A cardiac 'shadow' can refer to the outline of the heart on a scan result; there is nothing abnormal about this and is a usual thing to see, however the characteristics of the shadow can tell us some things about our health (White et al, 2011). In your case when doctors have referred to their being 'a shadow on your heart' they may be referring to something being seen on a scan, such as a mass or a blood clot potentially. In order to understand what this means it would be helpful to get back in touch with your diagnosing doctor to ask then what they are referring to when they say 'a shadow'.
I will discuss a little bit some of the potential causes of finding a 'shadow' on the heart below:
Whilst these are rare you can develop a tumour in the cardiac muscle or adjacent structures which could be both malignant (cancerous) or benign (non-cancerous). Benign tumours are much more common that malignant tumours. What symptoms we might experience will depend on the size and location of the tumour, but most often there are no symptoms or only non-specific symptoms such as dizziness, fever, shortness of breath, chest pain and general fatigue (BHF, 2021).
If a tumour is non-cancerous and not causing any symptoms then it may be that no treatment is required, and active monitoring is the best thing, but if treatment is required generally this will mean the removal of the tumour via open heart surgery. (BHF, 2021). If the tumour is malignant then medication or chemotherapy may be needed along with surgery; in this situation surgery can be more complicated and some elements of reconstruction may be required (BHF, 2021). Sometimes in severe cases, there is no treatment that is available; as with any tumour the earlier the diagnosis the better the treatment prognosis.
A 'shadow' on the heart could also be referring to a blood clot that has built up inside the heart. Developing a blood clot in the heart may be more likely if you have a background condition of an irregular heart rhythm, called atrial fibrillation (AF) (Healthline, 2021).
If this blood clot moves, or part of it breaks off, it can travel to other areas of the body causing further damage (NHS, 2021; NHLBI, 2021):
Having AF can make you up to 5 times more likely to have a stroke (Stroke Association, 2020) although this does depend on other factors such as medical history, age and weight.
If you have been diagnosed with AF you will likely be prescribed anticoagulant (blood thinning) medication to reduce your risk of developing blood clots (Stroke Association, 2020).
There are four chambers in your heart – the left and right atria, and the left and right ventricle. Your left ventricle pushes blood that carries oxygen out into your aorta – the largest artery in your body – under high pressure. It then travels around a network of blood vessels around your body (BHF, 2021).
Several things can cause us to have damage to the left ventricle:
This means that you heart is having to work harder to pump blood around your body, due to a high level of resistance within the arteries. Having high blood pressure for an extended length of time can affect our left ventricle and cause enlargement. This shows that your cardiovascular system is under strain and can put you at higher risks of complications such as heart attack and stroke. Whilst lowering your blood pressure won't reverse this damage it can significantly reduce your risk factors going forward (Hendriks et al, 2019).
This problem could affect the valves that separate the chambers of your heart, or the valve between the left ventricle and the aorta. Valves stop blood flowing the wrong way around your heart so if they become damaged or do not work properly, it can increase the strain on your left ventricle, leading to enlargement (John Hopkins Medicine, 2021).
Sometimes our doctors will refer to the damage to the muscle as ventricular damage, such as from a heart attack (NHS, 2021).
Unfortunately, we can’t be specific about what your doctor meant because we would need to know a lot more about your medical history. However, we hope this explanation gives you some help about what sort of issues your doctor might have been referring to. You should definitely get in touch with them for further clarification.
For more information and support, visit our heart centre.
Answered by our Health at Hand team.
Pulmonary Embolism – NHS factsheet
Deep Vein Thrombosis (DVT) – NHS factsheet
Heart attack – NHS factsheet
Stroke – NHS factsheet
British Heart Foundation, 2021. All about cardiac tumours. (Accessed 26 Feb 2021).
British Heart Foundation, 2021. How your heart works. (Accessed 26 Feb 2021).
Healthline, 2021. How to tell if you have a blood clot. (Accessed: 26 Feb 2021).
Hendriks, T., Abdullah Said, M., Janssen, L., Yldau van der Ende, M. Dirk van Veldhuisen, J., Verweij, N. and Van der Harst, P. (2019) 'Effect of systolic blood pressure on left ventricular structure and function'. Hypertension. 74(4): 826-832.
John Hopkins Medicine, 2021. Heart valve diseases. (Accessed 26 Feb 2021).
National heart, lung and blood institute, 2021. Atrial fibrillation. (Accessed: 26 Feb 2021).
NHS, 2021. Arterial thrombosis. (Accessed 26 Feb 2021).
NHS, 2021. Heart attack - complications. (Accessed 26 Feb 2021).
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