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Chapter 7 Resistance-Training Strategies for Individuals with Chronic Heart Failure Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Heart Failure Defined • Pathological state in which abnormality of cardiac function causes failure of heart to pump blood at rate commensurate with requirements of metabolizing tissues – Or to do so only from elevated filling pressure Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Chronic Heart Failure Defined • Multi-system syndrome with multiple pathological abnormalities that reduce exercise tolerance and contribute to functional disability • Systolic dysfunction – Reduced pumping capacity Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Exercise Intolerance and Resistance Training • Exercise tolerance – Inability to sustain sub-maximal level of exercise/activity • Previously contraindication for resistance training • Now included in conjunction with aerobic exercise Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Prevalence of Chronic Heart Failure • Affects approximately 5 million individuals in US • More than 550,000 individuals diagnosed each year Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Prevalence of Chronic Heart Failure • At age 65, rate increases from 2 to 3 percent – Affecting one in 100 individuals • Over age 80, affects more than 80 percent of individuals Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Economic Impact • Most common cause of hospitalization for people age 65 or more • Individuals unable to perform activities of daily living due to deconditioning, dyspnea, and fatigue • Approximately $30 billion total direct cost annually Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Common Symptoms • • • • Muscle weakness Dyspnea on exertion General fatigue Cardiovascular (central) and muscular (peripheral) dysfunction contribute to symptoms of heart failure Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Etiologic Factors • Ischemic heart disease – Underlying factor in approximately 60 percent of cases • Hypertensive heart disease • Valvular heart disease • Variety of metabolic, infectious, and toxic agents Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. “Muscle Hypothesis” • Connection between cardiovascular and skeletal muscle dysfunction contributes to symptoms of heart failure Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Effects of Chronic Heart Failure on Skeletal Muscle • • • • Reduces blood flow Increases blood lactate levels during exercise Increases fatigue rates Causes structural alterations in peripheral vasculature • Causes muscle atrophy and loss of muscle strength/endurance Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Effects of Chronic Heart Failure at Muscular Level • Reduces slow-twitch oxidative fibers – Type I • Increases fast glycolytic fibers – Type IIB • Reduces mitochondrial function Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Effects of Chronic Heart Failure at Muscular Level • Increases inducible nitric oxide synthase (iNOS) and nitric oxide associated with down-regulation of mitochondrial creatine kinase expression Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Benefits of Resistance Training • Increases skeletal muscle and endothelial function – Decreasing negative effects associated with “muscle hypothesis” • Improves physical and psychosocial factors • Decreases fatigue Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Benefits of Resistance Training • • • • • Improves emotional function Increases functional ability Improves peripheral blood flow Decreases sympathetic activation Improves heart rate variability Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Benefits of Resistance Training • May improve autonomic function • Increases muscle mitochondria size • Improves muscle strength and endurance – Allowing greater efficiency when performing activities of daily living Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Research Supports Resistance Training • Cumulative research results indicate resistance training leads to increases in: – – – – Muscular strength Muscular endurance Quality of life Functional measures Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Research Limitations • Choice of subjects has mainly been “younger” males at low to moderate risk – Age 40 to 60 • Many studies not reproducible due to various factors Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Research Limitations • Typical 12-week program may be insufficient to impact both neural and muscle adaptations • Focus on localized training strategies not ideal for long-term compliance Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Program Design Considerations • Individuals in highest risk level due to greater overall morbidity/mortality rates • Extensive medical and physical activity history required prior to training Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Program Design Considerations • Other co-morbidities – E.g., diabetes, age • Degree of severity of heart failure – Use categorization system established by American Heart Association (AHA) and American College of Cardiology (ACC) Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Heart Failure Classification System • Stage A – At risk for developing heart failure • Stage B – Asymptomatic and free of structural abnormalities Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Heart Failure Classification System • Stage C – Structural abnormalities with/without mild to moderate symptoms • Stage D – Advanced structural concerns – Quite limiting symptoms Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. New York Heart Association (NYHA) Classification System • Class I – Level of exertion that would elicit symptoms for normal person • Class II – Symptoms with ordinary exertion • Class III – Symptoms during less than ordinary exertion Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. New York Heart Association (NYHA) Classification System • Class IV – Symptoms at rest • Individuals with symptoms in Class II-IV also fall within AHA/ACC Stage C and D Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Drug Regimen Considerations • Consider possible drug side effects when planning training • Diuretics reduce blood volume and edema • Vasodilators reduce blood pressure and systemic vascular resistance Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Drug Regimen Considerations • Beta-adrenergic receptor blockers interrupt “toxic effects” of over-active sympathetic nervous system • Digoxin may be used – Also controversial • Antiplatelet and anticoagulation therapies • Aldosterone antagonist Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Exercise Testing Requirements • Physical examination • Symptom-limited cardiopulmonary exercise test using modified Naughton protocol • Resting echocardiogram Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Testing Protocol • Stress applied during test should reflect combination of static and dynamic loads on heart occurring during resistance training • Echocardiographic stress test using leg press simulates training session Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Testing Protocol • Measure: – – – – – – – Heart rate Blood pressure End diastolic volume End systolic volume Stroke volume Ejection fraction Cardiac output Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Testing Protocol • If all variables assessed within normal limits, resistance training likely to be safe • Next step: – Maximal strength testing • Measure muscle strength by 1 RM method for all exercises to be included in resistance training program Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Contraindications for Resistance Training • Post-exercise hypotension • Arrhythmias • Worsening heart failure symptoms: – Weight gain of 1.5 to 2.0 kilograms (kg) over previous three to five days – Increased heart rate and dyspnea – Auscultatory findings of pulmonary edema Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Cautions • Some individuals experience temporary increase in fluid accumulation two to six weeks after starting exercise • Take care during lifting exercises due to possibly altered reflex response to positional changes Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Program Components • Consider individual’s loss of muscular endurance – Contributes to up to 40 percent of exercise intolerance • First 12 weeks: – Circuit training protocol – Eight weeks of machines followed by four weeks adding free weights Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Program Components • First 12 weeks: – Use sequence with minimal rest between exercises • 30 to 60 seconds – Perform approximately 8 to 12 repetitions of each exercise per circuit • 50 to 80 percent of 1 RM – Progress to 3 sets of 8 repetitions at 80 percent of 1 RM Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Program Components • Second 12-weeks: – Two, six-week cycles • Cycle 1 at club • Cycle 2 at both home and club • Review sample 24-Week Program Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Additional Training Considerations • Should be entire body progressive resistance training program • Ensure adequate rest/recovery – Critical to optimal outcomes • Understand how varied differences in training intensity prevent training plateaus Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Additional Training Considerations • Constantly supervise and spot • Properly orientate individuals to each procedure and piece of equipment • Perform intermittent monitoring of heart rate and blood pressure Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED.