Related Experiment Videos
[Real-time coronary blood flow measurement in patients with atrial fibrillation: a study using a catheter-tip Doppler
K Negishi1, S Handa, S Ishikawa
1Cardiopulmonary Division, School of Medicine, Keio University, Tokyo.
Insights
In atrial fibrillation, longer cardiac cycles and diastolic periods increase coronary blood flow, particularly during diastole. Systolic coronary flow is less affected by these changes.
Area of Science:
- Cardiovascular Physiology
- Hemodynamics
- Coronary Circulation
Context:
- Chronic atrial fibrillation presents complex hemodynamic challenges.
- Understanding coronary blood flow regulation is crucial for managing cardiac conditions.
- Previous research has not fully elucidated the impact of varying cardiac cycle lengths on coronary flow dynamics in this patient group.
Purpose:
- To investigate the relationship between cardiac cycle length (R-R interval) and aortic pressure with coronary blood flow in patients with chronic atrial fibrillation.
- To quantify the influence of systolic (S) and diastolic (D) periods on coronary flow velocity integrals in the left anterior descending (LAD) and right coronary arteries (RCA).
Summary:
- Beat-by-beat analysis of coronary flow velocity integrals (S, D, T) was performed using Doppler velocimetry in 16 patients with chronic atrial fibrillation.
- Prolonged R-R intervals and diastolic periods were found to significantly increase diastolic coronary flow integral (integral of D) and total cardiac cycle flow integral (integral of T).
- Diastolic flow integral correlated with diastolic period, while systolic flow integral showed less correlation with systolic period and was inversely related to the preceding R-R or diastolic interval in most LAD cases.
Impact:
- Findings highlight the dominant role of diastolic filling time in determining coronary blood flow during atrial fibrillation.
- Provides insights into the altered coronary hemodynamics in patients with chronic atrial fibrillation and underlying heart conditions.
- Suggests that interventions aimed at optimizing diastolic filling may be beneficial for improving coronary perfusion in these patients.
Abstract:
To clarify the influence of changes in the cardiac cycle length (R-R) and aortic pressure on the coronary blood flow, a catheter-tip Doppler velocimeter was applied for 16 patients with chronic atrial fibrillation (11 with valvular heart disease, 2 with coronary artery disease, 2 with cardiomyopathy and one with atrial septal defect). An area under the coronary flow velocity curve during systole (integral of S), diastole (integral of D) and one cardiac cycle (integral of T) for the proximal portion of the left anterior descending artery (LAD: 12 cases) or the right coronary artery (RCA: 10 cases) was calculated in beat-by-beat. Then, the correlations between each area and the R-R, systolic period (S), diastolic period (D) and aortic pressure were assessed. In both the LAD and RCA, prolongation of R-R associated with prolonged D increased integral of D, which caused an increase of integral of T. Integral of D correlated with D (p < 0.05), but integral of S did not correlate with S, and the degree of change in integral of S or S was much less than that in integral of D or D. R-R or D of the preceding beat correlated inversely (p < 0.05) with integral S in 11 of 12 LAD cases. In the RCA, positive correlations between R-R or D of the preceding beat and integral of S were observed in cases with mitral stenosis (n = 6) or coronary heart disease (n = 1), but not in other cases; a case with aortic regurgitation or hypertrophic cardiomyopathy, negative, and dilated cardiomyopathy, no correlation.(ABSTRACT TRUNCATED AT 250 WORDS)