Relationship between Urinary Norepinephrine, Fibrosis, and Arrhythmias in Chronic Chagas Heart Disease with Preserved...

Area of Science:

• Cardiology
• Electrophysiology
• Cardiac Imaging

Background:

• Chronic Chagas Cardiomyopathy (CCC) requires identification of arrhythmogenic risk factors, especially in patients without moderate to severe ventricular dysfunction.
• Understanding these factors is crucial for managing sudden cardiac death risk in early-stage CCC.

Purpose of the Study:

• To investigate the correlation between frequent premature ventricular contractions (PVCs), left ventricular ejection fraction (LVEF), myocardial fibrosis extent (via Cardiac Magnetic Resonance - CMR), and urinary norepinephrine (NOREPI) in CCC patients with preserved or mildly reduced LVEF.
• To assess the predictive ability of these variables in early-stage CCC.

Main Methods:

• Prospective study including 59 CCC patients.
• Holter monitoring for PVCs (>30/h), CMR for LVEF and fibrosis quantification, and urinary NOREPI measurement (Muskiet method).
• Correlation coefficient matrix analysis was used to determine relationships between variables (p < 0.05 significance).

Main Results:

• Fibrosis was inversely proportional to LVEF (R=-0.61) and NOREPI (R=-0.68).
• PVCs were inversely proportional to LVEF (R=-0.33) and NOREPI (R=-0.27).
• LVEF showed a direct positive correlation with NOREPI (R=0.83).

Conclusions:

• In CCC patients with preserved/mildly reduced LVEF, autonomic nervous system integrity correlates with less myocardial fibrosis and higher LVEF.
• A significant correlation exists between NOREPI levels, LVEF, and myocardial fibrosis.
• However, PVCs were not found to be correlated with these parameters in this specific patient subgroup.