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This was treated with further PTCA in 6
patients and CABG in 1.
In conclusion, PTCA in the elderly is
larqely performed for unstable or refractory
angina and complete revascularisation may not
be essential. In this high-risk group, the
primary success and early mortality rates seem
acceptable, and recurrent angina may be
amenable to further coronary intervention.
127 INVERSE CORRELATION OF BP WITH HEIGHT
MJ BROWN, MR HUGHES, R WHITE, J ASHBY-SWAIN,
D TRUTWEIN, R HOPPER and CR MOLTON
Clinical Pharmacology Unit, University of Cambridge.
We are undertaking a prospective outcome study in general
practice of vitamin E and aspirin in hypercholesterolaemia, and
have so far screened 4950 subjects aged 40-69. The data has been
used to investigate whether the reported risks of low birthweight
would cause an inverse correlation of BP and cholesterol (CH)
with height. BP was recorded by the Datascope 2000. CH was
measured on capillary blood by the Reflotron. Subjects in whom
the CH was >6.2 mmol/L received dietary advice, and returned to
a follow-up in 2 months. Those with CH levels still >6.2 mmol/L
were pre-stratified for known coronary risk factors, including
BP, CH and HDL, and randomised to receive a lipid-lowering
agent aspirin 300 mg o.d, vitamin E 200 i.u. bd., or neither. The
study is ‘PROBE’ in design (Prospective Randomised Open with
Blind Endpoint determination). The multiple regression analysis
presented here concerns screening and follow-up data from the
first 16 general practices.
After correction for age and weight, there were steep negative
correlations between BP and height in men and women (e.g.
r=-0.26+0.046 for systolic BP in women), and a weaker but highly
significant negative correlation between CH and height
(r=0.021+0.002, p=O.OOOO). The results confirmed the well known
positive correlations of both BP and CH with weight. However,
the top 2 percentiles for CH (>8.0 mmol/L) were of only average
weight. 29% of subjects had CH values >6.2; half of these subjects
reduced their CH to less than 6.2 on diet, with a mean reduction
of 15%. The incidence of hypertension (DBP >90 mmHg) was only
4.8%. of whom the majority became normotensive at follow-up.
Both low height and birthweight have previously been found to
correlate with glucose intolerance, and we suggest that the inverse
correlations we have found with height may be another example
of the longterm effects of maternal nutrition in pregnancy. On the
analogy of Barker’s anatomical explanations for diabetes and
airways disease, we postulate that a factor in setting blood
pressure may be the number of resistance vessels, whereas in the
case of CH it is the number of hepatocytes bearing the LDL
receptor. The low prevalence of hypertension in our population
raises the possibility that the incidence of hypertension is falling
because of post war improvements in maternal nutrition.
128 I S O V O L U M I C R E L A X A T I O N T I M E A N D
INCOORDINATION :IMPORTANT DETERMINANTS O F T H E
DOPPLER AIE RATIO IN LEFT VENTRICULAR DISEASE
SJD BRECKER, CH LEE and DG GIBSON
The A/E ratio correlated with age in normal subjects (r=0.74), to a lesser
extent in LVH (r=0.41), but not significantly in IHD. In LVH and those
IHD patients without left ventricular dilatation, the A/E ratio was
correlated both with IVRT (r=0.67 and 0.68 respectively), and with
incoordinate relaxation (r=O.64 and 0.58). In those IHD patients with left
ventricular dilatation (end diastolic dimension >6cm), the influence of
incoordination was lost and IVRT became the dominant influence upon the
A/E ratio (r=0.83) (all p values <0.01). This was despite marked
incoordinate relaxation being evident in this subgroup. Stepwise
regression confirmed that weak correlations of left ventricular end diastolic
pressure and RR interval with the A/E ratio, became insignificant once
IVRT had been taken into account.
Hence filling pressure and RR interval are not significant independent
determinants of filling pattern in patients with left ventricular disease.
Age is an important influence in normal subjects, but this effect is
attenuated in LVH and lost in IHD. Thus, the filling pattern is effectively
determined before mitral valve opening from the duration of IVRT and to
a lesser extent by incoordinate relaxation when cavity size is normal.
129 ASSESSMENT O F PEAK TRICUSPID REGURGJTANT
VELOCITY AND RIGHT VENTRICULAR RELAXATION
FROM T H E DYNAMICS O F RETROGRADE FLOW
SJD BRECKER, HB XIAO and DG GIBSON
The Royal Brompton National Heart and Lung Hospital, London,
SW3 6NP, United Kingdom
The Doppler derived peak tricuspid regurgitation (TR) velocity is
commonly used to estimate peak right ventricular and hence
pulmonary artery pressure, yet the peak velocities are often of low
intensity on the spectral display. By contrast the lower velocities
recorded during the last 200 ms of the signal are often clear and
reproducible. To evaluate the usefulness of measuring the time
interval from pulmonary closure, P,, to the end of the T R signal (P,
- T R end) in predicting peak T R velocity, we performed
echocardiography, Doppler and simultaneous phonocardiography on
65 patients with right ventricular disease (53 with pulmonary
hypertension), and 24 with dilated cardiomyopathy.
For the group with right ventricular disease, the time from P2 to the
end of the TR signal correlated strongly with the peak T R velocity
(R=0.83, p<O.Ol) and it was possible to predict the right
ventricular - right atrial pressure drop (RV-RA dP). The regression
equation of RV-RA d P on the time interval P2- T R end is :
RV-RA d P (mmHg) = 15.9 0.3 P, - T R end (ms).
The effect of heart rate was not significant, however the
prolongation of TR in severe pulmonary hypertension is
considerable, and may limit the time for forward flow. In contrast
however, in the group with dilated cardiomyopathy, the actual time
interval P, - TR end exceeded the value predicted by the above
equation by 4 0 k 9 ms (mean & SE), suggesting additional
impairment to right ventricular relaxation in this group.
Conclusion : This method permits estimation of the peak TR
velocity in a greater proportion of patients with pulmonary
hypertension or right ventricular dilatation, in whom it may not be
possible to record the peak TR velocity. Furthermore it sheds light
on additional abnormalities of right ventricular relaxation in left
ventricular disease.
+
The Royal Brompton National Heart and Lung Hospital, London,
SW3 6NP, United Kingdom
It is widely believed that left ventricular filling pressure, age and heart
rate determine peak mitral flow velocity and the Doppler A E ratio. To
assess possible additional effects of abnormal relaxation, we examined left
ventricular filling with Doppler and M-mode echocardiography in 47
patients with ischaemic heart disease (IHD), 35 with left ventricular
hypertrophy (LVH), and in 26 normal subjects. We digitised M-mode
traces and measured incoordinaterelaxation as % change in left ventricular
dimension before mitral valve opening and time from minimum dimension
to mitral valve opening, isovolumic relaxation time (IVRT)(from aortic
closure to mitral opening), and rates of left ventricular dimension increase
and posterior wall thinning. Left ventricular end diastolic pressure was
measured at cardiac catheterisation.
130 COAGULATION FACTOR ANALYSIS AND CLINICAL
CHARACTERISTICS O F ACUTE MYOCARDIAL INFARCTION
WITH NORMAL CORONARY ARTERIES
SJD BRECKER, R ROBERTS, RN STEVENSON,
UTHAYAKUMAR, AD TIMMIS and R BALCON
S
Cardiac Department, London Chest Hospital, London E2 9JX
Of 342 patients (pa)undergoing cardiac catheterisation following
thrombolysis, we identified 12 with definite myocardial infarction
(MI) and unequivocally normal coronary arteries (NCA). Spasm,