--- title: Cardiac sarcoidosis description: What cardiac sarcoidosis is, why it develops, how it is recognised, which treatment approaches clinical guidelines describe and when urgent help is needed. type: disease aliases: - cardiosarcoidosis - sarcoidosis of the heart - sarcoid myocarditis sources: - tier: guideline org: minzdrav-rf title: Саркоидоз year: 2025 url: https://cr.minzdrav.gov.ru/view-cr/736_2 - tier: guideline org: minzdrav-rf title: Желудочковые нарушения ритма сердца. Внезапная сердечная смерть year: 2025 doi: 10.15829/1560-4071-2025-6670 url: https://cr.minzdrav.gov.ru/view-cr/569_2 - tier: guideline org: minzdrav-rf title: Брадиаритмии и нарушения проводимости year: 2025 doi: 10.15829/1560-4071-2025-6669 url: https://cr.minzdrav.gov.ru/view-cr/160_2 - tier: guideline org: minzdrav-rf title: Миокардиты year: 2025 url: https://cr.minzdrav.gov.ru/view-cr/153_2 - tier: guideline org: esc title: 2022 ESC Guidelines for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death year: 2022 doi: 10.1093/eurheartj/ehac262 url: https://doi.org/10.1093/eurheartj/ehac262 - tier: guideline org: esc title: 2023 ESC Guidelines for the management of cardiomyopathies year: 2023 doi: 10.1093/eurheartj/ehad194 url: https://doi.org/10.1093/eurheartj/ehad194 - tier: reference org: msd-manuals title: Sarcoidosis (MSD Manual Professional Version) year: 2025 url: https://www.msdmanuals.com/professional/pulmonary-disorders/sarcoidosis/sarcoidosis - tier: reference org: msd-manuals title: Sarcoidosis (MSD Manual Consumer Version) year: 2025 url: https://www.msdmanuals.com/home/lung-and-airway-disorders/sarcoidosis/sarcoidosis sources_checked: 2026-10-13 review: null --- Sarcoidosis is an inflammatory disease of unknown cause in which granulomas — collections of inflammatory cells — form in organs. It most often affects the lungs and lymph nodes, but it can affect any organ, including the heart. Cardiac sarcoidosis is one type of granulomatous [myocarditis](../myocarditis/), that is, inflammation of the heart muscle. It can be part of sarcoidosis that affects the whole body or involve only the heart, but this isolated form is extremely rare. Heart involvement develops to some extent independently and may not coincide in time with disease activity in the lungs; the Russian Ministry of Health guideline advises that these patients be followed and treated in tertiary-level medical institutions or federal centres.

The heart cut through all four chambers. The impulse from the sinus node travels over the atria and on to the ventricles: through the atrioventricular (AV) node, the bundle of His and its branches.

In sarcoidosis, foci — granulomas — appear in the heart muscle, including in the interventricular septum; the places of the foci in the diagram are an example. Granulomas near the conduction system can disrupt conduction of the impulse from the atria to the ventricles, and AV block then develops. The affected muscle can cause ventricular arrhythmias and contracts less strongly.

## Why it happens The cause of sarcoidosis is unknown. It is thought that in a person with an inherited predisposition, the immune system responds too strongly to something in the environment. Sarcoidosis is not contagious, and it is neither a tumour nor tuberculosis. It affects people of both sexes and of any age. According to MSD, sarcoidosis most commonly affects people aged 20 to 40; according to 2012 data from Moscow cited in the Russian Ministry of Health guideline, the average age of patients was 42 years in men and 53 years in women. In the heart, granulomas appear in the heart muscle, including in the septum between the ventricles and in the papillary muscles, and less often in the layers that cover and line the heart. Because of this, the heart rhythm and the conduction of the impulse are disturbed, the heart contracts less strongly, and sudden death is possible. Granulomas near the heart's electrical conduction system can cause potentially fatal heart rhythm problems. In severe sarcoidosis of the lungs, the right side of the heart may fail because pressure rises in the artery that carries blood from the heart to the lungs. This is a different mechanism from involvement of the heart muscle itself. Sarcoidosis is a systemic inflammatory disease of unknown aetiology characterised by the formation of non-caseating granulomas and multisystem involvement; environmental exposure in a genetically predisposed person plays the decisive role. Granulomas are collections of mononuclear cells and macrophages that differentiate into epithelioid and multinucleated giant cells and are surrounded by lymphocytes, plasma cells, fibroblasts and collagen. Cardiac sarcoidosis usually manifests in three forms: LV dysfunction, AV conduction disturbances and ventricular arrhythmias (VA). Heart failure in sarcoidosis can be due to [restrictive cardiomyopathy](../restrictive-cardiomyopathy/) (primary) or group V pulmonary hypertension (multifactorial). In its list of causes of bradyarrhythmias, the Russian Ministry of Health guideline classes sarcoidosis among infiltrative processes, together with [amyloidosis](../cardiac-amyloidosis/) and haemochromatosis. ## Symptoms Signs of heart involvement can include discomfort in the area of the heart, palpitations, a feeling of skipped beats or a slow pulse. Dizziness and [heart failure](../heart-failure/) can occur. Usually the disease shows itself in three forms: disturbed conduction of the impulse ([AV block](../av-block/)), ventricular rhythm disturbances, for example [ventricular tachycardia](../ventricular-tachycardia/), or weakened function of the left ventricle. The course varies widely. It can be fulminant — with sudden cardiac arrest, a picture resembling a heart attack, or a sharp fall in blood pressure (shock). The disease can also progress quickly, or slowly and chronically, with flare-ups and improvements. By clinical presentation, three main syndromes are distinguished: pain (cardialgic), arrhythmic (rhythm and conduction disturbances) and circulatory failure. Variants of the course: fulminant (sudden cardiac death, infarct-like presentation, cardiogenic shock), rapidly progressive (severity rising to a critical level within 1–2 years at most) and slowly progressive (chronic, with relapses and improvements). According to MSD, the most common cardiac manifestations are conduction blocks and arrhythmias, sometimes causing sudden death; transient papillary muscle dysfunction and pericarditis are rare. ## How it is diagnosed For everyone with newly diagnosed sarcoidosis, whichever organs are affected, the Russian Ministry of Health guideline advises an [ECG](../../diagnostic/ecg/) and [echocardiography](../../diagnostic/echocardiography/). Heart complaints are a reason for [Holter monitoring](../../diagnostic/holter-monitoring/), echocardiography and a contrast-enhanced cardiac MRI. The European guidelines list features that should make doctors think of sarcoidosis: enlarged lymph nodes at the roots of both lungs, changes in the lungs, inflammation of the eye (uveitis), involvement of the digestive tract, high-degree AV block and frequent ventricular ectopic beats. There is no specific blood test for cardiac sarcoidosis; troponin and NT-proBNP are among the most informative tests. A contrast-enhanced cardiac MRI shows the affected areas of the heart muscle. Positron emission tomography (PET-CT) shows where inflammation is active and in some cases helps choose a site for a biopsy. The diagnosis is made from the results of these tests and, when possible, from a biopsy of the heart muscle. The European guidelines also name lung biopsy among the diagnostic methods. A person with cardiac sarcoidosis is looked after by a team: a cardiologist, a lung specialist (pulmonologist), a heart rhythm specialist (arrhythmologist) and, if needed, a neurologist and a gastroenterologist. Red flags for sarcoidosis in ESC 2023: bilateral hilar lymphadenopathy, pulmonary infiltrates, uveitis, gastrointestinal involvement, high-degree AV block, frequent ventricular ectopic beats, thinned basal interventricular septum, extended late gadolinium enhancement (LGE) on CMR. In the dilated cardiomyopathy phenotype, AV block on the ECG is one of the findings that should raise the possibility of sarcoidosis; regional wall motion abnormalities on echocardiography or CMR also raise suspicion of it. ESC 2023 recommends contrast-enhanced CMR in patients with cardiomyopathy at initial evaluation (I B) and, in sarcoidosis, for serial follow-up and assessment of therapeutic response (IIa C); 18F-FDG PET scanning should be considered in the diagnostic work-up of patients with cardiomyopathy in whom cardiac sarcoidosis is suspected (IIa C). The Russian Ministry of Health guideline on sarcoidosis recommends cardiac MRI when cardiac sarcoidosis is suspected (grade of recommendation C, level of evidence 5); the affected area may show increased signal intensity on T2-weighted images and, after contrast, on T1-weighted images. Echocardiography shows isolated foci in the myocardium, including in the interventricular septum; over time they may calcify. There are no laboratory markers specific to cardiac sarcoidosis; the most informative are considered to be troponin T, NT-proBNP, creatinine, angiotensinogen and its derivatives, and angiotensin-converting enzyme. Rare cases of isolated cardiac sarcoidosis require differential diagnosis with arrhythmogenic cardiomyopathy and primary cardiomyopathies with a dilated or hypertrophic phenotype. ## How it is treated Heart involvement is a reason for active treatment: the Russian Ministry of Health guideline starts it when there is a threat of organ failure or a threat to life, and MSD explicitly names heart involvement as a reason to treat with corticosteroids. Corticosteroids (steroid hormones) are the mainstay of treatment for cardiac sarcoidosis. If needed, other medicines that suppress the immune system are added; they allow the steroid dose to be reduced. For severe AV block, a permanent pacemaker is recommended. To protect against sudden death, an implantable cardioverter-defibrillator (ICD) is used, which stops a dangerous arrhythmia; there is more about it in the article on [ventricular tachycardia](../ventricular-tachycardia/). The European guidelines and the Russian Ministry of Health guideline advise an ICD when the pumping function of the left ventricle is markedly reduced, and the European guidelines also after cardiac arrest or sustained ventricular tachycardia. An ICD is also considered when a pacemaker is needed because of AV block. If the pumping function is less reduced or preserved, the decision is based on scarring on MRI and sometimes on an electrophysiological study, once active inflammation has settled. Recurrent ventricular arrhythmias may require antiarrhythmic medicines. If the person already has an ICD and the medicines do not work or are not suitable, catheter ablation in a specialised centre is sometimes considered. For severe heart involvement or rhythm disturbances that cannot be controlled, heart transplantation is considered, but sarcoidosis may come back in the transplanted organ. Impaired heart or lung function and treatment with medicines that suppress the immune system raise the risk of severe infections, so MSD strongly recommends vaccination against influenza, pneumococcus, COVID-19 and respiratory syncytial virus (RSV) for people with sarcoidosis. The doctor and the patient decide together which path to take. Do not start, stop or change any medicines on your own. Glucocorticoid therapy is the mainstay of treatment for cardiac sarcoidosis, but its effect on VA has been described only in observational studies. Immunosuppressive therapy (glucocorticoids and/or immunosuppressants) is recommended in proven autoimmune forms of myocarditis, including cardiac sarcoidosis, in the absence of contraindications. ESC 2023 names steroids and steroid-sparing immunosuppressant drugs. Pacing according to the Russian Ministry of Health guideline: in sarcoidosis with second-degree Mobitz type II, high-degree or third-degree AV block, permanent pacing is recommended (grade of recommendation B, level of evidence 3); in cardiac sarcoidosis with persistent or transient AV block, pacemaker implantation should be considered (ESC class IIa C); with LVEF below 50% and an indication for permanent pacing, a CRT device (ESC class IIa C). ICD according to ESC 2022: recommended in patients with documented sustained VT or aborted cardiac arrest (I B) and with markedly reduced LVEF (I B); should be considered in patients with an indication for permanent pacing related to high-degree AV block, regardless of LVEF (IIa C), and with a higher LVEF but significant LGE at CMR after resolution of acute inflammation (IIa B); with moderately reduced LVEF and minor LGE, programmed electrical stimulation (PES) for risk stratification should be considered (IIa C), and with sustained monomorphic VT (SMVT) inducible at PES, an ICD (IIa C). The Russian Ministry of Health guideline on ventricular arrhythmias contains the same provisions on reduced LVEF (ESC class I B), second- to third-degree AV block with an indication for pacing (IIa C), significant contrast enhancement on MRI after resolution of active inflammation (IIa B) and an electrophysiological study for risk stratification (IIa C). In recurrent symptomatic ventricular arrhythmias, antiarrhythmic drug treatment should be considered (IIa C); in ICD recipients with recurrent symptomatic SMVT or ICD shocks for SMVT, in whom antiarrhythmic drugs are ineffective, contraindicated or not tolerated, catheter ablation in specialised centres may be considered (IIb C). Heart transplantation is recommended for adults with cardiac sarcoidosis with myocardial involvement and/or refractory arrhythmias (grade of recommendation C, level of evidence 4). ## When to call an ambulance Cardiac sarcoidosis can have a fulminant course, up to sudden cardiac arrest. In acute progressive sarcoidosis with complications, including heart rhythm disturbances, the Russian Ministry of Health guideline considers emergency or urgent hospital admission indicated. Call your local emergency number (112 in the EU, 911 in the US and Canada, 999 in the UK) if an episode of arrhythmia comes with dizziness, weakness, feeling faint, loss of consciousness or a racing heartbeat, and also if your ICD fires (delivers a shock or another treatment). As with any heart condition, call an ambulance for fainting, chest pain or severe breathlessness: this is the site's general safety rule, repeated at the bottom of every page.