Acute heart failure occurs when the heart suddenly becomes unable to pump enough blood to meet the body’s demands. This condition is characterized by a rapid onset or worsening of symptoms, often requiring immediate medical attention and hospitalization. It represents a sudden decline in the heart’s function, making it a medical emergency.
What is Acute Heart Failure?
Acute heart failure refers to a sudden and severe inability of the heart to circulate sufficient blood, contrasting with chronic heart failure which develops gradually. Acute heart failure manifests with abrupt, severe symptoms requiring urgent intervention. The physiological process involves the heart’s sudden inability to adequately pump blood, either because it cannot contract strongly enough (systolic heart failure) or cannot relax and fill properly (diastolic heart failure). This can lead to increased pressure within the heart chambers and a backup of fluid, particularly in the lungs. This rapid decline in pumping function means the body’s tissues and organs do not receive enough oxygen and nutrients, leading to systemic congestion and potentially organ dysfunction.
Recognizing the Symptoms and When to Seek Emergency Care
Recognizing the symptoms of acute heart failure is important for timely intervention. A prominent symptom is sudden, severe shortness of breath, which may worsen when lying flat. Individuals might also experience a persistent cough, sometimes producing white or pink frothy mucus, and wheezing.
Fluid retention is another common sign, manifesting as rapid weight gain, and swelling in the legs, ankles, feet, or abdomen. Other indicators include overwhelming fatigue, general weakness, and a reduced ability to perform daily activities or exercise. Some people may also notice a rapid or irregular heartbeat, chest pain, dizziness, or even fainting.
Immediate emergency care is necessary for these symptoms. If you experience sudden, severe shortness of breath, chest pain, fainting, or a rapid or irregular heartbeat accompanied by shortness of breath, call emergency services immediately. A sudden weight gain of 2 to 3 pounds in one day or 5 pounds in a week also warrants urgent medical attention, as it can indicate worsening fluid retention.
Causes and Underlying Conditions
Acute heart failure can be triggered by a range of underlying conditions that suddenly place excessive strain on the heart. One common cause is an acute coronary syndrome, such as a heart attack, where a blockage in a coronary artery damages heart muscle due to insufficient blood supply. This damage weakens the heart’s pumping ability, leading to acute failure. Uncontrolled high blood pressure can also suddenly stress the heart, causing the muscle to work too hard and eventually weaken.
Heart rhythm problems, or arrhythmias, can significantly impair the heart’s pumping efficiency, especially if the heart beats too fast or too slow, or irregularly. Conditions affecting heart valves, where they do not open or close properly, can force the heart to pump harder, leading to acute failure if the workload becomes too great. Additionally, severe infections like myocarditis, an inflammation of the heart muscle, or even systemic infections like sepsis, can directly damage the heart or place an overwhelming demand on it, precipitating acute heart failure. Worsening of pre-existing chronic heart failure, often due to factors such as not adhering to prescribed medications or excessive salt and fluid intake, can also lead to an acute episode.
Emergency Diagnosis and Treatment
Upon arrival at the hospital with suspected acute heart failure, the diagnostic process begins swiftly to assess the heart’s function and identify the underlying cause. A physical examination focuses on signs of fluid overload, such as crackling sounds in the lungs (rales), elevated jugular venous pressure, and swelling in the extremities. Blood tests are routinely performed, including levels of B-type natriuretic peptide (BNP) or N-terminal pro-BNP, hormones released when the heart is under stress, which can help support the diagnosis. Troponin testing can also assist in detecting underlying heart muscle injury or ischemia.
An electrocardiogram (ECG) records the heart’s electrical activity to identify any rhythm abnormalities or signs of a heart attack. A chest X-ray is often used to check for fluid buildup in the lungs or an enlarged heart, although a normal chest X-ray does not rule out acute heart failure. An echocardiogram, an ultrasound of the heart, provides detailed images of heart movement, blood flow, and the pumping ability of the ventricles, helping to determine the type and severity of heart failure. Point-of-care ultrasound can also be used to assess for pulmonary edema, fluid volume status, and myocardial function.
Immediate treatments aim to stabilize the patient and improve heart function. Oxygen therapy is administered to maintain blood oxygen saturation above 90%, often through a mask or nasal cannula. For patients with significant respiratory distress, non-invasive positive pressure ventilation (NIPPV), such as CPAP or BiPAP, can be used to improve breathing and reduce the heart’s workload. Diuretics, commonly loop diuretics like furosemide, are a primary treatment and are given intravenously to help the body eliminate excess fluid and reduce congestion.
Vasodilators, such as nitroglycerin, are also administered intravenously, particularly in patients with normal or elevated blood pressure, to open narrowed blood vessels, reduce pressure on the heart, and improve blood flow. Nitroglycerin can rapidly redistribute fluid from the pulmonary system, improving respiratory status. In cases of low blood pressure or signs of inadequate blood flow to organs (hypoperfusion), inotropic agents like dobutamine or milrinone may be used to enhance the heart’s pumping strength. For the most severe cases, where pharmacological treatments are insufficient, mechanical circulatory support devices may be considered. These devices, such as intra-aortic balloon pumps, Impella devices, or extracorporeal membrane oxygenation (ECMO), temporarily assist the heart in pumping blood and supporting organ function. The specific treatment plan is tailored to the patient’s hemodynamic status and the underlying cause of the acute heart failure episode.
Life After an Acute Episode: Long-Term Management
After an acute heart failure episode, ongoing management is necessary to prevent future occurrences and improve overall well-being. This includes a comprehensive medication regimen, often involving a combination of drugs such as ACE inhibitors, angiotensin receptor blockers (ARBs), beta-blockers, and mineralocorticoid receptor antagonists. These medications work to improve heart function, manage blood pressure, and reduce fluid retention.
Lifestyle modifications play an important role in long-term heart health. Patients are encouraged to adopt a low-sodium diet, typically aiming for 2,000 milligrams or less of salt per day, to minimize fluid retention. Fluid intake may also need to be limited, especially in cases of advanced heart failure. Regular physical activity, as recommended by a healthcare provider, helps strengthen the heart muscle and improve cardiovascular function, often as part of a structured cardiac rehabilitation program.
Weight management, smoking cessation, and limiting or avoiding alcohol are also advised to reduce strain on the heart. Cardiac rehabilitation programs offer a supervised, multidisciplinary approach that includes exercise training, nutritional counseling, stress management, and education on medication adherence, all designed to improve quality of life and reduce hospital readmissions.