Study population and data collection
We enrolled all patients at a large academic echocardiography laboratory
referred for TEE between the dates of 10/16/2017 and 11/22/2017 in which
one of the three following TEE protocols was chosen by the
physician/operator: aortic stenosis (AS), atrial fibrillation (AF), or
mitral regurgitation (MR). The protocol was chosen by the primary
operator (physician) based on the clinical indication for the TEE. While
all patients did not have an AS, AF, or MR indication for the exam, the
primary operator chose the TEE protocol that would best answer the
clinical indication for the exam. All TEE exams were performed on the
same echocardiogram (Siemens ACUSON SC2000, Mountain View, CA) using
customized procedure-specific study protocol (Siemens eSie
ScanTM workflow protocol software, Mountain View, CA).
TEE procedural data, including exam duration, and sonographer/machine
keystrokes were prospectively collected at the time of the TEE exam.
Patient demographics and baseline data were obtained on subsequent
retrospective chart review.
TEE image acquisition was performed for each TEE exam/patient using both
a manual and an automated protocol image acquisition by the same
sonographer and operator (physician). The physician operator was
responsible for TEE probe insertion and manipulation (moving the TEE
probe proximally and distally within the esophagus; ante-flexion,
retro-flexion, sideways movement of the TEE probe; clockwise or
counterclockwise rotation of the TEE probe). The sonographer was
responsible for the operation of the echocardiogram cart/machine,
including the use of all adjustments on the machine console and image
acquisition. A third researcher was responsible for videotaping of the
echocardiogram machine counsel during each exam for subsequent analysis
of sonographer keystrokes and procedure duration.
Performing each protocol (manual and automated) for each patient allowed
for control of patient-specific factors that may influence exam duration
or complexity. The order for which type of protocol was performed in
each patient (manual first or automated first) was alternated between
patient exams ensuring that the same number of patients had the manual
protocol performed first and the automated protocol performed first. The
same sonographer was used for every acquisition with each operator.
Operators were categorized as a novice (<3 years of TEE
experience) or expert (>3 years TEE experience). At no
point did any TEE exam need to be stopped or truncated due to patient or
clinical factors. If additional, more complex, and non-standard
views/images outside of the pre-specified protocol views were required,
these views were obtained after the protocol was complete and were not
included in analysis. No adverse events occurred during any of the TEE
exams performed.
Statistical power analysis was performed to determine the sample size;
20 patients per cohort were required to detect a difference of\(2\pm 3\) minutes in mean exam durations between the two cohorts with
95% confidence interval and 80% power.