Cardiovascular Health & Nutrition
BIOMARKERS
Frequency Domain
Bandwidths vary with population age and norms
VLF Power – (Very low frequency 0.0 – 0.04 hz)
LF Power – (Low frequency 0.04 – 0.15hz)
VHF Power – (Very high frequency 0.4 – 3.0hz)
HF/RSA Power – (High frequency/Respiratory sinus arrhythmia ratio)
LF/HF Ratio – (Low frequency/High frequency ratio)
RSA – (Respiratory sinus arrhythmia)
Time Domain
RR – peak to peak interval
NN – peak to peak interval
SDNN – (Standard deviation of the RR (NN) intervals)
AVNN – (The average of all RR (NN) intervals)
RMSSD – (Square root of the mean squared differences between successive RR (NN) intervals)
NN50 – (The number of RR (NN) intervals which differ by more than 50ms from the previous interval)
pNN50 – (NN50 divided by the total number of RR (NN) intervals)
BP Stats
MEAN SYSTOLIC
MEAN DIASTOLIC
MEAN MAP – (Mean arterial pressure)
MEAN IBI – (Mean inter beat interval)
HR – (Heart rate)
RSA – (Repiratory sinus arrhythmia)
#BRS SERIES – (Number of baroreceptor series)
AVG BRS – (Average length of the series)
HR Power Stats
VLF, LF, HF/RSA, and LF/HF ratio
BP Power Stats
VLF, LF, HF/RSA, and LF/HF ratio
EQUIPMENT
The MindWare Cardio Mobile Ambulatory Impedance Cardiograph has the same features of the MW1000A, but also the following improvements:
– High performance and small form factor
– Collects EKG, GSC, EMG, Z0, dZ/dT and respiratory signals
– Local-mode recording to SD card
– Real time multi-unit synchronized wireless data transmission
– Native 24 hour run time capability
– Built in 3-axis accelerometer
– Simple electrode wire interface
– Built-in subject response buttons for event marking
The continuous noninvasive blood pressure system employs a double finger cuff that is comfortable for the subject to wear and easy to place on the hand. The system outputs a continuous noninvasive blood pressure waveform that is similar to a direct arterial blood pressure waveform and displays values for systolic, diastolic, mean blood pressure, and heart rate.
The MP150 system is a complete and expandable data acquisition system that functions like an on-screen chart recorder, oscilloscope and X/Y plotter, allowing you to record, view, save and print data. It includes all the necessary hardware and software required to turn any computer into a powerful data acquisition workstation specifically designed for life science applications.
This product was designed to be the workhorse of most laboratories. It contains 8 user configurable slots providing up to 32 channels of custom signal conditioning. These slots can be configured using any combination of the six available BioNex modules. It also supports high speed data acquisition, simultaneous digital input / output, stimulus generation, and flexible triggering options.
CLINICAL SIGNIFICANCE
HEART RATE VARIABILITY (HRV)
HRV is the physiological phenomenon of variation in the time interval between heart beats (HP). It is measured by the variation in the beat to beat intervals. We call this the Time Domain. A healthy heart rate variability is reflected by lots of variation in the time domain between successive heart beats. This would indicate a very robust autonomic nervous system. Someone with less variation between one heart beat to the next has low heart rate variability and indicates decreased autonomic nervous system regulation. The importance of Heart Rate Variability is that it is controlled by the autonomic nervous system and therefore is a window into its function.
The second component of Heart Rate Variability besides the time domain is the spectral analysis. The ECG is broken down into very specific frequency band widths that correspond to specific functions. Low frequency, for example, has to do with the Sympathetic nervous system and high frequency has to do with Parasympathetic nervous system function.
LF/HF ratio: the relative power of the LF and HF components (the LF/HF ratio) might provide an accurate index of sympathovagal balance.
VLF activity is associated with the thermoregulation of vasomotor tone and with the rennin– angiotensin–aldosterone system.
VHF: the spectral power of VHF of HRV is a reliable evaluation index of cardiovascular diseases, such as chronic heart failure and coronary artery disease.
LF activity is associated with the intrinsic oscillations of the baroreceptor reflex (i.e. blood pressure fluctuations). HRV components in the low-frequency (LF) range are mediated via both sympathetic and parasympathetic systems.
HF activity is associated with heart rate modulation via the influence of respiration. The high-frequency (HF) components of the HRV signal are mediated via the parasympathetic system. (C ardiac vagal modulation)
Respiratory sinus arrhythmia (RSA) is a naturally occurring variation in heart rate that occurs during a breathing cycle. RSA is also a measure of parasympathetic nervous system activity – which denotes “rest and digest” behaviors.
Vagal tone is an internal biological process referring to the activity of the vagus nerve, the tenth cranial nerve located in the medulla oblongata of the brainstem. The vagus nerve serves as the key component of the parasympathetic branch of the autonomic nervous system, regulating the homeostasis (or “resting state”) of the majority of the body’s internal organ systems that operate on a largely subconscious level, such as the heart, lungs, eyes, adrenal glands, and digestive tract. Due to the regulatory nature of the PNS, vagal activity is continuous, chronic, and passive (“tone” in this usage is analogous to “tension”).
BLOOD PRESSURE VARIABILITY (BPV)
An essential part of each health screening is the examination of the cardiovascular system since a major cause of death is due to coronary artery disease. High blood pressure is a major risk factor for heart disease and also for a number of other diseases, such as stroke, kidney failure, etc. Not only adults but also children benefit from blood pressure screenings. Standard blood pressure devices record data only from one single beat, so short term disturbances in hemodynamics cannot be tracked.
The baroreflex or baroreceptor reflex is one of the body’s homeostatic mechanisms for maintaining blood pressure. It provides a negative feedback loop in which an elevated blood pressure reflexively causes heart rate and thus blood pressure to decrease; similarly, decreased blood pressure depresses the baroreflex, causing heart rate and thus blood pressure to rise. The system relies on specialized neurons, known as baroreceptors, in the aortic arch, carotid sinuses, and elsewhere to monitor changes in blood pressure and relay them to the brainstem. Subsequent changes in blood pressure are mediated by the autonomic nervous system. Atrial natriuretic peptide forms a parallel negative feedback loop in an endocrinological contrast to the renin-angiotensin system.
BIOMARKERS
PEP – Pre-Ejection
LVET – Left Ventricular Ejection Time
PEP/LVET – Systolic Time Ratio
PEP + LVET – Electromechanical Systole
Stoke Volume
Cardiac Output
Heart Rate
Derived Measures
CAB – Cardiac Autonomic Balance
CAR – Cardiac Autonomic Regulation
EQUIPMENT
The MindWare Cardio Mobile Ambulatory Impedance Cardiograph has the same features of the MW1000A, but also the following improvements
– High performance and small form factor
– Collects EKG, GSC, EMG, Z0, dZ/dT and respiratory signals
– Local-mode recording to SD card
– Real time multi-unit synchronized wireless data transmission
– Native 24 hour run time capability
– Built in 3-axis accelerometer
– Simple electrode wire interface
– Built-in subject response buttons for event marking
CLINICAL SIGNIFICANCE
Cardiovascular research and the ability to monitor: Mental Workload, Parasympathetic & Sympathetic Measures, Respiration, Motion and Muscle Activity. There is a wide range of studies that use Impedance cardiography including: Psychophysiology, Stress & Health, Behavior, Children to Gerontology, Performance, Pschology and more.
Stoke volume can be used to determine Cardiac Output and if Continuous BP is also collected then, TPR (total peripheral resisitance) can be calculated.
PEP is an index of Sympathetic Cardiac Control.
CAB is a significant predictor of diabetes.
CAR is a significant predictor of MI.
BIOMARKERS
Total Weight
Fat Mass
Fat-Free Mass
Resting Metabolic Rate
Total Energy Expenditure
Thoracic Gas Volume
Hemoglobin A1c
Pulse Wave Analysis
Adiponectin
Vitamin D
C-Reactive Protein
Homocysteine
Insulin
Adiponectin
Interleukin-1
Interleukin-6
Interleukin-10
Leptin
Resistin
Tumor Necrosis Factor (TNF-a)[/column]
EQUIPMENT
The BOD POD Gold Standard Body Composition Tracking System is an air displacement plethysmograph which uses whole-body densitometry to determine body composition (fat and fat-free mass) in adults and children, and can accommodate a wide range of populations. A full test requires only about 5 minutes, and provides highly accurate, safe, comfortable, and fast test results. Each BOD POD Gold Standard is a complete turnkey system with a dedicated computer system, the ability to measure thoracic gas volume (TGV), and data management capabilities.
The Lange Skinfold Caliper is manufactured by Beta Technology Inc. and has been produced since 1962, and is widely used in schools, colleges and fitness centers. For many professionals it is the definitive instrument for measuring skinfold thickness. This device is sturdy yet lightweight, made out of metal with an anticorrosive coating and comes with an attractive case.These calipers feature spring-loaded arms providing a constant standard pressure of 10 gm./sq.mm. over the operating range. Another feature of these calipers are floating (pivoted) tips that can adjust to enable parallel measurement of skinfolds. The face area is approximately 30 square mm. An easy-to-read scale permits reading up to 60 mm. Accurate to +/- 1 mm.
CLINICAL SIGNIFICANCE
Bodpod is a highly reliable and valid method for determining %FAT in adult humans in comparison to hydrostatic weighing (HW). This new method has several advantages over (HW) in that it is quick, relatively simple to operate and may be able to accomodate special populations such as the obese, elderly and disabled.
Diabetes Mellitus is a group of metabolic diseases associated with high levels of blood glucose, resulting from defects in insulin secretion, insulin action or both. It is associated with long-term complications that affect almost every part of the body including the heart, cardiovascular system and the kidneys. It is associated with a higher risk of chronic kidney disease, stroke, blindness, nerve damage, amputations, dental disease and complications during pregnancy.
The Sphygmocor pulse wave analysis system has been shown to be a highly reproducible measurement for assessment of endothelial function.
The role of Obesity in Vitamin D status has become increasingly important and has been found to be associated with lower serum concentrations of Vitamin D.
BIOMARKERS
Aortic
Systolic Pressure
Diastolic Pressure
Mean Pressure
Pulse Pressure
Brachial
Systolic Pressure
Diastolic Pressure
Mean Pressure
Pulse Pressure
PWV in (meters/sec)
Augmentation Pressure (AP)
Augmentation Index (AIx)
EQUIPMENT
The SphygmoCor system family of products provides tools for non-invasive assessment of the cardiovascular system function, focused on central blood pressures, measures of arterial stiffness and autonomic function. The technology that powers these products is centered on an algorithm that derives the pressure wave at the ascending aorta from an external measurement taken at the radial artery. The SphygmoCor system allows non-invasive measurement of the pressure the heart, brain and kidneys actually experience.
CLINICAL SIGNIFICANCE
The SphygmoCor system is a non-invasive tool for measuring central arterial pressure and indices that characterize the central pressure waveform. Assessment of the central pressure waveform provides individual-specific information regarding arterial stiffness and the effects of the reflected pressure wave on left ventricular load, myocardial perfusion and ventricular-vascular coupling.
Central pressure is more predictive of outcome than brachial pressure. Aortic PWV has been shown to be a significant and independent marker of the risk of cardiovascular disease, including coronary artery disease, congestive heart failure and fatal stroke.
BIOMARKERS
Thiobarbituric Acid-Reactive Substances (TBARS)
Glutathione (GSH)
Glutathione peroxidase (GPX)
Catalase
Isoprostanes
Superoxide Dismutase (SOD)
Muscle Mass
Strength
Basal Metabolic Rate
Body Fat Percentage
Aerobic Capacity
Glucose Tolerance
Total Cholesterol /HDL Ratio
Blood Pressure
Bone Density
Temperature Regulation
EQUIPMENT
The Actical’s small size, waterproof case, and ability to be worn in multiple locations makes it easy for subjects to wear regardless of their activity. The device is positioned securely on the subject using a wristband, waistband, or ankle band. Once the device is on, subjects can wear it and forget it and go about their normal daily activities, including rigorous exercise, swimming or bathing. There is no need to worry about subjects repositioning, damaging, or removing the device. Now with 32MB of on board memory, and high speed sampling capabilities, the Actical system makes monitoring physical activity for days or weeks a practical reality. Powerful, fast, and flexible, Actical helps you collect valuable physical activity and energy expenditure data simply and reliably. The Actical physical activity monitoring system is a rigorous solution designed with the needs of serious researchers in mind.
This view is of two days of minute-by-minute physical activity data with hourly averages for energy expenditure in kilocalories. Total activity energy expenditure for the day is shown on the right. You can view anywhere from 1 to 99 days of physical activity, steps, and energy expenditure. The Actical system allows you to easily collect and examine detailed data on subjects’ physical activity, steps and energy expenditure levels. You can quickly change how you view data, what data you want to analyze and rapidly calculate values over minutes, hours, days or weeks.
CLINICAL SIGNIFICANCE
Aerobic exercise testing clearly provides valuable clinical information in apparently healthy adults as well as a number of patient populations. Maximal aerobic capacity, either estimated from workload or measured directly, is perhaps the most frequently analyzed variable ascertained from such testing. Other variables obtained from the aerobic exercise test, such as the heart rate response during exercise and into recovery, the systolic and diastolic blood pressure responses during exercise, oxygen consumption at anaerobic threshold, and the ventilatory response to exercise, also provide important insight into an individual’s health and prognosis. Furthermore, the aerobic exercise test is highly valuable in developing an individualized and safe exercise prescription.
Regular exercise reduces A1C levels, adiposity, and triglyceride levels. The Cochrane review provides strong evidence that exercise programs ranging in duration from eight weeks to one year reduce A1C levels by approximately 0.6 percent, as well as reducing adipose tissue and triglyceride levels.