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BACKGROUND
The size of the heart as measured by cardiothoracic ratio
on chest x-ray is often used to screen for CHF and to
estimating its severity.

METHODS
We compared cardiothoracic ratio (CTR), left ventricular
ejection fraction (EF) from MUGA and left ventricular size
from ECHO in 91 patients (average age 60 years) with a
diagnosis of chronic CHF.

RESULTS
There was a weak relation between CTR and LVEF and
fractional shortening by echo. EF and fractional
shortening were more closely linked. No measure of
left ventricular function correlated with exercise
capacity as measured by peak oxygen consumption
(Vo2max).
	For the group of patients with normal
fractional shortening (17 patients), the left ventricle was
enlarged in all but 2 (average end diastolic dimension
5.9 mm or 0.7 cm). The two patients with normal
dimensions had a low EF.
	For the 12 patients with a normal CTR, the
left ventricular end diastolic size was only slightly smaller
than for the rest (6.2 mm or 0.9 cm versus 6.9 mm or
1.2 cm).

CONCLUSIONS
Chest x-ray is not a reliable indicator of the degree of
left ventricular dysfunction. Echo and MUGA are more
appropriate for testing heart function.

Title: Unreliability of cardiothoracic ratio as a marker
of left ventricular impairment: comparison with
radionuclide ventriculography and echocardiography.
Authors: Clark AL, Coats AJ
Source: Postgrad Med J 2000 May;76(895):289-91
PMID: 10775282, UI: 20237872