Sudden congestive heart failure can be potentially life-threatening.
The human heart is an amazing contraption. About once every second, more than 86,000 times each day, your heart squeezes a fistful of blood into your arteries and sends oxygen, nutrients, hormones and other vital substances coursing toward every cell in your body. It's a miracle this hardworking pump doesn't fail more frequently. When it does -- and your heart can fail quite suddenly -- some of the fluid within your blood vessels backs up into your tissues and organs, leading to the "congestion" that characterizes heart failure.
A Closed Circuit
Your circulatory system is essentially a closed loop that consists of your heart and a series of tubes that transmit blood throughout your body. Blood leaving your heart is pumped into arteries, which divide into smaller vessels called arterioles. These divide into even smaller vessels called capillaries. Within the extensive capillary beds of your body, oxygen, carbon dioxide and nutrients are exchanged. Your capillaries then join into successively larger venules, which become veins that lead back to your heart. Thus, all of the blood that leaves your heart must eventually return. Any insult that damages your heart or impairs its pumping ability can interrupt cyclic blood flow and lead to congestive heart failure.
"Myocarditis" is a term doctors use to describe inflammation of your heart. Myocarditis can stem from a number of causes, including viral or bacterial infections, toxins, recreational drugs, medications and autoimmune diseases, such as lupus. Inflammation within the muscle of your heart wall decreases its ability to contract. Heart failure due to myocarditis -- regardless of the cause -- can develop within days.
Your heart is a 4-chambered pump whose compartments are separated by muscular walls and valves. Sudden injury to the chambers' walls, such as that incurred during a heart attack, or failure of one of the heart's valves can lead to an abrupt decline in pumping efficiency and the sudden onset of congestive heart failure. A study published in the October 2011 issue of "The American Journal of Medicine" reported that 10 to 40 percent of patients suffering from heart attacks develop new-onset heart failure.
Even if your heart is otherwise healthy, certain metabolic or physiologic processes can trigger congestive heart failure. In many cases, the onset of heart failure can be quite abrupt. Severe anemia, thyroid disease and some nutritional disorders, such as a severe thiamine deficiency, can lead to sudden heart failure. Studies suggest that 10 to 15 percent of people with thyrotoxicosis -- abnormally high thyroid hormone levels -- develop heart failure. When the underlying metabolic disorder is treated, heart failure often resolves.
Your heart works most efficiently when it contracts regularly and relatively slowly. By interfering with your heart's ability to fill between contractions or reducing the strength of each contraction, sudden disruptions in your heart's rhythm can cause congestive heart failure. A 2010 review in the "Journal of Emergencies, Trauma and Shock" reviewed the medical management of several abnormal rhythms -- atrial fibrillation being the most common -- that can begin abruptly and present with congestive heart failure. In many cases, reestablishing a normal rhythm will correct the congestive heart failure.
Fatigue, shortness of breath, dizziness and poor exercise tolerance -- all symptoms of congestive heart failure -- may be attributed to less serious conditions by people who are otherwise healthy. However, even young, vital people can suddenly develop congestive heart failure. If such symptoms appear abruptly and persist, see your doctor right away for an evaluation.