Assessment of dyssynchrony in patients with severe heart failure by nuclear imaging: paradise lost and regained or lost and gone forever?
Cardiac resynchronization therapy, based on biventricular and/or left ventricular preexcitation, is a recently introduced therapeutic option for patients with severe heart failure and intraventricular conduction disturbances. The invasive nature and expense of resynchronization therapy has highlighted the need to prospectively identify optimal candidates, because of the poor correlation of QRS duration with patient response. Scintigraphy and positron emission tomography made it possible the research investigation of the pathophysiological consequences of cardiac conduction disturbances on myocardial contraction, metabolism, and perfusion. Increasing evidence shows that nuclear imaging techniques allow a comprehensive evaluation of the candidates to resynchronization. In fact, phase analysis of equilibrium radionuclide angiography enables a simple, quick and reliable measurement of both of inter- and intraventricular mechanical dyssynchrony, affording an optimal predictive accuracy of the response. In addition, being scintigraphic data highly reproducible, they are suitable for sequential longitudinal follow-up of the ventricular performance and mechanical dyssynchrony in patients implanted with devices.
Mule
Jacopo Dalle
JD
Civic Hospital, ULSSI, Pieve di Cadore (BL), ULSSI, Belluno, Italy. jacopo.dallemule@libero.it
Martinelli
Felice
F
D001145:Arrhythmias, Cardiac / Q000000981:diagnostic imaging*; D002304:Cardiac Pacing, Artificial; D006333:Heart Failure / Q000000981:diagnostic imaging*; D006801:Humans; D011379:Prognosis; D011875:Radionuclide Angiography; D018570:Risk Assessment; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging