Abstract Body (Do not enter title and authors here): Background
Patients undergoing cancer therapies with QTc prolonging effects are required to make frequent clinic visits to obtain 12-lead ECGs for QTc monitoring. This practice is associated with a significant financial burden and inconvenience for the patient and the healthcare system.

Research Question
What is the reliability, cost-effectiveness, patient and provider satisfaction of Kardia single lead and 6-lead smartphone ECG as compared to the gold standard 12-lead ECG?

Methods
We conducted a prospective cohort study and included ambulatory patients with cancer that were undergoing cancer treatments associated with the QTc prolonging effects. Patients received sequential 30-second screening ECGs with the AliveCor Kardia single lead and six lead devices (AliveCor Inc, Cupertino, CA) paired with an iPad (Apple, Cupertino, CA), in addition to the gold standard 12-lead ECG during the same visit.
The primary outcome was the reliability of AliveCor ECG compared to a standard 12-lead ECG defined as a mean difference in QTc of ± 15ms using the Fridericia formula for QT correction. The secondary outcome was to evaluate the cost-effectiveness of AliveCor ECG. Cost effectiveness was defined as the difference between smart-phone ECG and 12-lead ECG along with the cost of physician interpretation and travel costs for patients. The tertiary outcome was to assess the patient and healthcare provider satisfaction measured by a questionnaire.

Results
A total of 22 patients and 26 healthcare providers were included. The mean age of patients was 66 years (range: 43–87), 45.4% were female, and 77.2% were of the white race, 45.4% were on immune checkpoint inhibitors, 18% were on anthracyclines, and 9% were on proteasome inhibitors.
Kardia single lead and six lead ECG were reliable in measuring QTcF with the mean difference of ±6 ms and ±3 ms in comparison to standard 12-lead ECG, respectively. On average, Kardia single-lead and six-lead ECG saved $183 and $133 dollars per visit as compared to standard 12-lead ECG. Patients assigned a median satisfaction score of 5, 5, and 3 on a Likert scale to the Kardia single lead, six lead, and standard 12 lead ECG, respectively. In contrast, healthcare providers had a median satisfaction score of 4 for all the screening methods.

Conclusions
Smartphone compatible ECG is reliable and a cost-effective method of QTc interval monitoring of cancer therapies that is acceptable to patients and providers.