Know The Difference Between Right vs Left Heart Failure

The heart’s pumping action moves oxygen-rich blood from the lungs to the left atrium, then to the left ventricle, which pumps the blood to the rest of the body.  

Heart failure (HF) is when the heart cannot pump blood effectively, leading to inadequate blood circulation and oxygen circulation to meet the body's needs. In this condition, the heart muscle or different parts of the heart are either too weak or not elastic enough.

HF is one of the main reasons people 65 and older are admitted to the hospital. There are two main types of heart failure( HF): right heart failure and left heart failure. Although they can occur separately, they often occur together. There is also Biventricular heart failure where both sides of the heart are affected.

In this article, we will discuss in detail right vs left heart failure, the symptoms and causes of each, its differences, treatment and its effects on daily life. Read on.

What is heart failure?

Heart failure does not happen in an instant! It is more gradual and there can be one or more signs and symptoms. Heart failure can be life-threatening. Depending on the stages, patients may need a heart transplant or a device to help the heart pump blood.  Let us understand more below.

Flow of Blood Through the Heart

To understand more about heart failure, you must know about the flow of blood through the heart.

• The heart is the main circulatory organ that pumps oxygenated blood.
• It has four chambers; two on the top (atrium, plural atria) and two on the bottom (ventricles).
• Two large veins deliver oxygen-deficient blood to the right atrium. The superior vena cava carries blood from the upper body and the inferior vena cava brings blood from the lower body. The right atrium then pumps the blood to the right ventricle.
• The lower right chamber/ ventricle pumps the oxygen-less blood to the lungs through the pulmonary artery. The lungs then oxygenate the blood.
• The pulmonary veins carry the oxygenated blood to the left atrium which pumps the blood to the left ventricle.
• The left ventricle is slightly larger than the right and pumps oxygen-rich blood to the rest of the body.

Heart failure

• Heart failure is not the complete stoppage of the heart. Instead, it is a chronic condition where the heart doesn't pump blood as well as it should, leading to the insufficient circulation of blood and oxygen.
• As a result, there can be the following symptoms that develop slowly:
  • Lesser oxygen supply to the organs
  • Shortness of breath (also called dyspnea)
  • Narrowing of blood vessels
  • Heart enlargement
  • Stiffer and thicker heart muscles
  • Increased heart rate
  • Fluid builds up in your arms, legs, ankles, feet, lungs, or other organs
  • Tiredness, fatigue
  • Confusion, impaired thinking
  • Nausea and lack of appetite
  • Difficulty concentrating or decreased alertness
  • Chest pain, if caused by a heart attack
  • Rapid or irregular heartbeat
  • Reduced ability to exercise
  • Wheezing
  • Persistent cough or a cough with white or pink mucus with spots of blood.
• HF can occur either on one or both sides of the heart.
• It is caused by Coronary artery disease, Heart attack, Cardiomyopathy, or conditions that overwork the heart like, high blood pressure, heart valve disease, thyroid disease, kidney disease, diabetes, or congenital heart defects.

What are the Stages of Heart Failure?

As mentioned above, HF is not a sudden stoppage of the heart’s function.  

• Heart failure can progress through four stages of the disease- A, B, C and D.
• Healthcare professionals also classify heart failure when it has progressed to stages C and D.
• It helps to measure a patient’s overall heart function and the severity of symptoms.

In alliance with the American College of Cardiology, the American Heart Association has established four stages of heart failure which are as follows;

Stage A (At risk for heart failure):

• In this stage, you do not have symptoms yet, structural or functional heart disease.
• Risk factors include hypertension, coronary vascular disease, diabetes, obesity, exposure to cardiotoxic agents, genetic variants for cardiomyopathy and family history of cardiomyopathy.
• To manage risk factors and prevent the development of heart failure, the doctor will recommend regular exercise, and advise to stop drinking alcohol, smoking, and using illegal drugs. They may also prescribe beta-blockers for high blood pressure. For diabetes, hypertension or other heart and blood vessel conditions like coronary artery disease, you may need to take an ACE inhibitor or an angiotensin II receptor blocker (ARB).

Stage B (Pre-heart failure):

• People without current or previous symptoms of heart failure but with either structural heart disease ventricular hypertrophy (enlargement of the left ventricle), previous myocardial infarction (heart attack), valvular heart disease, increased filling pressures in the heart or other risk factors.
• Your doctor may suggest an ACE inhibitor or angiotensin II receptor blocker (ARB), ARNI,  beta-blockers, or SGLT2 inhibitors after a heart attack.
• Also, surgery is done to repair coronary arteries and valves or if valves need to be replaced. Sometimes, an implantable cardiac defibrillator (ICD) will be used as required.

Stage C (Symptomatic heart failure):

• People with current or previous symptoms of heart failure are categorized under this stage.
• You are likely to have symptoms such as shortness of breath, fatigue and less ability to exercise.
• Lifestyle changes such as eating less salt, losing weight if you're overweight, drinking fewer fluids if necessary, and stopping drugs that make your condition worse etc. should be implemented.
• Treatment aims to manage symptoms, improve quality of life, and slow the progression of heart failure.

Stage D (Advanced heart failure):

• People with heart failure symptoms that interfere with daily life functions or lead to repeated hospitalizations are classified under this stage.
• You will have persistent symptoms despite optimal medical therapy.  
• Treatment includes heart transplants, ventricular assist devices, surgery options, and continuous infusion of intravenous inotropic drugs.

Types of Heart Failure

Heart failure often only affects the left or right side of the heart but can affect both. 

There are three types of heart failure:

• Left-sided heart failure
• Right-sided heart failure
• Biventricular heart failure
• Congestive heart failure

Left-sided heart failure

• A normal left ventricle ejects about 55% to 60% of the blood in it.
• In left-sided heart failure, the left ventricle is larger and pumps more of the heart's blood.  
• This type of heart failure is broken down into two categories:
  • Systolic failure, where the left ventricle is too weak to push enough blood.  
  • Diastolic failure, where the left ventricle is too stiff, can't relax, and can't fill with blood during the resting period between each beat.

Right-sided heart failure

• The advanced left-sided heart failure leads to right-sided heart failure.
• The left ventricle fails and can’t pump enough blood out, and increased fluid pressure is transferred back through the lungs. This damages the heart’s right side. When the right side loses pumping power, blood backs up in the body’s veins.
• The increased pressure inside the veins can push fluid out of the veins into the surrounding tissue. It leads to a build-up of fluid in the legs, or less commonly in the genital area, organs or the abdomen (belly).
• It is also caused by high blood pressure in the lungs, an embolism in the lungs (pulmonary embolism), or certain lung diseases such as COPD.

Biventricular heart failure

• In this, both sides of the heart are affected.
• The symptoms are the same as those of right and left-sided heart failure.

Congestive heart failure

• Congestive heart failure (CHF) is a condition in which the blood slows down as it leaves the heart and is slower when it comes back causing the blood to back up in your veins.  
• It causes edema/dwelling in the legs, ankles and lungs( pulmonary edema).
• If left untreated, pulmonary edema can cause respiratory distress.

What Is Right-Sided Heart Failure?

• It usually happens after the left side fails. More fluid pressure through the lungs damages the right side of your heart.
• Right heart failure is most commonly a result of left ventricular failure via volume and pressure overload.
• The pressure overload-causing conditions are -Pneumonia, Pulmonary embolism (PE), Mechanical ventilation, and Acute respiratory distress syndrome (ARDS).
• Chronic conditions of pressure overload such as Primary pulmonary arterial hypertension (PAH) and secondary pulmonary hypertension (PH) as seen in chronic obstructive pulmonary disease (COPD) or pulmonary fibrosis, and Congenital heart disease lead to RVF.
• The volume overload-causing conditions are- Valvular insufficiency (tricuspid or pulmonic) and congenital heart disease with a shunt.
• When the right side of the heart cannot pump blood effectively, blood builds up in the veins, leading to swelling, fluid retention, and other symptoms.
• More than 6 million Americans have heart failure. Each year, more than 900,000 people receive a heart failure diagnosis.
• Heart failure is rare in people younger than 50.

What are the symptoms of Right-Sided Heart Failure?

The signs and symptoms of left and right-sided heart failure depend on the type of heart failure you have, how serious it is and also on whether you have left-sided or right-sided heart failure.

The below picture shows an image of the body and labels which parts are affected by the major symptoms of heart failure.

One of the first symptoms you may observe is shortness of breath after routine activities like climbing stairs. The common symptoms will start to appear more severe as the condition worsens.

People who have right-sided heart failure may also have the following symptoms:

• Nausea and loss of appetite
• Pain in your abdomen  
• Swelling in your ankles, feet, legs, abdomen, and the veins in your neck
• Needing to pee often
• Weight gain due to fluid retention

You may also not feel like eating, your skin is cold and sweaty, very tired, confused and forget things.

What are the causes of right-sided heart failure?

• Usually, left-sided heart failure causes right-sided heart failure.  
• The left ventricle does not work efficiently, causing increased fluid pressure through the lungs, which transfers to the right side of the heart. When the right side cannot pump well, the blood builds up in the veins and the lungs.  
• Other health issues that have damaged or weakened your heart also is a contributing cause.

Some other causes of right-side heart failure include:

Coronary artery disease

• It is the most common form of heart disease and the cause of heart failure. The accumulated plaque blocks your arteries, causing blood flow to your heart muscle to slow or even stop.
• Blockages or narrowing of the coronary arteries supplying the right ventricle can impair its ability to pump effectively, leading to right-sided heart failure. 

High blood pressure

• It measures how hard your heart pumps blood through your arteries.  
• The higher your blood pressure means the heart is working extra hard to pump it.  
• Over time, your heart muscles can thicken and weaken because of their extra work.
• A high reading in a Sphygmomanometer or a BP device indicates that your heart is under stress.

Damaged heart valves

• Valves help the blood flow in the right direction through your heart.  
• Any infection or heart defect causes valve damage and increases the load on the heart.  
• This in turn causes heart failure.

Congenital heart defects

• Some kids are born with problems in their heart structure.
• The odds of heart failure will be higher if you have CHF.

Arrhythmia

• Arrhythmia is when a heart has an irregular heartbeat. It may beat too fast, or too slow and pump an insufficient amount of blood through the body. It could weaken your heart over time and cause heart failure.

Lung disease

• Problems in the lungs cause the right side of the heart to enlarge and fail.
• Cor pulmonale (right-sided heart failure) is a complication of COPD, blood clots in the lungs, and other issues.

Other long-term health conditions               
Diabetes, HIV, thyroid problems etc. can also contribute to right-side heart failure

What Is left-sided heart failure?

• In this condition, the left ventricle no longer pumps enough blood around the body or it should work harder to pump the same amount of blood.  
• As a result, blood builds up in the pulmonary veins (the blood vessels that carry blood away from the lungs) causing shortness of breath, trouble breathing or coughing, especially during physical activity.  
• Left-sided heart failure is the most common type.
• It is usually caused by coronary artery disease (CAD), a heart attack or long-term high blood pressure.

There are two types of left-sided heart failure:

A) Systolic failure:

• The left ventricle loses its ability to contract normally and is unable to push the blood effectively for circulation.  
• The percentage of blood the heart can pump with each beat is measured by a unit called ejection fraction, or EF.
• Systolic failure is also known as heart failure with reduced ejection, or HFrEF. When this occurs, the heart is pumping less than or equal to 40% EF.

B) Diastolic failure:

• The left ventricle loses its ability to relax normally because of the stiff heart muscle and the heart can't properly fill with blood during the resting period between each beat.
• It is also called heart failure with preserved ejection, or HFpEF and the heart is pumping greater than or equal to 50%.

What are the symptoms of Left-Sided Heart Failure?

The initial symptoms are very mild, which progress as the disease worsens. According to the Cleveland Clinic, you can find the following symptoms for left-sided heart failure:

• Constant coughing.
• Shortness of breath with walking or bending over.
• Waking up short of breath or unable to lie flat at night.
• Weight gain.
• Swelling (edema) in your ankles, legs or abdomen.

Over time, the heart works harder to do its job causing complications like:

• Cardiogenic shock- a serious condition that happens when your heart can’t supply enough oxygen-rich blood to your body leading to organ failure.
• Enlarged heart.
• Abnormal heart rates and rhythms (arrhythmia).

What are the causes of left-sided heart failure?

• Coronary Artery Disease (CAD): Blockages or narrowing of the coronary arteries supplying the heart muscle can lead to myocardial ischemia (reduced blood flow to the heart muscle) and eventual damage to the left ventricle.
• Heart attack: Acute blockage of a coronary artery leading to a heart attack can cause sudden damage to the heart muscle, particularly in the left ventricle. Scar tissue formation and remodeling of the ventricle can impair its ability to pump effectively.
• High blood pressure: Chronic high blood pressure can cause the left ventricle to work harder to pump blood against increased resistance. Over time, this can lead to left ventricular hypertrophy (thickening of the heart muscle) and impaired pumping function.
• Valvular heart disease: Conditions such as aortic stenosis (narrowing of the aortic valve), mitral regurgitation (leakage of the mitral valve), or aortic regurgitation (leakage of the aortic valve) can lead to increased pressure or volume overload on the left ventricle, eventually causing left-sided heart failure.
• Abnormal heart rhythms: Abnormal heart rhythms such as atrial fibrillation or ventricular tachycardia can impair the coordination and effectiveness of ventricular contraction, reducing the heart's pumping efficiency.
• Infiltrative diseases such as amyloid and sarcoid.

Other risk factors for left-sided heart failure include:

• Cardiotoxicity causing chemotherapy treatments for cancer.
• Diabetes.
• Obesity.
• Sleep apnea.
• Older age.
• Smoking.
• Certain drugs and energy drinks.
• Less commonly, certain medications for treating different disease processes, like autoimmune diseases and attention-deficit/hyperactivity disorder (ADHD).

What is the difference between right vs left heart failure? 

The following table outlines the key differences between right vs left heart failure.

The differences between right-sided and left-sided heart failure also include the treatment approaches and the medications given based on the symptoms that arise.

Does right-sided and left-sided heart failure impact daily life differently?

• As mentioned in the right vs left-sided heart failure chart there are a few differences in the symptoms of both. 
• Right heart failure and left heart failure both feel fatigue, weakness and shortness of breath. So, individuals may find it challenging to perform routine tasks, such as household chores or walking short distances, due to decreased stamina. Also, the fluid build-up symptoms can cause discomfort, difficulty with mobility, and limitations in performing daily activities.
• Does left-sided heart failure cause right-sided heart failure? Yes. Therefore there will be dietary modifications, such as reducing sodium intake to manage fluid retention and blood pressure and regular exercise within recommended guidelines for individuals with left-sided heart failure. Several studies have demonstrated that exercise training improves quality of life as well as functional capacity, systolic–diastolic function and BNP and NT-proBNP expression. This will arrest the progress of the disease and prevent right-side heart failure.

Is there a connection between left- and right-sided heart failure?

Yes, there is a connection between left and right-sided heart failure, and they often coexist or influence each other's progression. This connection is known as biventricular heart failure when both the left and right sides of the heart are affected simultaneously.

• Heart failure affects both the pulmonary circulation (right side of the heart) and the systemic circulation (left side of the heart). Dysfunction on one side of the heart can exert pressure on the other side, leading to a cascade of effects that worsen overall cardiac function.
• Left-sided heart failure can lead to increased pressure in the pulmonary circulation due to pulmonary congestion or pulmonary edema. This elevated pressure can eventually affect the right side of the heart, contributing to or worsening right-sided heart failure.
• Conditions such as chronic lung diseases (e.g., COPD) or pulmonary hypertension can lead to right-sided heart failure. Over time, these conditions may also contribute to left-sided heart failure.  
• Conditions such as hypertension, coronary artery disease, or valvular heart disease can initially lead to left-sided heart failure, eventually impacting the right side of the heart.

Are right-sided and left-sided heart failure treated differently?

The treatment of heart failure is done based on the symptoms, type and stage of heart failure.  

• The goals of treatment are a reduction in symptoms, a decrease in the rate of hospitalization, and the prevention of premature death.  
• The cornerstone of treatment is pharmacologic therapy.  
• Lifestyle modification may also be needed.  
• Surgery, implantable devices, or even heart transplantation may be required in selected cases.

The differences between right vs left heart failure can be summarized in the table below: 

Conclusion

Heart failure may occur when the heart cannot pump blood forcefully or effectively enough to supply the body's tissues. Left-sided heart failure is more common, and right-sided heart failure usually occurs as a result of left-sided heart failure. Certain conditions, such as CAD and high blood pressure, have close links to heart failure.

Right vs left heart failure has differences in symptoms and underlying causes, but the treatment strategies focus on improving heart function, relieving symptoms, and addressing underlying conditions.

Proper management of symptoms, adherence to treatment regimens, lifestyle modifications, and regular medical follow-up are essential for optimizing quality of life and functional capacity in individuals with heart failure.