ccf
congestive cardiac failure
introduction
cardiac failure is the commonest cause for hospital admission in those aged over 65 yrs
prevalence of CCF increases with increasing age and affects about 10% of the population older than 75 years.
in spite of significant advances in the treatment of heart failure, mortality rates remain high: 30 to 40 percent of patients with advanced disease and 5 to 10 percent of patients with mild symptoms die within five to 10 years.
there are two pathophysiologic types of CCF (or congestive heart failure (CHF))
systolic failure (impaired ability to contract) characterised by an ejection fraction < 45%
diastolic failure (impaired ability to fill in diastole) which is more poorly quantified and agreed criteria has not been reached
the two types have similar symptoms and signs and usually require echocardiography or angiography to discriminate.
diastolic heart failure is more common in women and elderly persons and accounts for 25-50% of patients hospitalised with cardiac failure.
although patients with diastolic heart failure have a lower annual mortality rate than patients with systolic heart failure, they have a higher rate than the general population.
Framington criteria for Dx of CCF
major criteria
paroxysmal nocturnal dyspnea
weight loss of 4.5 kg in 5 days in response to treatment
neck vein distention
rales
acute pulmonary edema
hepatojugular reflux
S3 gallop
central venous pressure greater than 16 cm water
circulation time of 25 seconds
radiographic cardiomegaly
pulmonary edema, visceral congestion, or cardiomegaly at autopsy
minor criteria
nocturnal cough
dyspnea on ordinary exertion
a decrease in vital capacity by one third the maximal value recorded
pleural effusion
tachycardia (rate of at least 120 bpm)
bilateral ankle oedema
clinical features of CCF
symptoms
LV failure
SOBOE - most sensitive symptom but not specific
orthopnoae/PND - more specific but less sensitive (20-30% pts)
cough with pink, frothy sputum is highly suggestive
RV failure
signs
peripheral edema, jugular venous distention, and tachycardia are highly predictive of CCF but occur in only 10-20% pts.
other signs may also occur:
hypertension, cold & sweaty skin, pulsus alternans, wheezes, third or fourth heart sounds.
CXR only 80% sensitive
a negative BNP has 98% NPV
a positive BNP is non-specific but more useful if higher values in older people and intermediate pre-test probability - not helpful if low or high pretest probability
systolic heart failure
diastolic heart failure
diastole
The relaxation process has four identifiable phases:
isovolumetric relaxation from the time of aortic valve closure to mitral valve opening;
early rapid filling after mitral valve opening;
diastasis, a period of low flow during mid-diastole; and
late filling of the ventricles from atrial contraction
Diastole is a complex process that is affected by a number of factors, including:
ischemia
heart rate
velocity of relaxation
cardiac compliance (i.e., elastic recoil and stiffness)
hypertrophy
hypertrophied ventricle has a steeper diastolic pressure-volume relationship; therefore, a small increase in left ventricular end-diastolic volume (which can occur with exercise, for example) causes a marked increase in left ventricular end-diastolic pressure.
segmental wall coordination of the heart muscle.
aetiology of diastolic failure
hypertension
ischaemia
tachycardia:
AF:
systolic failure
aging
increased
collagen cross-linking, increased smooth muscle content, and loss of elastic fibers due to aging results in decreased ventricular compliance, increasing susceptibility to diastolic failure.
diagnosis of diastolic failure
Rx principles of diastolic failure
normalise blood pressure (to less than 130/85mmHg) to promote regression of LVH
-
reduce ischaemia
Rx symptoms - consider diuretics, ACEIs, digoxin
consider dihydropyridine calcium channel blockers with care
References
ccf.txt · Last modified: 2016/08/08 19:24 (external edit)