Valvular Heart Disease

VHD Fundamentals - Valve Trouble Basics

• Valvular Heart Disease (VHD): Defects in heart valves (aortic, mitral, tricuspid, pulmonary) impairing unidirectional blood flow.
• Two main dysfunctions:
  • Stenosis: Narrowed valve obstructs blood passage → chronic pressure overload.
  • Regurgitation/Insufficiency: Leaky valve allows backflow → chronic volume overload.
• Dominant etiology in India: Rheumatic Heart Disease (RHD), an inflammatory sequel to streptococcal infection.

⭐ Rheumatic Heart Disease is the leading cause of acquired Mitral Stenosis in developing countries, including India.

Mitral Valve Diseases - MS & MR Signs

• Key Radiological Differences:

  Feature	Mitral Stenosis (MS)	Mitral Regurgitation (MR)
  LA Size	Marked ↑ (double density, splayed carina)	Moderate-Marked ↑
  LV Size	Normal / ↓	Normal / ↑ (chronic)
  Key CXR	Straight LHB, PVH	Cardiomegaly, PVH (late)
  Key Echo	"Hockey-stick" leaflet, ↓MVA (<1.5 cm²), doming	Regurgitant jet, flail/prolapse

• Pulmonary Venous Hypertension (PVH) CXR Signs: Cephalization, Kerley B lines, pleural effusion.

⭐ "Giant LA" in chronic MS can cause Ortner's syndrome (hoarseness due to recurrent laryngeal nerve compression).

Aortic Valve Diseases - AS & AR Alerts

• Aortic Stenosis (AS): Obstruction to LV outflow.
  • Echo: Calcified valve, ↓ mobility, AVA < 1 cm² (severe), mean gradient > 40 mmHg.
  • CXR: Calcified aortic valve (fluoroscopy), post-stenotic aortic dilatation, LVH (late).
• Aortic Regurgitation (AR): Backflow from aorta to LV.
  • Echo: Dilated LV, aortic root dilatation, diastolic AR jet (color Doppler), incomplete valve closure.
  • CXR: Cardiomegaly (LV type, "boot-shaped" heart), dilated ascending aorta.

⭐ Severe Aortic Stenosis: Aortic Valve Area (AVA) < 1.0 cm², mean gradient > 40 mmHg.

Right-Sided Valve Diseases - TV & PV Pointers

• Tricuspid Stenosis (TS): Rare; rheumatic. RA enlargement, dilated SVC/IVC.
• Tricuspid Regurgitation (TR): Functional > primary (carcinoid, Ebstein). RV & RA enlargement, pulsatile liver. CXR: cardiomegaly.

  ⭐ Carcinoid heart disease classically affects right-sided valves (TV & PV), causing TR & PS, with valves appearing thickened & fixed.

• Pulmonary Stenosis (PS): Usually congenital (Noonan, Tetralogy of Fallot). RV hypertrophy, post-stenotic pulmonary artery dilatation. Normal LA/LV.
• Pulmonary Regurgitation (PR): Often functional (pulmonary HTN). RV dilatation.

VHD Imaging Modalities - Visualization Tools

• Chest X-Ray (CXR):
  • Initial assessment: cardiac size/silhouette, pulmonary vasculature, gross calcification.
  • Signs: Chamber enlargement, pulmonary edema.
• Echocardiography (TTE/TEE):
  • TTE (Transthoracic): First-line for diagnosis, severity assessment (e.g., stenosis area, regurgitant jet), LV/RV function, hemodynamics.
  • TEE (Transesophageal): Superior views for posterior structures (mitral valve, LA appendage), prosthetic valves, endocarditis, aortic dissection. Used if TTE is suboptimal or for specific indications.
• Cardiac CT (CCT):
  • Valve calcification scoring (e.g., Agatston for aortic stenosis).
  • Pre-procedural planning for TAVI/TMVR (annular sizing, coronary anatomy, access routes).
  • Assessing complex valve/root anatomy.
• Cardiac MRI (CMR):
  • Gold standard for ventricular volumes, mass, function.
  • Accurate quantification of regurgitant volumes and fractions.
  • Myocardial tissue characterization (fibrosis, scar, infiltration).
  • Complex congenital heart disease with VHD.

⭐ Cardiac MRI is the reference standard for quantifying valvular regurgitation (e.g., regurgitant fraction) and assessing right ventricular size and function, crucial in conditions like severe tricuspid or pulmonary regurgitation when echo is suboptimal.

High‑Yield Points - ⚡ Biggest Takeaways

• Rheumatic heart disease: MCC of mitral stenosis; CXR shows LA enlargement, pulmonary venous hypertension.
• Mitral regurgitation: causes LA & LV enlargement; characteristic "c-v" wave in LA pressure.
• Aortic stenosis (calcific/bicuspid): CXR shows LVH, post-stenotic aortic dilatation.
• Aortic regurgitation: leads to LV dilatation & hypertrophy; wide pulse pressure.
• Echocardiography: gold standard for diagnosis & severity assessment of valvular lesions.
• Cardiac MRI: valuable for quantifying regurgitant volumes & ventricular function assessment.