Atrioventricular Defect with Atrial Shunting

An atrioventricular septal defect (AVSD) is a birth heart condition where the wall between the top chambers (atria) and the bottom chambers (ventricles) does not develop fully, and the two heart valves in the middle (mitral/left AV valve and tricuspid/right AV valve) share tissue or are partly fused. “With atrial shunting” means blood is moving abnormally through an opening at the atrial level (usually a primum atrial septal defect), typically from the left atrium to the right atrrium (left-to-right shunt). This extra blood flow overloads the right heart and lungs and, over time, can enlarge the heart, cause valve leakage, and raise lung blood pressure if not corrected. NCBI+1

AVSD arises from incomplete fusion of the endocardial cushions during fetal development, leaving a “common AV junction” and defects in the atrial and/or ventricular septum. Depending on how much tissue is missing, AVSD ranges from partial (primum ASD with a cleft in the left AV valve) to complete (large combined ASD+VSD with a single common AV valve). The “atrial shunt” component dominates symptoms in partial AVSD; in complete AVSD, both atrial and ventricular shunts matter. NCBIUnrepaired shunts lead to right-sided volume overload, progressive AV valve regurgitation, arrhythmias, and in some, pulmonary vascular disease (PVD) and Eisenmenger physiology if pulmonary pressures become fixed and high. Timely diagnosis and surgical repair usually produces excellent long-term outcomes. PubMed+1

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Alternate names

• Atrioventricular canal defect (AV canal)

• Endocardial cushion defect

• Partial/Transitional/Complete AVSD (subtypes)

• Primum atrial septal defect (when the atrial shunt is the dominant lesion) NCBI

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Types

1. Partial AVSD: Primum ASD + cleft in the left AV (mitral) valve; separate AV valve orifices. Atrial left-to-right shunt is the main problem. NCBI

2. Transitional/Intermediate AVSD: Atrial primum ASD with a small restrictive VSD and AV valve anomalies; shunt at both levels but ventricular shunt is smaller. NCBI

3. Complete AVSD: Large primum ASD + inlet VSD + single common AV valve; major shunting and early heart failure if unrepaired. NCBI

4. Balanced vs. unbalanced AVSD: Whether the left and right ventricles are similar in size (balanced) or one ventricle is small (unbalanced), which affects surgical planning. PubMed Central

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Causes / risk factors

1. Chromosomal: Trisomy 21 (Down syndrome)—the most common association with AVSD. NCBI

2. Other genetic syndromes (e.g., heterotaxy, Noonan)—less common but important. NCBI

3. Familial congenital heart disease—heritability modest but above population risk. NCBI

4. Maternal diabetes—hyperglycemia may influence embryonic heart development. NCBI

5. Maternal rubella or viral infections—teratogenic effects in early pregnancy. NCBI

6. Maternal alcohol exposure—can disrupt cardiac morphogenesis. NCBI

7. Retinoic acid/teratogenic drug exposure—rare, dose-dependent risks. NCBI

8. Maternal phenylketonuria (poorly controlled)—linked to CHD risk. NCBI

9. Assisted reproduction / advanced maternal age—small risk elevation noted. NCBI

10. Maternal obesity—associated with higher CHD risk in offspring. NCBI

11. Maternal smoking—modestly raises CHD risk. NCBI

12. Maternal folate deficiency—inadequate periconceptional folic acid may raise CHD risk. NCBI

13. Consanguinity—increased risk of recessive variants. NCBI

14. Small mutations in heart developmental genes (e.g., CRELD1)—rare, research-level. NCBI

15. Maternal hypothyroidism/thyroid disease—inconsistent but possible association. NCBI

16. Uncontrolled lupus/autoimmune disease—rare fetal cardiac effects. NCBI

17. Maternal lithium exposure (first trimester)—older data suggest small risk. NCBI

18. Maternal vitamin A excess—teratogenic in high doses. NCBI

19. Poor antenatal care—missed prevention/early detection opportunities. NCBI

20. Unknown—most AVSDs have no single identifiable cause. NCBI

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Common symptoms

• Breathlessness or rapid breathing with feeding or activity (infants/children). NCBI

• Poor feeding and slow weight gain in infants. NCBI

• Frequent respiratory infections (due to pulmonary over-circulation). NCBI

• Fatigue and reduced exercise tolerance. NCBI

• Heart murmur found on routine exam. NCBI

• Palpitations (atrial arrhythmias as people age). PubMed

• Swelling of legs/abdomen (fluid retention in advanced cases). PubMed

• Cough/wheeze not explained by asthma. NCBI

• Cyanosis (blue lips) in advanced pulmonary hypertension/Eisenmenger. AHA Journals

• Chest pain (usually non-ischemic strain). PubMed

• Dizziness/fainting (arrhythmia or high pulmonary pressures). AHA Journals

• Newborn heart failure signs (sweating with feeds, tachypnea). NCBI

• Liver enlargement on exam (congestion). PubMed

• Clubbing of fingers/toes in chronic cyanosis. AHA Journals

• No symptoms (sometimes discovered incidentally). NCBI

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Diagnostic tests

A. Physical examination 

1. Cardiac auscultation: Murmur of AV valve regurgitation and increased flow across the pulmonary valve; fixed/wide S2 may be present. Guides urgency for imaging. NCBI

2. Vital signs & growth chart: Tachypnea, tachycardia, poor weight gain in infants suggest significant shunt. NCBI

3. Signs of heart failure: Hepatomegaly, peripheral edema later in life. PubMed

4. Clubbing/cyanosis check: Points to pulmonary hypertension/Eisenmenger. AHA Journals

5. Blood pressure & differential saturations: Low systemic saturations with high pulmonary pressures in advanced disease. AHA Journals

B. Bedside/manual tests 

1. Pulse oximetry (rest/exertion): Detects hypoxemia; 6-minute walk test for adults to track functional capacity. PubMed
2. Respiratory assessment with feeding (infants): Practical gauge of cardiorespiratory stress. NCBI
3. Blood pressure response to mild exertion: Helps judge reserve in clinic. PubMed
4. Diuretic response trial (monitored): Symptomatic relief can support volume-overload physiology while awaiting repair. PubMed

C. Laboratory & pathology 

1. BNP/NT-proBNP: Elevated with heart failure; helpful for trending. PubMed
2. Iron studies & CBC: Iron deficiency worsens exercise capacity and pulmonary hypertension outcomes. AHA Journals
3. Thyroid function: Hypo- or hyperthyroidism can aggravate heart failure/arrhythmia. PubMed
4. Genetic testing (when indicated): Trisomy 21 or syndromic work-up in pediatrics. NCBI

D. Electrodiagnostic 

1. 12-lead ECG: Left axis deviation is classic in AVSD; PR prolongation/atrial arrhythmias may appear. NCBI
2. Ambulatory ECG (Holter): Detects intermittent atrial flutter/fibrillation or AV block. PubMed
3. Cardiopulmonary exercise testing (adults): Quantifies capacity and guides timing of intervention. AHA Journals

E. Imaging / hemodynamics 

1. Transthoracic echocardiogram (TTE): First-line test; defines primum ASD, AV valve anatomy, regurgitation, and shunt size; estimates pulmonary pressures. NCBI
2. Transesophageal echo (TEE): For surgical planning or poor TTE windows; details cleft valve and rims. PubMed
3. Cardiac MRI/CT: Assesses ventricular volumes, AV valve regurgitation, extracardiac anatomy; helps in complex or re-operation cases. PubMed
4. Cardiac catheterization with vasoreactivity testing: Definitive pulmonary vascular resistance (PVR) and operability when pulmonary hypertension is suspected; guides PAH-targeted therapy. PubMed+1

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Non-pharmacological treatments

Note: These measures support health and symptoms. They do not close the defect. For operable AVSD, timely surgical repair is the definitive treatment. Follow ACHD/CHD team advice. PubMed

1. Structured follow-up with a congenital cardiology team: Regular reviews detect valve leakage, arrhythmias, and rising lung pressures early so timing of surgery is right. AHA Journals+1

2. Nutrition & growth support (infants): Calorie-dense feeds and feeding strategies reduce fatigue with feeds and support weight before/after repair. NCBI

3. Activity as tolerated: Normal developmental activity for children; graded aerobic activity for adults improves capacity unless severe PH or heart failure is present. PubMed

4. Sodium awareness (heart-failure symptoms): Modest salt restriction can lessen fluid retention; aggressive restriction is not routine without clinician input. PubMed

5. Fluid management plan: In symptomatic volume overload, clinician-guided fluid targets help with congestion. PubMed

6. Vaccinations (influenza, pneumococcal, RSV where indicated): Reduces respiratory infections that strain the heart/lungs. PubMed

7. Dental hygiene and routine dental care: Good oral care lowers infective endocarditis risk; antibiotic prophylaxis is not universal—used per guideline in high-risk settings. PubMed

8. Smoking cessation & clean-air strategies: Smoking raises pulmonary pressures and worsens outcomes. AHA Journals

9. Weight optimization: Healthy weight lowers cardiovascular workload and sleep apnea risk, which can worsen pulmonary pressures. PubMed

10. Sleep apnea screening (adults): Treating OSA reduces PH/arrhythmia burden. AHA Journals

11. Anemia identification and treatment: Low iron worsens exercise tolerance and PH; treat iron deficiency appropriately. AHA Journals

12. Pregnancy planning with ACHD team: Pre-pregnancy counseling optimizes timing (prefer after repair) and risk management. PubMed

13. Heart-failure self-management education: Recognize early fluid retention, weight changes, and when to call. PubMed

14. Cardiac rehabilitation (adults post-repair): Supervised exercise improves stamina and quality of life. PubMed

15. Respiratory infection prevention (hand hygiene/early care): Lowers decompensation events. PubMed

16. Avoid unmonitored high-altitude hypoxia when pulmonary pressures are high: Hypoxia raises PVR; discuss travel plans. AHA Journals

17. Medication review to avoid PH-worsening drugs (e.g., certain appetite suppressants): Prevents avoidable PVR increases. AHA Journals

18. Psychosocial support: Chronic CHD affects mood and adherence; support improves outcomes. PubMed

19. Genetic counseling for families with CHD history or syndromic features: Helps with screening and future planning. NCBI

20. Timely referral for surgical repair (definitive): Prevents irreversible PVD and valve damage. PubMed Central+1

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Drug treatments

Medicine does not close an AVSD. Drugs are used to: ease heart-failure symptoms, control arrhythmias, and treat pulmonary arterial hypertension (PAH) when present. Always individualize, especially in infants/children and pregnancy. Follow guideline pathways. AHA Journals+1

1. Furosemide (loop diuretic)—class: diuretic. Typical adult dose 20–40 mg once/twice daily; purpose: reduce fluid overload and breathlessness; mechanism: blocks Na-K-2Cl in loop of Henle → more urine; side effects: low potassium, dehydration, kidney effects. PubMed

2. Spironolactone (MRA)—class: aldosterone antagonist. 12.5–25 mg daily; purpose: adjunct diuresis, potassium sparing; mechanism: blocks aldosterone in distal nephron; side effects: high K⁺, breast tenderness. PubMed

3. ACE inhibitor (e.g., enalapril)—class: RAAS blocker. 2.5–20 mg/day titrated; purpose: afterload reduction if LV systolic dysfunction or significant regurgitation; mechanism: inhibits angiotensin-converting enzyme; side effects: cough, high K⁺, kidney effects. PubMed

4. ARB (e.g., losartan)—alternative to ACEi. 25–100 mg/day; similar purpose/mechanism; side effects: high K⁺, kidney effects. PubMed

5. Beta-blocker (e.g., metoprolol succinate)—class: β₁-blocker. 25–200 mg/day; purpose: rate control, symptom relief in LV dysfunction/arrhythmias; mechanism: slows heart rate; side effects: fatigue, low BP. PubMed

6. Digoxin—class: cardiac glycoside. 0.125–0.25 mg/day (adult); purpose: symptomatic HF/AF rate control; mechanism: increases inotropy, slows AV node; side effects: arrhythmias if toxicity. PubMed

7. SGLT2 inhibitor (e.g., dapagliflozin)—class: glucose/renal sodium transporter blocker. 10 mg daily; purpose: HF benefit in reduced EF; mechanism: natriuresis/metabolic effects; side effects: genital infections. (Use is extrapolated HF care; apply selectively in ACHD). PubMed

8. Loop/thiazide synergy (e.g., add metolazone)—careful specialist use for refractory edema; risk of electrolyte shifts. PubMed

9. Anticoagulation (e.g., warfarin/DOAC)—indication: atrial fibrillation, prior thromboembolism, or prosthetic valve as per guideline; purpose: stroke prevention; risks: bleeding. PubMed

10. Rate/rhythm control for AF/atrial flutter—β-blocker, diltiazem (rate) or antiarrhythmic per specialist; ablation considered in recurrent cases. PubMed

11. Oxygen (supervised)—in selected decompensation; avoids hypoxia that raises PVR; avoid excess in some shunt lesions—specialist guided. AHA Journals

12. Iron therapy (if deficient)—IV or oral; improves exercise capacity in PH; risks: GI upset (oral), infusion reactions (IV). AHA Journals
    Targeted PAH therapy when pulmonary arterial hypertension is present (specialist-only):

13. Sildenafil—class: PDE-5 inhibitor; 20 mg three times daily in adults with PAH; purpose: lower PVR, improve walk distance; side effects: headache, flushing; often combined if response inadequate. American College of Cardiology+1

14. Tadalafil—class: PDE-5 inhibitor; 40 mg daily in PAH; similar benefits/risks. AHA Journals

15. Bosentan—class: endothelin-receptor antagonist; 62.5–125 mg twice daily; purpose: lowers PVR, improves symptoms in PAH-CHD; monitoring: liver enzymes, teratogenicity precautions. AHA Journals+1

16. Ambrisentan/Macitentan—class: ERA; once-daily alternatives; similar monitoring. AHA Journals

17. Selexipag—class: prostacyclin IP receptor agonist; titrated oral agent for PAH if inadequate response; side effects: jaw pain, headache. AHA Journals

18. Epoprostenol (IV)/Treprostinil (IV/SC/inhaled)—class: prostacyclin analogues; for advanced PAH with close monitoring; potent vasodilators; side effects: hypotension, line complications. AHA Journals

19. Combination PAH therapy—ERA + PDE-5 ± prostacyclin improves risk scores in PAH-CHD when step-up is needed. PubMed Central+1

20. Diuretics + PAH regimen + careful anticoagulation (selected)—team-based titration to avoid renal dysfunction/hypotension. AHA Journals

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Dietary molecular supplements

Use supplements cautiously and only with your cardiology team, especially in infants/pregnancy. Evidence varies; avoid interactions with PAH therapies/anticoagulants. PubMed

1. Omega-3 fatty acids (fish oil): May modestly aid HF symptoms/arrhythmia burden; typical adult dose ~1 g/day EPA/DHA equivalents; mechanism: anti-inflammatory/antiarrhythmic effects. PubMed

2. Iron (if deficient): Correcting deficiency improves exercise capacity in PH/HF; doses individualized; mechanism: restores oxygen transport and muscular enzymes. AHA Journals

3. Vitamin D (if deficient): Supports bone/immune health; low levels are common in chronic disease; dose per labs; mechanism: endocrine/immune modulation. PubMed

4. Coenzyme Q10: Small studies suggest HF symptom benefit; 100–200 mg/day; mechanism: mitochondrial electron transport aid; interactions possible with anticoagulants. PubMed

5. Magnesium (if low): Supports rhythm stability; dose guided by level/kidney function; mechanism: membrane stabilization. PubMed

6. Thiamine (B1) repletion in diuretic users: Loop diuretics can increase B1 loss; replenishment may aid HF symptoms; dose per clinician. PubMed

7. Folate (periconception): Public-health measure to reduce CHD risk in future pregnancies; dose usually 400–800 mcg/day pre-pregnancy. NCBI

8. Electrolyte solutions (medical guidance): For patients on diuretics with losses; avoid excess sodium. PubMed

9. Probiotics (general gut support): Limited cardiac-specific data; ensure product safety; dose per label. PubMed

10. Protein-dense supplements (infants/children under dietician): To support growth if oral intake is limited; prescription formulas used under supervision. NCBI

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Immunity booster / regenerative / stem-cell drugs

Transparent note: There are no approved “immunity boosters,” regenerative, or stem-cell drugs that treat or reverse AVSD or atrial shunts in routine care. Experimental cell-based therapies in congenital heart disease remain investigational and are not standard treatment; outside of a regulated clinical trial, they are not recommended. Below are safer, evidence-based alternatives or clarifications. PubMed

1. Vaccinations (influenza, pneumococcal, RSV per age/season): Reduce infection-triggered decompensation; mechanism: immune priming. PubMed

2. Nutritional optimization (iron, vitamin D if deficient): Supports immune and muscular function; mechanism: corrects deficiencies. AHA Journals

3. Cardiac rehabilitation/exercise prescription: Improves mitochondrial and endothelial function over time; mechanism: physiologic “regeneration” via conditioning—not a drug. PubMed

4. Evidence-based PAH therapy (ERA/PDE-5/prostacyclin): Targets vascular remodeling in PAH-CHD; mechanism: endothelin blockade, NO-cGMP augmentation, prostacyclin pathways. AHA Journals

5. Treatment of sleep apnea if present: Lowers inflammatory burden and sympathetic drive; mechanism: improves nocturnal oxygenation. AHA Journals

6. Participation in regulated clinical trials only (when appropriate): Ensures safety oversight for any novel “regenerative” approach. AHA Journals

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Surgeries

1. Partial AVSD repair (primum ASD patch + left AV valve cleft closure): Through open-heart surgery, a patch closes the atrial hole and the surgeon stitches (and sometimes patches) the cleft in the left AV (mitral) valve to reduce leakage; done to stop the left-to-right atrial shunt, prevent heart enlargement, and protect lungs/valves. Annals of Thoracic Surgery+1

2. Complete AVSD repair (double-patch or single-patch/Nunn technique): Patches close the primum ASD and inlet VSD, and the common AV valve is divided/reconstructed into two valves; done in infancy to prevent early heart failure and pulmonary vascular disease. PubMed Central+1

3. Left AV (mitral) valve repair/re-repair: For significant residual or recurrent regurgitation after initial repair; preserves native valve when possible. Journal of Thoracic Disease

4. Valve replacement (selected cases): If repair is not feasible; requires lifelong follow-up and often anticoagulation (mechanical valves). PubMed

5. Pulmonary artery banding (rare, palliative): Used selectively in infants with complex anatomy to protect lungs until definitive repair is safe. PubMed

Outcomes: Modern series show excellent early and long-term results with low reoperation rates when repair is timely and anatomy is suitable. PubMed Central

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Preventions

1. Timely surgical repair when operable—prevents irreversible lung vascular disease. PubMed

2. ACHD life-long follow-up—detects valve/arrhythmia issues early. AHA Journals

3. Vaccinations & infection prevention—less decompensation. PubMed

4. Dental care—lowers endocarditis risk; prophylaxis only when indicated. PubMed

5. Heart-healthy lifestyle—no smoking, active living, weight control. PubMed

6. Manage anemia, thyroid, and sleep apnea—reduces HF/PH burden. AHA Journals

7. Medication review—avoid PH-worsening drugs. AHA Journals

8. Pregnancy counseling—optimize timing and delivery planning. PubMed

9. Family planning with folate before conception—reduces CHD risk in general population. NCBI

10. Genetic counseling when indicated—helps with screening and expectations. NCBI

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When to see a doctor (or go to the ER)

• New or worsening breathlessness, swelling, or rapid weight gain—possible fluid overload. PubMed

• Blue lips/fingers, dizziness, fainting, chest pain, or palpitations—could be arrhythmia or rising pulmonary pressures. Seek urgent care for fainting or chest pain. AHA Journals

• Fever with new murmur or severe fatigue—possible endocarditis; urgent review. PubMed

• Pregnancy planning or positive test—contact ACHD team early. PubMed

• Any infant with poor feeding, sweating with feeds, fast breathing, or poor weight gain—see pediatric cardiology promptly. NCBI

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What to eat / what to avoid

What to eat:

• Plenty of vegetables, fruits, whole grains, legumes, lean proteins, and unsalted nuts: supports heart and general health; high-fiber foods help weight control. PubMed

• Adequate iron-rich foods (if iron-deficient): beans, lean meats, fortified grains—guided by labs. AHA Journals

• Fluids as advised by your team when diuretics are used. PubMed

What to limit/avoid:

• Excess salt (packaged foods, salty snacks) if you have fluid retention. PubMed

• Smoking and heavy alcohol—worsen heart/lung strain and arrhythmias. AHA Journals

• Unverified supplements that interact with PAH drugs/anticoagulants. Ask first. PubMed

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FAQs

1. Can AVSD with atrial shunt close by itself?
   Partial defects rarely close fully; significant primum ASDs and cleft valves usually need surgery for a durable fix. NCBI

2. What is the usual timing for repair?
   Infants with complete AVSD are repaired in the first months of life; partial AVSD is typically repaired in early childhood when there is significant shunt or valve leakage. Adults with residual defects are assessed individually. PubMed

3. How successful is surgery?
   Modern techniques have excellent survival and good long-term valve function; some patients need later re-repair for valve leakage. PubMed Central

4. Will medicines cure AVSD?
   No. Medicines ease symptoms, control rhythm, and treat pulmonary hypertension when present. Surgery fixes the anatomy. PubMed

5. What is pulmonary hypertension and why does it matter?
   Long-standing large shunts can damage lung arteries, raising pressure (PAH). If pressures become fixed and high, surgery may no longer be safe; PAH drugs then help symptoms. Early repair aims to prevent this. AHA Journals

6. Is pregnancy safe?
   Many repaired patients do well with careful planning; unrepaired significant shunts or PAH carry risks. Always plan with an ACHD team. PubMed

7. Do I need antibiotics before dental work?
   Only if you have specific high-risk features (e.g., prosthetic valve). Good daily oral care is essential for everyone. PubMed

8. Can I exercise?
   Usually yes, tailored to your status. Avoid competitive/high-intensity training if you have severe valve leakage or PAH until cleared. PubMed

9. Will I need a pacemaker?
   Some patients develop AV block or arrhythmias and require pacemaker/ablation; your team checks this during follow-up. PubMed

10. What if I was diagnosed as an adult?
    Adults can still benefit from repair if operable; evaluation includes echo, MRI, and sometimes catheterization to measure PVR. PubMed

11. Are there foods that “heal” the hole?
    No food or supplement can close a septal defect. Healthy eating supports overall heart health. PubMed

12. Is “stem-cell therapy” available for AVSD?
    Not as routine care. Any such approach should only be in regulated clinical trials. PubMed

13. How often will I need checkups after repair?
    Life-long ACHD follow-up—often annually or biannually—depending on valve function and rhythm status. AHA Journals

14. Can AVSD be prevented in future pregnancies?
    Not fully, but folic acid before conception, avoiding teratogens, and good diabetes control lower CHD risk in general. Genetic counseling helps with planning. NCBI

15. What outcomes matter most long-term?
    Valve function, rhythm stability, exercise capacity, and absence of pulmonary hypertension. With timely care, most patients live full lives. PubMed Central+1

Disclaimer: Each person’s journey is unique, treatment plan, life style, food habit, hormonal condition, immune system, chronic disease condition, geological location, weather and previous medical  history is also unique. So always seek the best advice from a qualified medical professional or health care provider before trying any treatments to ensure to find out the best plan for you. This guide is for general information and educational purposes only. Regular check-ups and awareness can help to manage and prevent complications associated with these diseases conditions. If you or someone are suffering from this disease condition bookmark this website or share with someone who might find it useful! Boost your knowledge and stay ahead in your health journey. We always try to ensure that the content is regularly updated to reflect the latest medical research and treatment options. Thank you for giving your valuable time to read the article.

The article is written by Team RxHarun and reviewed by the Rx Editorial Board Members

Last Updated: September 26, 2025.

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