Cardiovascular Autonomic Neuropathy is a Predictor for Chronotropic Incompetence Measured by Treadmill Excercise Test
Author : F. Rusnanta, F. S. Laitupa, Vidyawati, A. Rizal
Upload Date : 19-04-2018
Background: Cardiovascular autonomic neuropathy (CAN) is defined as an impairment of cardiac autonomic nerve fibers in the cardiovascular system. The prevalence of CAN varies between 16.1% and 22.1% on performing at least two abnormal cardiovascular heart rate tests. CAN may contribute to chronotropic incompetence (CI) which is the inability of the heart rate (HR) to rise in proportion to an increase in metabolic demand. Determination of CI is widely based on measurement of maximum HR during exercise testing. This study aimed to evaluate contribution of CAN to determine CI.
Methods: We included 105 patients, 50 patients with CI and 55 patients with non-CI determined by exercise treadmill test. CAN was assessed by analyzing heart rate variations during three standard tests (deep breathing, lying to standing and Valsava maneuver).
Results: Definite CAN was present in 72 patients (68.6%) and 49 patients had CI. CI group showed significantly CAN than non-CI group (p < 0.001). CI group showed significantly lower values of among three standard test of heart rate variations (p < 0.05). All three standard tests were found to be an independent risk factor for CI from multivariate regression analysis. Valsava maneuver showed the best predictor to the CI (p < 0.001). The accuracy of different CAN parameters in the prediction of CI was described by the receiver operating curve (ROC) analysis. Regarding Valsava maneuver, the cut-off value was 0.9 and the area under the curve (AUC) was 0.867, with a sensitivity of 92% and a specificity of 44%. ROC curve analysis for deep breathing and lying to standing showed AUC 0.662 and a cut-off value of 10 (sensitivity 62% and specificity 54%) and AUC 0.670 and a cut-off value of 0.9 (sensitivity 67% and specificity 46%), respectively.
Conclusion: The decrease in heart rate variations during CAN parameters seems to be related to the development of chronotropic incompetence, especially during Valsava maneuver.
KEYWORDS : cardiovascular autonomic neuropathy, chronotropic incompetence.