Left ventricular (LV) systolic dysfunction associated with coronary artery
disease (CAD) comprises a major diagnostic and therapeutic dilemma.
Hibernating myocardium refers to a chronic dysfunctional condition, as a result of
repeated episodes of ischemia, of a still viable myocardium. In viable dysfunctional
myocardium, the integrity of myocyte membrane and contractile fibers are preserved.
Revascularization may promote LV function in cases of residual myocardial viability in
dysfunctional segments of the heart. The identification of viability
is pivotal for patients’ management, and viability testing is a valuable tool to
guide therapeutic options in these patients. Various non-invasive viability assessment
procedure can be used in the clinical practice and novel applications are emerging
which are likely to provide higher diagnostic accuracy in the future. Nuclear
myocardial perfusion imaging with single photon emission computed tomography
(SPECT) has been used for several decades and is a well-established method for
viability evaluation, while positron emission tomography (PET) has been considered
the “gold standard” for this scope. Other non-radioisotopic cardiac imaging modalities
have been also developed, such as cardiac magnetic resonance (CMR) and
echocardiography with high image quality and no radiation exposure, and lastly cardiac
computed tomography (CCT). In the last years, great advances have been made in
image processing software, as well as in hybrid imaging for the simultaneous analysis
of functional and anatomical datasets based on different modalities.
Keywords: Cardiac computed tomography, Cardiac magnetic resonance,
Echocardiography, Left ventricular dysfunction, Myocardial infarction, Myocardial
viability, PET radiotracers, Positron emission tomography, Single photon emission
tomography, Technetium-99m, Thallium-201.