What are the physiological and clinical definitions of heart failure?
Physiological: cardiac disorder that prohibits delivery of sufficient output to meet the perfusion requirements of metabolising tissues
Clinical: caused by an abnormality of the heart and recognised by a characteristic pattern of haemodynamic and hormonal responses
List some causes of heart failure.
What are some aggravating factors?
Coronary artery disease (will cause ischaemic damage -> MI), hypertension, cardiomyopathy (heart muscle disease), valvular heart disease, other causes (e.g. pericardial disease from cardiac tamponade).
Cardiac arrhythmias (AF), hypertension, anaemia, infections. Aggravating factors are targets for treatment.
What are some symptoms and signs of heart failure?
Symptoms: Fatigue (decreased C.O.), dysnopea and oedema (fluid retention), increase in sympathetic activity
VERY NON-SPECIFIC SYMPTOMS!
Signs: cool skin, peripheral cyanosis (as C.O. falls, autonomic NS shuts down less imp circulations e.g. cutaneous and Hb increasingly desaturated as it goes slowly through), basal crackles, increased JVP, ankle swelling, ascites, tachycardia, sweating, S2, alternating pulse
What are the complications of heart failure?
Intravascular thrombosis (due to sluggish flow -> PE or SE), infection (chest/ulcerated cellulitic legs), functional valvular dysfunction, multi-organ failure (renal, liver), cardiac arrhythmias (AF, VT, VF), sudden death.
Heart failure ECGs are never normal. What 3 things might you see?
Inferior Q waves (maybe previous MI)
Anterior T wave + ectopics
Left bundle branch block
What features of heart failure are on these CXRs?
Name 2 other key investigations in heart failure?
What is the difference in dysfunction between coronary heart disease and cardiomyopathy?
L: pulmonary congestion (prominant upper lobe veins due to raised pressure to fill failing ventricle and pulm venous pressure raised)
R: pulmonary oedema (batwing)
Echocardiogram, 2D echo
CHD: regional LV dysfunction; Cardiomyopathy: global LV dysfunction
What is brain natriuretic peptide (BNP)?
ID'd in blood test to help make heart failure diagnosis. Secreted by myocardial cells in response to raised L arterial pressure, promotes natriuresis (excretion of sodium in urine) and vasodilation, inhibits ADH and aldosterone release. Levels >100pg/ml indicate heart disease as likely cause of dyspnoea and fluid retention.
NB: works in opposite way to ACE (converts hormone angiotensin I to vasoconstrictor angiotensin II)
What are the steps for heart failure diagnosis?
1) detailed history + examination
2) If previous MI: specialist assessment and echo dopp -> if abnormal then systolic/diastolic dysfunction diagnosis
3) If no previous MI, measure BNP and if >100pg/ml then specialist assessment and echo dopp
Why are beta blockers and ACE inhibitors mandatory for heart failure (describe neurohormonal inhibition)?
Sympatho-adrenal activation (increaases ionotropic state) and Renin-angiotensin activation (increases myocardial mass) are hallmarks of heart failure and increase contractile function. BUT lead to ventricular dilation as salt and water are retained and there's redistribution of venous flow. These mechanisms thus have limited potential and as time goes on become counter productive for pt.
Block SAA with B blockers e.g. propanolol, and block RAA with ACE inhibitors e.g. ramipril = pt lives longer.
What is the treatment for:
a) systolic and diastolic failure?
b) systolic failure?
a) treat aetiological and aggravating factors, and fluid retention with diuretics
b) all pt's should have ACE inhibitor (or ARB if not ACE), and a beta blocker, spironolactone for grade 3 and 4 HF, and devices: cardioresynchronisation therapy +/- ICD. ALso angiotensin receptor neprilysin inhibitor (new drug)
What is cardiac rescynchronisation therapy?
What are the precise indications for CRT?
Normally L ventricle contracts a few milliseconds before R, and as heart dilates this may become disrupted -> disadvantage to cardiac function. SO can put pacemaker wires into both ventricles, stimulate them both and restore synchronous contraction. Generally for pts with bundle branch block (broad QRS)
Sinus rhythm (not if AF), Left ventricle ejection fraction (LVEF) <35%, grade 3/4 HF, QRS prolonged >150ms
What criteria do you need to meet for a heart transplant?
What is the procedure and prognosis?
Resistant congestive cardiac failure without:
Major organ failure, major co-morbidity, psychological disability, severe pulmonary hypertension (if put new heart in, weedy ventricle may fail)
Orthotopic heart transplant, 80% 1yr survival
What is diastolic heart failure with normal ejection fraction?
How is HeFNEF treated?
What is the normal EF value?
Impaired L ventricle filling due to increased chamber stiffness and/or decreased relaxation. More common in females and old. Most pts have element of both systolic and diastolic.
Treat underlying cause e.g. hypertension, treat systolic components if mixed, treat fluid retention