IJCS | Volume 31, Nº6, November / December 2018

646 Jorge et al. Myocardial dysfunction and mortality in sepsis Int J Cardiovasc Sci. 2018;31(6)643-651 Review Article reducedmyocardial contractility occurring in 100%of the cases of severe sepsis, 20 studies estimate that only 20 to 60% of the patients with septic shock have decreased LV ejection fraction (LVEF) 21-23 in the first 3 days of treatment, with a gradual return to the baseline value around the tenth day from the onset of sepsis among the survivors. 21 Despite the importance given to the occurrence of systolic dysfunction during sepsis, its association with mortality is controversial. Ognibene et al. 24 observed that, paradoxically, patients with lower LVEF and greater LV end-diastolic volume (LVEDV) had a greater chance of surviving and recovering their myocardial function in the course of sepsis. 24 Additionally, Vieillard-Baron et al. 22 identified that acute and reversible left ventricular dysfunction was not associated with worse prognosis. Narvaéz et al. 25 reported a 22.8% incidence of septic cardiomyopathy among patients with severe sepsis or septic shock, with no difference in mortality when compared with patients with LVEF ≥ 50% and normalization of LV function after recovery from the acute event. 25 De Geer et al., 26 using speckle tracking, observed that the global longitudinal strain is often reduced in patients with septic shock, either alone or associated with a reduction in the LVEF or the average mitral annular motion velocity measured by tissue Doppler (e’). 26 The authors also observed that the global longitudinal strain presents a strong correlation with NT-proBNP levels on the first day of hospitalization, but is not significantly different between survivors and nonsurvivors, therefore, is not a good predictor of mortality. 26 In a recent meta-analysis that included seven prospective observational studies evaluating the relationship between systolic dysfunction associatedwith sepsis andmortality, the presence of a new-onset systolic dysfunction was not a sensitive or specific predictor of mortality due to the heterogeneity and low statistical power of the studies involved. 27 The assessment of the systolic function during sepsis can be a complex and challenging task, 28 which may lead to the myocardial depression not being readily identified 29 or the LVEF to be even overestimated, depending on the moment it is assessed. 30 This occurs because the heart, despite being a central component of the cardiovascular system, is affected during sepsis by disorders of capillary permeability and peripheral vascular tonus, with fluid loss to the third space, absolute hypovolemia, and consequent decrease in preload, in addition to peripheral vasodilation with a direct reduction of the afterload and relative hypovolemia, leading to an additional decrease in preload. 28 Since myocardial contractility is invariably reduced in sepsis, the LVEF ends up reflecting the balance between preload and afterload; in this way, despite the reduction of the intravascular volume directly affecting even more the myocardial function, 31 the arterial vasodilation, by reducing the afterload, may temporarily mask the myocardial depression and allow the LV systolic function to be preserved, i.e., overestimated despite a severely compromised intrinsic contractility, while the correction of the vasoplegia by volume resuscitation and the use of vasopressors unveil the contractile deficit. 30 In fact, Boissier et al., 32 using tissue Doppler and speckle tracking, showed that most patients with septic shock have reduced LV strain, and observed an inverse correlation between most indices of contractility and afterload. 32 In addition, the diagnosis of systolic dysfunction in this clinical scenario can be hindered by the high prevalence of heart failure with reduced ejection fraction (HFREF) in the population, often done retrospectively by the observation of improvement in ventricular function through serial echocardiographic assessments. Left ventricular diastolic dysfunction and mortality Diastolic dysfunction is equally prevalent in the presence of sepsis, occurring in approximately 40%of the patients, 33,34 although this number may vary according to the criteria used to evaluate the diastolic function. This has been observed in a study conducted by Clancy et al., 35 in which 60% of the patients evaluated on the first day of an episode of severe sepsis or septic shock presented diastolic dysfunction and 23% presented indeterminate diastolic function according to the guidelines published in 2016 by the American Society of Echocardiography along with the European Association of Cardiovascular Imaging, while 21% and 74% had diastolic dysfunction or indeterminate diastolic function, respectively, according to the 2009 guidelines of the American Society of Echocardiography. 35 It is not yet clear whether diastolic dysfunction is induced by this condition or changed by its treatment (with volume expansion and use of vasopressors) or, even, if it is a preexisting condition aggravated by the infection. 31 The prevalence of diastolic dysfunction is known to increase significantly with age, 36 especially with the occurrence of comorbidities like hypertension and ischemic cardiopathy, characteristics often present