Overview
This study aims to examine the correlation and agreement of regional and global measurements of ventricular function in the apical 4 chamber and subcostal 4 chamber view. Additionally, we will explore limitations of the technology and explore the effect of left lateral positioning.
Description
In transthoracic echocardiography, a number of measures are endorsed by current guidelines for quantifying ventricular function. These include conventional (mitral annular plane velocities, ejection fraction) and novel, speckle-tracking (STE) technologies. However, these measurements are standardized to be measured in the left lateral decubitus position in the apical (4-chamber) view of awake spontaneously breathing patients.
In the perioperative period, however, attaining these measurements in the endorsed circumstances may be challenging for a number of reasons. First, obtaining usable AP4C images may be difficult in ventilated or post-surgical patients. While the SC4C is generally obtainable visualized structures are not identical to those of the AP4C and measurement technologies such as Doppler are misaligned Secondly, patient conditions (e.g. in distress, or during surgery) may preclude positioning the patient in the left lateral decubitus position. Finally, patients may be ventilated and under anesthesia.
Newer technologies - such as speckle-tracking- may partially overcome these difficulties as these technologies are considered to be relatively angle independent. For quantification, it would be important to know whether or not speckle-tracking based measurements in the SC4C are sufficiently close to those measured under the endorsed conditions.
Eligibility
Inclusion Criteria:
- Consenting adult patients undergoing elective non-cardiac surgery
Exclusion Criteria:
- Inability to follow the procedures of the study, e.g. due to language problems, psychological disorders, dementia, etc. of the participant,
- Previous enrolment into the current study,
- Emergency procedures mandating expeditive patient care,
- Nonregular heart rhythm
- Valvular heart disease in the LV at least midgrade