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Neuroendocrine tumours (NETs) are a unique group of cancers arising from neuroendocrine cells, which are responsible for producing hormones and peptides.
These tumours can impact various organs, including the heart, leading to a range of cardiac symptoms. Understanding the cardiac involvement in NET patients is crucial for timely diagnosis and management.
This article delves into the causes, symptoms, diagnosis, and management of cardiac symptoms in NET patients, providing a comprehensive guide for patients and healthcare providers.
Neuroendocrine Cancer Australia (NECA), is dedicated to assisting individuals with neuroendocrine cancer and their families. NECA offers a wealth of resources, educational programs, and advocacy efforts aimed at deepening the understanding of NETs, improving patient care, and encouraging research advancements. Patients diagnosed with NETs can engage with NECA’s comprehensive support and information by calling the NET nurse line.
There are a range of causes of cardiac symptoms related to NETs. These often manifest in the form of adjacent conditions that affect the heart, or the tumour directly affecting the heart.
Carcinoid heart disease is a significant cause of cardiac symptoms in NET patients. It occurs when NETs, particularly those originating from the gastrointestinal tract, secrete excessive amounts of serotonin and other vasoactive substances.
These substances can cause thick plaques within the heart muscle and the heart valves, leading to valvular dysfunction and heart failure. The right side of the heart is typically more affected than the left, resulting in tricuspid and pulmonary valve abnormalities.
NETs can secrete a variety of hormones and bioactive substances, such as serotonin, histamine, and tachykinins, which can have direct and indirect effects on the heart. These hormonal effects can lead to:
In rare cases, NETs can directly encroach upon the heart or its surrounding structures, causing mechanical obstruction, pressure effects, or direct myocardial involvement. This can lead to various cardiac symptoms, depending on the location and extent of the tumour involvement.
Paraneoplastic syndromes are conditions that arise from the indirect effects of tumours, often due to hormone or cytokine secretion. These syndromes complicate the clinical picture and require a multidisciplinary approach to management.
Cardiac symptoms can vary from patient to patient, and also by cause. We’ve covered the most common cardiac symptoms reported by NET patients below. You should consult a healthcare professional if you report any of these, at any time.
Palpitations, or the sensation of irregular or forceful heartbeats, are common cardiac symptoms in NET patients. They can be caused by arrhythmias induced by hormonal imbalances or the direct effects of tumours on the heart’s conduction system.
Heart murmurs are sounds made by turbulent blood flow within the heart, often detected during a physical examination. In NET patients, murmurs can result from valvular dysfunction caused by carcinoid heart disease
Dyspnoea, or shortness of breath, is a frequent symptom in NET patients with cardiac involvement. It can be caused by heart failure due to valvular disease, myocardial dysfunction, or pericardial effusion. Dyspnoea can significantly impair a patient’s ability to perform daily activities and reduce their quality of life.
Oedema, or swelling, often occurs in the legs, ankles, and feet due to fluid accumulation. In NET patients, oedema can result from heart failure, where the heart is unable to pump blood effectively, leading to fluid buildup
Fatigue and weakness are common symptoms in NET patients with cardiac involvement. These symptoms can be caused by reduced cardiac output, leading to inadequate oxygen delivery to the tissues. Additionally, hormonal imbalances and systemic effects of NETs can contribute to overall fatigue and muscle weakness.
A thorough clinical assessment and detailed medical history are crucial for diagnosing cardiac symptoms in NET patients. Healthcare providers should inquire about the onset, duration, and severity of symptoms, as well as any associated factors such as previous heart conditions or known NETs.
Echocardiography is a key diagnostic tool for evaluating cardiac involvement in NET patients. It uses ultrasound waves to create images of the heart, allowing for the assessment of heart structure and function. Echocardiography can detect valvular abnormalities, myocardial dysfunction, and pericardial effusion.
Echocardiogram remains the gold standard tool for diagnosis and follow up of carcinoid heart disease and should be considered every 12 months when functional syndrome or elevated 5-HIAA is present.
An electrocardiogram (ECG) records the electrical activity of the heart and is essential for detecting arrhythmias, conduction abnormalities, and other cardiac issues. It can help identify specific patterns associated with NET-related cardiac involvement.
Cardiac MRI and CT scans may provide detailed images of the heart and surrounding structures. These imaging modalities can help assess the extent of tumour involvement, detect fibrosis, and evaluate the overall cardiac function. They are particularly useful for planning surgical or interventional procedures.
Biomarker testing, including measurements of NT-proBNP (N-terminal pro b-type natriuretic peptide), can help assess the severity of heart failure and monitor treatment response. Elevated levels of NT-proBNP indicate increased cardiac stress and are commonly seen in patients with carcinoid heart disease and other cardiac conditions. This test is currently not on the MBS and is non-rebatable.
The cardiac symptoms of NETs can be managed with a range of methods, including medically, surgically, and via lifestyle changes. What works best for each patient will depend on their situation.
Medications play a critical role in managing heart failure in NET patients.
Hormone therapy aims to control the secretion of bioactive substances by NETs, thereby reducing hormone-related cardiac symptoms. Somatostatin analogs, such as octreotide and lanreotide, are often used to manage hormone secretion and alleviate symptoms like flushing and wheezing.
Diuretics are medications that help remove excess fluid from the body, reducing symptoms of heart failure such as edema and shortness of breath.
For patients with significant valvular dysfunction due to carcinoid heart disease, surgical valve replacement or repair may be necessary. This procedure can alleviate symptoms and improve cardiac function. Mechanical or bioprosthetic valves may be used, depending on the patient’s condition and preferences.
Surgical resection of tumours is often considered for localised NETs with direct cardiac involvement. Removing the tumour can alleviate symptoms, improve cardiac function, and potentially cure the disease if caught early.
Dietary changes are essential for managing cardiac symptoms in NET patients. A heart-healthy diet rich in fruits, vegetables, whole grains, and lean proteins can help reduce the workload on the heart. Patients should also limit their intake of salt, sugar, and unhealthy fats to manage blood pressure and cholesterol levels. Contact our NET Nurse to find out if you are eligible for appointments with a NET Dietician.
Regular exercise and cardiac rehabilitation programs can help improve cardiovascular fitness, reduce symptoms, and enhance overall well-being. Patients should work with their healthcare team to develop a personalised exercise plan that takes into account their specific conditions and limitations.
The physical and emotional effects of cardiac symptoms in NET patients can be profound.
Effective management of cardiac symptoms in NET patients requires a comprehensive approach that includes medical treatments, lifestyle modifications, and psychological support. Strategies for managing these symptoms include:
Access to support resources is essential for the wellbeing of both patients and caregivers. These resources can provide information, practical advice, and emotional support.
Research on the cardiac involvement of NETs is ongoing, with studies focusing on:
These studies aim to enhance the quality of life for NET patients by addressing the root causes of cardiac symptoms.
Emerging therapies and clinical trials hold promise for better managing cardiac symptoms in NET patients.
Understanding the complexities of cardiac symptoms in neuroendocrine tumours is essential for providing comprehensive care to patients.
Through a combination of medical treatments, surgical interventions, lifestyle modifications, and psychological support, patients can manage these debilitating symptoms and improve their overall quality of life.
Ongoing research and emerging therapies offer hope for even better management strategies in the future, helping NET patients lead fuller, more active lives.
Further information and support for people diagnosed with NETs is available by calling the NECA NET nurse line.
