Left-sided heart failure is a life-threatening condition in which the left side of the heart cannot pump enough blood to the body.

Heart failure may affect the right side, the left side, or both sides of the heart. The left side of the heart receives blood rich in oxygen from the lungs and pumps it to the remainder of the body. As the ability to pump blood forward from the left side of the heart is decreased, the remainder of the body does not receive enough oxygen especially when exercising. This results in fatigue.

In addition, the pressure in the veins of the lung increases, which may cause fluid accumulation in the lung. This results in shortness of breath and pulmonary edema.

Common causes of left-sided failure include the following:

• Heart attack
• Chronic blockages of the heart arteries
• High blood pressure
• Excessive alcohol consumption
• Leaking or narrow heart valves
• Hypothyroidism
• Heart muscle infections
• Any other disease that damages the heart muscle

In children, common causes include heart birth defects such as abnormal heart valves, abnormal blood vessel connections, or viral infections.

Left-sided heart failure occurs in approximately 1 to 3 of every 100 people and becomes more prevalent with age.

• Shortness of breath
• Difficulty lying down; need to sleep with the head elevated to avoid shortness of breath
• Sensation of feeling the heartbeat (palpitations)
• Irregular or rapid pulse
• Cough (produces frothy or blood-tinged mucus)
• Fatigue, weakness, faintness
• Weight gain from fluid retention
• Decreased urine production (oliguria)
• Infants may have poor feeding, weight loss, and failure to thrive

Physical examination may reveal an irregular or rapid heartbeat and increased rate of breathing. Listening to the heart may reveal heart murmurs or extra heart sounds, and listening to the lungs may reveal crackles or decreased breath sounds at the bottom. The skin of the legs may have excessive fluid and may remain dimpled when pressed.

Tests may include the following:

• Electrocardiogram (ECG) may show evidence of prior heart attack, an enlarged heart, or abnormal heart rhythm.
• Chest X-ray may show an enlarged heart and fluid in or around the lungs.
• Ultrasound of the heart (echocardiogram): poor pumping action of the heart, leaking or narrow heart valves.
• Blood tests to evaluate thyroid, liver, and kidney function.
• Stress test to evaluate for heart disease.
• Coronary angiography to evaluate blockages in the heart arteries.