What happens during left-sided heart failure?

In left-sided heart failure, the primary issue is that the left ventricle cannot effectively pump blood out to the body. This inefficiency leads to fluid backing up into the lungs, a condition known as pulmonary congestion or pulmonary edema. As the left atrium receives blood from the lungs, the increased pressure from the backed-up blood causes fluid to seep into the lung tissues, resulting in symptoms such as shortness of breath, coughing, and difficulty breathing, especially when lying down.

While other options may represent complications or related issues of heart failure, they are not the hallmark manifestations of left-sided heart failure. For example, fluid accumulation in the abdomen is more characteristic of right-sided heart failure, where the right ventricle fails to effectively pump blood to the lungs, causing congestion and fluid retention in the peripheral circulatory system, including the liver and abdomen. Reduced blood flow to the extremities and electrolyte imbalances can occur as a consequence of heart failure but are not the definitive or direct results of left-sided heart failure itself.