Steps Forward in the Assessment of Myocardial Viability in Left Ventricular Dysfunction

he compelling pathophysiology of the states of reversible LV dysfunction, myocardial hibernation, and myocardial stunning have spawned a voluminous literature as clinical investigators attempt to optimize the noninvasive identification of patients with these conditions before consideration of revascularization. Such techniques have direct relevance in patients with clinical syndromes associated with LV dysfunction. This is perhaps most important and most relevant in patients with a clinical syndrome of heart failure and a significant degree of global LV dysfunction, a subset of whom will derive considerable benefit in terms of outcome and recovery of LV function after revascularization. Several studies have now suggested that revascularization in the setting of LV dysfunction and significantly retained myocardial viability is associated with an improved natural history 1-5 as well as improvement in heart failure symptoms and functional capacity. Besides providing clinically relevant data, noninvasive scintigraphic and echocardiographic techniques have also helped to illuminate the complex perfusion, metabolic, and functional correlates of these states of reversible LV dysfunction, which remain subjects for debate. 7,