TV and PV

Dr. Gehan Youssef's Lecture Notes on Tricuspid and Pulmonic Valve Disorders

Introduction

• Presenter: Dr. Gehan Youssef, MBBCh, RDCS, RCCS

• Role: Cardiovascular Program Director at WCUI, Los Angeles

• Date: 5/4/2021

Tricuspid Valve Stenosis (TS)

Definition

• Tricuspid Valve Stenosis: Narrowing of the tricuspid valve (TV) that obstructs diastolic flow from the right atrium (RA) through the TV into the right ventricle (RV).

Clinical Features

• Murmur: Diastolic rumble that varies with respiration.

Causes

1. Rheumatic Disease: Most common cause. Requires checking other valves such as the mitral valve (MV) and aortic valve (AOV).

2. Congenital Abnormalities: Ebstein anomaly.

3. Carcinoid Syndrome: Also involves tricuspid regurgitation (TR), pulmonic stenosis (PS), and pulmonary regurgitation (PR).

4. Secondary Causes: Includes pacemaker leads, clots, tumors, and vegetations.

5. Systemic Lupus Erythematosus (SLE): A less common secondary cause.

6. Prosthetic Dysfunction.

Complications

• Tricuspid valve stenosis is seldom an isolated condition and can lead to:

  • Infective Endocarditis: Increased risk due to turbulent flow.

  • Embolization Risk: Associated with any tumor or clot present.

Signs and Symptoms

• Ascites

• Abdominal swelling

• Jaundice

• Peripheral edema

• Right upper quadrant pain

Echocardiographic Findings

• 2D-Echo:

  • Thickened TV leaflets

  • Diastolic doming of TV leaflets in left atrial long axis and four-chamber views

  • Decreased TV orifice area

  • Right atrial enlargement (RAE) due to volume and pressure overload

  • Dilated inferior vena cava (IVC)

  • Turbulent diastolic flow may be present.

Doppler Assessment

• Pressure Half Time (P½t): Used to estimate the tricuspid valve area (TVA).

  • Formula: $TVA = \frac{190}{P_{1/2t}}$

• Mean Pressure Gradient (PG):

  • Requires tracing the peak waveform from the Doppler readings and ensuring both the start and end points align at the zero baseline.

Severity Scale of Tricuspid Valve Stenosis

• Degree: P½t (ms), TV Area (cm²), Mean PG (mmHg)

  • Normal: 7-9 ms

  • Severe TS: P½t >= 190 ms, TV area < 1 cm², Mean PG > 5 mmHg.

Tricuspid Valve Regurgitation (TR)

Definition

• Tricuspid Valve Regurgitation: Incompetent tricuspid valve leading to backward flow from the right ventricle through the TV into the right atrium.

Treatment Options

• Surgical Solutions: TR is usually a secondary problem, and treatment includes annuloplasty or valve replacement.

Clinical Features

• Murmur: Holosystolic murmur that increases with inspiration.

Causes

• Primary Cause:

  • Myxomatous degeneration (most common).

• Secondary Causes:

  • Annular dilatation, right atrial (RA) and RV enlargement, pulmonary hypertension (PHT), RV dysfunction, and left heart disease.

  • Other Causes:

  • Rheumatic disease, TV prolapse, pacemaker wires, flail leaflets due to chest trauma or biopsy, vegetations, congenital abnormalities, and carcinoid syndrome.

Complications and Symptoms

• Enlargement of:

  • Right atrium (RA), right ventricle (RV), inferior vena cava (IVC), superior vena cava (SVC), hepatic veins, neck veins.

• Symptoms:

  • Leg and abdominal swelling, liver enlargement, portal hypertension.

Echocardiogram Findings

• 2D Echo:

  • Right atrial enlargement, dilated annulus of the tricuspid valve, thickened TV leaflets, endocarditis signs, RV volume overload (with a paradoxical D-shaped septum), dilated IVC, and hepatic veins.

• RV Systolic Pressure (RVSP):

  • Estimated using the Bernoulli equation:
    $RVSP/PAP = 4(TR ext{ peak velocity})^2 + RAP$

  • Or, more generally:
    $RVSP/PAP = 4(V)^2 + RAP$

Pulmonic Valve Stenosis (PS)

Definition

• Pulmonic Valve Stenosis: Narrowing of the pulmonic valve that impedes systolic flow from the RV through the PV into the pulmonary artery (PA).

  • Types include subvalvular (infundibulum, RV outflow tract obstruction), valvular, and supravalvular.

Murmur Characteristics

• Murmur: Harsh systolic ejection murmur.

Causes

• Congenital Issues: Typically part of more complex anomalies such as tetralogy of Fallot, atrioventricular (AV) canal defects, or double outlet right ventricle.

• Other Causes:

  • Subvalvular obstruction from sinus of Valsalva aneurysms, functional obstruction due to tumors, and less commonly, rheumatic heart disease.

Complications

• Dyspnea

• Jugular venous distention (JVD)

• Right ventricular hypertrophy (RVH), RV dilatation, and right atrial enlargement (RAE).

• Presence of associated congenital anomalies.

Echocardiographic Findings

• Echocardiogram:

  • Thickening of PV leaflets, RV hypertrophy (RVH), septal flattening due to RV pressure overload, RAE, and post-stenotic dilation.

  • M-Mode: Increased a wave noted during examination.

Doppler Calculations

• Continuity Equation:

  • $PVA = \frac{(VTI<em>{RVOT})(CSA</em>{RVOT})}{(VTI_{PV})}$

• Bernoulli's Equation for Gradient:

  • $PG = 4(V)^2$

Pulmonic Valve Regurgitation (PR)

Definition

• Pulmonic Valve Regurgitation: Ineffectively closing pulmonic valve leading to backflow from the pulmonary artery through the PV into the RV.

• Causes:

  • Includes incomplete closure leading to pulmonary artery (PA) and PV annulus dilation; may stem from infective endocarditis, rheumatic heart disease, and congenital anomalies.

Murmur Characteristics

• Low-Pitched Diastolic Murmur: May increase with inspiration.

• Graham-Steel Murmur: High-pitched blowing diastolic murmur present in cases with pulmonary hypertension (PHT).

Complications

• Generally well-tolerated, increasing risk for infective endocarditis.

• Symptoms may include dyspnea, and severe PR could lead to right heart failure (RHF).

Echocardiographic Findings

• 2D Echo:

  • 87% of patients typically exhibit trivial to mild PR, demonstrating RV volume overload patterns and premature PV opening.

Doppler Evaluation

• Doppler and Color Doppler Analysis:

  • Comparison of left and right ventricular outflow tract measurements using the modified Bernoulli equation for evaluating pressure gradients.

  • Normal ranges (EDPR) for pressure gradient assessment are 0-5 mmHg.

  • Evaluating turbulent diastolic flow in RVOT is essential for assessing PHT and cardiac dysfunction.

Conclusion

• Dr. Gehan Youssef emphasized the importance of understanding both tricuspid and pulmonic valve disorders, their diagnosis, treatment, echocardiographic findings, and the complexities involved in managing these heart conditions.