What causes parasternal lift?

Causes of Parasternal Lift

The primary cause of a parasternal lift is right ventricular hypertrophy or dilation secondary to pulmonary hypertension. 1

Pathophysiology of Parasternal Lift

A parasternal lift (also called left parasternal heave) is an abnormal cardiac physical finding characterized by a palpable outward movement of the chest wall in the left parasternal area during systole. This finding indicates increased right ventricular pressure or volume overload. The pathophysiological mechanisms include:

Primary Causes

1. Pulmonary Hypertension

   • The most common underlying cause 2, 1
   • Results in right ventricular pressure overload
   • Mean pulmonary artery pressure ≥25 mmHg at rest 3

2. Right Ventricular Hypertrophy

   • Develops in response to chronic pressure overload
   • Causes the right ventricle to push against the chest wall during contraction

3. Right Ventricular Dilation

   • Occurs with volume overload conditions
   • Pushes the interventricular septum leftward

Specific Conditions Associated with Parasternal Lift

Congenital Heart Disease

• Pulmonary Stenosis

  • Creates resistance to right ventricular outflow 2
  • Results in right ventricular hypertrophy

• Atrial Septal Defects

  • Causes right ventricular volume overload
  • Can lead to pulmonary hypertension over time 2

• Ventricular Septal Defects

  • Large defects can lead to pulmonary hypertension 2
  • Eventually may progress to Eisenmenger syndrome

• Eisenmenger Syndrome

  • Represents advanced pulmonary hypertension due to congenital heart defects
  • Characterized by shunt reversal (right-to-left) 2

Acquired Conditions

• Pulmonary Arterial Hypertension (Group 1)

  • Idiopathic or associated with connective tissue diseases
  • Characterized by progressive vascular remodeling 4

• Left Heart Disease (Group 2)

  • Most common cause of pulmonary hypertension in adults 3
  • Due to increased left atrial pressure transmitted backward

• Lung Disease/Hypoxia (Group 3)

  • COPD, interstitial lung disease
  • Hypoxic vasoconstriction and vascular remodeling

• Chronic Thromboembolic PH (Group 4)

  • Unresolved pulmonary emboli
  • Progressive vascular obstruction

• Right Ventricular Infarction

  • Rare cause of isolated parasternal lift 5
  • Due to anterior right ventricular wall dysfunction

Clinical Assessment

Physical Examination Findings Often Associated with Parasternal Lift

• Accentuated pulmonary component of S2 (P2)
• Right ventricular S3 gallop
• Tricuspid regurgitation murmur
• Jugular venous distention
• Peripheral edema in advanced cases 1

Diagnostic Evaluation

• Echocardiography

  • First-line diagnostic test when pulmonary hypertension is suspected 1
  • Estimates pulmonary artery systolic pressure (PASP)
  • Assesses right ventricular size and function

• Right Heart Catheterization

  • Gold standard for diagnosing pulmonary hypertension
  • Confirms elevated mean pulmonary artery pressure ≥25 mmHg 2

Clinical Significance

The presence of a parasternal lift is a concerning physical finding that warrants thorough evaluation. Even mildly elevated pulmonary artery pressure (PASP 30-50 mmHg) is associated with poor outcomes 2. Patients with congenital heart disease require periodic screening for pulmonary hypertension with echocardiography 2.

Pitfalls and Caveats

1. Absence of Murmur in Severe PAH

   • Patients with severe pulmonary hypertension may not have loud murmurs because RV and LV pressures are similar 2

2. Normal ECG Does Not Exclude PAH

   • A normal ECG does not rule out severe pulmonary hypertension 1

3. Multiple Contributing Factors

   • Always consider multiple potential causes of pulmonary hypertension in each patient 2

4. Pregnancy Risk

   • Pregnancy is contraindicated in women with pulmonary arterial hypertension due to high maternal-fetal morbidity 6

The finding of a parasternal lift should prompt appropriate diagnostic evaluation to identify the underlying cause, as early diagnosis and treatment of conditions like pulmonary hypertension can significantly impact morbidity and mortality.