Relationship between cardiac adrenergic image and exercise testing in heart failure

The exercise treadmill test can be used in ventricular dysfunction patients for functional capacity or predicting prognosis. The cardiac image with 123I MIBG shows cardiac sympathetic activation.To evaluate the relationship between exercise treadmill test variables and cardiac image changes in 123I MIBG.23 patients with LVEF ≤ 45% performed scintigraphy cardiac with 123I MIBG and divided into two groups. G1: Washout rate27%; G2: ≥ 27%. Systolic blood pressure (SBP), heart rate (HR) and functional capacity were evaluated. It was performed Student t test or Mann-Whitney U test, Spearman coefficient and linear regression.SBP at exercise peak (G1: 181.00 ± 28.01; G2: 153.27 ± 27.71 mmHg, p = 0.027), SBP variation [G1: 64(47.5-80.5); G2: 36(25-47) mmHg, p = 0.015], the HR at exercise peak (G1: 136.91 ± 19.66; G2: 118.45 ± 13.98 bpm, p = 0.018) and chronotropic response (G1: 70.42 ± 17.94; G2: 49.47 ± 14.89%, p = 0.006), and functional capacity [G1: 8.37(6.47-10.27); G2: 4.42(2.46-6.38) METs, p = 0.003] were smaller in G2 group. There was negative correlation between Washout rate and SBP at exercise peak (r = -0.505, p = 0.014), variation in SBP (r = -0.493, p = 0.017) and functional capacity (r = -0.646, p = 0.001). Nevertheless, SBP at exercise peak (r = -0.422, p = 0.016) and functional capacity (r = -0.804, p = 0.004) were the only variables associated with Washout rate, after linear regression.In heart failure patients, the SBP at exercise peak and functional capacity were the variables associated with Washout rate.