Week Four - Case One Flashcards
what is heart failure typically defined as;
the inability of the heart to pump adequate amounts of blood to meet the body’s metabolic demands
what is the classic presentation of heart failure
shortness of breath (especially on exertion and on lying flat), fatigue and ankle oedema
what are the classic signs of heart failure
Signs may include hepatomegaly, tachycardia, tachypnoea and raised JVP.
what are the two broad groups heart failure can sometimes be divided into
those with a normal ejection fraction (>50%), and those with a reduced ejection fraction (<50%), however, the management is similar
There is a correlation between ejection fraction and prognosis – the lower the ejection fraction, the worse the prognosis
what is the mainstay drug of treatment that has been shown to improve survival
ACE inhibitors
what is systolic HF
Systolic HF – inability of the heart to contract efficiently to eject adequate volumes of blood to meet the body metabolic demand [most common].
what is diastolic HF
Diastolic HF – reduction in the heart compliance resulting in compromised ventricular filling and therefore ejection [pericardial disease, restrictive cardiomyopathy, tamponade]. Increasingly recognised as an important cause of heart failure – it is often present in elderly patients with a normal CXR and otherwise unexplained SOBOE (shortness of breath on exertion)w
what is left HF
Left HF – inability of the left ventricle to pump adequate amount of blood leading to pulmonary circulation congestions and pulmonary edema. Usually results in RHF due to pulmonary hypertension. Defined as an ejection fraction of <40%.
what is right HF
Right HF – inability of the right ventricle to pump adequate amount of blood leading to systemic venous congestion, therefore peripheral edema and hepatic congestion and tenderness.
Most commonly the result of respiratory disease – especially COPD
The presence of raised JVP and peripheral oedema are suggestive of right HF in particular
what is congestive HF
failure of both the right and left ventricles, which is common
what is low-output HF
heart failure resulting from reduced cardiac output [most common type] – also referred to as HFrEF – Heart Failure reduced Ejection Fractions
what is high-output HF
High-output HF – heart failure that occurs in normal or high cardiac output due to metabolic demand and supply mismatch, either due to reduced blood oxygen carrying capacity [anaemia] or increase body metabolic demand [thyrotoxicosis] – also referred to as HFpEF – Heart Failure preserved Ejection Fraction
what is acute HF
acute onset of symptom presentation often, but not always due to an acute event [MI, persistent arrhythmia, Mechanical event (ruptured valve, ventricular aneurysm)]
Often an acute presentation to hospital
May be the first presentation, or may be “acute on chronic”
what is chronic HF
– slow symptoms presentation usually due to slow progressive underlying disease [CAD, HTN]
Typically a GP based diagnosis
what is acute-on-chronic HF
Acute-on-chronic – acute deterioration of a chronic condition, usually following an acute event [anaemia, infections, arrhythmias, MI
how many people does HF affect in the uK
920,000 people - about 1 in 70
what is the average age of diagnosis of HF
77
what are the ischaemic heart disease causes of HF
- myocardial ischaemia
- myocardial infarction
- in IHD infarction causes impaired ventricular function, therefore reduced contractility function and HF. IHD is the most common cause of HF along with HTN
how does hypertension cause HF
increases strain on the heart, since the heart has to pump blood against a high after load, leading to hypertrophy which increase the chances of arrhythmias.
the heart eventually gets too big for the coronary system to perfuse leading to IHD and compromised ventricular function
what valvular diseases lead to HF
Mitral Regurgitation [volume overload]
Aortic stenosis [Pressure overload] – particularly chronic excessive afterload
Tricuspid Regurgitation [volume overload]
VSD/ASD [volume overload] – excessive preload
what pericardial diseases lead to HF
pericarditis
pericardial effusion
what drugs are the most common cause of HF
- chemotherapeutic drugs; beta-blockers are the most common cause, but calcium channel blockers and ant-arrhythmatics are also implicated
- alcohol; acute heart failure, arrhythmias such as AF and dilated cardiomyopathy are more common in alcoholics. Alcohol also increases the risk of infection – infection can worsen chronic heart failure due to toxic effects of infection on heart itself along with vasodilation and tachycardia increase myocardial oxygen demand
- cocaine
how can thyrotoxicosis/myxedema cause heart failure
can cause HF due to direct effets on myocardium, bradycardia and peridcardial disease
how does bradycardia induce HF
Bradycardia – CO = HR X SV. Therefore reduced HR reduces CO