Non-Invasive Assessment of Left Ventricle Ejection Fraction: Where Do We Stand?

The left ventricular (LV) ejection fraction (EF) is the preferred parameter applied for the non-invasive evaluation of LV systolic function in clinical practice. It has a well-recognized and extensive role in the clinical management of numerous cardiac conditions. Many imaging modalities are currently available for the non-invasive assessment of LVEF. The aim of this review is to describe their relative advantages and disadvantages, proposing a hierarchical application of the different imaging tests available for LVEF evaluation based on the level of accuracy/reproducibility clinically required.

Sevoflurane-Based Enhancement of Phase-Amplitude Coupling and Localization of the Epileptogenic Zone

Objective: Phase-amplitude coupling between high-frequency (>150 Hz) and delta (3-4 Hz) oscillations - modulation index (MI) - is a promising, objective biomarker of epileptogenicity. We determined whether sevoflurane anesthesia preferentially enhances this metric within the epileptogenic zone. Methods: This is an observational study of intraoperative electrocorticography data from 621 electrodes chronically implanted into eight patients with drug-resistant, focal epilepsy. All patients were anesthetized with sevoflurane during resective surgery, which subsequently resulted in seizure control. We classified "removed" and "retained" brain sites as epileptogenic and non-epileptogenic, respectively. Mixed model analysis determined which anesthetic stage optimized MI-based classification of epileptogenic sites. Results: MI increased as a function of anesthetic stage, ranging from baseline (i.e., oxygen alone) to 2 minimum alveolar concentration (MAC) of sevoflurane, preferentially at sites showing higher initial MI values. This phenomenon was accentuated just prior to sevoflurane reaching 2 MAC, at which time, the odds of a site being classified as epileptogenic were enhanced by 86.6 times for every increase of 1 MI. Conclusions: Intraoperative MI best localized the epileptogenic zone immediately before sevoflurane reaching 2 MAC in this small cohort of patients. Significance: Prospective, large cohort studies are warranted to determine whether sevoflurane anesthesia can reduce the need for extraoperative, invasive evaluation.

Non-Invasive Evaluation of Patients Undergoing Percutaneous Coronary Intervention for Chronic Total Occlusion

Background: As percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) gains wider acceptance as a therapeutic option for coronary artery disease, the importance of appropriate patient selection has increased. Although cardiovascular magnetic resonance imaging (MRI) allows segmental and quantitative analyses of myocardial ischemia and scar transmurality, it has limitations, including contraindications, cost, and accessibility. This study established a non-invasive method to evaluate patients undergoing CTO-PCI using two-dimensional speckle-tracking echocardiography (2D-STE). Methods: Overall, we studied 55 patients who underwent successful CTO-PCI. Cardiovascular MRI and 2D-STE were performed before and 8 ± 2 months after CTO-PCI. Segmental findings of strain parameters were compared with those obtained with late gadolinium enhancement and stress-perfusion MRI. Results: With a cutoff of −10.7, pre-procedural circumferential strain (CS) showed reasonable sensitivity (71%) and specificity (73%) for detecting segments with transmural scar. The discriminatory ability of longitudinal strain (LS) for segments with transmural scar significantly improved during follow-up after successful CTO-PCI in the territory of the recanalized artery (area under the curve (AUC) 0.70 vs. 0.80, p < 0.001). LS accuracy was lower than that of CS at baseline (AUC 0.70 vs. 0.79, p = 0.048), and was increased at follow-up (AUC 0.80 vs. 0.82, p = 0.81). Changes in myocardial perfusion reserve from baseline to follow-up were significantly associated with those in LS but not in CS. Conclusions: Use of 2D-STE may allow the non-invasive evaluation of patients undergoing CTO-PCI to assess the indication before the procedure and treatment effects at follow-up.