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Published on: December 22, 2023
V-shaped trough in autonomic activity is a possible precursor of life-threatening cardiac events
Motohisa Osaka1, Eiichi Watanabe, Hiroshige Murata
1Department of Basic Science, Nippon Veterinary and Life Science University, Tokyo, Japan. osaka@nms.ac.jp
Insights
A novel V-trough pattern in heart rate variability (HRV) may predict sudden cardiac death. This autonomic activity marker, observed before lethal events, offers a potential precursor for cardiac events like ventricular fibrillation or atrioventricular block.
Area of Science:
- Cardiology
- Autonomic Nervous System Research
- Biomedical Signal Processing
Background:
- Sudden cardiac death (SCD) lacks reliable predictors.
- Understanding autonomic activity's role in SCD is crucial.
Purpose of the Study:
- To identify potential precursors of sudden cardiac death.
- To investigate heart rate variability (HRV) patterns preceding cardiac events.
Main Methods:
- Compared Holter ECGs of 34 patients with cardiac events to 191 controls.
- Analyzed HRV parameters, including low-frequency (LF), high-frequency (HF) components, and their ratio (LF/HF).
- Identified V-shaped troughs (sV-trough for LF/HF, pV-trough for HF) in HRV patterns.
Main Results:
- A V-trough pattern preceded cardiac events in 31 of 34 patients.
- An sV-trough predicted ventricular fibrillation or acute myocardial infarction (AMI) with 88% accuracy.
- A pV-trough predicted complete atrioventricular block with 100% accuracy.
Conclusions:
- A novel V-trough in autonomic activity is a potential precursor for lethal cardiac events.
- This finding may lead to improved prediction and prevention strategies for sudden cardiac death.
Background:
No reliable precursor of sudden cardiac death is known.
Methods And Results:
Holter electrocardiograms of 34 patients experiencing a cardiac event (event group, 20 deaths) were compared with 191 controls (no event group). The event group included 25 patients with ventricular fibrillation or acute myocardial infarction (AMI), and 9 with cardiac arrest due to complete atrioventricular block. The logarithms were calculated of the moving average of 5 successive values for the low-frequency component (LF), the high-frequency component (HF), and the ratio LF/HF of heart rate variability: ln(LF), ln(HF) and ln(LF/HF). A V-shaped trough appeared in the curve of ln(LF/HF) [sV-trough] or ln(HF) [pV-trough] before such an event in 31 patients in the event group. The V-trough was marked by a small variation lasting 2 h, an abrupt descent lasting 30 min, and a sharp ascent for 40 min. An sV-trough was observed in 22 patients before the onset of ventricular fibrillation or AMI. A pV-trough was observed in all 9 patients before the onset of complete atrioventricular block. In the no event group, an sV-trough and a pV-trough were observed in 10 subjects (5%) and 20 subjects (10%), respectively. The positive predictive accuracy of an sV-trough for ventricular fibrillation or AMI and that of a pV-trough for complete atrioventricular block was 88% and 100%, respectively.
Conclusions:
A previously unidentified V-trough of autonomic activity is a potential precursor of lethal events.
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