Change of Heart Rate Variability and Baroreflex Sensitivity After Ventral Cardiac Denervation

2014-07-24 14:27:33 | BioPortfolio


Atrial fibrillation (Af) is the most common morbid event after open heart surgery. Its incidence ranges from 19% to 27%, as reported by the Society of Thoracic Surgeons database. Many groups have tried to understand and treat this difficult problem and have formulated different hypotheses to explain its origin. An imbalance of the autonomic nervous system after surgical intervention has been accepted as a major determinant for this morbidity. Ventral cardiac denervation is a fast and low-risk procedure. This intervention has shown significantly reduction of the incidence and severity of Af after routine coronary artery bypass surgery. This technique could be applied both on-pump or off-pump and used as an adjunctive procedure to achieve Af prophylaxsis. However, the detailed mechanism remains unclear. Theoretically, heart receives its innervation from the autonomic nervous system (ANS) via the great vessels and pericardial attachment. The propensity and distribution of ANS nerve fibers are different in location. In this study, we would like to evaluate the ANS function after ventral cardiac denervation by using heart rate variability (HRV) and baroreflex (BRS) sensitivity. 30 patients proposed to have elective off-pump coronary artery bypass surgery are enrolled. After induction of anesthesia, the depth of anesthesia is controlled by inhalation agents and monitored by bispectral index. After the major cardiac operation, ventral cardiac denervation is performed by using electrocautery. The digital signals of heart rate and blood pressure are acquired before and after the surgical procedures under the same range of bispectral index (50~60). The paired HRV and BRS are analyzed. This will provide us more information to justify the procedure.


Coronary artery bypass and ventral cardiac denervation:

Off-pump coronary artery bypass (OPCAB) is performed based on patient's coronary angiography. Following the completion of coronary anastomoses, ventral cardiac denervation is achieved by removing the nerves around the large vessels of the base of the heart that run from the right side of the superior vena cava and end at the level of the midportion of the anterior pulmonary artery. This was done by excising the fat pads that surround the superior vena cava, the aorta, and the anterior and right lateral aspects of the main pulmonary artery.

Hemodynamic study:

All patients underwent OPCAB have Swan-Ganz catheter in our institute. Cardiac output measurement is obtained by thermodilution method. Hemodynamic variables (systemic blood pressure, pulmonary artery pressure, central venous pressure, pulmonary capillary wedge pressure, systemic vascular resistance, and pulmonary vascular resistance, etc) are recorded during the measurement.

ECG and blood pressure monitoring system:

ECG and radial arterial blood pressure were recorded by an analog to digital converter system (National Instrument Inc.). The ananlog signals were digitized in a rate of 500Hz and were stored in a hard disk. The data were then analyzed by a program written with MATLAB language (version 5.2, Mathwork Co.). QRS complexes were automatically classified and manually verified as normal sinus rhythm, arterial or ventricular premature beats, or noise by comparison of the adjacent QRS morphologic features. The N-N interval time series were then transferred to a personal computer and post-processed.

Data acquisitions:

Immediately after induction of anesthesia, the patient was intubated. Routine indwelling catheters, like CVP and SG catheter were inserted. Prior to skin incision, the depth of anesthesia was monitored by BIS system using bispectral index (60~70) and adjusted by inhalation agents. Digital ECG and BP signals were recorded for 15 min without any mechanical or pharmacological interference. After completion of surgical procedures, the data acquisition was repeated once again in the operation room under the same level of anesthesia.

Baroreflex sensitivity analysis:

The analysis of BRS was conducted by both the sequence method and the spectral (α-index) method. Sequence method: In brief, the beat-by-beat time series of systolic arterial blood pressure and ECG R-R intervals were scanned to identify sequences of over three consecutive beats in which the systolic blood pressure (SBP) and R-R intervals of the next beat changed concomitantly in increasing or decreasing sequence. Such beat-to-beat sequences were identified as baroreflex sequences. A linear regression was applied to the individual sequence and only r2 values >0.85 were accepted. The measure of each type of the integrated spontaneous BRS was obtained by averaging all accepted slopes of the same type during a 5-minute recording. Spectral (α-index) method: The α-index (α) was obtained by means of the simultaneous spectral analysis of the R-R intervals and the SBP variabilities, with the calculation being made from the square root of the ratio between the R-R intervals and the SBP variability in low frequency (LF) band (αLF, 0.04 to 0.15 Hz). The coherence between the R-R intervals and SBP was assessed by a cross-spectral analysis. The α-index was calculated only when the magnitude of squared coherence (K2) between the RR and the SBP signals exceed 0.5 in LF band.

Heart rate variability analysis:

The missing intervals of the raw N-N data were linearly interpolated and resampled at 4 Hz by the Ron-Berger method. Each 5-minute segment of N-N intervals was taken for HRV analysis. The time domain measurements of HRV included SDNN, r-MSSD. The frequency-domain measurements of HRV included LF and HF, which were calculated by Welch's averaged periodogram of the N-N intervals.

Study Design

Allocation: Randomized, Control: Placebo Control, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Parallel Assignment, Masking: Open Label, Primary Purpose: Treatment


Atrial Fibrillation


ventral cardiac denervation


Not yet recruiting


Far Eastern Memorial Hospital

Results (where available)

View Results


Published on BioPortfolio: 2014-07-24T14:27:33-0400

Clinical Trials [1638 Associated Clinical Trials listed on BioPortfolio]

Prevention of AtriaL Fibrillation After Cardiac Surgery

The purpose of this study is to determine if preforming a posterior left pericardiotomy prevents atrial fibrillation after cardiac surgery.

Renal Denervation Therapy in Hypertensive Patients Undergoing A-Fib Ablation

We propose a pilot study to assess safety and benefit of renal artery ablation at the time of planned atrial fibrillation ablation.

Treatment of Atrial Fibrillation in Patients by Pulmonary Vein Isolation, Renal Artery Denervation or Both.

Prospective, randomized, controlled, multicenter, international clinical trial. The study population consist of patients with paroxysmal or persistent atrial fibrillation with out range hy...

Comparison of Effectiveness of Ranolazine Plus Metoprolol Combination vs. FlecainidE pluS Metoprolol Combination in ATrial Fibrillation Recurrences FOllowing PhaRmacological or Electrical CardioverSion of AtRial Fibrillation

Atrial fibrillation (AF) is the most common arrhythmia in clinical practice with a prevalence reaching 5% in patients older than 65 years and an incidence that increases progressively with...

D-dimer In Patients With atRial Fibrillation rEceiving antiCoagulation Therapy

This is a sigle-center, prospective study to evaluate the role of D-Dimer testing in patients with atrial fibrillation receiving Dabigatran or warfarin anticoagulation therapy.

PubMed Articles [4761 Associated PubMed Articles listed on BioPortfolio]

Preventing Postoperative Atrial Fibrillation after Non-Cardiac Surgery: a Meta-Analysis.

Although post-operative atrial fibrillation is common after non-cardiac surgery, there is a paucity of data regarding prophylaxis. We sought to determine if pharmacologic prophylaxis reduces the incid...

The Role and Outcome of Cardiac Rehabilitation Program in Patients with Atrial Fibrillation.

Atrial fibrillation (AF) is associated with diminished cardiac function, and exercise tolerance.

Is atrial fibrillation a risk factor for in-hospital cardiac arrest?: a Swedish retrospective cohort study.

Atrial fibrillation (AF) is associated with increased morbidity and mortality. Recent findings suggest that AF is also associated with out-of-hospital cardiac arrest. However, whether that association...

Cardiac telocytes. From basic science to cardiac diseases. I. Atrial fibrillation.

Atrial fibrillation (AF) is nowadays considered to be one of the most important causes of heart failure, stroke, cognitive decline, vascular dementia, sudden death and overall cardiovascular morbidity...

Physician decision making in anticoagulating atrial fibrillation: a prospective survey of a physician notification system for atrial fibrillation detected on cardiac implantable electronic devices of patients at increased risk of stroke.

The objectives of this study were to evaluate the effectiveness of a physician notification system for atrial fibrillation (AF) detected on cardiac devices, and to assess predictors of anticoagulation...

Medical and Biotech [MESH] Definitions

Rapid, irregular atrial contractions caused by a block of electrical impulse conduction in the right atrium and a reentrant wave front traveling up the inter-atrial septum and down the right atrial free wall or vice versa. Unlike ATRIAL FIBRILLATION which is caused by abnormal impulse generation, typical atrial flutter is caused by abnormal impulse conduction. As in atrial fibrillation, patients with atrial flutter cannot effectively pump blood into the lower chambers of the heart (HEART VENTRICLES).

A potentially lethal cardiac arrhythmia that is characterized by uncoordinated extremely rapid firing of electrical impulses (400-600/min) in HEART VENTRICLES. Such asynchronous ventricular quivering or fibrillation prevents any effective cardiac output and results in unconsciousness (SYNCOPE). It is one of the major electrocardiographic patterns seen with CARDIAC ARREST.

Long-term changes in the electrophysiological parameters and/or anatomical structures of the HEART ATRIA that result from prolonged changes in atrial rate, often associated with ATRIAL FIBRILLATION or long periods of intense EXERCISE.

A cardiotonic glycoside obtained mainly from Digitalis lanata; it consists of three sugars and the aglycone DIGOXIGENIN. Digoxin has positive inotropic and negative chronotropic activity. It is used to control ventricular rate in ATRIAL FIBRILLATION and in the management of congestive heart failure with atrial fibrillation. Its use in congestive heart failure and sinus rhythm is less certain. The margin between toxic and therapeutic doses is small. (From Martindale, The Extra Pharmacopoeia, 30th ed, p666)

Abnormal cardiac rhythm that is characterized by rapid, uncoordinated firing of electrical impulses in the upper chambers of the heart (HEART ATRIA). In such case, blood cannot be effectively pumped into the lower chambers of the heart (HEART VENTRICLES). It is caused by abnormal impulse generation.

More From BioPortfolio on "Change of Heart Rate Variability and Baroreflex Sensitivity After Ventral Cardiac Denervation"

Quick Search


Relevant Topics

Cardiovascular disease (CVD)
Acute Coronary Syndromes (ACS) Blood Cardiovascular Dialysis Hypertension Stent Stroke Vascular Cardiovascular disease (CVD) includes all the diseases of the heart and circulation including coronary heart disease (angina...

Cardiology is a specialty of internal medicine.  Cardiac electrophysiology : Study of the electrical properties and conduction diseases of the heart. Echocardiography : The use of ultrasound to study the mechanical function/physics of the h...

Searches Linking to this Trial