Distinctive abnormal responses to tilting test in chronic chagas' disease

Palmero, H A; Caeiro, T; Iosa, Daniel

doi:10.1007/bf01478139

Cited by 24 publications

(18 citation statements)

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“…Thus, the cardiac autonomic impairment previously detected in Chagas' heart disease patients by complex and invasive or simple noninvasive tests (Amorim et al, 1982;Gallo et al, 1987;Marin-Neto et al, 1980, 1998Junqueira, 1990;Guzzetti et al, 1991;Dávila et al, 1998) was also presently noted in chagasic patients with the apparent indeterminate form. This observation reinforces previous findings of suggestive cardiac dysautonomia in these chagasics based on different methodologies of cardiac autonomic evaluation (Macêdo et al, 1974;Iosa et al, 1980;Palmero et al, 1980;Guzzetti et al, 1991;Ribeiro et al, 2001). The prolonged time and the reduced velocity of heart interval change from the maximum tachycardia to maximum bradycardia post-manoeuvre may be consequent to delayed inhibition or reversion of the ongoing sympathetic hyperactivity in phases II and III with retarded suppression of tachycardia in phase III and installation of bradycardia in phase IV, or to delayed stimulation of the attenuated or normal parasympathetic activity in phases II and III with slow installation of bradycardia in phase IV.…”

Section: Discussionsupporting

confidence: 92%

Impaired autonomic control of heart interval changes to Valsalva manoeuvre in Chagas' disease without overt manifestation

Soares

2002

Autonomic Neuroscience

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Background: In the apparent indeterminate form of Chagas' disease, which lacks any overt clinical, electrocardiographic, and radiological manifestations of organ damage, lesions of the intrinsic autonomic innervation of heart are not striking features and evidences for cardiac autonomic dysfunction are elusive and conflicting. Objective: To evaluate the cardiac autonomic modulation based on Valsalva manoeuvreassociated heart interval variation in Chagas' disease subjects with apparent indeterminate form. Subjects and methods: We examined 36 outpatient volunteers aged 15 -51 years old (median: 36.5), in comparison with 52 healthy control individuals aged 17 -49 years old (median: 29) ( p < 0.001). Each subject sequentially performed in the supine position three to four manoeuvres at an intra-oral pressure of 40 mm Hg during 20 s, under continuous DII lead electrocardiographic registration, and rate-and time-dependent indices of Valsalva manoeuvre-associated R -R interval variation were obtained. The t-test or the Mann -Whitney test was employed to compare the data between the groups. Results: No correlation was found between every index and age for the control group ( p = 0.39 -0.71). The chagasic group presented similar basal to phase IV median increment (relative bradycardia) (23.7% vs. 22.7%; p = 0.63) and smaller basal to phase III median decrement of R -R interval (relative tachycardia) ( À 31.7% vs. À 35%; p = 0.02) in comparison to the control group, respectively. The median Valsalva ratio showed a tendency for reduction in chagasics (1.78 vs. 1.90; p = 0.08). Prolonged median time (14.2 vs. 10.3 s; p < 0.001) and slowed median velocity (5.1%/s vs. 8.9%/s; p < 0.001) of the phases III -IV bradycardia were also observed in chagasic group. The majority (58.3%) of the chagasics presented exclusively at least one depressed, and 8.3% presented at least one enhanced index of rateand/or time-dependent heart interval responses beyond the 25th or 75th control percentiles, and 27.8% presented at least one depressed and other enhanced index, while 5.6% showed all indices within the control interquartile range. All the indices outside the 25th or 75th control percentiles were noted in 13.9% of chagasics. Conclusion: Chagas' disease subjects without overt manifestations presented variable and subtle depression and less frequent enhancement or normality of the rate-and time-dependent tachycardia and bradycardia reflex responses related to Valsalva manoeuvre, which demonstrates distinct patterns of finely disturbed cardiac sinus parasympathetic and sympathetic modulation, probably due to inflammatory or autoimmunological damage of intrinsic innervation and/or to autoantibodies-induced derangement in neurotransmitter receptors. D

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Section: Discussionsupporting

confidence: 92%

Impaired autonomic control of heart interval changes to Valsalva manoeuvre in Chagas' disease without overt manifestation

Soares

2002

Autonomic Neuroscience

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“…5 However, with the use of a passive postural stress test (tilt test), it was possible to demonstrate that patients with Chagas' disease had a compromised control of blood pressure, such as a decrease in systolic blood pressure and a blunted increase in diastolic blood pressure. 14,15 Regarding the control of heart rate, an impairment in heart rate control in Chagas' disease was demonstrated in other functional studies. 14,16,17 Besides the anatopathological demonstration of cardiac denervation, 4 a recent study that used cardiac scanning with 123 I-labeled metaiodobenzylguanidine has identified in vivo regional sympathetic denervation in patients with Chagas' disease.…”

Section: Discussionmentioning

confidence: 90%

Decreased Cardiopulmonary Baroreflex Sensitivity in Chagas’ Heart Disease

et al. 2000

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Abstract-No study has been performed on reflexes originating from receptors in the heart that might be involved in the pathological lesions of Chagas' heart disease.Our study was undertaken to analyze the role of cardiopulmonary reflex on cardiovascular control in Chagas' disease. We studied 14 patients with Chagas' disease without heart failure and 12 healthy matched volunteers. Central venous pressure, arterial blood pressure, heart rate, forearm blood flow, and forearm vascular resistance were recorded during deactivation of cardiopulmonary receptors. By reducing central venous pressure by applying Ϫ10 and Ϫ15 mm Hg of negative pressure to the lower body, we observed (a) a similar decrease of central venous pressure in both groups; (b) a marked increase in forearm vascular resistance in the control group but a blunted increase in the Chagas' group; and (c) no significant changes in blood pressure and heart rate. To analyze cardiopulmonary and arterial receptors, we applied Ϫ40 mm Hg of lower-body negative pressure. As a consequence, (a) central venous pressure decreased similarly in both groups; (b) blood pressure was maintained in the control group, whereas in patients with Chagas' disease, a decrease in systolic and mean arterial pressure occurred; (c) heart rate increased in both groups; and (d) forearm vascular resistance increased significantly and similarly in both groups. Unloading of receptors with low levels of lower-body negative pressure did not increase forearm vascular resistance in patients with Chagas' disease, which suggests that the reflex mediated by cardiopulmonary receptors is impaired in patients with Chagas' disease without heart failure. Overall control of circulation appears to be compromised because patients did not maintain blood pressure under high levels of lower-body negative pressure. (Hypertension. 2000;36:1035-1039.)

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“…Deficient chronotropic responses have been noted during both dynamic 57,72 and isometric 73 exercise in chagasics with heart disease. The inability to achieve adequate tachycardia and blood pressure stabilisation upon standing has also been demonstrated [74][75][76] . Depressed sensitivity of the baroreflex mechanism resulting in blunted bradycardia or tachycardia in response to acute elevation or reduction of arterial pressure has been observed 32,77 , as have altered baroreflex responses traduced by deficient heart rate responses during and after the Valsalva manoeuvre in chagasics with any form of the disease 8,33,36,78,79 .…”

Section: Disturbed Cardiovascular Homeostatic Neural Regulationmentioning

confidence: 99%

Insights into the clinical and functional significance of cardiac autonomic dysfunction in Chagas disease

Junqueira Junior

2012

Rev. Soc. Bras. Med. Trop.

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INTRODUCTION: Exclusive or associated lesions in various structures of the autonomic nervous system occur in the chronic forms of Chagas disease. In the indeterminate form, the lesions are absent or mild, whereas in the exclusive or combined heart and digestive disease forms, they are often more pronounced. Depending on their severity these lesions can result mainly in cardiac parasympathetic dysfunction but also in sympathetic dysfunction of variable degrees. Despite the key autonomic effect on cardiovascular functioning, the pathophysiological and clinical significance of the cardiac autonomic dysfunction in Chagas disease remains unknown. METHODS: Review of data on the cardiac autonomic dysfunction in Chagas disease and their potential consequences, and considerations supporting the possible relationship between this disturbance and general or cardiovascular clinical and functional adverse outcomes. RESULTS: We hypothesise that possible consequences that cardiac dysautonomia might variably occasion or predispose in Chagas disease include: transient or sustained arrhythmias, sudden cardiac death, adverse overall and cardiovascular prognosis with enhanced morbidity and mortality, an inability of the cardiovascular system to adjust to functional demands and/or respond to internal or external stimuli by adjusting heart rate and other hemodynamic variables, and immunomodulatory and cognitive disturbances. CONCLUSIONS: Impaired cardiac autonomic modulation in Chagas disease might not be a mere epiphenomenon without significance. Indirect evidences point for a likely important role of this alteration as a primary predisposing or triggering cause or mediator favouring the development of subtle or evident secondary cardiovascular functional disturbances and clinical consequences, and influencing adverse outcomes.

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Distinctive abnormal responses to tilting test in chronic chagas' disease

Cited by 24 publications

References 11 publications

Impaired autonomic control of heart interval changes to Valsalva manoeuvre in Chagas' disease without overt manifestation

Impaired autonomic control of heart interval changes to Valsalva manoeuvre in Chagas' disease without overt manifestation

Decreased Cardiopulmonary Baroreflex Sensitivity in Chagas’ Heart Disease

Insights into the clinical and functional significance of cardiac autonomic dysfunction in Chagas disease

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