heart failure Flashcards
definition of heart failure according to AHA?
HF is a complex clinical syndrome with symptoms and signs that result from any structural or functional impairment of ventricular filling or ejection of blood
introduction of hf
and when it reffers to CHF
Heart failure is inability of the heart to pump enough blood to meet the blood flow and metabolic demands of the body
It results from any structural or functional cardiac disorder that impairs the ability of the ventricle to fill with or eject blood.
When the condition is accompanied with S & S of congestion it is referred to as CHF
what are Four major determinants contribute to left ventricular (LV) workload?
Preload: forces acting on the venous side of circulation that affect myocardial wall tension
Afterload: tension in the ventricular wall as contraction (systole) occurs
Contractility: the myocardium’s intrinsic ability to develop force and shorten its fibers independent of preload and afterload
Heart rate (HR)
what is Stroke volume (SV) and normal level?
is the volume of blood ejected by the heart with each systolic contraction
(normal, 4–7 L/minute)
Cardiac output (CO)
is the amount of blood pumped in 1 minute (CO = SV × HR).
Left ventricular ejection fraction (LVEF)
and normal level
is the percentage of LV end-diastolic volume expelled during each systolic contraction (normal, 60%–70%).
Systolic dysfunction
also known as low ejection fraction HF, is when the LVEF is <40%.
Compensatory Mechanisms in CHF
Hemodynamic Responses:
* Increased contractility
* Increased HR
* Vasoconstriction: leading to cardiac remodelling
Neural Responses: Symapthetic ANS
Renal Responses: RAAS
Hormonal Responses: Aldosterone
Cardiac Remodeling
Cardiac remodeling and its 3 types
Progression of HF results in a process referred to as cardiac remodeling
1. Restrictive cardiomyopathy: the left ventricular walls may be normal, hypertrophic, or slightly dilated
2. Dilated cardiomyopathy: results in thinning of the left ventricular walls and a decrease in systolic function
3. Hypertrophic cardiomyopathy: there is a marked thickening of the left ventricular walls leading to diastolic or systolic failure
types of heart failure
- Low output, systolic dysfunction(dilated cardiomyopathy)
- Diastolic dysfunction
- High-output failure
(uncommon)
Systolic Dysfunction due to
decreased contractility
* Dilated cardiomyopathies (dilated left ventricle)
* Reduction in muscle mass (e.g. myocardial infarction)
↑Afterload
* pressure overload: HTN, aortic stenosis
- EF less than 40
less blood pump out of the ventricle in each beat causing accumulation of blood in ventricles
diastolic dysfuntion
Restriction in Ventricular Filling
Thickened left Ventricle (hypertrophic cardiomyopathy
Stiff left ventricle (restrictive cardiomyopathy)
impaired left ventricular filling
pressure and/or volume overload)
Pericardial disease (e.g. pericarditis, pericardial tamponade)
Drugs That May Precipitate or Exacerbate HF
Agents Causing –ve Inotropic Effect
Antiarrhythmics(disopyramide, flecainide))
betablocker
non dihydropyridine ccb
Itraconazole
Terbinafine
Cardiotoxic Agents
Doxorubicin
Daunorubicin
Cyclophosphamide
Cocaine & Amphetamines (Long-term use)
Agents Causing Na+ and Water Retention
* nsaid, cox II inhibtor, salisylate
* androgen, estrogen, glucocorticoid
* Na+-containing drugs (e.g. carbenicillin disodium)
Thiazolidinediones
Licorice
Na and water retetion: Slangent
Cardiac: deadly drug after coctail (ddac)
Congestion in HF
Left-Sided Heart Failure:
Results from LV dysfunction – Blood backs up into Left atrium – Pulmonary congestion and edema
Right-Sided Failure:
Results from diseased right ventricle - Blood backs up into right atrium and venous circulation – Peripheral oedema & Ascites
Diagnostic Tests:
Clinical history
Physical Exam
ECG
Initial lab investigations (e.g. SrCr, CBC)
Chest X-ray
Transthoracic Echocardiography
Radionuclide Angiography
Coronary Angiography
Cardiac MRI
Assessment of Functional Capacity: e.g. NYHA
Classification / Staging of HF
Stage A: At-Risk for Heart Failure
Stage B: Pre-Heart Failure
Stage C: Symptomatic Heart Failure
Stage D: Advanced Heart Failure
Stage A: Heart Failure
- Patients at risk for HF but without current or previous symptoms or signs of HF.
- No structural or functional heart disease or abnormal biomarkers.
- This stage includes individuals with conditions like hypertension, diabetes, obesity, or a family history of cardiomyopathy.
Stage B: Heart Failure
patients without current or previous symptoms/signs of HF but with evidence of 1 of the following:
Structural heart disease
Evidence of increased filling pressures
Risk factors and increased natriuretic peptide levels or persistently elevated cardiac troponin in the absence of competing diagnoses
Stage C: Heart Failure
Patients with current or previous symptoms/signs of HF.
Stage D: Heart Failure
Patients with current or previous symptoms/signs of HF and:
Marked HF symptoms that interfere with daily life.
Recurrent hospitalizations despite attempts to optimize guideline-directed medical therapy (GDMT).
Non-pharmacological Treatment
Dietary modifications e.g. Sodium and fluid restriction
Risk factor reduction e.g. smoking & alcohol cessation
Immunizations: influenza and pneumococcal vaccines (to reduce risk of serious respiratory infections)
Moderate physical activity
Daily weighing is recommended & any increase in weight or decline in exercise tolerance might indicate exacerbation
increase in weight 1-2 kg –> pheripheral edma loop dirutic pnr for 2-3 days twice
Goals in Pharmacotherapy of HF
slowing disease progression, and improving survival in chronic HF act by targeting neuro-hormonal blockade.
These include: ACE inhibitors, ARBs, β-blockers, and aldosterone antagonists
Management of HF Stage A patients:
Goals for Stage A
minimize the impact of diseases that can injure the heart.
Key Lifestyle Modifications:
regular physical activity, maintaining normal weight, healthy dietary, and avoiding smoking
Medications:
Antihypertensive and lipid-lowering therapies: to decrease the risk for stroke, MI, and HF.
ACE inhibitors should be considered in high-risk vascular disease patients.
Management of HF Stage B patients
Goals for Stage B HF Patients:
prevent or slow the Syndrome of Clinical HF
Interfere with neurohormonal pathways
Key Medications:
ACE inhibitors (ACEi): In patients with LVEF ≤ 40%,
Statins: In patients with a history of (MI) or (ACS)
Beta-blockers: history of ACS and LVEF ≤ 40%, beta-blockers can be added to ACEi therapy
hormone that increased in HF
Norepinephrine, Ag2 & aldosterone levels
Management of HF Stage C patients
goals and treament?
goals:
alleviating fluid retention, Minimize disability, Slow disease progression, Reduce hospitalizations and mortality
treatment:
Diuretics: for patient with fluid retention, improving symptoms, relive congestion and preventing worsening HF.
Thiazides: Added to loop diuretics only if not responding to moderate/high doses, to minimize electrolyte abnormalities.
Neurohormonal antagonists:to minimize the effects of the RAAS and SNS.
ARNi is ARB + Neprilysin inhibitors (Valsartan + Sacubitril) reduced the cardiovascular death or HF hospitalization by 20% but avoid concurent with ace or after 36 hrs of ace dose or in case of angioedema.
**ACE inhibitors (or ARBs),
β-blockers, and aldosterone antagonists **
Digoxinmay be added to improve symptoms.
hydralazine and isosorbide dinitrate in black patients.
avoiding excessive sodium intake is reasonable to reduce congestive symptoms
In some cases, these include the combination of ACE inhibitors and ARBs, although the evidence for this option is limited.
Management of HF Patients with advanced stage D disease:
goal: improve quality of life.
Treatment:
mechanical support,
transplantation,
continuous use of I.V. vasoactive therapies
In addition to maintaining an optimal regimen of chronic oral medications.
Diuretics for HF
Indicated for rapid symptomatic relief of congestion or cardiac distension
Guidelines recommend diuretics, both acutely and chronically, but ONLY if clinical volume overload is evident.
ACEI in HF
drug of choice in HF even in low lf failure
initaited low does and increased to high dose
ace + BB typically used
ace + aldoestron = dont use together
side effects
if angioedma its CL and stop using if occur
cough continue using
captopril is DOC in emergency
Have both preload- and afterload-reducing properties and consequent volume reducing potential.
Benefits of ACE inhibitors & ARBs in CHF
Improvement in: LV size and function, Clinical symptoms & QoL
Increase exercise tolerance
Decrease disease progression
Reduce rate of: Hospitalization & Mortality
also effective in preventing HF development in high-risk patients e.g. post – MI when used early.
Beta-Adrenergic blocking agents in HF
bb + ace first line
bisoprolol, metoprolol or carvedilol
initiated at low doses, with gradual increase as tolerated.
Symptoms can worsen with β-blockers, and it may take weeks or months before patients notice improvement.
It may take 2 to 3 months of therapy to see a beneficial response with some agents e.g. metoprolol
Abrupt withdrawal of beta-blockers therapy can lead to clinical deterioration and should be avoided
Aldosterone antagonists in HF
are mid dirutic
Recommended when EF < 35%
Spironolactone most common 25-20 mg
Hyperkalemia risk in elderly and kidney disese or use with ace
hydralazine and nitrate in HF
hydralazine = dialted artery = decrease afterload
nirate = dialted venus = decease preload
complementary action when used together and effective in pulmonary edma
used in patient non responsive to bb and ace
Digoxin in HF
have negative introtropic effect, which increase contrctility,
use 0.125-0.20 mg daily with therapeutic level 1ng/ml
Digoxin has many D/D interactions e.g. Amiodarone, Atorvastatin, CCBs.
Ocular manifestations of digoxin toxicity include xanthopsia, or seeing yellow.
Digoxin toxicity and management
toxicity:
* hypokalemia
* hyper ca+ and hyper mg+
* renal failure
* drug that cause digoxin tox: quidine, verapmil, loop dirutic
managment:
discountine therpy
serum k+ level if less give k+ supps
if arrythemia and severe toxicity give antidote digoxin specific AB ( digibind)
