Left-sided Heart Failure

Left-sided Heart Failure

1. Common Causes

   • Coronary Artery Disease (National Health Service, 2018)
     • Occurs when fatty deposits called atheromas, build up in the coronary arteries of the heart
       • This build up of fatty deposits lead to the narrowing of the arteries, decreasing blood flow to the heart.
         • As blood flow is decreased to the heart, so do the important nutrients and oxygen needed to sustain the hearts functioning. This inadequate supply of blood and nutrients to the heart is called ischemia
           • Ischemia of the heart leads to the death of healthy heart tissue and the development of scar tissue formation. This scar tissue provides less elasticity and decreases the ability of the left ventricle to effectively pump blood to the rest of the body.
           • Figure 6
   • High Blood Pressure (Baptist Health, 2017)
     • Increased blood pressure places a greater stress on the internal walls of the arteries leading to damage over time.
       • This damage attracts the formation of fatty plaque deposits, which are used by the body to patch up damage. These plaque deposits lead to a narrowing of the blood vessels called 'atherosclerosis,' which affect the elasticity and contractibility of the blood vessels, further increasing the blood pressure
         • In an attempt to adequately circulate blood, the heart must now work harder to overcome the increased pressure within the blood vessels. Over time this increase workload leads to the hypertrophy of the Left ventricle, and the formation of scar tissue.
     • Figure 4
   • Diabetes (Baptist Health, 2017)
     • High levels of glucose in the blood stream create microscopic damage which lead to long term inflammation if not controlled
       • This inflammation leads to the development of atherosclerosis as fatty deposits promote decreased lumen size in the arteries.
         • Over time, atherosclerosis can lead to ischemia and myocardial infarction, which causes long term damage to the muscles of the heart, affecting their ability to circulate blood via the left ventricle.
     • Figure 3
   • Congenital Defects (National Health Service, 2018)
     • Genetic factors, substance abuse and certain medications during pregnancy can lead to congenital heart defects in newborns.
       • Septal defects, underdeveloped heart muscle and pulmonary valve stenosis can lead to the ineffective functioning of the left ventricle, leading to premature left sided heart failure.
         • Figure 5
   • Additional Causes (Baptist Health, 2017)
     • Smoking: Causes damage to arteries, leading to increased blood pressure and workload on the left ventricle
     • Excessive Alcohol Intake: Can lead to increased triglyceride levels and high blood pressure
     • Sleep Apnea
       • Obstructive sleep apnea (OSA) is linked to obesity. In a cyclical manner, obesity may lead to sleep deprivation and sleep deprivation is associated with further obesity. This causes an increased cardiac workload and potential left ventricular hypertrophy (American Heart Association, 2015).
     • Cardiomyopathy: Increased rigidity leading to a decrease in heart contractility
     • Obesity: Increased cardiac workload leads to left ventricular hypertrophy
     • Anemia : Decreased oxygenation of blood leading to increased cardiac output and workload of left ventricle
     • Nutritional Deficiencies: Decrease muscle mass and tone of heart, leading to impaired cardiac output
   • Figure 2

2. Manifestations (The National Centre for Biotechnology, 2019; Lewis, Dirksen, Heitkemper, Bucher, & Camera, 2014)

   • Signs
     • Crackles: Due to pulmonary edema
     • Left ventricular hypertrophy: In response to increased cardiac workload
     • Peripheral Cyanosis: Due to insufficient circulation to extremeties
       • Figure 7
     • Decreased breath sounds: Due to pleural effusion
     • Pulses alternans
     • S3 & S4 upon auscultation
     • Increased heart rate
       • Normal HR: 60-100 bpm
     • Cheyne-Stokes respirations
     • Left ventricular heaves
     • Decrease in PaO2 and slight increase in PaCO2
       • Normal PaO2: 80-100 mmHg
       • Normal PaCO2: 35-45 mmHg
     • Left sided heart failure is the most common form of initial heart failure. Usually it results from left ventricular dysfunction, causing blood to back up through the left atrium and in the lungs and this is manifested as pulmonary congestion and edema.
   • Symptoms (Costa, Costa, & Souza, 2016)
     • Fatigue: Due to decrease in circulating oxygen
     • Dyspnea: Due to pulmonary edema
     • Pulmonary edema: Due to fluid backup
     • Paroxysmal nocturnal dyspnea
     • Nocturia
     • Orthopnea
     • Dry, hacking cough
   • Figure 8

3. Treatment

   • Medications (Lewis et al, 2014)
     • Beta-Adrenergic Blockers
       • Work to limit the negative impact of the SNS on the compromised heart by prohibiting effects like increased heart rate. These drugs must be started gradually since they can reduce the heart's contractility.
         • Should be used in all stable patients with current or previous symptoms of HF and decreased LVEF unless contraindicated (RxFiles, 2017).
           • Ex: metoprolol, bisoprolol, carvedilol
     • Angiotensin Converting Enzyme Inhibitors (ACEI)
       • First-line therapy as they block the conversion of angiotensin I to angiotensin II, stopping the vasoconstrictive effects of angiotensin II and therefore improving cardiac output. However, these medications can cause a cough and angioedema that is intolerable to patients.
         • Should be used in all patients with no symptoms and a LVEF <35% and all patients with HF symptoms and LVEF <40% as soon as possible and continue indefinitely. There is good evidence to support its ability to decrease mortality in those with HF and they may be used with diuretics (RxFiles, 2017).
           • Example: Ramipril
     • Nitrates/Hydralazine (RxFiles, 2017)
       • Increases arterial blood flow to the heart by promoting release of nitric oxide from the endothelium which causes vasodilation of venous and arterial systems.
         • Combination of isosorbide dinitrate and hydralazine is recommended for those unable to tolerate ACEI or ARB, and for those that are African-American in addition to standard therapy..
     • Diuretics
       • Work to eliminate excess fluid in the body by encouraging the kidneys to excrete sodium and water. In doing so, less blood returns to the heart and the heart's ability to function is more efficient.
         • Loop diuretics recommended for most patients with HF and congestive symptoms. Can be used in combination with a thiazide diuretic if hypervolemia persists, but weight, renal function, and serum potassium need to be closely monitored (RxFiles, 2017).
           • Ex: Furosemide and Hydrochlorothiazide
       • Figure 11
     • Angiotensin II Receptor Blockers (ARB)
       • Prevent angiotensin II from binding with its receptors so vasoconstriction is not initiated and the blood vessels dilate.
         • Should be used in patients that are unable to tolerate ACEI, or used in conjunction with an ACEI for those who do not tolerate beta-blockers or have persistent HF symptoms despite other treatment (RxFiles, 2017)...
           • Ex: Valsartan, Candesartan, Losartan
     • Aldosterone Antagonists
       • Similar to the loop and thiazide diuretics, these drugs promote excretion of sodium and water, but K+ is not lost in the process (potassium-sparing diuretics). Therefore,, the potential for hyperkalemia must be monitored. The normal range for serum K+ is 3.5-5 mEq/L.
         • Recommended only for select patients with moderate to severe symptoms of HF and reduced LVEF whose renal functioning and K+ can be closely monitored (RxFiles, 2017).
           • Ex: Spironolactone and Eplerenone
     • Positive Inotropes
       • A class of medications that strengthen the force of the heart's contraction to improve cardiac output. For HF, there are 3 subsections of drugs in this class.
         • Digitalis Glycoside
           • Ex: Digoxin
         • B-Adrenergic Agonists
           • Ex: Dopamine and dobutamine
         • Phosphodiesterase Inhibitors
           • Ex: Milrinone
   • Surgical Interventions
     • Heart Transplantation
       • This high-risk procedure is a last resort that is only used when all other treatments fail. This involves removing the heart and replacing it with a healthy heart from a donor. However, there is a shortage of donor hearts available and only pre-selected candidates are eligible to receive a donated heart, often having to wait months to years to receive a new heart. Additionally, the follow-up after the surgery is extensive because there are many risks associated with the procedure, such as organ rejection by the body (Colucci, 2019).
     • Devices
       • Cardiac resynchronization therapy (CRT) uses an implantable biventricular pacemaker that sends electrical signals to both ventricles of the heart telling them to contract at the same time. This maximizes the amount of blood pumped from the heart to the rest of the body (Mayo Clinic, 2019c).
         • CRT can be done using a pacemaker (CRT-P) or an implantable cardioverter-defibrillator (CRT-D) with the difference being that while the CRT-D can pace like a CRT-P, it can also shock the heart if the patient's heart enters into a lethal rhythm such as ventricular tachycardia.
       • A left ventricular assist device (LVAD) is a surgically implanted mechanical pump that helps the left ventricle pump blood to the rest of the body. This treatment option is used either as a means of a bridge for those awaiting transplant, or is also a destination therapy for those that are not candidates for a heart transplant. This device has been proven to prolong and improve patients' lives (Stanford Health Care, 2019).
         • Late right-sided heart failure has been shown to be a potential complication in patients with LVADs. Patients with late right-sided HF have a worse quality of life and are more likely to die sooner than those without late right-sided heart failure (Rich et al., 2017).
       • An intra-aortic balloon pump (IABP) is a short-term treatment that uses a balloon attached to a catheter. One end of the catheter is attached to a computer system, while the end with the balloon is inserted through the femoral artery into the aorta. Once positioned correctly, the balloon inflates when the heart relaxes and deflates when it contracts. As a result, blood flows back towards the coronary arteries and the heart is able to pump out more blood without using as much energy (Johns Hopkins Medicine, 2019).
       • Pacemakers and implantable cardioverter-defibrillators (ICDs) are similar devices that are implanted under the skin and detect abnormal heart rhythms. When detected, both of these devices send electrical signals to the heart in an effort to prompt the heart to beat at a normal rate. The main difference between these two devices however, is that if it detects a dangerous rhythm, ICDs are able to shock the heart in an effort to return the heart to a normal rhythm (Beyerbach, 2019).
     • Coronary Artery Bypass Grafting (CABG)
       • Also known as Heart Bypass Surgery, this procedure works to improve blood flow to the heart by taking blood vessels from other parts of the body (such as the arms and legs), and connecting them above and below the narrow/blocked artery as a means of bypassing the compromised coronary arteries. After surgery, medications and lifestyle changes will be ordered to help reduce further symptoms (NIH, 2019).
     • Ventricular Reconstruction
       • If a patient had an MI that affected the left ventricle, scar tissue will form and can become an aneurysm which can cause the left ventricle to enlarge and cause HF.. In this case, surgeons remove some of this scar tissue and use a patch to reshape the heart into its normal form. While this intervention is not a HF cure, it improves the heart's ability to pump properly and therefore, leads to a reduction in HF symptoms such as chest pain (UChicago Medicine, 2019).
     • Mitral Valve Repair/Replacement
       • The mitral valve is located between the left atria and the left ventricle. This procedure involves either repairing or replacing this valve and it is done when the valve has hardened so the blood cannot move forward through the valve, or if the valve is too loose causing blood to flow backwards through the valve. This procedure is a means of symptom management, rather than reducing mortality (Medline Plus, 2019).

4. Potential Complications (Baptist Health, 2017)

   • Angina
     • Chest, jaw, and neck discomfort may result due to lack of blood flow to the heart..
   • Atrial Fibrillation
     • This abnormal heart rhythm can increase the risk of blood clot formation and stroke.
   • Myocardial Infarction
     • Once the heart muscle is injured by a lack of blood flow for an extended period of time, the infarcted area cannot be restored and that section of the heart becomes useless.
   • Decreased Renal Function
     • With a lack of blood flow to the kidneys, they are unable to work as effectively. If this lack of blood flow to the kidneys continues for long, this may lead to renal failure.
   • Right-sided Heart Failure
     • The right side of the heart becomes weakened by left-sided heart failure because fluid backs up into the lungs. This causes eventual right-sided heart failure and potentially GI and liver issues as well.
   • Left Ventricular Thrombus (Lewis, 2014)
     • Both the enlargement of the left ventricle (LV) and decreased cardiac output increase the risk of developing thrombi in the LV.
   • Cardia Cachexia
     • Weight loss of at least 7.5% of one's total body weight within 6 months that is unintentional. This can be life-threatening if adequate nutrition is not used to supplement.

5. Patient Teaching (Baptist Health, 2017; Lewis et al, 2014)

   • What HF is
     • Discuss expectations of life with this disease and the treatment process
   • Health Promotion
     • Work to decrease stress levels
       • Stress can cause irregular or fast heartbeats
       • Figure 16
       • Figure 17
     • Smoking cessation
     • Get the flu vaccine annually to reduce risk of viral infection HF complications
     • Reduce alcohol intake to 1 drink per night
   • Exercise & Rest
     • Live an active lifestyle that is balanced between exercise activities and rest
     • Do not participate in exercise activities until your HCP has ruled it is safe to do so
       • Figure 15
   • Drug Therapy
     • Take medications as prescribed, even if the patient begins to feel better, as stopping the medications can exacerbate their HF.
     • Take pulse and blood pressure each day before taking medications to monitor for therapeutic effect of medications
       • Figure 18
     • Adopt a system that allows patients to easily track when medications are taken (ex. a daily chart)
   • Dietary Therapy
     • Monitor weight daily
       • Weight should be taken at the same time each day and should be done in the mornings after urinating
     • Maintain a healthy diet
       • Restrict fluid to a maximum of 6-8 cups a day, noting that foods such as fruit have hidden fluids
       • Do not add salt to foods or have it easily accessible. Also, demonstrate how to read food labels as a means of identifying and avoiding foods high in sodium such as processed foods.
         • Figure 14
   • Contacting the Health Care Provider (HCP)
     • Visit your HCP regularly for checkups to help with early detection of worsening HF conditions
     • Report any undesirable signs/symptoms of medications to the HCP promptly, as your medication regime may be able to be adjusted
     • Immediately report to the HCP if you experience the onset or worsening of any of the HF signs and/or symptoms
       • Figure 19

6. Priority Nursing Interventions & Collaborative Care (Lewis et al, 2014)

   • Reducing patients' activity intolerance
     • Work with occupational, physical, and/or recreational therapists to develop and implement an exercise program tailored to the patient's abilities
     • Help ensure activities/exercise are being scheduled around adequate amounts of rest in order to decrease cardiac workload
     • Teach patients and their loved ones about oxygen conservation and monitor patient's oxygen response to increased activity levels
   • Managing fluid and electrolytes
     • Monitor patients' intake and output to assess renal function
     • Weigh patients daily and track patterns as a means of early identification of diuresis and weight loss or fluid retention and weight gain
     • Keep track of respiratory pattern to assess for early symptoms of pulmonary congestion
     • Monitor electrolyte levels as an indicator of therapeutic treatment benefits/changes that need to be made
   • Addressing impaired gas exchange
     • Place patients in positions such as semi-Fowler's when dyspnea presents in order to improve ventilation
     • Administer additional oxygen as ordered when needed to maintain/improve O2 levels, and tailor oxygen delivery route based upon activity (ex. switch to nasal prongs from mask when eating)
       • Ideal O2 Sat is 95-100% however, if not feasible, levels should be kept to at least 92%
     • Auscultate lungs to assess for adventitious/altered breath sounds to identify presence of congestion, and observe respiratory pattern to assess respiratory status
       • Figure 12
   • Reducing patients' anxiety
     • Guide patients through use of different relaxation techniques and help to identify triggers
     • Be calm and transparent with patients, taking the time to explain all procedures thoroughly
   • Enhancing patients' knowledge base
     • Always begin by assessing patients' current knowledge base in order to identify areas that need further reinforcement
       • Alter education to suit each patient's unique needs
       • Figure 13

7. Risk Factors (Baptist Health, 2017)

   • Age
     • The risk of HF generally increases with age, with 50-70 years old presenting the highest risk of development.
   • Race
     • African-American individuals are at increased risk of developing heart failure due to their increased likelihood of having hypertension.
   • Gender
     • In general, males are more at risk than females.
   • Viral infections
     • Viral infections including adenovirus, herpes simplex virus, and hepatitis B and C can cause myocarditis, an inflammation of the myocardium. This leads to a risk of weakening the heart muscle and subsequent HF (Mayo Clinic, 2019d).
   • Aortic stenosis
     • Narrowing of the aortic valve opening slows the flow of blood and can weaken the heart, impacting the heart's ability to pump.
   • Chronic diseases
     • Diabetes, HIV, hyperthyroidism, and hypothyroidism all increase risk of HF.
   • Congenital heart defects
     • Structural heart defects may inhibit blood from properly pumping to the rest of the body.
   • History of MI
     • Previous injury to the heart may affect its ability to pump properly.
   • Dysrhythmias
     • Frequent and fast heart rates especially can weaken the heart muscles and therefore increase the risk of developing HF.

8. Diagnostic Procedures and Technologies

   • Cardiac Catheterization
     • A procedure to find diseases of the heart muscle, valves or coronary (heart) arteries. During the procedure, a thin, hollow tube called a catheter is inserted into a large blood vessel that leads to the heart (American Heart Association, 2019a; Mayo clinic, 2019).
     • Coronary angiography
       • This procedure is done during cardiac catheterisation. During this procedure, a contrast dye visible in X-ray is injected through the catheter. X-ray images show the dye as it flows through the heart arteries. This shows where arteries are blocked (American Heart Association, 2019a; Mayoclinic, 2019).
     • Checks pressures in all four chambers of the heart (American Heart Association, 2019a)
     • Evaluates the heart chambers' ability to contract and pump blood (American Heart Association, 2019a)
   • Chest X-ray
     • Chest X-ray is used to show pulmonary venous congestion or edema in patients with heart failure (Ponikowski et al., 2016). There may be significant left ventricular dysfunction without cardiomegaly on chest X-ray (Ponikowski et al., 2016). The current standard is computed tomography of chest (Ponikowski et al., 2016). Chest X-ray reveals information about fluid build up in lungs (Mayo clinic, 2019a).
   • Echocardiogram
     • A term referred to all cardiac ultrasound imaging techniques, including two-dimensional and three dimensional echocardiography, pulse and continuous wave doppler, colour flow Doppler, tissue Doppler imaging (TDI) contrast echocardiography and deformation imaging (Ponikowski et al., 2016). It provides important information about the heart's chamber volumes, ventricular systolic and diastolic function, wall thickness, valve function, and pulmonary hypertension (Ponikowski et al., 2016; Baptist health, 2017)
       • Transthoracic echocardiography (TTE) is the method of choice for assessment of myocardial systolic and diastolic function of both left and right ventricles. (Ponikowski et al., 2016).
   • Brain Natriuretic peptides (BNPs)
     • If more than one of these signs and symptoms are present than assessment of natriuretic peptides is done (Ponikowski et al., 2016). If BNPs are elevated then echocardiography is performed (Ponikowski et al., 2016).
     • It is used as an initial diagnostic test. It is used when echocardiography is not readily available. Elevated BNPs help establishes initial diagnosis, but requires further cardiac investigation. (Ponikowski et al., 2016).
     • BNP levels correlate positively with the degree of left ventricular dysfunction and can help differentiate dyspnea caused by heart failure vs dyspnea from other causes. (Lewis et al, 2014)
     • BNP < 100 ng/L means HF is very probable, BNP of 100-150 ng/L means HF is probable, and BNP > 500 ng/L means HF is very probable (Lewis et al, 2014 p. 934).
   • 12 lead Electrocardiogram (ECG)
     • 12-lead ECG determines heart rhythm, heart rate, QRS morphology, and QRS duration and helps determine if parts of the heart are enlarged, overworked or damaged (Ponikowski et al., 2016; Baptist health, 2017).
   • History and physical examination
     • For patients with suspected heart failure, a clinical history and physical examination should be done (Ponikowski, Voors, Anker, Bueno, John, Andrew, ... & Meer, 2016). Clinical history should include history of coronary artery disease such as myocardial ischemia (MI), history of arterial hypertension, exposition to cardiotoxic drugs or radiation, use of diuretics, orthopnea and paroxysmal nocturnal dyspnea (Ponikowski et al., 2016). Physical examination should include listening to lungs for rales, heart murmur (S3, S4 sounds), nocturia, dyspnea, orthopnea, dry, hacking cough, paroxysmal nocturnal dyspnea (Ponikowski et al., 2016; Lewis et al, 2014).
   • Exercise test
     • Measures the health of the heart in response to exertion (Mayo clinic, 2019b). It is recommended as a part of the evaluation for heart transplantation and/or mechanical circulatory support, is considered to optimize prescription of exercise training, used to identify the cause of unexplained dyspnoea and to detect reversible myocardial ischemia (Ponikowski, et al., 2016).
   • Diagnostic tests are done when a patient is newly diagnosed with heart failure to determine best therapies, to detect reversible/treatable causes of HF and identify comorbidities interfering with HF (Lewis et al., 2014)
     • Hemoglobin and white blood cells, sodium, potassium, urea, creatinine (with estimated GFR), liver function tests (bilirubin, AST, ALT,), glucose, HbA1c, lipid profile, TSH, ferritin, TSSAT, and natriuretic peptides tests are done (Ponikowski et al., 2016, p. 907).

9. Anatomy and Physiology

   • Oxygen rich blood travels from the lungs to the left atrium and then to the left ventricle, which is then pumped to the rest of the body (American Heart Association, 2019b). The left ventricle supplies most the heart's pumping power so it is bigger than the other three chambers of the heart (American Heart Association, 2019b). In left-sided (LV) heart failure, the left side of the heart must work harder to pump the same amount of blood (American Heart Association, 2019b).
     • Heart failure terminology is based on measurement of the left ventricular ejection fraction (LVEF) (Ponikowski et al., 2016). There are three types of left sided heart failure. Heart failure with reduced ejection fraction (HFrEF), heart failure with mid-range ejection fraction (HFmrEF), and heart failure with preserved ejection fraction (HFpEF) (Ponikowski, et al., 2016).
       • Patients with an LVEF in the range of 40-49% are considered to be in a ‘grey area’ and this is defined as HFmrEF (Heart failure with mid-range ejection fraction) (Ponikowski et al., 2016, p. 899).
         • Patients with HFmrEF primarily have mild systolic dysfunction with some diastolic dysfunction (Ponikowski et al., 2016)
       • Heart failure with reduced ejection fraction (HFrEF) is also called systolic failure: The left ventricle loses its ability to contract normally (American Heart Association, 2019b). The heart can't pump with enough force to push enough blood into circulation (American heart association, 2019). In HFrEF, LVEF is typically considered <40% (Ponikowski et al., 2016, p. 899).
         • Patients with HFrEF have subtle systolic dysfunction, but also have diastolic dysfunction (Ponikowski et al., 2016). This is why the term reduced left ventricular ejection fraction is preferred over preserved or reduced systolic function (Ponikowski et al., 2016)
       • Heart failure with preserved ejection fraction (HFpEF) is also called diastolic failure (or diastolic dysfunction): The left ventricle loses its ability to relax normally because the muscle has become stiff (American Heart Association, 2019b). The heart can't properly fill with blood during the resting period between each beat (American Heart Association, 2019b). Patients with HFpEF typically has LVEF of ≥50% (Ponikowski et al., 2016, p. 899).
         • HFpEF diagnosis is more challenging compared to HFrEF (Ponikowski et al., 2016). HFpEF patients generally have an increase in left ventricle wall thickness and/or increased left atrial size as a sign of increased filling pressures (Ponikowski et al., 2016)
           • Figure 9

10. Epidemiology

    • Globally, more than 37.7 million people are living with heart failure (Ziaeian & Fonarow, 2017). In 2011 in the USA, an estimated 5.7 million people were living with heart failure and 870,000 new cases are diagnosed every year (Ziaeian & Fonarow, 2017). In Canada, approximately 669,600 (3.6%) Canadian adults aged 40 years and older are living with diagnosed heart failure (Government of Canada, 2017). About 92,900 (5.2 per 1,000) Canadian adults aged 40 years and older get a new diagnosis of heart failure (Government of Canada, 2017). Diagnosed heart failure prevalence is higher among men than women (Government of Canada, 2017). On average men with diagnosed heart failure are 10% to 20% more likely to die than women (Government of Canada, 2017).
      • Heart failure with preserved ejection fraction (HFpEF ) accounts for 44% to 72% of all cases of HF (Ziaeian & Fonarow, 2017). According to Ziaeian & Fonarow (2017), prevalence of HFpEF is highest in the United States of America and Canada, followed by western Europe, and the lowest rates are in Eastern Europe and Russia.
    • Figure 10

11. Figure 1

Images and files in the map