CARDIOVASCULAR JOURNAL OF AFRICA • Vol 21, No 4, July/August 2010
214
AFRICA
Stage one is the mildest form of diastolic dysfunction with
delayed relaxation defined by an early filling to late or atrial fill-
ing (E/A) ratio less than 1, prolonged IVRT and prolonged DT.
The systolic to diastolic pulmonary venous (S/D) ratio is greater
than 1 (Fig. 3). Stage two is marked by a moderate level of
dysfunction and defined by E/A of greater than 1 and/or greater
than 2 with S/D less than 1, and is often called pseudonormalisa-
tion (with a normal diastolic filling pattern), caused by elevated
left atrial pressures. This can be unmasked by reducing preload,
for example by use of the Valsalva manoeuvre or application of
sublingual nitroglycerine (Fig. 4). Stage three is marked by a
restrictive filling pattern and signifies severe diastolic dysfunc-
tion, i.e. decreased compliance and marked increase in left atrial
pressure. The E/A is greater than 2, IVRT and DT are short, and
S/D is less than 1 (Fig. 5). The mitral A duration is shorter than
the PVa duration (Fig. 6).
Mitral annular velocity by tissue Doppler imaging also has
been used to assess diastolic function. This is referred to as E.
The Em (mitral)/E¢ (annular) ratio has been found to corre-
late well with increased pulmonary capillary wedge pressure
(PCWP). The E/E¢ ratio is normally less than 8. The E¢ is shown
to be low, in restrictive stage less than 8. A ratio of greater than
15 indicates elevated PCWP (Fig. 7).
9
Although rarely performed for evaluation of diastolic
dysfunction alone, the most accurate invasive diagnostic tech-
nique is cardiac catheterisation with direct measurements of left
ventricular end-diastolic pressure.
10,11
Parameters of chamber
stiffness are correlated with changes in pressure to changes in
chamber volume.
Left ventricular diastolic dysfunction
In its simplest form, left ventricular diastolic dysfunction is
defined as impairment in the capacity of the left ventricle to
accept blood without a compensatory increase in left atrial pres-
sure.
12
Patients with left ventricular diastolic dysfunction tend to
have elevated left ventricular diastolic pressure in the presence
of normal or even reduced left ventricular volume, as the pres-
sure–volume curve in these patients is shifted upwards.
13,14
Over
the years, a variety of co-morbid conditions have been associ-
ated with development of left ventricular diastolic dysfunction,
such as myocardial scarring, transmural myocardial infarction,
chronic constrictive pericarditis, chronic coronary artery disease,
dilated cardiomyopathy, hypertrophic cardiomyopathy, diabetic
cardiomyopathy, hypertension, aortic stenosis as well as normal
aging.
12
The underlying connection in the possible aetiologies of left
ventricular diastolic dysfunction is their ability to hinder one or
both of the intrinsic diastolic properties of compliance or relaxa-
tion. Pathological states such as fibrosis and concentric hyper-
trophy can reduce compliance of the myocardium by increasing
passive ventricular stiffness, thereby affecting the passive prop-
Fig. 3. Echocardiographic image of stage I diastolic
dysfunction: impaired relaxation E
<
A, E/A ratio
<
1.0, DT
>
200
<
IVRT
>
90.
Fig. 4. A shows stage II diastolic dysfunction with pseu-
donormalised pattern where E/A reverses with valsalva
manoeuvre (B).
A
B
