Evaluation of an alternative test for the diagnosis of atrial growth based on f-wave morphology in atrial fibrillation.

Evaluation of an alternative test for the diagnosis of atrial growth

Abstract

Atrial fibrillation, a frequent arrhythmia, shows in the ECG the substitution of p waves by f waves, some of greater amplitude. The latter are associated with atrial growth (a predictive factor in the management of AF); when an echocardiograph is not available in emergencies, an alternative diagnostic method is needed for atrial growth in unstable patients; we propose as a diagnostic test: Atrial growth [>40mm]>>0thick f wave [>0.1mV]". Our analytical study takes as universe patients attended by the cardiology service of the HCV of Cochabamba-Bolivia from 2005 to 2009, 1000 patients in a simple random sample of 150 patients. The prevalence rate of AF was 15% [IC95%:13;17]; male predominant sex, 54.7% [RR=1(X2=0 and p value >0.05-Not significant)]; age range 17-81 years, median 53 years [(IC95%:50;56)(RIC = 21 years)]; classifying it was found thick f wave in 65% [IC95%: 57;73] and left atrial growth in 88%[IC95%:83;93]; The correlation Atrial growth>>Coarse f wave found gave an OR=1.5; or 0.5 times more likely to present coarse f wave in atrial growth. Associated chagasic and rheumatic cardiomyopathy were found, representing 65%. Internal validity of the test: S=66%; E=44%; PPV=90% and NPV = 15%, the ability to determine atrial growth with the positive test (S) is low, acceptable, but the probability of having a positive test in atrial growth (PPV) is very high; external validity: kappa index = 0.6-Moderate inter-observer reproducibility, compared with echocardiography. Greater application was obtained in chagasic cardiopathy (S=70%, E=57%, PPV=94%).