What is Congestive Heart Failure?
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Congestive heart failure means that the heart’s pumping power is weaker than normal. With Congestive heart failure blood moves through the heart at a slower rate. This increases the pressure and the volume in the heart, therefor the heart becomes congested. As the result, the heart cannot pump enough blood, oxygen and nutrients to meet the body’s demand.
We can divide Congestive heart failure into the left sided heart failure, and the right sided heart failure. The left sided heart failure includes the left atrium and ventricle and the right sided heart failure includes the right atrium and ventricle.
Congestive heart failure can be either due to systolic dysfunction, which is the inability of the heart to contract and pump out the blood, or diastolic dysfunction, which is the inability for the heart to relax.
Risk Factors for Congestive Heart Failure:
- Coronary artery disease, in which the major blood vessels that supply the heart muscles with blood and oxygen come narrowed or diseased leading to ischemic damage to the heart muscles.
- Myocardial infarction or Heart attack, which is the death of the heart muscles due to an ischemic event.
- Hypertension, can lead to left ventricular hypertrophy, which makes it harder to oxygenate the hypertrophied heart muscles and can eventually lead to ischemic damage to the heart muscles.
- Obesity, can lead to coronary artery disease.
- Diabetes, can lead to coronary artery disease.
- Heart valve disease such as Aortic Stenosis which can eventually lead to LV hypertrophy and ischemic changes similar to Hypertension.
- Cardiomyopathy aka heart muscle disease, such as:
- Dilated Cardiomyopathy, in which the heart’s ability to pump blood is decreased because the main pumping chamber of the heart, the left ventricle, is enlarged and weakened.
- Hypertrophic Cardiomyopathy, which is associated with thickening of the heart muscle, most commonly at the septum between the right and the left ventricles.
- Restrictive Cardiomyopathy, a condition in which the walls of the lower chambers of the heart (the ventricles) are abnormally rigid and lack the flexibility to expand as the ventricles fill with blood.
Clinical Features of Left sided Congestive heart failure:
Even though both the left and the right sided heart failure pretty much have the same clinical features. The left sided heart failure presents with symptoms associated with Pulmonary edema, which is due to failure of the left ventricle to sufficiently remove blood from the pulmonary circulation. This leads to fluid accumulation in the lugs and the clinical features such as:
- Dyspnea (shortness of breath), specially with exertion and exercise,
- Paroxysmal nocturnal dyspnea, which is the sudden worsening of dyspnea during sleep at nights, and
- Orthopnea, which is SOB that occurs when laying flat and improves when sitting up or standing.
Also since the heart is not pumping out enough blood, there is going to be decreased in forward perfusion. This leads to activation of Renin Angiotensin Aldosterone system, which causes fluid retention and worsens the symptom of Congestive heart failure.
Clinical Features of Right sided Congestive heart failure:
The most common cause of right-sided heart failure is actually left-sided heart failure (either systolic or diastolic heart failure) and the common clinical features include,
- Dyspnea since the right heart is unable to pump blood into the lungs to get oxygenated.
- Elevated Jugular Venous Pressure and Jugular Venous Distention, since the jugular veins can not empty their blood into the congested right atrium.
- Pitting edema, which is due to fluid overload and increased hydrostatic pressure
- Ascites, which is due to fluid accumulation in the peritoneal cavity.
- Congestive hepatopathy, also known as nutmeg liver, which is due to chronic passive congestion of the liver and it resembles a cut nutmeg.
Diagnosis of Congestive heart failure:
- Distinguishes Systolic from Diastolic dysfunction by measuring, Ejection Fraction, which is the total amount of blood in the left ventricle that is pushed out with each heartbeat.
- Determine if Acute Myocardial Ischemia is the precipitating cause, by showing abnormal wall motion (hypokinesia) or absent wall motion (akinesia).
- Identifies Valve diseases.
- B-type natriuretic peptide (BNP):
- Secreted by the ventricles of the heart in response to excessive stretching of heart muscle cells.
- Differentiate between causes of dyspnea due to heart failure from other causes of dyspnea.
- Chest X-rays:
- May show cardiomegaly (enlargement of the heart).
- Identify arrhythmias, ischemic heart disease, right and left ventricular hypertrophy, and presence of conduction delay or abnormalities (e.g. left bundle branch block).
- Blood tests:
- Blood tests routinely performed include electrolytes (sodium, potassium), measures of renal function, liver function tests, thyroid function tests, a complete blood count, and often C-reactive protein if infection is suspected. An elevated B-type natriuretic peptide (BNP) is a specific test indicative of heart failure. Additionally, BNP can be used to differentiate between causes of dyspnea due to heart failure from other causes of dyspnea. If myocardial infarction is suspected, various cardiac markers may be used.
Treatment for Congestive heart failure:
In order to prevent Congestive heart failure we must first focus on the modifying the patients life style by encouraging the patient to:
- Loose weight,
- Stop smoking,
- Limiting their alcohol intake and
- have a healthier diet.
These are all equally effective in preventing diastolic and systolic heart failure
The pharmacological management for Systolic dysfunction heart failure includes:
- ACE inhibitors and or Angiotensin Receptor Blockers
- Digoxin which is given if nothing else works.
Medical therapies for diastolic dysfunction heart failure are not as well defined as therapies for systolic heart failure. Some of the medications that are used include:
- Beta-blockers are the first-line therapy as they induce bradycardia and give time for ventricles to fill.
- Calcium channel blocker drugs may be beneficial in reducing ventricular stiffness and lowering the heart rate.
- ACE inhibitors may be beneficial due to their effect on preventing ventricular remodeling but under control to avoid hypotension.
- Diuretics are useful, as these patients develop significant congestion. But they must be monitored because they frequently develop hypotension.