Reassessment of the diagnostic value of the vectorcardiogram in cystic fibrosis (correlation with clinical score, pulmonary function tests and echocardiogram).

In 21 children with cystic fibrosis, the vectorcardiogram (VCG) was correlated with 
various indices of the severity of the disease. The best correlation 
was found between (1) the azimuth angle of the spatial QRS 
loop area, representing the rightward and posterior shift of the main 
electrical forces, and pulmonary function tests (PFT): FEV1 % predicted (r 
= -0.671, P less than 0.005) and VC% predicted (r = 
-0.607, P less than 0.005), and (2) the right ventricular anterior 
wall index measured echocardiographically (r = 0.472, P less than 0.05). 
More VCG parameters correlated significantly with PFT than with the echocardiogram. 
This shows the major influence of pulmonary changes on the VCG 
of those patients. In several subgroups with different clinical scores, the 
VCG were analyzed and compared to normal limits of age- and 
sex-matched controls. In this small series, the VCG was a specific 
but not very sensitive method for predicting the degree of severity 
of the disease. Echocardiography and vectorcardiography can be considered as two 
complementary techniques in the evaluation of cystic fibrosis. 