Heart Failure Flashcards
What are the traditional and universal definitions for heart failure?
Traditional definition
Failure of the heart to pump blood at a rate commensurate with the requirements of the metabolizing tissues or is able to do so only with an elevated diastolic filling pressure.
Universal definition and classification of heart failure
HF is a clinical syndrome with symptoms and/or signs caused by a structural and/or functional cardiac abnormality and corroborated by elevated natriuretic peptide levels and/or objective evidence of pulmonary or systemic congestion.
ACCF/AHA (2013) and ESC (2016) definition of HF
ACCF/AHA (2013)
complex clinical syndrome that results from any structural or functional impairment of ventricular filling or ejection of blood. The cardinal manifestations of HF are dyspnoea and fatigue, which may limit exercise tolerance, and fluid retention, which may lead to pulmonary and/or splanchnic congestion and/or peripheral oedema.
ESC (2016)
A clinical syndrome characterized by typical symptoms (e.g. breathlessness,
What is the AHA/ACC Classification of HF?
• Stage A - At risk for HF
Patients at risk for HF but without current or prior symptoms or signs of HF and without structural, biomarker, or genetic markers of heart disease
Patients with HTN, CVD, DM, obesity, known exposure to cardiotoxins, family history of cardiomyopathy
• Stage B - Pre-HF
Patients without current or prior symptoms or signs of HF but evidence of one of the following:
Structural heart disease:
e.g. LVH, chamber enlargement, wall motion abnormality, myocardial tissue abnormality, valvular heart disease
Abnormal cardiac function: e.g. reduced LV or RV ventricular systolic function, evidence of increased filling pressures or abnormal diastolic dysfunction
Elevated natriuretic peptide levels or elevated cardiac troponin levels in the setting of exposure to cardiotoxins
• Stage C - Symptomatic HF
Patients with current or prior symptoms and/or signs of HF caused by
Structural and/or functional cardiac abnormality
Heart Failure in Remission
Persistent Heart Failure
• Advanced HF (Stage D)
Severe symptoms and/or signs of HF at rest, recurrent hospitalizations despite GDT, refractory or intolerant to GDMT
Requiring advanced therapies such as consideration for transplant, mechanical circulatory support, or palliative care
What is the classification of HF According to left ventricular ejection fraction (LVEF)?
• HFrEF - symptomatic HF with LVEF ≤40%
• HFmrEF - symptomatic HF with LVEF 41–
49%
• HFpEF - symptomatic HF with LVEF ≥50%;
• HFimpEF - symptomatic HF with a
baseline LVEF ≤40%, a ≥10 point increase
from baseline LVEF, and a second
measurement of LVEF > 40%.
What is the NYHA Classification - The Stages of Heart Failure?
• Class I - No symptoms and no limitations in ordinary physical activity
• Class II - Mild symptoms (mild shortness of breath and/or angina) and slight limitation during ordinary activity.
• Class III - Marked limitation in activity due to symptoms, even during less-than-
ordinary activity. Comfortable only at
rest.
• Class IV - Severe limitations. Experiences symptoms even whilst at rest
What are the three major determinants of LV performance (reflected as stroke volume)?
• the preload (reflected by venous return and end-diastolic volume)
• myocardial contractility (the force generated at any given end-diastolic
volume)
• the afterload (aortic impedance and wall stress)
What is pre-load and its association with Frank Sterlings Law?
Preload— Preload is defined as the particular stretch or length of LV myocardial fibres at end-diastole, which is determined by the resting force, myocardial compliance, and the degree of filling from the left atrium.
• Landmark studies by Frank and Starling established the relationship between ventricular end-diastolic volume (which is a measure of preload) and ventricular performance (stroke volume
Discuss contractility
Contractility— Myocardial contractility is defined by the force generated at any given preload.
• Thus, the stroke volume at any given fibre length is a function of contractility, as variations in contractility create nonparallel shifts in the developed force-length relation.
What are the two major types of ventricular dysfunction that lead to HF?
• Systolic dysfunction (impaired cardiac contractile function)
• Diastolic dysfunction (impaired cardiac filling)
• Although these mechanisms are interrelated and often concurrent.
What is LVSD?
LV systolic dysfunction (LVSD) refers to decreases in the length-tension relationship and myocardial contractility.
• LVSD causes a shift in the Frank-Starling curve downward and to the right, a downward shift in the end-systolic pressure-volume relationship (ESPVR), and a decrease in the slope of the ESPVR
relationship over a range of pressure
Hemodynamic changes associated with systolic dysfunction
Hemodynamic changes associated with systolic dysfunction trigger neurohumoral activation as well as cardiac remodeling.
• The fall in cardiac output leads to increased sympathetic activity,
which helps to restore cardiac output by increasing both contractility and heart rate.
• The fall in cardiac output also promotes renal salt and water retention, leading to expansion of the blood volume, thereby raising end-diastolic pressure and volume.
Left ventricular hypertrophy
• Left ventricular hypertrophy is also part of the adaptive response to systolic dysfunction since it unloads individual muscle fibres and thereby decreases wall stress and afterload.
• Decreased compliance due to hypertrophy and fibrosis may eventually produce disturbed diastolic function in many patients with advanced HF.
• The failing heart is progressively more afterload-dependent, and small changes in afterload can produce large changes in stroke volume
What is cardiac remodeling?
Remodelling is defined as an alteration in the structure of the heart in response to hemodynamic load and/or neurohormonal activation.
Cardiac remodelling may transition from an apparently compensatory process to a maladaptive one.
What are the factors of cardiac remodeling?
Factors influencing remodelling include alterations in hemodynamic load in response to myocardial injury, blood pressure, and neurohormonal activation.
• It generally includes increases in myocardial mass. The myocyte is the
major cell involved.
Other components include the interstitium, fibroblasts, collagen, and coronary vasculature.
Structural remodelling is often associated with
• Structural remodelling is often associated with molecular events leading to changes in the expression and/or activity of proteins
involved in virtually every aspect of myocardial function, including the
hemodynamic, energetic, and electrical properties of the heart.
What are the three general patterns of remodelling?
• Concentric LV remodelling (in response to pressure overload)
• Eccentric LV hypertrophy (in response to volume overload)
• Mixed concentric/eccentric hypertrophy as may occur following MI
Cellular and molecular alterations
• Myocyte hypertrophy
• Loss of myocytes due to apoptosis or necrosis
• Fibroblast proliferation and fibrosis
• Increased expression of genes that are typical of the fetal heart (eg, B-type natriuretic peptide, myosin heavy chain).
• Increased collagen synthesis and degradation
• Increases in circulating proinflammatory cytokines
• Oxidative stress
• Alteration in calcium handling
What is the Aetiology of Heart failure?
• Hypertensive heart disease
• Dilated cardiomyopathy
• Rheumatic valvular heart disease
• Ischemic heart disease
• Peripartum cardiomyopathy
• Restrictive cardiomyopathy– Cardiac amyloidosis
• Myocarditis
• Pericardial diseases
• Adult congenital heart disease
• Infections – HIV, Chagas disease
• DRUGS – Anthracyclines
What are the Risk factors for heart failure?
• Older age
• Hypertension
• Coronary disease particularly MI
• Diabetes mellitus
• Valve disease
• Cigarette smoking
• Obesity
• LVH on ECG or ECHO
What are the Precipitants Of Heart Failure?
• Infection
• Acute myocardial dysfunction (e.g. ischaemia due to myocardial infarction)
• Uncontrolled hypertension
• Arrhythmias
• Worsening chronic valve disease
• Non-adherence with drugs/diet
• Others-Anaemia, thyrotoxicosis
• Change in drug regimen
• Withdrawal/reduction of heart failure medications inappropriately
• Initiation/increase of rate-control medications inappropriately
• Other medications: steroids, non-steroidal anti-inflammatories, pioglitazones
What are the Clinical Features (signs and symptoms) of HF?
SYMPTOMS
• Exertional dyspnea and/or dyspnea at
rest
• Orthopnea
• Chest pain/pressure and palpitations
• Fatigue and weakness
• Nocturia and oliguria
• Anorexia, weight loss, nausea
SIGNS
• Tachycardia
• Distention of neck veins
• Weak, rapid, and thready pulse
• Rales, wheezing
• S 3 gallop and/or pulsus alternans
• Increased intensity of P 2 heart sound
• Hepatojugular reflux
• Ascites, hepatomegaly, and/or
anasarca
• Central or peripheral cyanosis, pallor
Discuss the Framingham criteria for the diagnosis of heart failure
The Framingham criteria for the diagnosis of heart failure consists of the concurrent presence of either two major criteria or one major and two minor criteria.
Minor criteria
Accepted only if they cannot be attributed to another medical condition are as follows
• Nocturnal cough
• Dyspnoea on ordinary exertion
• A decrease in vital capacity by one-third of
the maximal value recorded
• Pleural effusion
• Tachycardia (rate of 120 bpm)
• Hepatomegaly
• Bilateral ankle oedema
Major criteria
• Paroxysmal nocturnal dyspnoea
• Weight loss of 4.5 kg in 5 days in response to treatment
• Neck vein distention
• Rales
• Acute pulmonary oedema
• Hepatojugular reflux
• S 3 gallop
• Central venous pressure greater than 16 cm of water
• Circulation time of 25 seconds or longer
• Radiographic cardiomegaly
What are the Investigations for HF?
• Complete blood cell (CBC) count
• Electrolyte levels
• Renal and liver function studies
• Fasting blood glucose levels
• Lipid profile
• B-type natriuretic peptide levels/ N-
terminal pro-B-type natriuretic
peptide levels
• 12 lead Resting Electrocardiography
• Chest radiography
• Two-dimensional (2-D)
echocardiography
• Cardiac enzymes
• Urinalysis
• Iron studies
• Thyroid stimulating hormone (TSH) levels
• Lung ultrasound scan
• Nuclear imaging [10]
• Maximal exercise testing
• Pulse oximetry or arterial blood gas
• Noninvasive stress testing.
How can Natriuretic peptide be used for investigations?
• B-type natriuretic peptide (BNP): BNP is a sensitive but non- specific marker of heart failure.
• AHF is unlikely and can be ruled out if:
• BNP is less than 100 ng/litre
• NT-proBNP is less than 300 ng/litre
