RESUMEN
Regarding the lower cost and availability of chest X-ray in comparison with echocardiography, cardiothoracic ratio [CTR] is used to estimate left ventricular ejection fraction [LVEF]. To study CTR efficiency to estimate LVEF in Congestive Heart Failure [CHF] patients. In a one- year analytical study 96 CHF patients were examined consecutively at Qazvin Bou-Ali's hospital [1999-2000]. CTR was measured by Danzer method and LVEF by Echo. Ischemic, hypertensive and dilated cases were accepted, whereas valvular diseases corpolmonale, acute MI and persistent Arrythemia, were excluded. Correlation between CTR and LVEF was [r=-0.32] in all patients, and in subgroups was [-0.12] for ischemic, [-0.44] for Hypertensive, and [-0.49] for Dilated Sensitivity and specify of CTR in [0.5, 0.55 and 0.6] was calculated for Diagnosis of EF<40%. Direct measurement of EF by echocardiography is recommended for diagnosis, therapy and prognosis in CHF patients