Results
Thirty-four cardiologists volunteered to participate in the study. Fifteen participants were experienced with catheter manipulation. This included electrophysiology attendings (n = 8), cardiac catheterization attendings (n = 4), and electrophysiology fellows (n = 3) who were finishing their first or second year of specialist training. Nineteen participants did not specialize in catheter manipulation including cardiology fellows (n = 15) and attendings of non-interventional specializations (n = 4). Table 2 describes participants’ demographics in greater detail. Two participants (1 interventional and 1 non-interventional) withdrew from the study after one set of paired trials due to time constraints. All other participants completed two sets paired trials with and without the tool. The resulting 66 sets of paired trials were compared.
There was no significant difference in the time to reach the designated targets or total time to complete the task between the bare catheters and the catheters with the torque tool. Participants required an average of 1.6 attempts to complete the 60-s lesion both with the bare catheters and with the addition of the torque tool. These analyses held true when evaluated for the subgroup experienced with manipulating catheters. Interventional physicians did not have a significant difference in time or number of attempts between the bare catheter and with the use of the torque tool (Table 3).
Collectively, the participants reported a significant decrease in perceived physical demand (p < 0.0001), effort (p = 0.0003), and frustration (p = 0.0008) when using the torque tool, as well as a significant increase in perceived performance (p = 0.0061). There was no significant difference in mental or temporal demand. When evaluated for the subgroup experienced with manipulating catheters, they did not report a significant difference in mental demand, temporal demand, effort, frustration, or performance; however, they did report a significant decrease in physical demand (p < 0.0001) when using the catheter torque tool. It should be noted that frustration and performance were nearing significance (p ≈ 0.08). The average scores on the NASA TLX for each metric are shown in Table 4.
One EMG dataset of an interventional cardiologist was found to be corrupt and excluded from analysis along with its paired trial. In the remaining 65 paired trials, there was a significant reduction in maximum muscle activation, mean muscle activation, and total muscle work for the left abductor pollicis (p = 0.0011, p < 0.0001, and p = 0.0209, respectively). Additionally, a significant reduction was seen in the mean muscle activation for the left brachioradialis, left flexor carpi ulnaris, and left extensor carpi radialis (p = 0.0015, p = 0.0059, and p = 0.0003, respectively) (Fig. 5). No significant differences in muscle activation were observed for the left flexor carpi radialis and left extensor carpi ulnaris. When evaluated for the interventional group only (28 paired trials), a significant difference was noted for the mean muscle activation in the left abductor pollicis (p = 0.0221) and the left brachioradialis (p = 0.0041).