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Association between myocardial mechanical dispersion and ventricular arrhythmogenicity in chagas cardiomyopathy

A C A Azevedo1, M V L Barros1,2, L G Klaboe3

  • 1Department of Internal Medicine, School of Medicine of the Federal University of Minas Gerais. Av. Professor Alfredo Balena, 190, Santa Efigênia, Belo Horizonte, MG, 30130 100, Brazil.

The International Journal of Cardiovascular Imaging
|April 21, 2021
PubMed

Insights

Myocardial mechanical dispersion (MD) is linked to increased ventricular arrhythmias, including ventricular extrasystoles and non-sustained ventricular tachycardias, in Chagas cardiomyopathy patients. Higher MD indicates greater arrhythmogenicity and worse prognosis in this population.

Area of Science:

  • Cardiology
  • Medical Imaging
  • Electrophysiology

Background:

  • Chagas disease poses a significant health burden in Latin America.
  • Ventricular arrhythmia (VA) is a critical indicator of poor prognosis in Chagas cardiomyopathy (CCM).
  • Understanding the mechanisms underlying VA in CCM is crucial for risk stratification and management.

Purpose of the Study:

  • To investigate the association between myocardial mechanical dispersion (MD) and ventricular arrhythmogenicity in patients with Chagas cardiomyopathy.
  • To determine if MD can predict the presence and complexity of ventricular arrhythmias in CCM.
  • To explore the relationship between MD, global longitudinal strain (GLS), and non-sustained ventricular tachycardias (NSVT) in CCM.

Main Methods:

  • A cross-sectional study involving 77 patients diagnosed with Chagas cardiomyopathy.
  • Echocardiography with speckle tracking was used to assess global longitudinal strain (GLS) and myocardial mechanical dispersion (MD).
  • MD was quantified by measuring the time from QRS onset to peak longitudinal strain in 16 left ventricular segments; ventricular extrasystoles (VES) and NSVT were assessed via dynamic electrocardiography.

Main Results:

  • Increased MD correlated with higher frequency and complexity of ventricular extrasystoles (VES) and the presence of non-sustained ventricular tachycardias (NSVT).
  • Myocardial mechanical dispersion (MD) was the sole predictor for paired VES and ventricular bigeminy.
  • Both MD and GLS were associated with NSVT, with MD independently predicting NSVT (OR 1.04, p=0.031).

Conclusions:

  • Myocardial mechanical dispersion (MD) is significantly associated with increased ventricular arrhythmogenicity in Chagas cardiomyopathy.
  • MD serves as a valuable marker for predicting ventricular extrasystoles and non-sustained ventricular tachycardias in CCM patients.
  • These findings highlight MD's potential role in risk stratification and guiding therapeutic strategies for CCM.

Keywords:
ArrhythmiaChagas diseaseChronic chagas cardiomyopathyMechanical myocardial dispersionTwo-dimensional strain

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