Echocardiography for left ventricular assist device implantation and evaluation: an indispensable tool.

Echocardiography is an indispensable tool in the evaluation, placement, management and follow-up of patients with left ventricular assist devices (LVAD). While transoesophageal echocardiography is the ideal tool in guiding the implantation procedure, transthoracic echocardiography is essential during the initial evaluation, patient selection and in the post-operative follow-up. This review attempts to summarize which parameters the echocardiographic assessment should focused on during each step. In particular, during the pre-operative assessment, it is of paramount importance to assess the presence of aortic regurgitation and most importantly to evaluate right ventricular function, since it is one of the strongest predictor of post-implant right ventricular failure. During the procedure, through transoesophageal echocardiography, it is possible to confirm the correct placement of the inflow cannula, to assess right ventricular function and to guide the choice of the right pump speed. Transthoracic echocardiographic is an essential part in the patient's follow-up once the LVAD has been implanted, in order to attest the onset of possible complications.

Usefulness of echocardiography to detect cardiac involvement in COVID-19 patients.

Coronavirus disease 2019 (COVID-19) outbreak is a current global healthcare burden, leading to the life-threatening severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, evidence showed that, even if the prevalence of COVID-19 damage consists in pulmonary lesions and symptoms, it could also affect other organs, such as heart, liver, and spleen. Particularly, some infected patients refer to the emergency department for cardiovascular symptoms, and around 10% of COVID-19 victims had finally developed heart injury. Therefore, the use of echocardiography, according to the safety local protocols and ensuring the use of personal protective equipment, could be useful firstly to discriminate between primary cardiac disease or COVID-19-related myocardial damage, and then for assessing and monitoring COVID-19 cardiovascular complications: acute myocarditis and arrhythmias, acute heart failure, sepsis-induced myocardial impairment, and right ventricular failure derived from treatment with high-pressure mechanical ventilation. The present review aims to enlighten the applications of transthoracic echocardiography for the diagnostic and therapeutic management of myocardial damage in COVID-19 patients.

Assessment of left ventricular ejection fraction in critically ill patients at the time of speckle tracking echocardiography: intensivists in training for echocardiography versus experienced operators.

BACKGROUND: The biplane Simpson's method is considered the gold standard to assess and monitor left ventricular (LV) ejection fraction (EF) in critically ill patients. Recently, a new semi-automatic technique based on speckle tracking echocardiography called "Auto-EF" has been introduced. We compared LVEF values obtained with biplane Simpson's method and Auto-EF by two groups of operators: trainee echocardiography intensivists and experienced echocardiographers. METHODS: A standard transthoracic echocardiography was performed on 37 patients. According to image quality 29 patients were selected. Each inexperienced and experienced operator executed an off-line analysis using both Simpson's method and Auto-EF. LVEF obtained by the two groups of operators were then compared. RESULTS: EF values assessed with Simpson's method showed a moderate correlation (r=0.70, P<0.01) between inexperienced and experienced operators. The Bland-Altman analysis showed a mean bias of 0.3% with limits of agreement (LoA) from -24.4 to +25.1%. Values obtained with Auto-EF showed a good correlation (r=0.94, P<0.01) with a mean bias of 0.2% and LoA from -10.1 to +10.4%. CONCLUSIONS: Due to its semiautomatic nature, for inexpert operators Auto-EF seems more reproducible than the traditional Simpson's method for monitoring left ventricular function in critically ill patients.

Relationship between pulse pressure variation and echocardiographic indices of left ventricular filling pressure in critically ill patients.

BACKGROUND: Pulse pressure variation (PPV) is a dynamic index of fluid responsiveness. This parameter helps clinicians in improving haemodynamic status while avoiding potential fluid overload. Echocardiographic indices, such as E/E' ratio and left atrial (LA) strain by speckle tracking echocardiography (STE), are used to estimate left ventricular (LV) filling pressures. This study aimed at exploring the relationship between PPV and echocardiographic indices of LV filling pressures in critically ill patients. METHODS: Twenty-two patients (mean age of 50.9 ± 21.6, male/female = 15/7) admitted to intensive care unit, and requiring mechanical ventilation and invasive arterial pressure monitoring, were studied. In all patients, two independent operators assessed simultaneously PPV, using a pulse contour method, mean E/E' ratio and peak atrial longitudinal strain (PALS) by means of STE. PALS values were obtained by averaging LA segments measured in the 4-chamber and 2-chamber views (global PALS). RESULTS: A significant negative correlation was found between mean E/E' ratio and PPV (R(2) = -0.76; P<0.001). A positive correlation between global PALS and PPV was found (R(2) = 0.80, P<0.001). Mean global PALS of 26.2% demonstrated excellent accuracy (Area Under Roc Curve = 0.86, P<0.001), and good sensitivity (92%) and specificity (86%) in predicting a PPV >15%. CONCLUSION: In a group of mechanically ventilated patients PPV, derived from pulse contour analysis, and echocardiographic preload parameters were well correlated. Global PALS by STE provided better estimation of PPV than mean E/E' ratio. PALS seems a potential alternative to PPV in assessing fluid responsiveness in critically ill patients.

Pre-operative left atrial strain predicts post-operative atrial fibrillation in patients undergoing aortic valve replacement for aortic stenosis.

Post-operative atrial fibrillation (AF) is a common and serious complication in patients undergoing aortic valve replacement (AVR). Speckle tracking echocardiography (STE) has recently enabled the quantification of longitudinal myocardial left atrial (LA) deformation dynamics. Our aim was to investigate LA preoperative mechanical function in patients undergoing AVR for aortic stenosis using STE and determine predictors of post-operative AF. 76 patients with aortic stenosis in sinus rhythm, undergoing AVR, were prospectively enrolled. Conventional echocardiographic parameters, and peak atrial longitudinal strain (PALS) were measured in all subjects the day before surgery. PALS values were obtained by averaging all segments in the 4- and 2-chamber views (global PALS). All patients received biological valve prostheses and a standard postoperative care. Postoperative AF occurred in 15 patients (19.7 %). On univariate analysis among all clinical and echocardiographic variables, global PALS showed the highest diagnostic accuracy (HR 6.55 p < 0.0001; AUC of 0.89) with a cut-off value <16.9 %, having sensitivity and specificity of 86 and 91 %, respectively, in predicting postoperative AF. LA volume indexed and E/e' ratio had lower diagnostic accuracy (AUC 0.76 and 0.51, respectively). On multivariate analysis global PALS remains a significant predictor of postoperative AF (p < 0.0001). STE analysis of LA myocardial deformation is considered a promising tool for the evaluation of LA subclinical dysfunction in patients undergoing AVR, giving a potentially better risk stratification for the occurrence of postoperative AF.

Prediction of stroke volume by global left ventricular longitudinal strain in patients undergoing assessment for cardiac transplantation.

PURPOSE: Speckle-tracking echocardiography (STE) is a novel technique that can be used for assessment of left ventricular (LV) longitudinal deformation dynamics. Using cardiac catheterization as the reference standard, the aim of this study was to evaluate the relation between LV global longitudinal strain (GLS) assessed by STE and LV stroke volume in patients undergoing assessment for cardiac transplantation. METHODS: Conventional echocardiography and STE were performed during right-sided cardiac catheterization in 51 patients referred for cardiac transplant assessment. Thermodilution LV stroke volume indexed (LVSVI) was used as the reference standard. Univariate regression analyses and receiver operating characteristics curves were used to test correlations between LVSVI and GLS by STE. RESULTS: Global longitudinal strain was obtained successfully in 95.5% of patients. Among all variables analyzed, GLS best predicted the LVSVI (r = 0.79; P < .0001). Minor correlations with the LVSVI were observed for tissue Doppler-derived systolic mitral annular velocity (r = 0.51; P < .005) and for LV ejection fraction (r = 0.32; P < .05). CONCLUSIONS: In a group of patients referred for cardiac transplant assessment, LV longitudinal deformation analysis by STE closely correlates with LVSVI, suggesting that, in this particular clinical setting, this new parameter may help provide an accurate, noninvasive, and quantitative assessment of LV function.