speed up reading corresponding values from another matrix

Hi I have a Matrices hQ=[200x2] and H[50000]. I want to find the values of hQ(:,2) from hQ(:,1) that correspond to H().It should be possible to find H(i) = hQ(i,1) but because of extra decimal places I have to give a tolerance. I have written the following code but it takes a lot of time, do you think of a better way of doing the same.

for i=1:length(H)    
Q(i)=hQ(find(abs(hQ(:,1)-H(i))<0.0001,1),2);% find closest h value with tolerance of 0.0001m
end