Comparison was therefore made of the present series with that of Hamilton et al. (I954) , in which the blood pressure was recorded in hospital out-patients with no suspicion of heart disease. These patients were attending varicose-vein, skin, orthopzedic, fracture, and dental clinics: 1,2o 4 women and 827 men were included. In this series only a single record of blood pressure was taken in most cases, but in io6 women and 74 men a second reading was taken on another occasion. The diastolic blood pressure was found to have fallen in all pressure groups, and by as much as 9 mm. Hg. in women and 8-6 mm. Hg. in men with a pressure above ioo mm. Hg. on the first record. Therefore, the criteria adopted in the present series for calling a patient "hypertensive" will give a lower frequency than would be found by Hamilton's method. The age range of the two series was also compared. In the mitral series, the ages of the women ranged from 14 to 82, mean 42 years, standard deviation i o. 5 years. The ages of the men ranged from 16 to 72, mean 45"4 years, standard deviation 16"7 years. In the control series, the mean age of the women was 45"I years, standard deviation i6. 7 years; the mean age of the men was 42. 5 years, standard deviation x5"5 years. It was felt that the mean values were so close in the trial and the control groups that no age-correction was necessary. As valvotomy itself might reveal a hidden hypertension, the diastolic pressure before operation was compared with that afterwards in Ioo patients, both records being in the out-patients' department. As there was a mean fall of 2 mm. Hg. in pressure in the group as a whole, no further account is taken of the operation. Results Four hundred and twenty-eight women and I27 men were included in the series, a ratio of 3.37 to I. Seventy-nine of the women (I8. 5 per cent.) and 2I of the men (i6. 5 per cent.) were hypertensive. In Hamilton's series i5-2 per cent. of the women and 8.I per cent. of the men were hypertensive. Thus systemic hypertension may be more frequent in patients with mitral disease than would be expected. The differences are less significant in women (Table I). O f 104 women with evidence of both mitral disease and systemic emboli, 35 had hypertension (33.6 per cent.). O f 324 women without evidence of emboli, 44 had hypertension (I3.6 per cent.). Thus in women an association of hypertension with systemic emboli seems probable. In men the figures are less striking and not significant (Table II). A significant association between hypertension and atrial fibrillation in women is also shown, for 74 of 267 women with atrial fibrillation were hypertensive (27.8 per cent.), whereas only 5 of i6I without atrial fibrillation had hypertension (3.i per cent.). Again in men there was no significant association (see Table II).
15 °
DAVIES TABLE I . - - M I T R A L VALVE DISEASE AND SYSTEMIC HYPERTENSION
%
dVon-
Hypertensive
hypertensive
428
18"5
349
79
..
1,2o4
I5"2
I~O2I
I83
Mitral valve disease . .
I27
i6. 5
IO6
2I
Control
827
8.!
760
67
Total
Hypertensive
X2
P
Women M i t r a l valve disease Control
2"55
•2 o > P >
.io
Men
..
IO.6
.io>P>-ooi
TABLE II.--SYSTEMIC EMBOLI~ ATRIAL FIBRILLATION AND SYSTEMIC HYPERTENSION
Hypertension
No Hypertension
Emboli
. . . .
35
69
No emboli
. . . .
44
280
74
193
N o atrial fibrillation ..
5
156
Emboli
. . . .
9
29
No emboli
. . . .
12
77
I7
82
3
25
X~
P
21"1
< "OO1
40"5
< "00 I
Women A t r i a l fibrillation
••
2-0
-2o> P> .io
o.68
o'5>P>o'3
Men A t r i a l fibrillation N o atrial fibrillation
•.
Discussion Systemic hypertension seems to be associated with mitral valve disease. In women at least this appears to be related to systemic emboli and to atrial fibrillation. In men, where there is a clearer association between mitral valve disease and hypertension, these factors are not apparent. Subacute bacterial endocarditis is known to damage the kidneys and could be responsible for systemic hypertension. However, only 7 of the patients were known to have had endocarditis. Six were not hypertensive several years afterwards, but one developed hypertension ff years later. It appears most unlikely that subacute bacterial endocarditis could be important. There are two ways in which mitral valve disease could be related to systemic hypertension. First, Russell (I962) reported glomerulonephritis in 95 of 246 autopsies of patients with rheumatic heart disease (38.6 per cent.), and
SYSTEMIC H Y P E R T E N S I O N A N D R H E U M A T I C M I T R A L VALVE DISEASE
x5I
suggested that the rheumatic process and renal disease might be related. Secondly, emboli from a rheumatic heart may block small renal arterioles. Thus both ischremic renal disease and glomerulonephritis, either of which may cause hypertension, may be associated with rheumatic heart disease. Obeyesekere et al. (I965) studied 434 case records and I33 necropsy reports of patients with mitral valve disease. They found that systemic hypertension was commoner than in the population at large, but found no sex difference. They, too, found a close association between atrial fibrillation, renal infarction, and systemic hypertension. The significant association in women of mitral valve disease and systemic hypertension with systemic emboli, and with atrial fibrillation, where the chance of silent emboli is increased, seems to favour the hypothesis that it is renal infarction that causes the hypertension. However, failure to demonstrate a similar association in men, admittedly with small samples, calls for further study with larger numbers.
Summary and Conclusions Rheumatic mitral valve disease and systemic hypertension were found together more often than expected. In women but not in men, atrial fibrillation and episodes of systemic emboli were related to the increased frequency of hypertension. The association of hypertension with rheumatic heart disease may depend on the association of rheumatic heart disease with renal disease and that of renal disease with hypertension. ACKNOWLEDGEMENTS My thanks are due to Dr. Charles Baker for permission to study many of his patients, and to Dr. Lynne Reid for her helpful criticism. REFERENCES BEeHOAARD, P. (I946). Acta med. scan&, Supp., I72. HAMILTON,M., PmrmRiNC, G. W., FgASERRO~ERTS,J. A., & SOWRY, G. S. C. (1954). Glin. Sci., 13, I I. OBEYESEKERE, H. I., DULAKE,M., DEMERDASH, H., & HOLLISTER, R. (1965). Brit. med. 3 , 2, 44 I. PICKERXNG, G. ('963). Amer. o7. Med., 34, 7. RUSSELL, D. S. (I962). 3" din. Path., I5, 414 • WOOD, P. (I95o). Diseases of the Heart and Circulation. London : Eyre and Spottlswoode.