  Asteroseismology is a powerful tool to access the internal structure of
stars. Apart from the important impact of theoretical developments, progress in
this field has been commonly associated with the analysis of time-resolved
observations. Recently, the so-called macroturbulent broadening has been
proposed to be a complementary and less expensive way -- in terms of
observational time -- to investigate pulsations in massive stars. We assess to
what extent this ubiquitous non-rotational broadening component shaping the
line profiles of O stars and B supergiants is a spectroscopic signature of
pulsation modes driven by a heat mechanism. We compute stellar main sequence
and post-main sequence models from 3 to 70Msun with the ATON stellar evolution
code and determine the instability domains for heat-driven modes for degrees
l=1-20 using the adiabatic and non-adiabatic codes LOSC and MAD. We use the
observational material presented in Sim\'on-D\'iaz et al. (2016) to investigate
possible correlations between the single snapshot line-broadening properties of
a sample of ~260 O and B-type stars and their location inside/outside the
various predicted instability domains. We present an homogeneous prediction for
the non-radial instability domains of massive stars for degree l up to 20. We
provide a global picture of what to expect from an observational point of view
in terms of frequency range of excited modes, and investigate the behavior of
the instabilities with stellar evolution and increasing degree of the mode.
Furthermore, our pulsational stability analysis, once compared to the empirical
results of Sim\'on-D\'iaz et al. (2016), indicates that stellar oscillations
originated by a heat mechanism can not explain alone the occurrence of the
large non-rotational line-broadening component commonly detected in the O star
and B supergiant domain.
