# Dilated Cardiomyopathy > Dilated cardiomyopathy for NEET-PG Medicine covering aetiologies, echo features, genetic forms such as TTN and LMNA and end-stage management. - Canonical URL: https://prepelephant.com/topics/neet-pg/medicine/dilated-cardiomyopathy - Exam / course: NEET-PG · Subject: Medicine - Publisher: PrepElephant (https://prepelephant.com) — Prepared and reviewed by the PrepElephant Academic Review Team - First published: 2026-10-08 - Last updated: 2026-10-08 - Reference basis: Braunwald's Heart Disease; Harrison's Principles of Internal Medicine; Hurst's The Heart - How to cite: "Dilated Cardiomyopathy", PrepElephant, https://prepelephant.com/topics/neet-pg/medicine/dilated-cardiomyopathy ## Direct answer Dilated cardiomyopathy is left ventricular dilatation with reduced systolic function, usually an ejection fraction below 40 per cent, that is not explained by abnormal loading conditions or coronary disease. Causes include alcohol, viral myocarditis, peripartum pregnancy, anthracyclines, thyrotoxicosis and genetic variants, most often in the TTN gene. Treatment is guideline-directed heart failure therapy, with devices for selected patients and advanced therapies at end stage. ## What you must remember - **Alcohol:** a dose-related cause; abstinence can improve function if the disease is not advanced. - **Peripartum:** heart failure with reduced ejection fraction in the last month of pregnancy or within five months after delivery. - **Chemotherapy:** anthracyclines such as doxorubicin cause cumulative, dose-dependent cardiotoxicity. - **Genetics:** truncating TTN variants are the commonest genetic cause; LMNA variants bring conduction disease and early arrhythmia, so an ICD may be indicated sooner. - **Nutrition:** wet beriberi from thiamine deficiency causes high-output failure with vasodilatation, and thiamine reverses it. - **Core therapy:** an ACE inhibitor, ARB or ARNI, a beta-blocker, a mineralocorticoid antagonist and an SGLT2 inhibitor, with diuretics for congestion. - **Devices:** an ICD for primary prevention when the ejection fraction stays at 35 per cent or less after optimised therapy; CRT for LBBB with QRS of 150 ms or more. - **End stage:** inotropes as a bridge, LVAD or transplantation for advanced disease; non-dihydropyridine calcium channel blockers are harmful. ## Working up a new cardiomyopathy in a young woman A 31-year-old woman presents with breathlessness three months after delivery, with an ejection fraction of 30 per cent, a dilated left ventricle and a normal coronary angiogram. 1. **Exclude ischaemia:** A dilated ventricle with normal coronaries points away from infarction, so ischaemia is excluded first. 2. **Check reversible causes:** Thyroid function, alcohol history, medications and prior anthracycline exposure are checked, along with iron studies and screening for infection that might have triggered myocarditis. 3. **Image the heart:** Cardiac MRI separates patterns of myocarditis or infiltration from a non-specific dilated picture. 4. **Diagnose peripartum cardiomyopathy:** It is diagnosed when the ventricle is dilated and the ejection fraction reduced in the last month of pregnancy or within five months afterwards. It remains a diagnosis of exclusion. 5. **Start treatment:** Guideline therapy is started, with drug choice adjusted for breastfeeding, and anticoagulation is considered if a left ventricular thrombus is seen. 6. **Counsel and screen:** Future pregnancy is counselled against until function recovers, because the recurrence risk and haemodynamic load are significant. A family screen follows if the disease is familial, since genetic forms have consequences for relatives. ## Where the examiner expects a specific answer Dilated cardiomyopathy questions reward a stepwise exclusion and a few precise drug rules. - **Trap:** naming a cause before the reversible ones are excluded. — **Correct:** alcohol is the usual reversible cause in stems, but thyroid disease and tachycardia-induced cardiomyopathy must also be excluded first. - **Trap:** assuming an ACE inhibitor is routine for a woman planning pregnancy. — **Correct:** ACE inhibitors, ARBs and ARNI are contraindicated in pregnancy, even though they are standard care otherwise. - **Trap:** implanting an ICD at an early ejection fraction. — **Correct:** primary prevention ICD decisions follow at least three months of optimised therapy, so an ejection fraction of 30 per cent in a patient diagnosed only weeks ago means optimising therapy and rechecking rather than implanting at once. - **Trap:** giving the standard heart failure regimen for high-output failure. — **Correct:** wet beriberi from thiamine deficiency presents with a high-output heart, warm peripheries and oedema, and thiamine is the treatment. ## Frequently asked questions ### What are the commonest causes of dilated cardiomyopathy? The commonest causes include alcohol, viral myocarditis, peripartum pregnancy, anthracycline chemotherapy, thyrotoxicosis and genetic variants. Idiopathic disease is diagnosed when no cause is identified after standard evaluation. ### Which gene is most often implicated in genetic dilated cardiomyopathy? Truncating TTN variants, which affect titin, are the most frequently identified genetic cause. LMNA variants are less common but are linked to conduction disease and early arrhythmia. ### When is an ICD indicated in dilated cardiomyopathy? An ICD is indicated for primary prevention when the ejection fraction remains 35 per cent or less after at least three months of optimised medical therapy, with expected survival beyond a year. Earlier implantation is considered in some genetic forms such as LMNA. ### Which drugs are harmful in dilated cardiomyopathy? Non-dihydropyridine calcium channel blockers such as verapamil and diltiazem worsen systolic failure and should be avoided. ACE inhibitors, ARBs and ARNI are contraindicated in pregnancy, which matters when counselling young women. ### What does thiamine deficiency cause in the heart? Thiamine deficiency causes wet beriberi, a high-output heart failure with warm peripheries, tachycardia and oedema. It responds to thiamine replacement, which is why it is a classic reversible cause of dilated cardiomyopathy.