Heart failure Flashcards
Definition of heart failure + 3 categories of ejection fraction
Condition in which heart is unable to generate cardiac output sufficient to meet demands of body
- Due to an inherited or acquired abnormality of cardiac structure and/or function
- Commonly categorized into 3 broad groups
- HF with reduced ejection fraction (HFrEF = systolic failure): LVEF <40%
- HF with mildly reduced ejection fraction: LVEF = 40-50%
- HF with preserved ejection fraction (HFpEF = diastolic failure): LVEF > 50%
Epidemiology/RF of HF
- Hx of MI
- Diabetes mellitus
- Dyslipidaemia
- African/hispanic
- Old age (65+)
- Male sex
- Hypertension
- Left ventricular dysfunction
- Cocaine abuse
- Exposure to cardiotoxic agents
- Renal insufficiency
- Valvular heart disease
- Sleep apnoea
- Family history of heart failure
Precipitants of HF (HEART FIALED)
Hypertension (common) Endocarditis/environment (e.g.heatwave) Anaemia Rheumatic heart disease and other valvular disease Thyrotoxicosis Failure to take meds (very common) Arrhythmia (common) Infection/Ischemia/Infarction (common) Lung problems (PE, pneumonia, COPD) Endocrine (pheochromocytoma, hyperaldosteronism) Dietary indiscretions (common)
Afterload + Preload?
Afterload = Sqeeze
- pressure that the heart needs to exert to eject blood during systole
Preload = Stretch
- EDV –> volume of blood in ventricle after diastole –> stretch
Systolic Failure (HFrEF) mechanism
Contractility problem “pump dysfunction”
- -> dec. contractility
- -> systolic ventricular dysfunction
- -> dec. stroke volume
- -> dec. LV ejection fraction (LVEF)
- -> dec. CO (not enough blood pumped to circulation)
Causes of Systolic HF
- Ischaemia due to MI –> cardiac tissue damage
- Dilated cardiomyopathy (dilated & weakened ventricles)
- Long standing hypertension
- Cardiac arrhythmias
Diastolic Failure (HFpEF) mechanism
Very stiff ventricles / cannot relax normally
–> dec. ventricular compliance –> diastolic ventricular dysfunction –> red. ventricular filling + inc. diastolic pressure –> normal SV but dec. preload (abnormal filling) –> dec. CO with normal ejection fraction
Causes of Diastolic HF
Increased stiffness of ventricles
- ventricular hypertrophy
- long standing hypertension, AS, hypertrophic cardiomyopathy
- restrictive cardiomyopathy
Impaired relaxation of ventricle
- constrictive pericarditis
- pericardial tamponade
Left-sided HF (HFrEF):
- afterload & preload
Increased left ventricular afterload:
- increased mean aortic pressure; (e.g., arterial hypertension)
- outflow obstruction (e.g., aortic stenosis)
Increased left ventricular preload:
- left ventricular volume overload (e.g., backflow into the left ventricle caused by aortic insufficiency)
Right-sided HF (HFpEF):
- afterload & preload
Increased right ventricular afterload:
- increase in pulmonary artery pressure (e.g., pulmonary hypertension)
Increased right ventricular preload:
- right ventricular volume overload (e.g., tricuspid valve regurgitation, left-to-right shunt)
Left sided vs Right sided
Symptoms
Left:
- cough (frothy pink sputum)
- PND, orthopnoea
- crackles/rales
Right:
- nocturia
- peripheral oedema (swelling of ankles)
- Jaundice
- abdominal discomfort
- anorexia/nausea (GIT oedema)
Common:
- dyspnoea
- fatigue
Left sided vs Right sided
Signs
Left:
- Bilateral basilar crackles
- displaced apex beat laterally (beyond MCL)
Right:
- elevated JVP
- hepatojugular reflux
- hepatosplenomegaly
Common:
- Anaemic signs (pallor)
- poor peripheral perfusion/cyanosis
- reduced exercise tolerance
Approach in patient with suspected heart failure
Initial assesses (EUC, LFT, CBC, ECG, CXR)
- ->
- Echo (HF diagnosed)
- BNP or NT-proBNP (uncertain diagnosis –> high then echo)
- -> confirm HF + EF status
- -> Management according to:
- HFrEF
- HFpEF
- valvular, pericardial or congenital
+ Underlying causes
Diagnosis of HF (investigations)
Left:
- inc. BNP/NT-proBNP
- CXR: cardiomegaly, pulmonary vascular congestion, enlargement of LA/ventricle/pulmonary arteries
- Echo: LV hypertrophy with eccentric remodelling, LA enlargement
Right:
- inc. BNP/NT-proBNP
- LFT: inc. serum total bilirubin & aminotransferase (congestive hepatopathy), elevated AST, ALT & LDH, hypoalbuminemia (cardiac cirrhosis in long standing)
- CXR: cardiomegaly, pulmonary vascular congestion, enlargement of RA/ventricle/pulmonary
- Echo: evaluate RV size, function + detect haemodynamic alterations
- MRI: myocardial tissue, ventricular volume, muscle damage
Imaging for HF
Transoesophageal:
- only for emergency (aortic dissection)
Transthoracic Echo:
- assess cardiac structure & systolic/diastolic function of both ventricles
(results = see next card)
CXR:
- changes to the cardiac silhouette
- boot-shaped heart on PA view –> RV enlargement
- Alveolar oedema, Kelley B lines, Cardiomegaly, dilation of prominent pulmonary blood vessels, effusion (costodiaphragmatic recess = blunting of costophrenic angles)
- Kerley B lines
- dilation
Transthoracic echo looks at:
Systolic HF: depressed & dilated L&/R ventricle with low EF
Diastolic HF: normal LVEF but LV hypertrophy & abnormal diastolic filling patterns
Pulmonary hypertension
Pericardial/Pleural effusion
Complications: MR, LA enlargement
HF on CXR: ABCDE
Alveolar oedema
Kelley B lines
Cardiomegaly
Dilation of prominent pulmonary blood vessels
Effusion –> (costodiaphragmatic recess = blunting of costophrenic angles)
Investigations list for CHF
Echo ECG EUC LFT Troponin CXR D-dimer HbA1c (DM) BNP ABG CBE
Immediate management for Pulmonary oedema
ABCDE + POND +/- morphine
ABCDE:
- Airways (ensure latency, give O2, position patient)
- Breathing (assess rate & rhythm, attach pulse oximetry)
- Circulation (cyanosis, temperature, capillary refill, pulse, auscultation, obtain IV, ABG, ECG, BP)
- Disability
- Exposure
POND:
- Positive pressure/position:
- continuous positive airway pressure –> dec. preload & need for ventilation when appropriate, sit patient up with legs hanging down unless patient is hypotensive
- Oxygenation
- Nitrates: smooth muscle relaxation –> venous dilation –> preload reduction
- Diuretics –> furosemide IV/intramuscular
Morphine:
- used traditionally as it reduces dyspnoea secondary to its effects on ventilation resulting in reduced preload (this mech is considered to be less clear now).
- it also plays a role in reduced SNS activity and reduced anxiety and distress
BUT number of side effects
- acute pulmonary oedema (respiratory & CNS depression, reduced CO, and hypotension)
- may be a significant factor in increased ICU admissions & higher mortality rate
Furosemide Electrolyte changes + why
furosemide blocks Na/K/Cl transporter in the loop of Henle –> results in more sodium making its way to the distal convoluted tubule –> kidney senses this then tries to retain sodium –> swapping sodium for potassium and hydrogen ions –> hypokalaemia & alkalosis
HF Management (non-pharm)
Physical activity, diet, smoking, alcohol, coffee (can exacerbate arrhythmia by HR,BP), smoking, fluid management, vaccination, travel (PE)
HF Management (Pharm)
ACE-i
Cardio selective beta-blockers –> reduce mortality and risk of hospitalisation
Potassium-sparing/aldosterone antagonists diuretics
SGLT2 (cannot be used with ACE/ARB)
ARNI (angiotensin receptor nephrilysin inhibitor) - cannot be used with ACE/ARB
HF Management (Pharm)
ACE-i
Cardio selective beta-blockers –> reduce mortality and risk of hospitalisation
Potassium-sparing/aldosterone antagonists diuretics
SGLT2 (cannot be used with ACE/ARB)
ARNI (angiotensin receptor nephrilysin inhibitor) - cannot be used with ACE/ARB
Decompensation
- Forward failure:
- red. CO –> poor organ perfusion –> organ dysfunction (hypotension, renal dysfunction) - Backward failure:
- LV –> inc. LV volumes or pressure –> blood backup into lungs –> inc pulmonary capillary pressure –> cardiogenic pulmonary oedema (orthopnoea) & inc. pulmonary artery pressure
