Medical V02 Interpretation

V02  Cardiorespiratory Test Measurements (V02 Max)

• V02 Score : The Maximum or Peak Amount of Oxygen Your Body can Extract in 1 minute. This is your V02 Max or Peak. This is a very very important number. In fact this number has become the most important vital signs of current status and predictor of future health.
• VE: Minute ventilation (VE) is the quantity of air moved into and out of the lungs in one minute (Tidal Volume multiplied by Respiration Rate) and dictates CO2 elimination from alveoli. Pretesting with spirometry gives a predicted maximum ventilation that one should need less then <80% during the test. If this is not achieved, possible pathologies are considered.
• VE/VO2, which identifies the relationship between ventilation and oxygen consumption. Ventilatory Equivalents for Oxygen (VE/VO2): refers to number of liters of ventilation per liter of oxygen consumed. The normal value is typically around 25-30 and increases once the person reaches their ventilatory threshold. High values are a marker of inefficient ventilation, which can be due to hyperventilation or increased dead-space, a marker of poor gas exchange. For unknown reasons, subjects with heart failure have a high VE/VO2. On the exercise data sheet this term will be denoted by “EqO2” 
• VE/VC02 Ventilatory Efficiency Slope: The most studied parameter in this regard is the relationship between minute ventilation and carbon dioxide output (VE/VCO ₂ ), also called ventilatory efficiency slope. The rise in VE and VCO ₂ is strictly linked during aerobic exercise since increased VCO ₂ levels due to the increased metabolism drive ventilation. In healthy individuals, the values of VE/VCO ₂ slope are usually lower than 30. 
• Respiratory Exchange Ratio (RER): is the ratio between the amount of carbon dioxide (CO2) produced in metabolism and oxygen (O2) used. 
• Heart Rate: is the speed of the heartbeat measured by the number of contractions (beats) of the heart per minute (bpm). The heart rate can vary according to the body’s physical needs, including the need to absorb oxygen and excrete carbon dioxide
• Oxygen Pulse: refers to the volume of oxygen taken up by the pulmonary blood per heartbeat. It is calculated by dividing the VO2 by the simultaneously measured heart rate. The units are ml O2/beat. The term is derived from the Fick equation and equals the product of stroke volume and the arterial-mixed venous oxygen difference [C(a-v)O2], If one assumes that C(a-v)O2 reaches a steady state at maximal exercise, then the oxygen pulse can be used as a surrogate measure for stroke volume. The normal value depends on the size of the subject but can range between 8 and 18 ml O2/heart beat
• C02 Output: refers to the amount of carbon dioxide exhaled from the body per unit time. It is expressed in ml/min. A normal value at rest is around 200 ml/min. This value increases with progressive exercise. It continues to rise after the completion of exercise as the muscles continue to eliminate carbon dioxide before returning to baseline levels after several minutes. Note that carbon dioxide output can differ from carbon dioxide production by the body’s metabolic processes but in the steady state production and output are the same
• Aerobic Metabolism: is the way your body creates energy through the combustion of carbohydrates, amino acids, and fats in the presence of oxygen. Combustion means burning, which is why this is called burning sugars, fats, and proteins for energy. Aerobic metabolism is used for the sustained production of energy for exercise and other body functions. Examples of exercises that use aerobic metabolism include walking, running, or cycling with sustained effort.
• Anaerobic Metabolism: is the creation of energy through the combustion of carbohydrates in the absence of oxygen. This occurs when your lungs and/or heart, and/or vascular system cannot put enough oxygen into the bloodstream to keep up with the demands of your muscles for energy. It generally is used only for short bursts of activity, such as when you sprint when running or cycling or when you are lifting heavy weights.
• Anaerobic Threshold: (AT) is the exertion level between aerobic and anaerobic training. The AT is the point during exercise when your body must switch from aerobic to primarily anaerobic metabolism. Further, (AT) is the physiological point during exercise at which lactic acid starts to accumulate in the muscles, which occurs around the point during increasing intensity exercise that anaerobic processes become more dominant. For this reason it is also sometimes called the Lactate Threshold (LT).
• SP02: stands for peripheral capillary oxygen saturation, an estimate of the amount of oxygen in the blood. … SpO2 is an estimate of arterial oxygen saturation, or SaO2, which refers to the amount of oxygenated haemoglobin in the blood. Haemoglobin is a protein that carries oxygen in the blood.
• Blood Pressure: The force of circulating blood on the walls of the arteries. Blood pressure is taken using two measurements: systolic (measured when the heart beats, when blood pressure is at its highest) and diastolic (measured between heart beats, when blood pressure is at its lowest). Blood pressure is written with the systolic blood pressure first, followed by the diastolic blood pressure (for example 120/80).
• Peak Circulatory Power: Cardiac power, the product of CO and mean arterial pressure, is a powerful index of cardiac systolic  function (42). Circulatory power is a cardiac power surrogate obtainable from cardiopulmonary exercise testing, calculated as peak VO2 (in milliliters per kilogram per minute) multiplied by peak systolic blood pressure
• Ventilatory Power: Minute ventilation/CO(2) production (VE/Vco(2)) slope is an index determined by cardiopulmonary exercise testing, which incorporates pertinent cardiac, pulmonary, and skeletal muscle physiology into a substantive composite assessment. The VE/Vco(2) slope has many applications, including utility as a well-validated prognostic gauge for patients with heart failure (HF). We combine VE/Vco(2) slope with systolic blood pressure, creating a novel index that we labeled ventilatory power. Ventilatory power links the combined physiology inherent in the VE/Vco(2) slope to peripheral pressure, adding an additional dimension pertinent to HF assessment. Whereas the related concept of circulatory power links peak oxygen consumption with peak systolic blood pressure as a prognostic index, so ventilatory power would provide greater prognostic discrimination than VE/Vco2 slope, peak oxygen consumption, and circulatory power for patients with systolic HF.
• Definitions of Oxygen delivery and utilization systems. VE = minute ventilation; BF = breathing frequency; TV = tidal volume; P AO2 = alveolar oxygen partial pressure; P ACO2 = alveolar partial pressure
  of carbon dioxide; Q = cardiac output; SV = stroke volume; HR =
  heart rate; DO2 = oxygen delivery; CaO2 = arterial oxygen content; SaO2 = arterial oxygen saturation; Hb = haemoglobin;
  CvO2 = mixed venous oxygen content; SvO2 = mixed venous oxygen saturation; a-vO2 difference = arterio-venous oxygen difference; La + = lactate