Muhammad R Afzal1, Christopher Evenson2, Auroa Badin1, Dilesh Patel1, Hemant Godara1, Michael Essandoh3, Toshimasa Okabe1, Jaret Tyler1, Mahmoud Houmsse1, Ralph Augostini1, John Hummel1, Steven Kalbfleisch1, Emile G Daoud1, Raul Weiss4. 1. Division of Cardiovascular Medicine, Department of Internal Medicine, Electrophysiology Section, Ross Heart Hospital, The Wexner Medical Center at The Ohio State University Medical Center, Columbus, Ohio. 2. Department of Internal Medicine, The Wexner Medical Center at The Ohio State University Medical Center, Columbus, Ohio. 3. Department of Anesthesiology, The Wexner Medical Center at The Ohio State University, Columbus, Ohio. 4. Division of Cardiovascular Medicine, Department of Internal Medicine, Electrophysiology Section, Ross Heart Hospital, The Wexner Medical Center at The Ohio State University Medical Center, Columbus, Ohio. Electronic address: raul.weiss@osumc.edu.
Abstract
BACKGROUND: During early experience with subcutaneous implantable cardioverter-defibrillators (S-ICD), several patients had inappropriate shocks from T-wave oversensing (TWOS) during exercise. This prompted some operators to perform routine treadmill exercise tests after implantation of S-ICD to screen for TWOS. Meanwhile, improvements have been made in the detection algorithms by the manufacturer. OBJECTIVE: To assess whether routine treadmill exercise post S-ICD implantation is warranted. METHODS: Patients undergoing S-ICD implantation from October 2012 to December 2016 who were able to complete a treadmill exercise were included in the study. The amplitude of R and T waves as assessed by the device programmer at rest and peak exercise was calculated and incidence of TWOS recorded. RESULTS: Eighty-seven patients with complete treadmill exercise test data were included in the final analysis. The majority of the patients received S-ICD for primary prevention. Nine percent of the included patients had hypertrophic obstructive cardiomyopathy. During treadmill exercise, there was significant increase in the heart rate from rest (77 ± 14 beats per minute) to peak exercise (133 ± 14 beats per minute; P < .0001). There was no significant difference between R-wave amplitude at rest (2 ± 0.77 mV) and peak exercise (1.88 ± 0.94 mV; P = .36). Similarly, there was no significant difference between T-wave amplitude at rest (0.27 ± 0.19 mV) and peak exercise (0.33 ± 0.23 mV; P = .06). The incidence of TWOS during exercise was zero. CONCLUSIONS: With current screening and detection algorithms for S-ICD, routine treadmill exercise does not result in additional discrimination of patients susceptible to TWOS.
BACKGROUND: During early experience with subcutaneous implantable cardioverter-defibrillators (S-ICD), several patients had inappropriate shocks from T-wave oversensing (TWOS) during exercise. This prompted some operators to perform routine treadmill exercise tests after implantation of S-ICD to screen for TWOS. Meanwhile, improvements have been made in the detection algorithms by the manufacturer. OBJECTIVE: To assess whether routine treadmill exercise post S-ICD implantation is warranted. METHODS:Patients undergoing S-ICD implantation from October 2012 to December 2016 who were able to complete a treadmill exercise were included in the study. The amplitude of R and T waves as assessed by the device programmer at rest and peak exercise was calculated and incidence of TWOS recorded. RESULTS: Eighty-seven patients with complete treadmill exercise test data were included in the final analysis. The majority of the patients received S-ICD for primary prevention. Nine percent of the included patients had hypertrophic obstructive cardiomyopathy. During treadmill exercise, there was significant increase in the heart rate from rest (77 ± 14 beats per minute) to peak exercise (133 ± 14 beats per minute; P < .0001). There was no significant difference between R-wave amplitude at rest (2 ± 0.77 mV) and peak exercise (1.88 ± 0.94 mV; P = .36). Similarly, there was no significant difference between T-wave amplitude at rest (0.27 ± 0.19 mV) and peak exercise (0.33 ± 0.23 mV; P = .06). The incidence of TWOS during exercise was zero. CONCLUSIONS: With current screening and detection algorithms for S-ICD, routine treadmill exercise does not result in additional discrimination of patients susceptible to TWOS.
Authors: Babak Nazer; Zack Dale; Gianmarco Carrassa; Nosheen Reza; Tuna Ustunkaya; Nikolaos Papoutsidakis; Andrew Gray; Stacey J Howell; Miriam R Elman; Paolo Pieragnoli; Giuseppe Ricciardi; Daniel Jacoby; David S Frankel; Anjali Owens; Iacopo Olivotto; Stephen B Heitner Journal: Heart Rhythm Date: 2020-02-18 Impact factor: 6.343