Cardiopulm Unit 5 Cardiac Pathologies: Cardiac Muscle Dysfunction Flashcards
What is Cardiac Muscle Dysfunction (aka “Heart Failure”)?
Forward output of blood by the heart is insufficient to meet the metabolic needs to the body
- A syndrome with a variety of interrelated pathophysiologic phenomena of which impaired ventricular function is the most important
- Results in a reduction of exercise capacity and other characteristic clinical manifestations
With the Etiologies of Congestive Heart Failure, one of the causes is Hypertension. What is the Description of this?
Increased arterial pressure leads to left ventricular hypertrophy (increased myocardial cell mass) and increased energy expenditure
With the Etiologies of Congestive Heart Failure, one of the causes is Coronary Artery Disease (Myocardial Ischemia). What is the Description of this?
Dysfunction of the Left or Right ventrical, or both as a result of injury. Scar formation and decreased contractility may occur as well as reduced relaxation
With the Etiologies of Congestive Heart Failure, one of the causes is Cardiac Dysrhythmias. What is the Description of this?
Extremely rapid or slow cardiac arrhythmias impair the functioning ventricles. Dysfunction may be reversible if arrhythmias controlled
With the Etiologies of Congestive Heart Failure, one of the causes is Cardiomyopathy. What is the Description of this?
Contraction and relaxation of myocardial muscle fibers are impaired. Primary causes: pathologic process in the heart muscle itself, which impairs the hearts ability to contract. Secondary causes: systemic disease process
With the Etiologies of Congestive Heart Failure, one of the causes is Heart Valve Abnormaility. What is the Description of this?
Valvular stenosis or imcompetent valves cause myocardial hypertrophy and cause a decrease in venticular distensibility with mild diastolic dysfunction
What is Hypertensive Heart Disease?
A condition that relates to structural changes that occur in the heart as a response to chronic afterload changes that are implied by increased BP
With Hypertensive Heart Disease, what can cause Left Ventricular Hypertrophy?
- Hemodynamic load/stress
- Age, gender, genes, birth weight
- Salt intake, catecholamines, Angiotension II, Aldosterone
WIth Hypertensive Heart Disease, what can Left Ventricular Hypertrophy result in?
- Myocardial Ischemia (which can lead to infarction, then CHF)
- Impaired contractility (can lead to CHF)
- Impaired left ventricular filling (can lead to CHF)
- Atrial Fibrillation, Ventricular Arrhythmias (can lead to thromboembolism sudden death
What is Primary Cardiomyopathies?
Generally idiopathic or genetic in nature, involve pathologic processes in the heart muscle itself (often in the mitochondria) which impair the heart’s ability to contract
What is Secondary Cardiomyopathies?
The result of another underlying condition or external factor affecting heart muscle function. Can be classified according to the systemic disease that subsequently affects myocardial contraction (e.g., excessive alcohol consumption can lead to alcoholic cardiomyopathy)
What is Dilated Cardiomyopathy?
This is when the ventricals of the heart are enlarged, without hypertrophy. However there is not enough muscular capacity to pump out the blood, decreases cardiac output
Inotropic meds are used with this to increase contractility
What is Hypertrophic Cardiomyopathy?
When the walls of the Ventricles thicken and become stiff. CO will decease, because there is impaired filling and contractility and there is less blood supply. Arrythmias may present with this as well
What is Restrictive Cardiomyopathy?
When the walls of the ventricles become stiff, but not nessessarily thickened; this will affect systoli and diastoli
How are Cardiomyopathies distinguished from one another?
By electrocardiographics and myocardial biopsy results
What is Heart Failure Systolic Dysfunction? What are some causes?
(Systolic is when heart contracts)
This is impaired cardiac contractile function
Causes:
- Ischemic Heart disease (MI, Transient/persistent myocardial ischemia)
- Dilated Cardiomyopathy (Idiopathic, viral, genetic, alcohol, etc){over enlarged ventricles, not enough myocardium}
- Valvular Heart Disease (Aortic/Mitral valve stenosis or regurgitation)
What is Heart Failure Diastolic Dysfunction? What are some causes?
(Diastolic is when heart fills)
Impaired filling of the left or right ventricle due to hypertrophy and/or changes in the composition of the myocardium
Causes:
- Left Ventricular Hypertorphy (e.g., as a result of chronically increased afterloads in HTN)
- Restrictive Cardiomyopathy
- Myocardial Fibrosis
- Pericardial Effusion or Tamponade
With Hear Failure, what is the difference between HFrEF and HFpEF?
Due to significant overlap between systolic and diastolic dysfunction (i.e. many patients with HF suffer from both), it is common to categorize patients into having either:
- Heart Failure with reduced ejection fraction (HFrEF)
-< 40% EF
- Heart Failure with preserved ejection fraction (HFpEF)
-> 50% EF
This type of categorization is:
- useful, in part, because of the widespread availability of methods to measure LVEF (e.g., echocardiography)
- used as a variable in many clinical HF trials
- useful within medical management of individuals with HF
EF = Systolic / End-Diastolic volume (review)
What are the physiological responses to Decreased Cardiac Output?
- Increase/Activation of Sympathetic Nervous System
- Increased Renin-Angiotensin System
Also Increase in Antidiuretic Hormone (not as important for class)
When there is a decrease in CO, why is there activation of the sympathetic nervous system and renin-angiotensin system?
In order to:
- Increase myocardial contractility and HR
- Produce arterial vasoconstriction (to help maintain arterial pressure)
- Produce venous constriction (to increase venous pressure)
- Increase blood volume (to increase preload/ventricular filling)
With Decreased CO, what is the affect of Increased activity in the Sympathetic Nervous System? What may happen over time?
This will stimulate myocardial contractility, HR, and arterial/venous tone which results in an increase in central blood volume which serves to further elevate pre-load (to attempt to elevate CO).
- Over time though, the heart becomes insensitive to B-adrenergic stimulation, which results in a decreased force of myocardial contraction and an inability to attain higher heart rates during physical exertion
How does a decrease in CO affect the Renal System? What is the affect of the RAAS being activated?
Declining CO causes a reduction in renal blood flow and glomular filtration rate, which leads to sodium and fluid retention
- RAAS activation leads to further increases in peripheral vascular resistance and left ventrical after-load as well as sodium retention (pretty much making everything worse)
Using the graph as a representation, What happens when there is Chronic Sympathetic activation?
This leads to a blunted respons, weaker myocardial contractions, and limited HR increases during stress.
- The heart now operates under curve C contraints, unable to meet increased demands, signifying the progression of Heart Failure due to desensitization to sympathetic stimulation
Using the graph, what does the Normal Curve represent?
As the LVEDP (preload) increases, the stroke volume also increases, up to a certain point. This is due to the heart muscle fibers being optimally stretched, leading to a more forceful contraction due to the Frank-Starling Mechanism
Using the graph, what does the Mild Dysfunction curve represent?
The curve is flatter and indicates that the heart with mild dysfunction has a reduced response to increased preload. The heart still response with increased stroke volume as preload increases, but not as effectively as a normal heat
Using the graph, what does the Severe Dysfunction curve represent?
This curve is much flatter and indicates that increases in preload result in even smaller increases in stroke volume. The heart is significantly less responsive to changes in preload, reflecting a limited ability to enhance its contraction in response to increased filling.
- Eventually the increases in preload may even lead to a decrease in stroke volume
What happens has Cardiac Dysfunction worsens? With this we should monitor…
- The heart becomes less and less able to tolerate
the increases to afterload/systemic vascular resistance that aims to maintain arterial pressure - We should monitor:
-Fluid Status: reduced sensitivity to preload impairs the hearts ability to pump efficiently, leading to fluid retention as the kidneys compensate for perceived low blood volume
-Conditions that create excessive afterload such as unmanaged hypertension which can place additional strain on the heart, exacerbating myocardial workload and potentially worsening heart failure.
What commonly causes Left-Sided Heart Failure?
- CAD with ischemic LV damage (i.e., acute MI)
- Chronic HTN
- Dilated Cardiomyopathy
- Valvular hear disease with its pressure and/or volume overloading the heart
What commonly causes Right-Sided Heart Failure?
- Left-sided heart failure where there is an uncompensated left ventricular pressure that leads
to elevated pulmonary vascular pressures and then stress onto the right-ventricle
-This is considered “Biventricular Failure” - Diseases of the lung parenchyma or pulmonary vasculature (e.g. COPD, interstitial lung diseases, lung infection, pulmonary embolism)
-When right-sided heart failure is resultant of pulmonary processes, it is known as cor pulmonale
What increases Dyspnea/Increased work of Breathing?
- Increased pulmonary venous pressure can lead to a transudation of fluid into the alveoli (pulmonary edema) and pulmonary interstitium (making the lungs soggy and difficult to move) which both ultimately increase the work of breathing.
- The reduced blood flow to overworked respiratory muscles (i.e.., because of decreased cardiac output) and accumulation of lactic acid may also contribute to sensation of dyspnea.
What do Pulmonary Crackles/rales result from?
- Results from elevated pulmonary venous and capillary pressures and transudation of fluid into alveolar spaces
- Frequently heard at both lung bases but may extend upward, depending on the patient’s position, the severity of CHF, or both
What is Orthopnea?
Sensation of dyspnea or observation of labored breathing while lying flat which is relieved by sitting up
What is Orthopnea caused by?
- Caused by the redistribution of blood from the gravity-dependent portions of the body (e.g. abdomen and LEs) towards the lungs that increases venous return and work on the heart.
- Can be described by number of pillows on which the patient sleep on to avoid breathlessness (e.g. 3-pillow orthopnea).
- In severe cases, individuals end up preferring to sleeping in sitting on a recliner.
What is Paroxysmal Nocturnal Dyspnea?
Severe breathlessness that awakens the patient from sleep 1-3 hours after lying down
What does Parixysmal Nocturnal Dyspnea result from?
- Results from the gradual reabsorption into the circulation of LE interstitial edema after lying down and increase in venous return/load on heart.
- A nocturnal cough may also occur for similar reasons
Extra Heart Sounds
What does a S3 Heart Sound (aka Ventricular Gallop) indicate?
- Indicates a very compliant left ventricle. Thought to occur as blood passively fills a quickly distending left ventricle that makes contact with the chest wall during early diastole.
- May be normal (“physiologic S3”), particularly in young people, but in the presence of other indicators of heart disease, it is one of the most sensitive indicators of significant ventricular dysfunction
Extra Heart Sounds
What does a S4 Heart Sound (aka Atrial Gallop) indicate?
- Represents “vibrations of the ventricular wall during the rapid influx of blood during atrial contraction” from an exaggerated atrial contraction. It is found in diseases with ventricles so thick to require a strong atrial contraction. As it is related to atrial systole, this sound is appreciated in late diastole.
- Unlike S3, this extra heart sound is almost always abnormal.
Decreased Exertional Tolerance
Patients with cardiac muscle dysfunction, depending on the severity may display with what?
-
A more rapid heart rate rise during any submax
workload - A flat, blunted, and occasionally hypotensive
(decrease) response in SBP during exercise - A lower max/peak oxygen consumption (VO2)
- ECG signs of myocardial ischemia
- More easily provoked dyspnea and fatigue
What is Jugular Venous Pressure/Distension an indication of?
An indication of increased volume in the venous system and may be an early sign of right-sided heart failure
What does Peripheral Edema reflect?
- Reflects increased venous pressures due to retrograde movement of fluid from heart chambers and fluid retention by kidneys after the pressoreceptors of the body sense a decrease in volume of blood (due to pump failure/drop in cardiac output).
- Mostly collects around ankles and feet.
What is a 1+ on the Pitting Edema Scale?
Barely perceptible depression (pit)
What is a 2+ on the Pitting Edema Scale?
Easily identified depression; skin rebounds to its original contour within 15 seconds
What is a 3+ on the Pitting Edema Scale?
Easily identified depression; skin rebounds to its original contour within 15-30 seconds
What is a 4+ on the Pitting Edema Scale?
Easily identified depression; skin rebounds to its original contour within > 30 seconds
What are Sx of Left heart Failure?
Breathing Signs
- Dyspnea and increased WOB
- Orthopnea
- Paroxysmal Noctornal Dyspnea (PND)
What are the Physical Findins of Left Heart Failure?
- Diaphoresis
- Tachycardia/Tachypnea
- Pulmonary Rales
- S3/S3 (extra) heart sounds
What are Physical Findings of Right heart Failure?
- Jugular Venous Distension
- Peripheral Edema
What are Sx of Right heart Failure?
systemic signs
- Anorexia
- Right Upper Quadrant Discomfort (because of hepatic enlargement)
What is Heart Failure Exacerbation/Decompensation?
The presence of new or worsening signs/symptoms of dyspnea, fatigue, or edema that lead to hospitalization or unscheduled medical care (doctor visits or emergency department visits)
- This Typically requires hospitalization
With Heart Failure Exacerbation/Decompensation, what are the S/S?
- Dyspnea at rest
- Unrelieved Angina
- Wheezing or chest tightness at rest
- Paroxysmal nocturnal dyspnea: requiring to sit in chair to sleep
- Weight gain or loss of more than 5 lbs in 3 days
- Confusion
- Pulmonary Crackles
- S3 Heart Sound
- Jugular Venous Distention
With, Heart Failure Exacerbation/Decompensation what are common Test and Procedures that will be used?
- Chest X-rays
- Echocardiograms
- Invasive monitoring of cardiovascular performance
-Arterial lines
-Central lines (e.g., Pulmonary Artery Catheterization)
What are the benefits of Chest X-rays?
Assist in the clinical dx and monitoring of the
progression or regression of:
*Airspace consolidation
*Large intrapulmonary air spaces and presence of
mediastinal or subcutaneous air
*Lobar atelectasis
*Other pulmonary lesions
*Rib Fractures
- Determine proper placement of medical
equipment (e.g., ET tube, central lines, etc.) - Evaluate structural features such as cardiac or
mediastinal size and diaphragmatic shape and
position
What are the benefits of using an Echocardiogram?
Echocardiograms give information regarding:
* Size of cavities
* Thickness, integrities, and motions of walls and septa
* Functioning of the valves
Adding Doppler analysis is useful in assessing the hemodynamic significant of cardiac structural disease
What are Specific Question with Heart Failure?
- Is the LVEF preserved or reduced?
- What is the structure of the LV (hypertrophy, dilated, normal)?
- Are other structural abnormalities present
(pericardial, valvular functioning, right ventricle) that would affect LV functioning?
What is the purpose of the Arterial Catheters?
- Directly and continuously record systolic, diastolic, and MAP
- The MAP is useful clinically because it yields one number that relates to cardiac output and systemic vascular resistance.
- A MAP of less than 60 mm Hg may indicate inadequate tissue perfusion
- Repeat blood samples
- Deliver meds
With Arterial Catheters, what happens if the transduce is too high or low?
- If too low, BP will read high
- If too high, BP will read low
What happens if the A-line is dislodged? What are major comlications associated with arterial lines?
- If A-Line is dislodged, apply firm pressure and immediately notify RN
- Major complications are:
-Bleeding
-Infection
-Lack of blood flow to the tissue supplied by the artery
What are the indications of using Pulmonary Artery Catheter (Swan Ganz Catheter)?
- Evaluate volume status
- Evaluate cardiac function
- Guide medical therapy
- Monitor response to fluids, diuretics, vasoactive drugs
- Monitor high risk patients perioperatively
What are some Interventions related to Acute and/or Chronic muscle Dysfunction?
- Pharm.: Diuretics, ACEI, ARBs, B-Blockers, etc
- Dietary changes and nutritional supplementation (e.g., DASH diet)
- Intra-Arotic Balloon Pump (usually with 2 insertions: Fem. Artery and Left axillary/subclavian)
- Surgical management: Valvular Interventions, Left ventricular assistive device, etc.
What is the Intra-Aortic Balloon Pump (IABP)?
Mechanical device that is used to temporarily support the heart’s function in patients with severe heart failure, particularly those with cardiogenic shock or during high-risk cardiac procedures
With the Intra-Aortic Balloon Pump, what happens during inflation?
The balloon inflates during diastole, which is when the heart is at rest and the coronary arteries are filling with blood. The inflation of the balloon increases the aortic pressure during diastole, improving coronary artery perfusion and
thereby oxygen delivery to the heart muscle
With the Intra-Aortic Balloon Pump, what happens during Deflation?
The balloon deflates just before systole, when the heart is about to contract. This deflation creates a vacuum effect that reduces the afterload, making it easier for the heart to pump blood out into the body.
With Intra-Aortic Balloon Pump, what are the PT considerations with Femoral Artery Insertion (May vary with hospital rules/regulations)?
- No hip flexion is allowed in that LE. No HOB > 30 degrees. This is to prevent migration of catheter. You can log roll the patient.
- Overall patients on bed rest (no OOB activity allowed). Check for bed sores, and monitor pulmonary hygiene
- Once removed, typical protocols call for continued bed rest for ~8 hrs without LE therex (to prevent bleeding). After this period pt may need ROM/strengthening
With Intra-Aortic Balloon Pump, what are the PT considerations with Left Axillary/Subclavian?
OOB activity allowed and encouraged (with hemodynamic monitoring)
Why are Valvular Interventions useful?
Valvular interventions can be used to manage heart failure by repairing or replacing diseased heart valves that contribute to the heart’s dysfunction
Valvular Interventions
What is Percutaneous Balloon Valvuloplasty or Valvulotomy?
Minimally invasive via femoral artery access with balloon- mediated dilation procedure similar to PTCA
Valvular Interventions
What is Annuloplasty?
Replacement of valve ring (annulus), or rim, of mitral and/or tricuspid valves, which can get torn when the valve prolapses from prolonged insufficiency or from the chordae tendinae becoming overstretched and starting to tear away from the ring
Valvular Approach
With Median Sternotomy, what valves are accessed through this?
This is for the Aortic, Mitral or Tricuspid valve
Also used for Coronary Bypasss
Valvular Approach
With Right Anterior Thoracotomy, what valves are accessed through this?
Mitral or Tricuspid
Also used for Coronary Bypasss
Valvular Approach
With Upper Hemi-Sternotomy, what valves are accessed through this?
Aortic valve
Also used for Coronary Bypasss
Valvular Approach
With Lower Hemi-Sternotomy, what valves are accessed through this?
Mitral or Tricuspid
Also used for Coronary Bypasss
What is Ventricular Assist Device?
- Augments pumping ability of right, left, or both ventricles
*Most common device is LVAD
*Bridge to recovery
*Bridge to transplantation
*Destination therapy
(FITT recommendations)
What is the ACSM guideline for Aerobic Exercise for Individuals with Heart Failure?
F: Minimally 3 days per week; preferably up to 5 days per week
I: Start at 40 to 50% and progress to 70-80% VO2 reserve (HRR)
T: Progressively increase to 20-60min a day
T: Aerobic exercise: focusing on treadmill or free-walking and stationary cycling as capable
(FITT recommendations)
What is the ACSM guideline for Resistance Exercise for Individuals with Heart Failure?
F: 1-2 nonconsecutive days
I: Begin at 40% 1RM for Upper Body and 50% 1RM for Lower Body. Gradually increase to 70% 1RM over several weeks to months
T: 1-2 sets of 10-15 reps focusing on major muscles
T: Weight machines, dumbells, elastic bands and/or body weight can be used
