Excess CO2 is generated when lactate is increased during exercise because its [H+] is buffered primarily by HCO-3 (22 ml for each meq of lactic acid). We developed a method to detect the anaerobic threshold (AT), using computerized regression analysis of the slopes of the CO2 uptake (VCO2) vs. O2 uptake (VO2) plot, which detects the beginning of the excess CO2 output generated from the buffering of [H+], termed the V-slope method. From incremental exercise tests on 10 subjects, the point of excess CO2 output (AT) predicted closely the lactate and HCO-3 thresholds. The mean gas exchange AT was found to correspond to a small increment of lactate above the mathematically defined lactate threshold [0.50 +/- 0.34 (SD) meq/l] and not to differ significantly from the estimated HCO-3 threshold. The mean VO2 at AT computed by the V-slope analysis did not differ significantly from the mean value determined by a panel of six experienced reviewers using traditional visual methods, but the AT could be more reliably determined by the V-slope method. The respiratory compensation point, detected separately by examining the minute ventilation vs. VCO2 plot, was consistently higher than the AT (2.51 +/- 0.42 vs. 1.83 +/- 0.30 l/min of VO2). This method for determining the AT has significant advantages over others that depend on regular breathing pattern and respiratory chemosensitivity.

A new method for detecting anaerobic threshold by gas exchange

SUMMARY OF APPROACH The approach to surgery in the patient with COPD is summa-rized below. Surgery Definitely indicated Lung resection. Pulmonary function studies should be performedbefore lung resection. Simple spirometry has the greatest utilityin documenting physiologic operability. FEV, > 2 L in an adultman or > 60% of predicted is acceptable for pneumonectomy.Values below this suggest that further studies, such as split func-tion assessment by quantitative lung scintigraphy and exercisetesting, are warranted.FEV, predicted after lung resection to be less than 40 to 50%of normal for the patient’s sex, age, and height suggests highermorbidity and mortality. An exercise 90, of less than 10 to 15ml/min per kg of body weight is associated with higher mor-bidity and mortality after lung resection.All elective surgery Prophylaxis against deep venous throm-bosis should be given before most procedures that will requirepostoperative bed rest or significantly reduce mobility. Heparinin low doses seems well accepted for most procedures. Externalpneumatic compression of the lower legs can be used when anti-coagulants are contraindicated.

/pdf/standards-for-the-diagnosis-and-care-of-patients-with-13vz6fyao0.pdf

Standards for the Diagnosis and Care of Patients with Chronic Obstructive Pulmonary Disease

2D\n: two-dimensional\n99mTc-DPD\n: 99mTechnetium-3,3-diphosphono- 1,2-propanodi-carboxylic acid\nACE\n: angiotensin-converting enzyme\nAF\n: atrial fibrillation\nAL\n: amyloid light chain\nAR\n: aortic regurgitation\nARB\n: angiotensin receptor blocker\nATTR\n: amyloidosis-transthyretin type\nAV\n: atrioventricular\nBiVAD\n: biventricular assist device\nBNP\n: brain natriuretic peptide\nBPM\n: Beats per minute\nCCS\n: Canadian Cardiovascular Society\nCFC\n: cardiofacialcutaneous\nCHA2DS2-VASc\n: Congestive Heart failure, hypertension, Age ≥75 (doubled), Diabetes, Stroke (doubled), Vascular disease, Age 65–74, and Sex (female)\nCMR\n: cardiac magnetic resonance\nCRT\n: cardiac resynchronization therapy\nCRT-D\n: cardiac resynchronization therapy-defibrillator\nCRT-P\n: Cardiac resynchronization therapy with a pacemaker\nCT\n: computed tomography\nDC\n: direct current\nDNA\n: deoxyribonucleic acid\nE/A\n: ratio of mitral peak velocity of early filling (E) to mitral peak velocity of late filling (A)\nE/e’\n: ratio of early transmitral flow velocity (E) to early mitral annulus velocity (e’)\nEACTS\n: European Association for Cardio-Thoracic Surgery\nECG\n: electrocardiogram\nEF\n: ejection fraction\nEPS\n: electrophysiological study\nESC\n: European Society of Cardiology\nFDA\n: (US) Food and Drug Administration\nFHL1\n: four and a half LIM domains 1\nHAS-BLED\n: hypertension, abnormal renal/liver function, stroke, bleeding history or predisposition, labile INR, elderly (>65 years), drugs/alcohol concomitantly\nHCM\n: hypertrophic cardiomyopathy\nhs-cTnT\n: high sensitivity cardiac troponin T\nHTS\n: high throughput sequencing\nICD\n: implantable cardioverter defibrillator\nILR\n: implantable loop recorder\nINR\n: international normalized ratio\nIUD\n: intrauterine device\nLA\n: left atrium\nLAMP-2\n: lysosome-associated membrane protein 2\nLBBB\n: left bundle branch block\nLEOPARD\n: Lentigines, ECG abnormalities, Ocular hypertelorism, Pulmonary stenosis, Abnormal genitalia, Retardation of growth, and sensory-neural Deafness\nLGE\n: late gadolinium enhancement\nLV\n: left ventricular\nLVAD\n: left ventricular assist device\nLVH\n: left ventricular hypertrophy\nLVOTO\n: left ventricular outlow tract obstruction\nMADIT-RIT\n: Multicenter Automatic Defibrillator Implantation Trial—Reduce Inappropriate Therapy\nMAPK\n: mitogen activated protein kinase\nMELAS\n: mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes\nMERFF\n: myoclonic epilepsy with ragged red fibres\nMRA\n: mineralocorticoid receptor antagonist\nMYBPC3\n: myosin-binding protein C, cardiac-type\nMYH7\n: myosin-7 (s-myosin heavy chain)\nMYL3\n: myosin light chain 3\nNOAC\n: new oral anticoagulants\nNSVT\n: non-sustained ventricular tachycardia\nNT-proBNP\n: N-terminal pro brain natriuretic peptide\nNYHA\n: New York Heart Association\nOAC\n: oral anticoagulants\no.d.\n: omni die (every day)\nPC-CMR\n: phase contrast cardiac magnetic resonance\nPDE5\n: phosphodiesterase type 5\nPET\n: positron emission tomography\nPRKAG2\n: gamma-2 sub-unit of the adenosine monophosphate-activated protein kinase\nRAAS\n: renin angiotensin aldosterone system\nRV\n: right ventricular\nSAM\n: systolic anterior motion\nSCD\n: sudden cardiac death\nSAA\n: septal alcohol ablation\nS-ICD™\n: Subcutaneous lead implantable cardioverter defibrillator\nSPECT\n: single photon emission computed tomography\nSSFP\n: steady-state free precession\nSVT\n: supraventricular tachycardia\nTOE\n: transoesophageal echocardiography\nTNNI3\n: troponin I, cardiac muscle\nTNNT2\n: troponin T, cardiac muscle\nTPM1\n: tropomyosin alpha-1 chain\nTTE\n: transthoracic echocardiography\nTTR\n: transthyretin\nVF\n: ventricular fibrillation\nVKA\n: vitamin K antagonist\nVT\n: ventricular tachycardia\nWHO\n: World Health Organization\n\nGuidelines summarize and evaluate all available evidence at the time of the writing process, on a particular issue with the aim of assisting health professionals in selecting the best management strategies for an individual patient, with a given condition, taking into account the impact on outcome, as well as the risk-benefit-ratio of particular diagnostic or therapeutic means. Guidelines and recommendations should help the health professionals to make decisions in their daily practice. However, the final decisions concerning an individual patient must be made by the responsible health professional(s) in consultation with the patient and caregiver as appropriate.\n\nA great number of Guidelines have been issued in recent years by the European Society of Cardiology (ESC) as well as by other societies and organisations. Because of the impact on clinical practice, quality criteria for the development of guidelines have been established in order to make all decisions transparent to the user. The recommendations for formulating and issuing ESC Guidelines can be found on the ESC website (http://www.escardio.org/guidelines-surveys/esc-guidelines/about/Pages/rules-writing.aspx). ESC Guidelines represent the official position of the ESC on a given topic and are regularly updated.\n\nMembers of this Task Force were selected by the ESC to represent professionals involved with the medical care of patients with this pathology. Selected experts in the field undertook a comprehensive review of the published evidence for management (including diagnosis, treatment, prevention and rehabilitation) of a given condition according to ESC Committee for Practice Guidelines (CPG) policy. A critical evaluation of diagnostic and therapeutic procedures was performed including assessment of the risk-benefit-ratio. Estimates of expected health outcomes for larger populations were included, where data exist. The level of evidence and the strength of recommendation of particular management options were weighed and graded according to predefined scales, as outlined in Tables 1 and 2 .\n\nThe experts of …

2014 ESC Guidelines on diagnosis and management of hypertrophic cardiomyopathy The Task Force for the Diagnosis and Management of Hypertrophic Cardiomyopathy of the European Society of Cardiology (ESC)

SUMMARYACSM Position Stand on The Recommended Quantity and Quality of Exercise for Developing and Maintaining Cardiorespiratory and Muscular Fitness, and Flexibility in Adults. Med. Sci. Sports Exerc., Vol. 30, No. 6, pp. 975-991, 1998. The combination of frequency, intensity, and duration of chr

http://myweb.facstaff.wwu.edu/chalmers/pdfs/acsm position stand - quantity and quality of exercise.pdf

ACSM Position Stand: The Recommended Quantity and Quality of Exercise for Developing and Maintaining Cardiorespiratory and Muscular Fitness, and Flexibility in Healthy Adults

The purpose of this report is to provide revised standards and guidelines for the exercise testing and training of individuals who are free from clinical manifestations of cardiovascular disease and those with known cardiovascular disease. These guidelines are intended for physicians, nurses, exercise physiologists, specialists, technologists, and other healthcare professionals involved in exercise testing and training of these populations. This report is in accord with the “Statement on Exercise” published by the American Heart Association (AHA).1

These guidelines are a revision of the 1995 standards of the AHA that addressed the issues of exercise testing and training.2 An update of background, scientific rationale, and selected references is provided, and current issues of practical importance in the clinical use of these standards are considered. These guidelines are in accord with the American College of Cardiology (ACC)/AHA Guidelines for Exercise Testing.3

### The Cardiovascular Response to Exercise

Exercise, a common physiological stress, can elicit cardiovascular abnormalities that are not present at rest, and it can be used to determine the adequacy of cardiac function. Because exercise is only one of many stresses to which humans can be exposed, it is more appropriate to call an exercise test exactly that and not a “stress test.” This is particularly relevant considering the increased use of nonexercise stress tests.

### Types of Exercise

Three types of muscular contraction or exercise can be applied as a stress to the cardiovascular system: isometric (static), isotonic (dynamic or locomotory), and resistance (a combination of isometric and isotonic).4,5 Isotonic exercise, which is defined as a muscular contraction resulting in movement, primarily provides a volume load to the left ventricle, and the response is proportional to the size of the working muscle mass and the intensity of exercise. Isometric exercise is defined as a muscular contraction without movement (eg, handgrip) and imposes greater pressure than volume …

Exercise Standards for Testing and Training A Scientific Statement From the American Heart Association

WASSERMAN, KARLMAN, BRIAN J. WHIPP, SANKAR IX KOYAL, AND WILLIAM L. BEAVER. Anaerobic threshold and respiratory gas exchange during exercise. J. Appl. Physiol. 35(Z): 236-243. 1973.-Alterations in gas exchange were studied in man during exercise increasing in increments of 15 w each minute, to determine the noninvasive indicators of the onset of metabolic acidosis (anaerobic metabolism). Expired airflow and CO 2 and 0 2 tensions at the mouth during the breath were continuously monitored with rapid1 y responding gas analyzers. These measurements were recorded directly as well as processed by a minicomputer, on-line, to give minute ventilation (VE), COP production #co& 02 consumption (voz), and the gas exchange ratio (R), breath-by-breath. The anaerobic threshold (AT) could be identified by the point of I) nonlinear increase in VE, 2) nonlinear increase in Vco2, 3) an increase in end-tidal 02 without a corresponding decrease in endtidal COz, and 4) an increase in R, as work rate was increased during an incremental exercise test. Of these measurements, R was found least sensitive. The AT was determined in 85 normal subjects between 17 and 91 years of age, by these techniques. The lower limit of normal was 45 w (KTo 2 = 1 liter/min), while values for very fit normal adults were as high as 180 w. The patients studied with cardiac disease above functional class I have lower anaerobic thresholds than the least fit normal subjects. The I-min incremental work rate test is associated with changes in gas exchange which can be used as sensitive on-line indicators of the AT, thus bypassing the need for measuring arterial lactate or acid-base parameters to indicate anaerobiosis.

Anaerobic threshold and respiratory gas exchange during exercise.

For high-intensity cycling, power (P) can be well described as a hyperbolic function of tolerable work duration (t): P=(W'/t) + P LL W' is a constant and P LL is the lower limit (asymptote) for P which is shown to occur at an O2 uptake ([Vdot]O2) lying above the estimated threshold for sustained blood [lactate] increase (ΘIac) but below the maximum [Vdot]O2 ([Vdot]O2max) obtained during incremental cycling. This relation suggests that, above P LL, only a certain amount of work (W') can be accomplished regardless of its rate of performance, with [Vdot]O2 max being attained at fatigue. Hence, P LL defines a point of discontinuity in the [Vdot]O2-P relation for supra-ΘIac exercise. In order to determine the factors responsible for the continued increase in [Vdot]O2 (to the maximum fatiguing value) at power outputs >P LL, we documented the temporal profiles of metabolic (rectal temperature; blood [lactate], [pyruvate], [norepinephrine], [epinephrine]) and respiratory ([Vdot]E; [Vdot]O2; [Vdot]CO2; blood pH, P...

Metabolic and respiratory profile of the upper limit for prolonged exercise in man

Oxygen uptake kinetics for various intensities of constant-load work.

To determine the precise nonsteady-state characteristics of ventilation (VE), O2 uptake (VO2), and CO2 output (VCO2) during moderate-intensity exercise, six subjects each underwent eight repetition...

Brian J. Whipp

Papers

A new method for detecting anaerobic threshold by gas exchange

Anaerobic threshold and respiratory gas exchange during exercise.

Metabolic and respiratory profile of the upper limit for prolonged exercise in man

Oxygen uptake kinetics for various intensities of constant-load work.

Parameters of ventilatory and gas exchange dynamics during exercise