IJCS | Volume 32, Nº4, July/August 2019

371 Table 2 - Variables analyzed during the CPET Variable Value SBP at rest (mmHg) 117.3 ± 22.7 SBP (mmHg) 134.1 ± 31.0 HR (bpm) 68.3 ± 10.8 Peak HR (bpm) 105.9 ± 23.0 Peak VO 2 (ml.min -1 ) 973 ± 361 Peak VO 2 (mL.kg -1 .min -1 ) 13.3 ± 4.3 Predicted VO 2 (%) 49 ± 16.7 Peak LV (L.min -1 ) 53.8 ± 50 Peak VE/VO 2 51 ± 17.5 Peak VE/VCO 2 45 ± 14.4 Slope VE/VCO 2 42.4 ± 18.1 Peak RER 1.12 ± 0.14 Peak pulse O 2 (ml.beat -1 ) 10.3 ± 3.5 T1/2 (seconds) 150 ± 46.9 OUES 800 ± 479 SBP: systolic blood pressure; HR: heart rate; VO 2 : oxygen consumption; RER: respiratory exchange ratio; OUES: oxygen uptake efficiency slope; VE/VCO 2 : ventilatory equivalent for CO 2 ; VE/VO 2 : ventilatory equivalent for oxygen. Mizzaci et al. Cardiopulmonary testing in patients with ICD Int J Cardiovasc Sci. 2019;32(4):368-373 Original Article patients but it is also associated with an increased risk of death. 18 The ICDs present algorithms for the detection of ventricular tachyarrhythmia and discriminatory algorithms for supraventricular tachycardia. However, these may fail and result in inappropriate therapies, such as supraventricular tachycardia therapy. To avoid this risk, during CPET, it was established that the heart rate during exercise should have the zone of the first programmed therapy as a limit of attention. Hence the importance of prior knowledge of device programming by telemetry. Although exercise may predispose to ventricular arrhythmia, which is common in heart failure, the overall frequency of arrhythmia during exercise testing is low. In this study, we demonstrated that CPET is safe because no severe arrhythmia has been identified. This is consistent with an earlier study by Chinnaiyan et al., 13 who evaluated 84 patients (mean age 67 ± 12 years; 76% men). Participants underwent 107 stress tests, including 44 exercises and 63 pharmacological evaluations (22 dobutamine, 41 dipyridamole). No ICDs were inactivated before the test. Four patients presented nonsustained self-limited VT at the peak of stress. None of them had sustained VT requiring therapy. There were no deaths or hospital readmissions due to ventricular arrhythmias. Chart 1 - Incidence of ventricular arrhythmias in the study population. NO ARRHYTHMIAS RARE VENTRICULAR EXTRASYSTOLES COMPLEX ARRHYTHMIAS