Heart rate variability and functional severity of congestive heart failure secondary to coronary artery disease
G C Casolo1, P Stroder, A Sulla
1Cardiology Unit, Ospedale San Giovanni di Dio, Florence, Italy.
Insights
Heart failure (CHF) significantly reduces heart rate variability (HRV), impacting cardiac health. As CHF severity increases, heart rate rises while HRV declines, especially in advanced stages.
Area of Science:
- Cardiology
- Physiology
- Medical Diagnostics
Background:
- Heart rate variability (HRV) is a crucial indicator of cardiac autonomic function.
- Coronary artery disease (CAD) and congestive heart failure (CHF) are major cardiovascular conditions affecting HRV.
- Understanding HRV changes across different CHF severities is vital for patient management.
Purpose of the Study:
- To examine the relationship between advancing heart failure severity and heart rate variability.
- To differentiate the impact of CHF from CAD on HRV parameters.
- To assess HRV changes across New York Heart Association (NYHA) functional classifications.
Main Methods:
- Studied 20 healthy controls and 80 CAD patients categorized into four NYHA functional classes.
- Recorded 24-hour ECG Holter tapes for each participant.
- Analyzed heart rate (HR) and HRV using spectral and non-spectral time-domain measures, including R-R interval distribution width.
Main Results:
- CAD patients exhibited lower HRV than controls, primarily due to CHF, not CAD itself.
- A progressive increase in heart rate and a significant decrease in HRV were observed with increasing CHF severity (NYHA class).
- NYHA Class IV patients showed minimal HR variation and barely detectable spectral components; spectral power reduced significantly from Class I to II.
Conclusions:
- Advancing heart failure severity is strongly associated with reduced heart rate variability.
- HRV serves as a sensitive marker for the progression of heart failure.
- Time-domain and spectral HRV measures demonstrate progressive decline with increasing NYHA class.
Abstract:
To investigate the behaviour of heart rate variability (HRV) with the advancing severity of heart failure (CHF) we studied 20 normal subjects and 80 coronary artery disease (CAD) patients in sinus rhythm. CAD patients were selected consecutively in order to form four equal groups of 20 subjects with different degrees of CHF according to the New York Heart Association (NYHA) functional classification. In each subject a 24 h ECG Holter tape was recorded and subsequently analysed to obtain measures of heart rate and HRV. We used several measures of HR and both spectral and non-spectral measures of HRV. Among these we employed the width of the R-R interval distribution over 24 h at three different heights (TV, 10%Var, 50%Var). The CAD group showed significantly lower HRV counts and smaller spectral components than controls. However, these differences were due to the presence of CHF rather than to CAD. Indeed, a progressive and significant increase in heart rate and a contemporary decrease in HRV was observed with the advancing severity of CHF. Class IV patients had the smallest HR variation; the spectral composition in this group was barely detectable. The decrease in time domain measures of HRV followed the increase in NYHA Class in a progressive and regular pattern, while the low frequency and high frequency spectral power showed the largest reduction from NYHA Class I to NYHA Class II patients. No significant change was demonstrated in NYHA Class I patients as compared to Controls.(ABSTRACT TRUNCATED AT 250 WORDS)
More Related Videos
08:12Calculating Heart Rate Variability from ECG Data from Youth with Cerebral Palsy During Active Video Game Sessions
Published on: June 5, 2019
07:49Author Spotlight: Investigating HR-Dependent Cardiac Function in Mouse Models Through a Novel Atrial-Pacing Approach
Published on: July 21, 2023
Related Concept Videos
01:30Factors Influencing Heart Rate
Let us explore the significant factors affecting heart rate, including age, body temperature, posture, acute pain, chemical influences,...
01:17Pathophysiology of Heart Failure
01:29Heart Failure II: Pathophysiology
01:26Heart Failure III: Clinical Manifestations
01:30Heart Failure IV: Classification and Diagnostic Evaluation
01:30Cardiomyopathy II: Dilated Cardiomyopathy