Cardiologist reading my ekg said it showed "a blocked nerve on the right." he did not explain. what does this mean?

Signal block-- right: There are bundles of electrical pathways which travel down the heart muscle and are designated as right (stimulate right ventricle) and left sided (stimulate left ventricle) bundles. If your ekg shows a right sided bundle branch block then, the "nerve" pathways stimulating the right ventricle are blocked from normal electrical impulse conductance to the muscle. No true nerve per se is involved.