What is the management for conditions affecting the right and inferior heart borders?

Management of Conditions Affecting Right and Inferior Heart Borders

Right-Sided Heart Conditions

Pericardiectomy is the only definitive treatment for constrictive pericarditis affecting the right heart border, with surgical approach determined by the specific pathoanatomical form of constriction. 1

Constrictive Pericarditis Management

Constrictive pericarditis affecting the right heart border presents with specific pathoanatomical forms that require tailored surgical approaches:

1. Right-sided form of pericardial constriction:

   • Characterized by thickened pericardium along the right ventricle
   • Left-sided bending of the interventricular septum
   • Tube-like configuration of mainly right ventricle with enlarged atria
   • Treatment: Median sternotomy and partial pericardiectomy 1

2. Global form of pericardial constriction:

   • Bilateral thickening of the pericardium along both ventricles
   • Tube-like configuration of both ventricles with enlarged atria
   • Treatment: Median sternotomy and pericardiectomy 1

3. Contraindications to pericardiectomy:

   • Myocardial atrophy (thinning of interventricular septum and posterolateral wall <1 cm)
   • Perimyocardial fibrosis (right-sided thickened pericardium cannot be separated from the wave-like thin form of right-sided ventricular wall) 1

Surgical Approaches for Constrictive Pericarditis

Two standard surgical approaches are recommended:

1. Anterolateral thoracotomy (fifth intercostal space)
2. Median sternotomy (faster access to aorta and right atrium for extracorporeal circulation) 1

Important considerations:

• Primary installation of cardiopulmonary bypass is not recommended due to risk of diffuse bleeding
• For severe calcified adhesions, Excimer laser "shaving" may be considered
• Areas of strong calcification may be left as islands to avoid major bleeding
• Pericardiectomy mortality rate: 6-12%
• Complete normalization of cardiac hemodynamics occurs in only 60% of patients 1

Right Ventricular Outflow Tract Obstruction

For conditions affecting the right heart border related to right ventricular outflow tract obstruction (RVOTO):

• Intervention is indicated when Doppler peak gradient is >64 mmHg (peak velocity >4 m/s) regardless of symptoms 1
• For valvular pulmonary stenosis, balloon valvotomy should be the intervention of choice 1
• In asymptomatic patients where balloon valvotomy is ineffective, surgical valve replacement is indicated when systolic RV pressure >80 mmHg 1

Inferior Heart Border (6th to 8th ribs) Management

The inferior heart border corresponds to the right ventricle and may be affected in various conditions:

Right Heart Strain Management

• Treat underlying causes of right heart strain affecting the inferior border
• Optimize hemodynamics with proper volume management
• Avoid vasodilators that can worsen right ventricular failure 2
• Monitor for tricuspid regurgitation, which often results from right ventricular dilation and dysfunction 2

Right Ventricular Dysfunction Monitoring

• Serial echocardiography is essential for monitoring RV size and function 2
• Assess for tricuspid annular plane systolic excursion (TAPSE) as an important parameter reflecting right ventricular systolic function 3
• Evaluate right ventricular diastolic function, which is more prone to be affected in critically ill patients 3

Medication Considerations

• Use beta-blockers with caution in right heart conditions as they can cause depression of myocardial contractility and may precipitate heart failure 4
• If beta-blockers are needed, metoprolol should be carefully monitored and potentially discontinued if signs of heart failure develop 4

Diagnostic Approach

1. Echocardiography: Primary tool to assess right heart function, pericardial thickening, and hemodynamic consequences
2. CT/MRI: Essential for visualizing pericardial thickening, calcification, and right ventricular configuration
3. Cardiac catheterization: For hemodynamic assessment and confirmation of constrictive physiology

Pitfalls and Complications

• Cardiac mortality and morbidity at pericardiectomy is mainly caused by pre-surgically unrecognized myocardial atrophy or fibrosis 1
• Postoperative low cardiac output should be treated with fluid substitution, catecholamines, high doses of digitalis, and intraaortic balloon pump in severe cases 1
• Major complications of pericardiectomy include acute perioperative cardiac insufficiency and ventricular wall rupture 1
• Excessive preload reduction with vasodilators and diuretics can worsen right ventricular failure 2
• Delayed diagnosis of conditions like Scimitar syndrome (which can be misdiagnosed as dextrocardia) can lead to severe pulmonary hypertension and right ventricular failure 5

Early diagnosis and appropriate management of conditions affecting the right and inferior heart borders are crucial for improving outcomes and preventing progression to right heart failure.