Heart Failure Flashcards
What is the definition of heart failure
A clinical syndrome caused by an abnormality of the heart and recognised by a characteristic pattern of haemodynamic, renal, neural and hormonal responses.
Why are the kidneys associated with heart failure?
Often when the heart fails, the kidneys fail because they won’t be perfused enough (they receive 35-40% of cardiac output)
What are two things the consequences of heart failure are linked to?
Inability of the heart to maintain cardiac output and blood pressure
What are some of the causes of heart failure?
1) Arrhythmias - mainly tachycardias
2) Valve Disease - mitral or aortic regurgitation or valve stenoses
3) Pericardial Disease - if the pericardium becomes inflamed and fibrotic then the heart can’t relax and pump as well
4) Congenital Heart Disease - if there are holes or misconnections then there is an increased risk of heart failure
5) Myocardial Disease - commonest cause of myocardial disease in this country is coronary heart disease.
6) Cardiomyopathy
7) Some drugs can cause heart failure:
- overdosing on beta blockers can decrease the heart rate so much that you get heart failure type syndrome
- Anti-arrhythmics can cause dysfunction of the heart
- Calcium antagonists
7) Hypertension can cause heart failure
What percentage of MI survivors develop heart failure?
50%
Deaths due to MI decreasing but those from heart failure increasing - pop is aging and heart failure is more common in old age
What is myocardial remodelling?
The rest of the heart tries to remodel itself to cope with the damage that has occurred. Infarct expansion occurs - the fibrous tissue expands and the rest of the heart tries to remodel to maintain normal pumping activity. This includes cells stretching and loss of cells.It takes place over months or years.
What is cardiomyopathy and what are some types?
Cardiomyopathy is a heart disease without a known cause. Includes dilated cardiomyopathy, hypertrophic cardiomyopathy, restrictive cardiomyopathy, arrhythmic right ventricular cardiomyopathy, hypertrophic obstructive cardiomyopathy
and asymmetrical septal hypertrophy. It occurs in 5% of heart failures. Hypertrophic is most common cause of athletes dying suddenly.
What are the causes of dilated cardiomyopathy?
- idiopathic
- genetic
- infections: viruses (cocksackie), HIV, bacteria, fungi, parasites
- toxins/poisons: ethanol, cocaine, metals, hypoxia
- drugs: chemotherapeutics, antiviral agents
- metabolic disorders: endocrine disease, nutritional deficiencies
- collagen disorders
- autoimmune
- peripartum cardiomyopathy
- neuromuscular disorders
What are the causes of restrictive cardiomyopathy?
restricted means heart can’t dilate as it would. Patients can pump but the heart is slow in relaxing so patients are short of breath.
- infiltrative disorders: amyloidosis (proteins enter heart muscle), sarcoid disease (inflammatory cells clump in heart muscle), neoplasia, inborn errors of metabolism
- storage disorders: glycogen storage disease, Fabry disease, haemochromatosis, haemosiderosis
- endomyocardial disorders (lines inside of heart): carcinoid, metastases, radiation damage, endomyocardial fibrosis
- associated with fibrosis: hypertrophy, ischaemia, scleroderma
What causes death in people with heart failure?
Progression of Heart Failure: increased myocardial wall stress, increased retention of sodium and water
Sudden death: oppportunistic arrhythmia (commonest cause of death in heart failure)
Cardiac event e.g. myocardial infarction
Other cardiovascular event e.g. stroke, pulmonary vascular disease
Non-Cardiovascular causes e.g. pneumonia
Which hormones are present in heart failure, which are overactive and how can drugs target this?
Constrictors: noradrenaline, renin, angiotensin 2, vasopressin, endothelin
Dilators: prostaglandin E2, dopamine, ANP, EDRF
Growth factors: insulin, NO, catecholamines, angiotensin 2, growth hormone, TNF alpha
All these are switched on.
Body thinks it is bleeding to death so increase in adrenaline and noradrenaline.
To retain salt and water RAS system active.
Vasoconstrictors increased.
Beta blockers block sympathetic drive
ACE inhibitors block RAS system
Aldosterone antagonists
Which inflammatory markers and cytokines are present during heart failure?
heart: troponin T/I
Vessel walls: ICAM 1, VCAM 1, E selectin, P selectin
macrophages: lipoprotein associated phospolipase A2, secretory phosphlipase A2
In all cell types: interleukin 1b, interleukin 6, tissue necrosis factor alpha
liver: makes more c reactive protein, fibrinogen, serum amyloid A
All increased in heart failure
What is the prognosis of heart failure?
5-year mortality is 50%
Median survival following diagnosis:
Men = 1.7 years
Women = 3.2 years
What are the signs/symptoms of heart failure?
patient: ankle swelling, exertinal breathlessness, fatigue, nocturia, anorexia, weight loss, orthopneoa (short of breath when flat), PND (paroxysmal noctural dyspnoea - when they fall flat when asleep can’t breathe)
clinical: tachycardia, low pulse volume, oedema, ascites, hepatomegaly, weak pulses, high jugular venous pressure (pressure in right side of heart are high)
What investigations are done to determine whether someone has heart failure and following diagnosis?
- X ray
- echocardiogram
- ambulatory ECG monitoring
- cardiac catheter
- exercise test
- radionuclide ventriculography