Nuclear imaging in cardiac resynchronization therapy.
Recently, cardiac resynchronization therapy (CRT) has become implemented in the treatment of patients with severe heart failure. Although the improvement in systolic function after CRT implantation can be considerable, 20%-30% of patients do not respond to CRT. Evidence is accumulating that the presence of left ventricular (LV) dyssynchrony is mandatory for a response to CRT. Since the early 1980s attempts have been made to assess cardiac dyssynchrony with nuclear imaging, and it has been reported recently that information on LV dyssynchrony can be obtained from gated myocardial perfusion SPECT with phase analysis. Other studies with SPECT have shown that extensive scar tissue will limit the response to CRT; similarly, it has been demonstrated that viable tissue (assessed with SPECT) in the target zone for the LV pacing lead (usually the lateral wall) is needed for a response to CRT. Moreover, studies with PET have provided insight into the changes in myocardial perfusion, metabolism, and efficiency after CRT. In the current review, a comprehensive summary is provided on the potential role of nuclear imaging in the selection of heart failure patients for CRT. The value of other imaging techniques is also addressed.
Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands.
Maureen M
MM
Henneman
Ernst E
EE
van der Wall
Claudia
C
Ypenburg
Gabe B
GB
Bleeker
Nico R
NR
van de Veire
Nina Ajmone
NA
Marsan
Ji
J
Chen
Ernest V
EV
Garcia
Jos J M
JJ
Westenberg
Martin J
MJ
Schalij
Jeroen J
JJ
Bax
D002304:Cardiac Pacing, Artificial; D002921:Cicatrix / Q000503:physiopathology; D006333:Heart Failure / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009200:Myocardial Contraction; D049268:Positron-Emission Tomography / Q000379:methods*; D013318:Stroke Volume; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D016277:Ventricular Function, Left