[Kussmaul's paradoxical pulse. Etiopathogenic aspects]

Area of Science:

• Cardiology
• Pulmonology
• Physiology

Background:

• Paradoxical pulse is a clinical sign observed in various cardiopulmonary diseases.
• Understanding its underlying physiological mechanisms is crucial for diagnosis and management.

Observation:

• Three cases of pulmonary embolism presenting with significant paradoxical pulses (>30 mm Hg) were analyzed.
• These cases demonstrated elevated inspiratory right atrial pressure, with variable left ventricular transmural pressures.

Findings:

• The genesis of paradoxical pulse involves two primary factors: increased left ventricular afterload from negative inspiratory intrathoracic pressure and reduced left ventricular compliance due to interventricular mechanical interference.
• Increased left ventricular afterload is the predominant factor in conditions without elevated central venous pressure.
• Elevated central venous pressure, as seen in pulmonary embolism, exacerbates paradoxical pulses through enhanced right ventricular filling and increased left ventricular afterload.

Implications:

• This study elucidates the complex mechanisms of paradoxical pulse, differentiating contributions of afterload and mechanical interference in various pathologies.
• Recognizing these mechanisms aids in diagnosing conditions such as pulmonary embolism, cardiac tamponade, and constrictive pericarditis.
• Clinical insights into paradoxical pulse formation can improve patient assessment and therapeutic strategies for heart and lung diseases.