From the Guidelines
Septal respiratory variation is primarily caused by conditions that affect the interventricular septum's position due to changes in intrathoracic pressure during respiration, with the main causes including constrictive pericarditis, pericardial effusion, right ventricular volume or pressure overload, and severe chronic obstructive pulmonary disease (COPD) 1.
Causes of Septal Respiratory Variation
The causes of septal respiratory variation can be understood by examining the effects of various conditions on the heart's structure and function.
- Constrictive pericarditis: The thickened pericardium restricts cardiac filling, causing the septum to shift abnormally during respiration 1.
- Pericardial effusion: Creates similar pressure dynamics that affect septal motion, leading to abnormal septal movement during the respiratory cycle 1.
- Right ventricular overload: Conditions like pulmonary hypertension, pulmonary embolism, or right-sided heart failure can cause the right ventricle to push the septum toward the left ventricle during inspiration 1.
- Severe chronic obstructive pulmonary disease (COPD): Hyperinflation of the lungs alters intrathoracic pressures and cardiac filling patterns, leading to abnormal septal motion 1.
Diagnosis and Management
These conditions can be diagnosed through echocardiography, cardiac MRI, or CT imaging, which can visualize the abnormal septal movement during the respiratory cycle 1. Understanding these causes is important for proper diagnosis and management of underlying cardiac or pulmonary conditions.
Key Findings
- Changes in intrathoracic pressure during respiration affect the interventricular septum's position 1.
- Constrictive pericarditis and pericardial effusion create abnormal pressure dynamics that affect septal motion 1.
- Right ventricular overload conditions can cause the right ventricle to push the septum toward the left ventricle during inspiration 1.
- Severe COPD alters intrathoracic pressures and cardiac filling patterns, leading to abnormal septal motion 1.
From the Research
Causes of Septal Respiratory Variation
- Respiratory variation in mitral inflow E velocity can be caused by chronic obstructive pulmonary disease (COPD) or constrictive pericarditis 2
- In COPD, the respiratory variation is due to increased change in intrathoracic pressure with respiration 2
- Constrictive pericarditis, on the other hand, is characterized by dissociation of intrathoracic-intracardiac pressure changes 2
- Septal respiratory variation can also be affected by other conditions such as acute cardiogenic pulmonary edema (ACPE) 3, 4
- Non-invasive positive pressure ventilation (NPPV) can be used to treat respiratory distress due to ACPE and COPD, and may reduce hospital mortality and endotracheal intubation rates 3, 4
Doppler Flow Velocity Patterns
- Doppler flow velocity patterns in the superior vena cava can be used to differentiate COPD from constrictive pericarditis 2
- In COPD, the inspiratory superior vena cava systolic forward flow velocity is significantly higher than in constrictive pericarditis 2
- The respiratory variation in superior vena cava systolic forward flow velocity is also greater in COPD than in constrictive pericarditis 2
Treatment Options
- NPPV, including continuous positive airway pressure (CPAP) and bilevel NPPV, can be used to treat respiratory distress due to ACPE and COPD 3, 4
- Long-term home NPPV can be effective in stable, non-exacerbated COPD patients with daytime hypercapnia 5
- The choice of ventilatory strategy and patient selection are important factors in the effectiveness of NPPV 5