Respiratory sinus arrhythmia in Chagas disease

Area of Science:

• Cardiology
• Autonomic Nervous System Research
• Parasitic Diseases

Background:

• Chagas disease (ChD) is a parasitic infection with potential cardiac complications.
• Autonomic dysfunction, particularly involving the vagal nerve, is increasingly recognized in ChD.
• Respiratory sinus arrhythmia (RSA) is a non-invasive measure of cardiac vagal modulation.

Purpose of the Study:

• To investigate RSA in Chagas disease patients with and without left ventricular dysfunction (LVD).
• To assess the correlation between RSA and other heart rate variability (HRV) measures of vagal activity in ChD.
• To determine if RSA serves as a marker of vagal modulation in Chagas disease.

Main Methods:

• Applied a respiratory sinus arrhythmia (RSA) quantification algorithm.
• Analyzed 24-hour electrocardiogram (ECG) recordings.
• Compared RSA index values across three groups: Chagas disease with LVD (G1), Chagas disease without LVD (G2), and control subjects (G0).

Main Results:

• Both Chagas disease groups (G1 and G2) exhibited a significantly reduced RSA index compared to controls (though controls were not explicitly compared in the abstract, this is implied by the reduction in ChD groups).
• The RSA index in G1 was 299 (144-812) and in G2 was 335 (162-667).
• The reduced RSA index in ChD patients was correlated with established vagal indexes from heart rate variability analysis.

Conclusions:

• The RSA index is significantly reduced in Chagas disease patients, irrespective of left ventricular dysfunction.
• RSA serves as a valuable marker reflecting impaired vagal modulation in Chagas disease.
• These findings underscore the impact of Chagas disease on the autonomic nervous system.