Left-Sided Heart Failure: Causes, Symptoms, Diagnosis, and Treatment

The heart pumps oxygen-rich blood from the lungs to the left atrium. Then it goes to the left ventricle, which pumps the blood to the rest of the body. The left ventricle does most of the heart's pumping, so it’s larger than the other chambers. It is essential for the heart to function normally.

What are the types of left-sided heart failure (LHF)?

• SYSTOLIC FAILURE: The left ventricle does not contract normally, failing to pump enough blood into circulation. The ejection fraction (EF) is less than or equal to 40%. Hence, it is also known as heart failure with reduced ejection, or HFrEF. 
• DIASTOLIC FAILURE: Inability of the ventricular muscles to relax normally as it should, leads to inadequate filling of the ventricles. This is also known as heart failure with preserved ejection, or HFpEF, where the EF is 50% or higher. 
• Heart failure with mildly reduced ejection fraction (HFmrEF) is a newer concept. In this type of heart failure, the EF is between 41% and 49%. This places people with HFmrEF between the HFrEF and HFpEF groups. [1] 

How common is LHF? 

Heart failure is more prevalent and has a higher incidence in the elderly population. Approximately 5.7 million people in the United States have been diagnosed with heart failure. The incidence is around 10 per 1000 in people over 65. HFrEF is present in approximately 50% of the diagnosed patients.

What are the causes of LHF? 

• Coronary artery disease and narrowing of the blood vessels due to atherosclerosis.
• High blood pressure increases the workload on the heart to pump blood.
• Heart valve disease.
• Inflammation of the heart muscle is called myocarditis.
• Congenital heart defects.
• Irregular heart rhythms called arrhythmias.
• Other chronic conditions, such as diabetes, HIV infection, an overactive or underactive thyroid, or a buildup of iron or protein, may also contribute to eventual LHF. 
• Certain infections like Rheumatic fever or streptococcal infection. 
• Blood clots (thrombus or emboli) in the lungs or peripheral blood vessels.

What are the risk factors for LHF? 

Previous history of heart conditions with ongoing treatment, diabetes, sleep apnea, obesity, viral infections, smoking, excess alcohol intake, certain drugs (e.g., rosiglitazone (Avandia), pioglitazone (Actos), NSAIDs), male gender, sedentary lifestyle, and age are risk factors for LHF. 

What are the symptoms of LHF? 

Symptoms of heart failure may develop slowly or rapidly, depending on the pathophysiology.

• Shortness of breath with activity or when lying down.
• Fatigue and weakness.
• Swelling in the legs, ankles, and feet.
• Rapid or irregular heartbeat.
• Reduced ability to exercise.
• Wheezing.
• A cough that doesn't go away or a cough that brings up white or pink mucus with spots of blood.
• Swelling of the belly area.
• Very rapid weight gain from fluid buildup.
• Nausea and lack of appetite.
• Difficulty concentrating or decreased alertness.
• Chest pain in heart failure is caused by a heart attack.
• Fainting, light-headedness, or dizziness – this might warrant calling for emergency or 911. [2] 

How is LHF diagnosed?

Physical examination with the following blood testing in a laboratory can help to diagnose LHF:

• BNP (biomarker) blood test to check for hormones that occur with pressure changes inside the heart.
• Metabolic panel to check kidney or liver function, along with electrolytes such as sodium and potassium. 

Imaging studies may help to confirm the diagnosis:

• Electrocardiogram (ECG or EKG) 
• Echocardiogram (ECHO)
• Coronary angiography
• Cardiac MRI 

How is LHF treated? 

Medications:

• ACE inhibitors/ Angiotensin II receptor blockers (ARBs)/ Angiotensin-receptor neprilysin inhibitors (ARNIs) relax blood vessels and help remodel the heart. 
• Aldosterone antagonists control stress hormones to prevent symptoms from worsening also act as a mild water pill. 
• Beta blockers decrease your heart rate and how hard the heart has to work.
• Digoxin can help people feel better and help control their heart rate.
• Water pills (diuretics) help your body get rid of excess fluid.
• Sodium-glucose transport protein 2 (SGLT 2) inhibitors work in people with or without diabetes to help decrease excess fluid.

For worsening heart failure or no improvement with medication following options can be considered: 

• Cardiac resynchronization therapy (CRT): An implantable device that uses a gentle electrical current to stimulate your heart’s pumping action. It’s also called a biventricular pacemaker.
• Electrical cardioversion: This procedure helps restore a normal rhythm.
• Implantable cardioverter defibrillator (ICD): This implantable device detects arrhythmias and sends a gentle electrical current to restore a normal rhythm.
• Left ventricular assist device (LVAD): An implantable pump that helps the heart circulate blood.
• Heart transplant: Procedure to replace a worn-out heart with a healthy one from a donor. This treatment is for patients with the most severe forms of left-sided heart failure. [3]

If LHF is not treated, complications such as valvular failure, kidney damage or failure, liver damage, or sudden cardiac death can be expected.

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