Heart rate variability in dilated cardiomyopathy

Area of Science:

• Cardiology
• Autonomic Nervous System Research
• Medical Diagnostics

Background:

• Chronic heart failure (CHF) is characterized by excessive neurohormonal activation.
• Heart rate variability (HRV) analysis is a validated method for assessing cardiac autonomic balance.
• Dilated cardiomyopathy (DCM) is a common form of CHF often associated with autonomic dysfunction.

Purpose of the Study:

• To investigate heart rate variability parameters in symptomatic patients with dilated cardiomyopathy.
• To compare HRV in DCM patients with healthy controls.
• To explore the correlation between HRV and clinical parameters like ejection fraction and NYHA class.

Main Methods:

• 24-hour Holter monitoring was performed on 20 DCM patients (NYHA class II-IV) and 20 controls.
• Time-domain (SDNN, 5-min SD, RMSSD) and frequency-domain (LF, HF, Total Power) HRV analyses were conducted.
• Ejection fraction and NYHA class were recorded for correlation analysis.

Main Results:

• DCM patients exhibited significantly higher mean heart rate and lower mean hourly heart rate standard deviation compared to controls.
• Key HRV parameters, including SDNN, 5-min SD, and low-frequency power, were significantly reduced in DCM patients.
• Reduced HRV parameters correlated significantly with decreased ejection fraction and increased NYHA class.

Conclusions:

• Symptomatic dilated cardiomyopathy patients demonstrate significantly impaired heart rate variability compared to healthy individuals.
• HRV parameters are valuable indicators of autonomic imbalance in DCM.
• HRV analysis can aid in assessing disease severity and potentially predicting outcomes in DCM patients.