Congestive heart failure (CCF) is something that I’ve seen a lot in the last week in A&E. It occurs when the heart is no longer able to pump enough blood around the body to keep up with its metabolic demands. Certain conditions over time can lead to CCF; coronary heart disease, diabetes mellitus and hypertension. Over time these conditions cause ventricular dysfunction where the heart can’t pump enough blood out of it (low cardiac output) causing congestion of the blood, backing up in the pulmonary system for left sided heart failure and in the venous system for right sided heart failure. Clinically global or biventricular heart failure is most commonly seen.
Left and right sided heart failure present differently due to the back up of blood being within different systems. With Right sided heart failure there is systemic venous congestion which results in pitting oedema and hepatomegaly as the venous blood can’t drain properly from the legs and also backs up to the liver. With left sided heart failure results in fluid building up in the lungs, causing pulmonary oedema therefore resulting in difficulty breathing. Global heart failure presents with features of both. It can also cause atrial fibrillation which we discussed last week.
The New York Heart Association have a functional classification system which assesses patients functional capacities and has prognostic value:
- Class I – no limitations of physical activity, no symptoms of heart failure.
- Class II – slight limitations of moderate or prolonged physical activity, comfortable at rest
- Class III – limitations of physical activity, symptoms during activities of daily living, only comfortable when at rest.
- Class IV – confined to bed, discomfort with any form of physical activity, symptoms present at rest.
A useful investigation to aid diagnosis is BNP (Brain natriuretic peptide) levels, this is a hormone released by the atrium of the heart when they are in distress. If the value is <100 the heart failure is unlikely where are it is likely if the value is >400.
Emergency management of heart failure is dealing with the problems caused by this, such as atrial fibrillation and pulmonary oedema. Pulmonary oedema can be life threatening, so sitting the patient up, administering oxygen and frusemide to try and get rid of the fluid on the lungs is crucial. Intravenous nitrates can also help with the acute management.
Long term management involves general life style measure include salt and fluid restriction, weight loss and exercise, stopping smoking and drinking alcohol and also immunisations are important in this patient group. Diuretics such as frusemide are used to treat volume overload, ACE inhibitors to reduce blood pressure improving cardiac output, beta-blockers once the patient is stable on ACE inhibitors.
Look out for our blog later this week looking into these drugs and their mechanism of action.