Heart Failure – Types, Risk Factors and Mangement
Heart failure (HF), as the name implies is a general state of failure of heart’s functioning and the resultant inability to keep up with the body needs of blood supply and nutrition.
HF is not a disease by itself rather it is one of the serious late stage manifestations of various disorders of heart that are expressed in the form of an impaired pumping ability of the heart and its untoward consequences.
Heart being one of the prime vital organs in the body, its malfunctioning will undoubtedly have serious health ramifications and that is very much true with heart failure too.
Heart failure is classified in varieties of ways depending upon;
- The evolution of symptoms;
- Acute or
- Chronic heart failure
- The side of the heart involved;
- Left sided or
- Right sided or
- Both sided failure
- The cardiac out put status;
- Low out put or
- High out put failure
- The phase of the cardiac cycle mainly affected;
- Systolic or
- Diastolic failure
The NYHA (New York Heart Association) Functional Classification looks at the functional abilities of these patients and include;
- Class IV: most severe form, symptoms occur even at rest
- Class III: Only rest makes patients comfortable, not any activity
- Class II: Minor limitations of activities
- Class I: Quite stable patients, no symptoms from routine activities
Risk factors for Heart Failure
Any pathological condition that can negatively influence the pumping action of the heart muscle may precipitate low out put HF and several such conditions include;
- Ischemic heart disease (heart attack)
- Cardiac arrhythmias etc.
Generally the following factors contribute to the development of above mentioned conditions;
- Valve abnormalities (e.g. rheumatic heart disease)
- High blood pressure
- High cholesterol etc.
The other type of HF, the high out put one initially will present with an increased ejection fraction of blood however this is an abnormal state and in the process the heart muscle gets overburdened and gradually it fails and eventually manifests as low output HF.
The conditions giving rise to high output HF include
- Severe anemic states
- Aortic regurgitation
- Arterio-venous shunting
- Thiamine (Vitamin B1) deficiency state – beriberi etc.
The above discussion is generally for either left heart failure or a combination of both left & right heart failures. There are conditions that will present with isolated right heart failure and the term Cor pulmonale is used if this right HF is secondary to lung pathologies like chronic bronchitis, emphysema etc.
The following are common clinical feature (not every patient will present with all these features);
- Difficulty with breathing
- Edema (swelling of legs)
- Ascitis (distension of abdomen due to fluid accumulation)
- Generalized weakness & fatigue
- Chest pain (angina)
- Jaundice (rare)
- Wide pulse pressure
- Aortic regurgitation murmurs
- Abnormal lung auscultation findings (e.g. rales)
The investigations generally required for the confirmation of HF and its further management include;
- Chest x-ray
- Cardiac catheterization
- Coronary angiogram
- Blood tests (cardiac markers, natriuretic peptides etc)
Echocardiogram is an ultrasound technique for imaging the heart. The role of this test in the diagnosis of HF is invaluable.
It provides a clue regarding the global functioning of the heart, including its wall motion, chamber size, valve function, blood flow etc.
It gives us a measure of the EF (ejection fraction) which is the most useful index of left ventricular function. An EF equal or above 50% is considered adequate and it is considered significantly depressed when values are < 30 to 40%.
ECG records the electrical activities of the heart and may provide clues regarding what might have precipitated HF for example heart attack, arrhythmias etc.
The cardiac markers usually checked include
- Total CPK
- CPK MB fraction
These tests will reveal if any heart attack had occurred recently. The natriuretic peptides are usually elevated in HF.
Cardiac catheterization & coronary angiograms are generally performed together. These tests will detect conditions like cardiomyopathies, ischemic heart disease etc that might have precipitated HF.
A catheter is passed through an artery like femoral artery and advanced to the aorta and a radioactive dye in injected such that it enters the coronary arteries and the radiological pictures are taken to look for a blockage.
If required the catheter from the aorta is advanced to the left heart for additional evaluation.
1) Acute setting
- Bed rest (for short duration)
- Injection Lasix (Furesemide) to get rid of excessive water from the body
- Oxygen supplementation (nasal or through breathing machine as necessary)
- Fluid restriction
- Salt restriction
- Measures to avoid blood clots in the legs due to bed rest
- Low molecular heparin injections
- Intravenous heparin
- Identifying and treating what precipitated or caused HF
- Heart attack
- Cardiac arrhythmias
- Noncompliance with fluid and salt restrictions
- Poor control of blood pressure etc.
- Nitrate preparations for reducing the work load of the failing heart
- Nitrate preparations and/or morphine for chest pain/discomfort
- Medications to enhance the pumping action of the heart muscle:
- Inj Dobutamine
- Inj Dopamine
- Inj Milrinone
- Medication to constrict arteries (if blood pressure is too low)
- Inj Dopamine
- Inj Epinephrine
- Ultra filtration
- Dialysis etc.
2) Long term or maintenance therapy includes;
- Salt restriction
- Fluid restriction
- Tolerable amount of exercise
- Lifestyle modification like cessation of smoking etc
- Medications like;
- Anti-platelet agents (aspirin, clopidogrel)
- Blood thinners like warfarin if there is clot risk developing in the heart
- Angiotensin converting enzyme inhibitors like lisinopil
- Angiotensin receptor blockers like candesertan
- Aldosterone antagonists like eplerenon
- Antiarrhythmic agents like amiodarone (if arrhythmias are present)
- Cardiac resynchronization therapy (if ventricular asynchrony is present)
- Implantable cardiac defibrillator (if refractory arrhythmias are present)
- Cardiac transplantation (generally one of the last measures)