What is congestive heart failure?
Congestive heart failure (CHF) is the failure of the heart to pump blood appropriately. This is a long-term situation that gets worse over time. Usually, this occurs due to the weakening of the heart. Heart failure, regardless of its name, doesn't mean that the heart has failed. Rather it means that the heart muscle has become less contractile over time. As a result, blood returns to the heart quicker than it could be pumped out. Eventually, not enough oxygenated blood and nutrients can reach the other organs.
Symptoms of CHF
Sometimes CHF may start suddenly (acute). The followings are the signs and symptoms of heart failure :
- Shortness of breath
- Fatigue and weakness
- Wheezing
- Acute pulmonary edema
- Ankle edema (swelling in the ankles, legs, and feet)
- Irregular and rapid heartbeat
- Chest pain
- Cardiomegaly (enlarged heart)
- Hepatomegaly (enlarged liver)
- Difficulty in concentrating
- Pleural effusion
Types of CHF
Congestive heart failure is divided into left-sided and right-sided failure.
Left-sided heart failure
Causes of left-sided heart failure may include:
- Ischemia (decreased blood flow)
Decreased blood flow to the heart would damage the myocardium and hence, the myocardium would not function properly
Hypertension causes concentric ventricular hypertrophy as there is increased stress on the heart. Hence, as the wall of the heart becomes more hypertrophied, the arteries of the heart cannot supply oxygen to this wall. So the consequences of long-standing hypertension with hypertrophy of the wall can cause ischemic damage eventually, resulting in left-sided heart failure.
- Restrictive cardiomyopathy
Restrictive cardiomyopathy is a condition in which the heart cannot fill appropriately. Therefore, this leads to an insufficient blood pump leading to left-sided heart failure.
- Dilated cardiomyopathy
Dilated cardiomyopathy is a condition that causes the four chambers of the heart to widen. The dilation of the heart muscle causes the muscle to stretch and eventually become unable to contract. This is another cause of left-sided heart failure.
Clinical Consequences
The clinical consequences of left-sided heart failure would be predominantly due to pulmonary congestion. When the heart cannot pump the blood, it pools in the blood vessels of the lung, causing pulmonary congestion. This will increase the hydroplastic pressure within the blood vessels and lead to the following consequences
- pulmonary edema with dyspnea
- orthopnea
- paroxysmal nocturnal dyspnea
- crackles - edema or fluid within the interstitial space of the lung
- Intraalveolar hemorrhage - When the capillaries in the lung burst, blood enters the alveolar air sacs, and eventually, macrophages in the alveolar air sacs consume this blood and the iron it contains. These macrophages are called hemosiderin-laden macrophages and are also known as "heart failure cells"
Additional consequences of left-sided heart failure are the activation of the renin-angiotensin system. When blood flow to the kidney is reduced, the juxtaglomerular apparatus releases renin. Renin converts angiotensinogen to angiotensin I, then angiotensin I is converted to angiotensin II by angiotensin converting enzyme. Ultimately, this angiotensin II causes the following changes:
1) increasing the total peripheral resistance by constricting the arterioles, and
2) stimulating the adrenal gland to release aldosterone, which can increase blood volume by stimulating sodium and water reabsorption in the kidney.
Both increased total peripheral resistance and increased blood volume in a patient with congestive heart failure can exacerbate the problem. For this reason, ACE inhibitors are one of the main treatments for congestive heart failure.
Right-sided heart failure
Right-sided heart failure is most commonly due to left-sided heart failure. Other causes of RHF include
- Left-to-right shunt
- Chronic lung diseases - lung disease causes hypoxia. One of the consequences of hypoxia is that blood vessels in the lungs constrict in response to this hypoxia. Hence, the right side of the heart has to pump blood against narrowed blood vessels. Eventually, the right-sided heart will fail and this is called cor pulmonale.
Clinical Consequences
Clinical features of right-sided heart failure are due to congestion of those things that feed the right heart.
- painful hepatosplenomegaly - venous system coming from the bladder and spleen feeds the right heart. Hence, congestion of this venous system can cause this consequence.
- Jugular venous distension
- Cardiac cirrhosis - One of the consequences of long-standing congestion in the liver
- dependent pitting edema - because of increased hydroplastic pressure
Treatments for CHF
Congestive heart failure can be a long-term problem (chronic) or sudden (acute). However, there are several treatments for congestive heart failure. Most of the time, these treatments can improve the signs and symptoms of heart failure and even reduce the risk of death. Treatments for heart failure include balancing the proper medications, adopting a healthy lifestyle, and sometimes surgery and other procedures.
Medications
The followings are some main medications used to treat heart failure :
- Vasodilators - reduce blood pressure by expanding the blood vessels
- ACE inhibitors (angiotensin-converting enzyme inhibitors) - reduce blood pressure by reducing total peripheral resistance in arterioles and reducing blood volume
- Diuretics - reduce blood volume. When a diuretic is prescribed by a doctor, you may be given some supplements for potassium and magnesium. Because diuretics can lead to the loss of these crucial minerals.
- Beta-blockers - reduce blood pressure by decreasing the heart rate by inhibiting the neurotransmitter release in the sympathetic nervous system
- Angiotensin II receptor blockers - a replacement to ACE inhibitors
- Aldosterone antagonists - lower blood pressure by reducing blood volume by inhibiting the reabsorption of water in the kidney
- Anticoagulants - prevent blood clots
- Digitalis glycosides
- Positive inotropes
- Calcium channel blockers (CCB)
- Sodium/glucose cotransporter (SGLT2) inhibitors
- Verquvo
Surgery or other procedures
- Coronary bypass surgery - A new path for blood flow to the heart is created by connecting a new artery taken from the leg or arm to the severely blocked coronary artery.
- Implantable cardioverter-defibrillators (ICDs) - prevent complications of heart failure
- Heart valve repair or replacement
- Ventricular assist devices (VADs) - a device that helps the heart to pump blood from the lower chambers to the rest of the body
- Cardiac resynchronization therapy (CRT) - is a device that enables both ventricles of the heart to pump blood in a better-coordinated way
- Heart transplant - For patients with severe heart failure that can not be treated with surgery or medications are get replaced their heart
