What heart sounds are expected in patients with right heart strain?

Heart Sounds in Right Heart Strain

The most characteristic heart sounds in right heart strain include an accentuated pulmonary component of the second heart sound (P2), a right ventricular S3 or S4 gallop, a parasternal heave, and murmurs of tricuspid regurgitation and pulmonary regurgitation.

Key Auscultatory Findings in Right Heart Strain

Second Heart Sound (S2) Abnormalities

• Accentuated pulmonary component (P2) of the second heart sound, often audible at the apex, reflecting increased force of pulmonary valve closure due to elevated pulmonary artery pressure 1
• Fixed splitting of S2 during inspiration and expiration may suggest atrial septal defect with right heart volume overload 1
• A soft or absent aortic component (A2) may be present in severe cases 1
• Single S2 may be heard in some cases, particularly in patients with tetralogy of Fallot before pulmonary valve reoperation 2

Additional Heart Sounds

• Right ventricular S4 gallop due to forceful right atrial contraction against a stiff right ventricle 1
• Right ventricular S3 gallop (audible in 23% of patients), indicating right ventricular failure 1
• Palpable left parasternal lift produced by the impulse of the hypertrophied high-pressure right ventricle 1

Murmurs Associated with Right Heart Strain

• Holosystolic murmur of tricuspid regurgitation, audible at the lower left sternal border and augmented with inspiration 1
• Early systolic ejection click due to sudden interruption of pulmonary valve opening 1
• Midsystolic ejection murmur caused by turbulent transvalvular pulmonary flow 1
• Diastolic murmur of pulmonary regurgitation (low-pitched, early ending) in cases with pulmonary hypertension 1
• Right heart murmur in early to midsystole at the lower left sternal border may represent tricuspid regurgitation without pulmonary hypertension 1

Dynamic Auscultation in Right Heart Strain

• Right-sided murmurs generally increase with inspiration, while left-sided murmurs are louder during expiration 1
• After Valsalva maneuver release, right-sided murmurs tend to return to baseline intensity earlier than left-sided murmurs 1
• Murmurs caused by blood flow across stenotic valves (e.g., pulmonary stenosis) become louder with both isotonic and isometric exercise 1
• Transient arterial occlusion (by bilateral cuff inflation) augments murmurs of tricuspid and pulmonary regurgitation 1

Associated Physical Findings

• Prominent jugular "a" wave suggesting high right ventricular filling pressure 1
• Elevated jugular venous pressure with accentuated V waves in tricuspid regurgitation 1
• Hepatojugular reflux and a pulsatile liver in tricuspid regurgitation 1
• Peripheral edema (32% of patients) and ascites indicating right ventricular failure 1
• Low blood pressure, diminished pulse pressure, and cool extremities indicating reduced cardiac output and peripheral vasoconstriction 1

Specific Clinical Scenarios with Right Heart Strain

Pulmonary Hypertension

• Accentuated P2 component of the second heart sound is noted in 90% of patients with idiopathic pulmonary arterial hypertension 1
• Parasternal heave and mucocutaneous features may be present in cases associated with systemic sclerosis 1
• The intensity of P2 correlates with the severity of pulmonary hypertension, though this correlation is not always reliable 3

Tetralogy of Fallot (Post-repair)

• Soft ejection systolic murmur from the right ventricular outflow tract 1
• Low-pitched, delayed diastolic murmur in the pulmonary area consistent with pulmonary regurgitation 1
• Absent P2 component of the second heart sound is common 1
• Single second heart sound is observed in 60% of adult patients with tetralogy of Fallot 2

Congenitally Corrected Transposition of the Great Arteries

• Abnormal ventricular impulse with a right ventricular parasternal lift 1
• Palpable second sound (loud A2) related to the anterior aorta 1
• Holosystolic murmur at the apex or lower left sternal border when AV valve regurgitation develops 1

ECG Findings Associated with Right Heart Strain

• Right-axis deviation 1
• Right ventricular hypertrophy patterns (tall R wave and small S wave with R/S ratio >1 in lead V1) 1
• qR complex in lead V1 1
• rSR' pattern in lead V1 1
• S1, S2, S3 pattern 1
• ST-T segment wave depression and inversion in right precordial leads 1
• Right ventricular strain pattern on ECG has been associated with increased mortality in certain conditions like COVID-19 4

Clinical Implications and Management

• The presence of right heart strain sounds should prompt further evaluation with echocardiography to assess right ventricular function, pulmonary artery pressure, and tricuspid valve function 1, 5
• Echocardiographic findings of right ventricular strain include increased RV:LV size ratio, abnormal septal motion, tricuspid regurgitation, and decreased tricuspid annular plane systolic excursion 5
• Right atrial strain as measured by right atrial reservoir strain has prognostic implications in patients with severe secondary tricuspid regurgitation 6
• Careful auscultation during various hemodynamic states helps characterize murmurs and differentiate causes of right heart strain 7