NUR 324. Medications for Heart Failure-5

Medications for Congestive Heart Failure

Important medications used in the treatment of congestive heart failure are integral to managing this condition effectively.

Flow of Blood Through the Heart

The heart's anatomy and blood flow dynamics are essential for understanding heart function. The Superior Vena Cava returns deoxygenated blood from the upper body to the heart, while the Inferior Vena Cava performs the same function for the lower body. The Pulmonary Artery transports deoxygenated blood to the lungs for reoxygenation, and the Pulmonary Veins carry the newly oxygenated blood back to the heart. The chambers of the heart, comprising the Right Atrium, Right Ventricle, Left Atrium, and Left Ventricle, are responsible for receiving and pumping blood. Various valves, including the Tricuspid Valve (which controls blood flow from the right atrium to the right ventricle), the Pulmonic Valve (from the right ventricle to the pulmonary artery), the Mitral Valve (from the left atrium to the left ventricle) and the Aortic Valve (from the left ventricle to the aorta), regulate blood flow through the heart.

Overview of Heart Failure

Heart failure incidence is increasing in the U.S., putting a large portion of the population at risk. Key risk factors include hypertension, obesity, pre-diabetes or diabetes, cardiac diseases (especially myocardial infarction), familial or genetic cardiomyopathies, cardiotoxicity from cancer treatments, substance abuse, autoimmune disorders, iron overload, and inflammatory disorders such as COVID-19. Additionally, disparities show a higher incidence in African American and Hispanic populations.

Underlying Problems in Heart Failure

Heart failure can arise from muscle damage caused by atherosclerosis or cardiomyopathy. An increased workload on the heart may occur due to hypertension, alcoholism, myocardial infarction, atrial fibrillation, or valvular disease. Structural abnormalities, including congenital cardiac defects, can also contribute to heart failure.

Left-Sided Heart Failure

In left-sided heart failure, the left ventricle fails to pump oxygenated blood effectively to the left atrium. Symptoms include decreased cardiac output and pulmonary congestion. This type can be categorized into Systolic Heart Failure, where the left ventricle cannot contract forcefully enough (with an ejection fraction of less than 50%). Common symptoms of systolic heart failure include tiredness, decreased urine production, increased heart rate, elevated blood pressure, an enlarged heart, pulmonary congestion leading to shortness of breath, nocturnal coughing, weight gain, and decreased blood flow to extremities.

Diastolic Heart Failure

Diastolic heart failure occurs when stiff ventricles prevent adequate filling, although they can still contract effectively, often due to hypertension. Notably, there are currently no specific medications for treating diastolic dysfunction.

Pulmonary Congestion in Heart Failure

Signs of pulmonary congestion include paroxysmal nocturnal dyspnea, confusion, blood-tinged sputum, crackles, and wheezes. Other symptoms may include orthopnea, tachycardia, exertional dyspnea, fatigue, and cyanosis.

Right-Sided Heart Failure

Right-sided heart failure, which is less common than left-sided failure, causes a backup of deoxygenated blood into the body. Symptoms include weakness, fatigue, peripheral edema (swelling in legs and feet), distended neck veins, weight gain, increased urination, hepatomegaly (enlarged liver), and increased abdominal girth.

Activation of the Sympathetic Nervous System

The activation of the sympathetic nervous system results in increased heart rate and myocardial contractility, alongside vasoconstriction, activation of the Renin-Angiotensin System (RAS), and augmented myocardial oxygen demand and wall stress.

Patient Compliance

Patient compliance poses challenges as approximately 50% of patients have three or more comorbidities and are prescribed an average of six medications. There are notable issues surrounding prescription adherence and follow-up.

Goals of Treatment

The primary goals of heart failure treatment are to alleviate existing symptoms, prevent additional complications, and address the underlying causes of heart failure.

Stages of Heart Failure

Heart failure can be categorized into stages. Stage A represents individuals at risk without symptoms. Stage B indicates pre-heart failure conditions such as hypertension or cardiovascular disease. Stage C describes current or previous symptoms with evident structural disease, while Stage D signifies advanced heart failure with significant symptoms that impact quality of life.

Classification of Heart Failure

Heart failure classifications include New Onset/De Novo HF, which refers to newly diagnosed cases with no prior history; Resolution of Symptoms, where previous symptoms have resolved; Persistent HF, involving ongoing symptoms and limited functional capacity; and Worsening HF, characterized by escalating symptoms or deteriorating functional capacity.

Diagnostic Criteria for Heart Failure

Diagnostic criteria for heart failure include HFrEF (Heart Failure with reduced ejection fraction, LVEF ≤40%), HFmrEF (LVEF 41%-49%), and HFpEF (LVEF ≥50%). Testing for heart failure comprises clinical history assessment, ECG, and evaluation of natriuretic peptide levels.

Treatments for Heart Failure

Medications play a crucial role in treating heart failure. ACE Inhibitors are the first-line treatment options, as they help decrease preload and afterload. Diuretics are also administered to reduce blood volume and pressure, thereby improving symptoms. Beta-blockers assist in decreasing myocardial workload and enhancing survival rates. ENTRESTO, a combination of sacubitril and valsartan, is utilized specifically for systolic heart failure.

ACE Inhibitors

The actions of ACE inhibitors include the prevention of angiotensin conversion, leading to significant symptom improvement and cardiovascular remodeling prevention.

Loop Diuretics

Loop diuretics function by inhibiting sodium and chloride reabsorption, necessitating careful monitoring of electrolytes and input/output (I&O).

Spironolactone and Eplerenone

Spironolactone and eplerenone are indicated for the management of hypertension and heart failure, requiring cautious monitoring.

Beta Blockers

Beta blockers are utilized to improve symptoms and enhance survival rates, but they necessitate careful initiation and monitoring.

Nitrates

Nitrates are indicated for angina and work by dilating vessels to improve blood flow; strategies typically involve drug-free periods.

Digoxin

Digoxin has a positive inotropic effect, but it requires careful monitoring due to its narrow therapeutic range, with toxicity signs including vision changes.

Summary of Heart Failure Symptoms

Symptoms of heart failure can be differentiated based on the side affected: right-sided symptoms include ascites and peripheral edema, while left-sided symptoms manifest as crackles and shortness of breath (SOA).

Nursing Interventions for Heart Failure

Nursing interventions for heart failure involve monitoring lung sounds, heart rate, blood pressure, electrolytes, and weight. Patient education on dietary restrictions and medication adherence is crucial to successful management.

Monitoring Treatment Success

Success indicators of heart failure treatment include clearer lung sounds, decreased heart rate, and an overall improvement in the patient's condition.