Cardiac Muscle dysfunction Flashcards
What does CMD result from?
Abnormality of structure or function
How does CMD affect the heart?
Impairs heart’s ability to pump or receive blood
How does CMD affect function?
Exercise tolerance and functional abilities are mild/moderately reduced: myocardial ischemia/infarction, angina, cardiac arrhythmias, dyspnea
Decreased quality of life
T/F: CMD is the most common cause of congestive heart failure?
True
How is CHF manifested?
As pulmonary congestion, or pulmonary edema
What is the difference between chronic heart failure and congestive heart failure?
Chronic heart failure: person is living with heart failure
CHF: person has edema involved
What are the characteristics of CMD?
Ejection fraction: 30-40% Angina and myocardial ischemia Cardiac arrhythmias MI HTN Cardiac arrhythmias Renal insufficiency (acute/chronic)
What is cause for angina and myocardial ischemia in CMD?
Brought on by inadequate O2 supply/demand to heart
What do cardiac arrhythmias lead to?
Decreased myocardial function
What is the most common cause of CMD?
Myocardial infarction
What are causes for MI?
Chronically sustained ischemia to myocardium.
What are possible ways for chronic sustained ischemia to myocardium leading to an MI?
Coronary artery spasm (smooth muscle)
Sudden thrombotic occlusion (cell death)
Dysfunction of left or right ventricle or both from injury
Scar formation and decreased contractility occur
What is treatment for MI?
Fix underlying cause of infarction (surgical procedure, medications)
What happens to the cardiac muscle with chronic uncontrolled HTN?
Increased atrial pressure= strain of left ventricle: LVH, increased energy expenditure
Ventricle hypertrophies to compensate increased afterload
Myocardium stiffens: systolic and/or diastolic dysfunction
Left ventricle weakens and dilates: CHF
T/F: with chronic uncontrolled HTN there is increased energy expenditure in the heart because the muscles have to work harder to maintain adequate pump/cardiac output?
True
What is treatment for HTN?
Medications such as ACE inhibitors, Ca channel blockers, diuretics, and beta blockers
Regular exercise training
T/F: regular exercise training can reduce BP by 20 mmHg (systolic) and 15 mmHg diastolic?
False: reduces systolic 10 mmHg and 6-8 mmHg
T/F: if you stop exercise your blood pressure will stay the same?
False. Exercise needs to be maintained through life
What are cardiac arrhythmias and how is it a characteristic of CMD?
Decreased myocardial function: too rapid or slow which affects muscle function
Impaired atrioventricular conduction
What is treatment for cardiac arrhythmias?
Medications, pacemaker, ablation, ICD
What is renal insufficiency?
Fluid overload
What is treatment goal for renal insufficiency?
Decrease reabsorption of fluid (not just adjust fluid control) from kidney and rid the body of fluid (diuresed)
What is treatment for renal insufficiency?
Lasix (diuretic)
Monitor electrolyte levels for too high (further retention) or too low (cardiac arrhythmias)
Dialysis for severe cases
What is cardiomyopathy?
Disorder affecting the heart muscle: inadequate pumping of heart, contraction, relaxation
Primary/secondary causes
What does the heart do in cardiomyopathy?
It loses its ability to pump effectively. It becomes larger as it tries to compensate for its weakened condition
What are 2 categories of cardiomyopathy?
Ischemic: results from coronary artery disease
Nonischemic: disease of heart muscle itself, dilated, hypertrophic, restrictive
What is the most common cause of CHF?
Dilated cardiomyopathy
What populations normally get dilated cardiomyopathy?
Middle aged people
Men more than women (2.5 to 1)
what is cause of dilated cardiomyopathy?
Idiopathic in most cases Familial (30-40%) Viral infection Chronic, excessive consumption of alcohol Toxins (cobalt) Cancer drugs Pregnancy and childbirth Long term alcohol use Cigarette smoking
What is treatment for dilated cardiomyopathy?
transplantation
What are characteristics of dilated cardiomyopathy?
Dilated left ventricle and left atrium.
Bulging interventricular septum from left to right
Thin ventricular walls
Myocardial mitochondria dysfunction: energy
What structural changes occur in dilated cardiomyopathy?
Increased left ventricular mass
Normal or reduced left ventricular wall thickness
Increased left ventricular cavity size.
Ineffective/inefficient pump: poor cardiac output, end diastolic pressure not going up, bad squeeze.
T/F: in dilated cardiomyopathy normal activities will be easy for people
False; normal activities are harder
What is cause of hypertrophic cardiomyopathy?
Most are inherited (>100 mutations in 10 proteins)
Autosomal dominant trait
Who normally gets hypertrophic cardiomyopathy?
Most common early onset (10-25 years)
Principal cause of sudden death: young healthy individuals, athletes
What are characteristics of hypertrophic cardiomyopathy?
Hypertrophy is inappropriate for hemodynamic load.
Proper myocardial mitochondira function
Characterized by diastolic dysfunction
Increased LV diastolic pressure: eventually increased LA,PA, and pulmonary capillary pressures
What are structural changes in hypertrophic cardiomyopathy?
Severe thickening of interventricular septum.
Thickening of the left ventricular wall.
Tiny left ventricular chamber/ventricular cavity size
T/F: with hypertrophic cardiomyopathy the problem is that the heart will get a good squeeze but it can’t fill with blood so no blood will get out?
True
How does hypertrophic cardiomyopathy impair function?
Exaggerated pump function (hypercontractile systolic function)
Poor heart relaxation (diastolic dysfunction)
What are causes and characteristics of restrictive cardiomyopathy?
Rare form (5%) Worst prognosis Characterized by diastolic function
Does not appear to be inherited
What are the forms of restrictive cardiomyopathy?
Amyloidosis: abnormal protein fibers accumulate
Sarcoidosis: inflammatory, forms lumps in lungs
Hemochromatosis: iron overload of body
What is the restrictive cardiomyopathy that has abnormal protein fibers (amyloid) accumulate in the heart’s muscle?
Amyloidosis
What is the restrictive cardiomyopathy that is an inflammatory disease that causes the formation of small lumps in organs (lungs)?
Sarcoidosis
What is restrictive cardiomyopathy where there is iron overload of the body, usually due to a genetic disease
Hemochromatosis
What happens to heart muscle tissue in restrictive cardiomyopathy?
Stiffened walls of the ventricles with loss of flexibility due to infiltration by abnormal tissue
What are signs of CHF?
Chest X-ray EF Cold, pale, cyanotic extremities Abnormal heart sounds Sinus tachycardia Abnormal breathing patterns Peripheral edema Crackles/rales Systolic BP with controlled expiratory maneuver Jugular vein distention Decreased exercise tolerance Decreased quality of life
What will you see on X-ray with person with CHF?
Cardiac silhouette (size and shape increased) Fluid in lungs
What is ejection fraction in person with CHF?
What is cause of cold, pale, extremities in person with CHF?
Increased sympathetic activity
What are the abnormal heart sounds in CHF?
S3 occurs when LV is non-compliant and poor relaxation during diastole
Hallmark sign of CHF
What is cause of sinus tach in CHF?
Increased sympathetic activity
What does breathing pattern look like in person with CHF?
Quick, shallow breaths even with change in position
How does peripheral edema effect the body in CHF?
Inadequate blood flow to periphery: promotes decreased fluid excretion, fluid retention, weight gain > 3lbs
Why do you hear crackles/rales with CHF?
heard on inspiration and at lung base
Hear it because of alveolar opening in presence of pulmonary edema
What are symptoms of CHF?
Dyspnea
Paroxysmal nocturnal dyspnea
Orthopnea
What are causes of dyspnea in patients with CHF?
Poor gas transport: acute/chronic pulmonary edema
Abdominal ascites: peripheral edema, and limitation in diaphragmatic descent
Ventilatory muscle weakness
All contribute to inadequate oxygen supply: increased tidal volume and respiratory rate
What is paroxysmal nocturnal dyspnea?
Sudden SOB upon wakening from sleep
What is cause of paroxysmal nocturnal dyspnea?
Supine position increases venous return: this overloads the poorly functioning heart, increases pulmonary edema
What do patients who awaken with orthopnea occur?
Relief with upright position
Prefer to sleep with pillows, HOB propped up or in chair
What are NY Heart Association Classification?
Class 1: cardiac disease w/o limitations
Class 2: Cardiac disease slight limitation (physical activity results in fatigue, palpitations, dyspnea, angina pain
Class 3: Cardiac disease marked limitation (less than ordinary activity causes symptoms above)
Class 4: Cardiac disease but inability to perform physical activity w/o discomfort (symptoms may be felt at rest, physical activity intensifies symptoms)
If a person is okay at rest but less than ordinary activities cause symptoms what level are they at?
Level 3
If a person is doing activity and their heart pitter patters what class would they be?
Class 2
What is pathophysiology of CHF?
Neurohumonal: sympathetic symptoms
Muscle wasting
Pulmonary/edema
Renal: water retention d/t decreased Q, urine (oliguria)
For CHF what are the things we should look, listen, feel for?
Look: breathing pattern, color, edema, oximeter, JVD, changes in extremities, weight gain
Listen: breath and heart sounds, BP
Feel: edema, breathing pattern, pulse (rate, rhythm, force)
What happens when oxygen saturation is 90 and partial pressure of oxygen is 60?
Tachycardia, tachypnea, restlessness
What happens when oxygen saturation is 85 and partial pressure of oxygen is 50?
Incoordination, impaired judgement, labored respirations, confusion
What happens when oxygen saturation is 80 and partial pressure of oxygen is 45?
Tachycardia, tachypnea, restlessness
Incoordination, impaired judgement, labored respirations, confusion
Will someone have symptoms if their oxygen saturation and partial pressure O2 is 99-95 and 100-80 respectively?
No signs or symptoms
What are medical interventions for CHF?
Directed at pathophysiologic cause.
Improve hearts pumping ability: beta block, vasodilator therapy
Control sodium intake: diet, heart healthy, low cholesterol and fat
Water retention: diuretics will increase urine output
Devices
Cardiac transplantation
What should people with CHF avoid?
Antiarrhythmic agents: act as cardio depressants and have pro arrhythmic effects
Ca channel blockers: can worsen CHF, increase risk of CV events
Nonsteroid anti-inflammatory drugs: increases sodium retention, peripheral vasoconstriction
What are devices that can be used as medical interventions for CHF?
Bi-ventricular pacing
ICD (implantable cardiac difibrillators)
Intraaortic balloon pump
Left ventricular assistive device
When is and ICD used?
EF
What does a intra aortic balloon pump do
Inflates during diastole, improves myocardial blood flow
What does left ventricular assistive device do?
Helps maintain pumping ability of heart that can’t work on its own.
Sometimes used as “bridge to transplant”
Hospitalization ~7-10 days
What is part of assessment for people with CMD?
When did sx begin?
Stable, worse, what brings on sx
Chest pain, claudication, SOBOE, sleeping hx
Activity level: FITT principle
Objective measures/labs: EKG, echo, blood gas levels, auscultation, 6MWT, questionnaires, physical appearance, RR, breathing pattern
What is inpatient care for CMD?
Flexibility exercises, cycle ergometry, treadmill ambulation Energy conservation Self management Transfers Education
What are guidelines for geometry/treadmill?
30 minutes
3-5 days/week
2-4 weeks
50-70% peak cycle work rate
Improvements reported in decreased symptoms, improved HR and exercise tolerance
What is done with home care PT for cardiac patients?
Flexibility exercises, cycle ergometry, walking
Self management of sx, diet, activity, energy conservation, ther ex/act
ADLs/IADLs
What are parameters of home care exercises? improvements?
20-60 minutes
3-7 days/wk
2-6 months
50-80% peak cycle heart rate or O2
Improvements: decreased symptoms, improved HR, BP, exercise tolerance via GXT
What methods of aerobic activity can be found with cardiac rehab centers?
Most use cycle erg
20-60 minutes, 3-7 days/wk, 2-57 months, 40-90% of peak cycle heart rate or VO2
Improvements reported in decreased symptoms, improved HR, BP, and exercise tolerance
Can SLE be used for PT with CHF?
Unilateral exercise better than 2 legged: severe CHF, limited exercise tolerance, low cardiac output especially with exercise
What are PT interventions for strength and breathing?
Strength: 10 reps for 2-4 months OR 60-80% of maximum voluntary contraction. Progress is slow
Breathing: inspiratory muscle training with hand held device, limited data on yoga (positive for decreasing dyspnea)
What is criteria for modification or termination of exercise?
Marked dyspnea or fatigue RR >40 breaths/min Development of S3 heart sound Increase pulmonary crackles Decrease in HR or BP of >10 bpm or mmHg during steady state or progressive exercise Diaphoresis, pallor, or confusion
What are other causes of CMD?
Heart valve abnormalities
SCI: transection to cervical spinal cord
Pericardial effusion
How do heart valve abnormalities cause CMD?
Heart must contract more forcefully to expel Q because of the blocked/incompetent valves.
Leads to hypertrophy: decreased ventricular distensibility, diastolic dysfunction, incompetent valves associated with hypertrophy (regurgitated blood fills atria or ventricles)
How does a SCI cause CMD?
Disconnect between cardiovascular system and control with SNS
What does pericardial effusion cause CMD?
Increased pressure (fluid fills pericardial sac) Decreased diastolic function
