IJCS | Volume 32, Nº4, July/August 2019

DOI: 10.5935/2359-4802.20190066 Carolina Christianini Mizzaci Instituto Dante Pazzanese de Cardiologia Doutora em Ciências pela Universidade Federal de São Paulo carolina.mizzaci@hotmail.com 368 ORIGINAL ARTICLE International Journal of Cardiovascular Sciences. 2019;32(4):368-373 Mailing Address: Thiago Fagundes Av. Dr. Dante Pazzanese, 500. Postal Code: 04012-909, São Paulo, SP – Brazil. E-mail: thiagotsfagundes@hotmail.com Cardiopulmonary Exercise Testing in Patients with Implantable Cardioverter- Defibrillator: A Retrospective Study Carolina Mizzaci , T hiago Fagunde s, Felipe Malafai a, S andro Felicion i, S usimeire Buglia , C arlos Alberto Hossr i, A lmir Ferra z, R ica Buchle r, R omeu Meneghel o, L uiz Mastrocoll a Instituto Dante Pazzanese de Cardiologia, São Paulo, SP – Brazil Manuscript received on March 14, 2019, revised manuscript on June 05, 2019, accepted on July 07, 2019. Abstract Background: Cardiopulmonary exercise testing is widely used in the evaluation of patients with left ventricular dysfunction, and some of these patients have an implantable cardioverter-defibrillator (ICD). However, this test presents specific challenges because of the susceptibility to ventricular arrhythmias during maximal levels of exercise. Objective: To evaluate the safety of cardiopulmonary exercise testing in patients with ICD. Methods: The study included patients with ICD who underwent cardiopulmonary exercise testing between 2007 and 2015. The tests were completed once the electronic devices were programmed. The maximum allowed heart rate reached during exercise was 10 beats below the first therapy zone programmed. Results: The study included 69 patients with mean age 53.7 ± 10.8 years, including 68% men. Exercise time was 8.7±2.3 minutes, with peak oxygen consumption of 13.3 ± 4.3 ml.kg - 1 .min -1 . Peak heart rate was 62.9 ± 13.4% of the maximum rate predicted, with all patients taking specific medication. Ventricular arrhythmia was observed in 29% of the patients, and paired ventricular extrasystoles, ventricular bigeminism or non-sustained ventricular tachycardia were observed in only 14.5% of the patients. There was no sustained ventricular arrhythmia resulting in ICD therapy or other complications, such as inappropriate therapies. The frequency of severe events was 0%, 95% CI (0 – 5.2%). Conclusion: In the sample of patients evaluated, the cardiopulmonary exercise testing was shown to be safe during its performance in a hospital setting, following the safety standards. (Int J Cardiovasc Sci. 2019;32(4):368-373) Keywords: Cardiovascular Diseases; Sudden Cardiac Death; Left Ventricular Dysfunction; Breathing Exercise; Defibrillators, Implantable; Arrhythmias, Cardiac. Introduction Sudden cardiac death (SCD) is a major problem in patients with cardiovascular disease and it is mostly caused by ventricular arrhythmia. 1 The pathophysiology of SCD involves an electrical instability event with induction of ventricular tachycardia (VT), which leads to ventricular fibrillation (VF) in 80 to 85% of the cases. Since the first report of implantable cardioverter- defibrillator (ICD) implantation in 1980, treatment of ventricular tachyarrhythmia underwent major changes. Initially used in patients surviving SCD, ICD was also recommended as a preventive therapy in patients at high risk for arrhythmic events. 1-5 Cardiopulmonary exercise testing (CPET) adds information on ventilatory dynamics and gas exchange during exercise, allowing greater precision in the evaluationof the aerobic functional capacityof individuals