V-Shaped Trough in Autonomic Activity Is a Possible Precursor of Life-Threatening Cardiac Events

Abstract

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. (Circ J 2010; 74: 1906 - 1915

Customized Heart Check System by Using Integrated Information of Electrocardiogram and Plethysmogram Outside the Driver’s Awareness from an Automobile Steering Wheel

“…Our system will open doors to new strategies to minimize driver's risk by making available the relevant data during the actual process of driving. We reported that a V-shaped trough in autonomic activity is a possible precursor of life-threatening cardiac events (Osaka et al, 2010). The V-trough including the small variations that precede it spans approximately 190 minutes.…”

“…We aimed at finding a consistent precursor of a lethal cardiac event by examining Holter recordings in which such a spontaneous event was recorded. Holter recordings of 34 patients experiencing a cardiac event (Event-group, 20 deaths) were compared with 191 controls (NoEvent-group) (Osaka et al, 2010). The Event-group included 25 patients with ventricular fibrillation or acute myocardial infarction, and 9 with cardiac arrest due to complete atrioventricular block.…”

Sudden Cardiac Death Thirty Years Ago and at Present. The Role of Autonomic Disturbances in Acute Myocardial Infarction Revisited

“…Neuroautonomic changes were assessed by the authors using spectral analysis of R-R intervals obtained from Holter electrocardiograms. A sudden switch from parasympathetic activation into sympathetic activation resulted in AMI or VF in 22 of 34 patients whereas nine patients developed AV block during a switch from sympathetic to parasympathetic activation (Osaka et al 2010).…”

Sudden Cardiac Death from the Perspective of Nonlinear Dynamics

“…The V-trough was marked by a small variation lasting 2 hours, an abrupt descent lasting 30 minutes, and a sharp ascent for 40 minutes. The criteria for a V-trough were defined mathematically to automatically determine if a V-trough has occured 23 . The sensitivity and specificity of an LF/HF Vtrough for predicting ventricular fibrillation are 87% and 95%, respectively.…”