From the Guidelines
Anemia-related heart murmurs are typically systolic, soft, and best heard at the left sternal border or apex, occurring due to increased cardiac output and decreased blood viscosity in anemic states, and their management involves identifying and treating the underlying cause of anemia, which may include iron supplementation, vitamin B12, folate, or blood transfusions for severe symptomatic cases, as supported by the study published in the American Journal of Hematology in 2017 1.
Clinical Manifestations
The clinical manifestations of anemia-related heart murmurs are associated with the onset, severity, and duration of the anemia, as well as other factors influencing tissue demands for oxygen, as noted in the study published in the Journal of the National Comprehensive Cancer Network in 2012 1. Some key points to consider include:
- The murmur is not indicative of structural heart disease and will resolve once the underlying anemia is treated.
- Patients with anemic murmurs may experience symptoms like fatigue, dizziness, palpitations, and dyspnea on exertion.
- The murmur's intensity often correlates with the severity of anemia, and its disappearance can be a clinical indicator of successful anemia treatment.
Pathophysiology
The pathophysiology of anemia in patients with heart failure is multifactorial, involving factors such as iron deficiency, inflammation, and the use of cardiovascular drugs, as discussed in the study published in the American Journal of Hematology in 2017 1. Key points to consider include:
- Iron deficiency is a common cause of anemia in patients with heart failure, with a prevalence of up to 50-70% in ambulatory or hospitalized patients.
- Inflammation can also contribute to anemia, with increased production of inflammatory cytokines such as TNF-a and IL-6.
- The use of cardiovascular drugs can also play a role in the development of anemia.
Management
The management of anemia-related heart murmurs involves identifying and treating the underlying cause of anemia, which may include:
- Iron supplementation, typically ferrous sulfate 325 mg orally three times daily.
- Vitamin B12, 1000 mcg daily orally or monthly injections.
- Folate, 1 mg daily.
- Blood transfusions for severe symptomatic cases. As noted in the study published in the American Journal of Hematology in 2017, an algorithm for the evaluation and management of anemia in patients with heart failure is essential for optimal patient care 1.
From the Research
Clinical Manifestations of Anemia-Related Heart Murmurs
- Anemia can lead to poor clinical status and worse outcomes in patients with heart failure 2
- Chronic anemia may present with worsening fatigue, dyspnea, lightheadedness, or chest pain 3
- Anemia can cause cardiac stress through tachycardia and increased stroke volume, and can also cause reduced renal blood flow and fluid retention, adding further stress to the heart 4
- Long-standing anemia of any cause can cause left ventricular hypertrophy (LVH), which can lead to cardiac cell death through apoptosis and worsen the heart failure 4
Symptoms of Anemia-Related Heart Murmurs
- Pallor is the most frequent presenting feature of iron deficiency anemia 5
- Poor appetite, fatigability, lassitude, lethargy, exercise intolerance, irritability, and dizziness may be seen in mild to moderate iron deficiency anemia 5
- Tachycardia, shortness of breath, diaphoresis, and poor capillary refilling may occur in severe iron deficiency anemia 5
- Neurodevelopmental and cognitive deficits may occur in children with severe and prolonged iron deficiency anemia 5
Diagnosis and Treatment of Anemia-Related Heart Murmurs
- Accurate and affordable tools for diagnosing anemia and its main determinants are essential for understanding the magnitude and distribution of the problem and the appropriate interventions needed for its timely prevention and treatment 6
- Oral iron therapy is the first-line treatment for iron deficiency anemia 5
- Parenteral iron therapy or red blood cell transfusion is usually not necessary 5
- Primary prevention of iron deficiency anemia can be achieved by supplementary iron or iron fortification of staple foods, and secondary prevention involves screening for, diagnosing, and treating iron deficiency anemia 5