From the Guidelines
Atrial fibrillation (A-fib) significantly increases left ventricular (LV) filling pressures due to the loss of coordinated atrial contraction and the resulting irregular and often rapid ventricular response. This condition leads to reduced LV preload, decreased stroke volume, and shortened diastolic filling time, ultimately causing elevated left atrial pressures and increased pulmonary venous pressures 1. The combination of these factors can result in symptoms such as dyspnea and fatigue, and over time, may lead to left atrial enlargement, pulmonary hypertension, and right heart dysfunction.
Key Mechanisms
- Loss of coordinated atrial contraction, eliminating the "atrial kick" that normally contributes to LV filling
- Irregular and often rapid ventricular response, shortening diastolic filling time and further compromising LV filling
- Elevated left atrial pressures, increasing pulmonary venous pressures and potentially causing symptoms
Clinical Implications
- Management focuses on rate control using beta-blockers, calcium channel blockers, or digoxin, as well as rhythm control in selected patients and anticoagulation to prevent thromboembolism
- In patients with heart failure and elevated filling pressures, diuretics may be needed to reduce congestion and improve symptoms, as evidenced by the 2022 AHA/ACC/HFSA guideline for the management of heart failure 1
- Diagnosis of heart failure requires supporting evidence of increased filling pressures, particularly in patients with preserved or mildly reduced left ventricular ejection fraction (LVEF) 1
From the Research
Atrial Fibrillation and Left Ventricular Filling Pressures
- Atrial fibrillation (A-fib) is associated with left ventricular (LV) diastolic dysfunction, which can lead to elevated LV filling pressures 2, 3.
- The E/e' ratio, a measure of LV filling pressure, is related to worse outcomes in patients with A-fib 2, 3.
- Successful atrial fibrillation ablation can improve LV filling pressure, as assessed by a reduction in the E/e' ratio 2.
- LV filling pressure, as estimated by the E/e' ratio, is a determinant of A-fib recurrence after cardioversion 3.
- Elevated LV filling pressures can be demonstrated noninvasively in patients with heart failure and preserved or reduced LV ejection fraction, including those with A-fib 4, 5, 6.
Mechanisms and Assessment
- Elevated LV filling pressures can affect the distribution of diastolic filling, whereas mitral regurgitation affects the peak rate of rapid filling 5.
- Doppler echocardiography can provide objective noninvasive evidence of abnormal LV filling in patients with heart failure and preserved or reduced LV ejection fraction 4, 6.
- Innovative methods, such as Doppler echocardiographic methods, are emerging to provide greater precision in diastolic function assessment in A-fib, but their clinical utility remains to be established 6.
Clinical Implications
- The evaluation of diastolic function and LV filling pressure is important in the clinical management of patients with A-fib 2, 3, 6.
- Assessing LV filling pressure can help predict the risk of A-fib recurrence after cardioversion 3.
- Improving LV filling pressure, such as through successful atrial fibrillation ablation, can have a positive impact on patient outcomes 2.