scholarly journals Altered left atrial 4D flow characteristics in patients with paroxysmal atrial fibrillation in the absence of apparent remodeling

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ahmet Demirkiran ◽  
Raquel P. Amier ◽  
Mark B. M. Hofman ◽  
Rob J. van der Geest ◽  
Lourens F. H. J. Robbers ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Sinus Rhythm ◽  
Flow Velocity ◽  
Paroxysmal Atrial Fibrillation ◽  
Left Atrial ◽  
Peak Flow ◽  
Thrombus Formation ◽  
Clinical Value ◽  
4D Flow ◽  
Ssfp Cine

AbstractThe pathophysiology behind thrombus formation in paroxysmal atrial fibrillation (AF) patients is very complex. This can be due to left atrial (LA) flow changes, remodeling, or both. We investigated differences for cardiovascular magnetic resonance (CMR)-derived LA 4D flow and remodeling characteristics between paroxysmal AF patients and patients without cardiac disease. In this proof-of-concept study, the 4D flow data were acquired in 10 patients with paroxysmal AF (age = 61 ± 8 years) and 5 age/gender matched controls (age = 56 ± 1 years) during sinus rhythm. The following LA and LA appendage flow parameters were obtained: flow velocity (mean, peak), stasis defined as the relative volume with velocities < 10 cm/s, and kinetic energy (KE). Furthermore, LA global strain values were derived from b-SSFP cine images using dedicated CMR feature-tracking software. Even in sinus rhythm, LA mean and peak flow velocities over the entire cardiac cycle were significantly lower in paroxysmal AF patients compared to controls [(13.1 ± 2.4 cm/s vs. 16.7 ± 2.1 cm/s, p = 0.01) and (19.3 ± 4.7 cm/s vs. 26.8 ± 5.5 cm/s, p = 0.02), respectively]. Moreover, paroxysmal AF patients expressed more stasis of blood than controls both in the LA (43.2 ± 10.8% vs. 27.8 ± 7.9%, p = 0.01) and in the LA appendage (73.3 ± 5.7% vs. 52.8 ± 16.2%, p = 0.04). With respect to energetics, paroxysmal AF patients demonstrated lower mean and peak KE values (indexed to maximum LA volume) than controls. No significant differences were observed for LA volume, function, and strain parameters between the groups. Global LA flow dynamics in paroxysmal AF patients appear to be impaired including mean/peak flow velocity, stasis fraction, and KE, partly independent of LA remodeling. This pathophysiological flow pattern may be of clinical value to explain the increased incidence of thromboembolic events in paroxysmal AF patients, in the absence of actual AF or LA remodeling.

scholarly journals Left atrial 4D flow cardiovascular magnetic resonance: a reproducibility study in sinus rhythm and atrial fibrillation

2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Marco Spartera ◽  
Guilherme Pessoa-Amorim ◽  
Antonio Stracquadanio ◽  
Adam Von Ende ◽  
Alison Fletcher ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Blood Pressure ◽  
Heart Rate ◽  
Cardiovascular Magnetic Resonance ◽  
Magnetic Resonance ◽  
Sinus Rhythm ◽  
Left Atrial ◽  
Peak Velocity ◽  
4D Flow ◽  
Mean Velocity

Abstract Background Four-dimensional (4D) flow cardiovascular magnetic resonance (CMR) allows sophisticated quantification of left atrial (LA) blood flow, and could yield novel biomarkers of propensity for intra-cardiac thrombus formation and embolic stroke. As reproducibility is critically important to diagnostic performance, we systematically investigated technical and temporal variation of LA 4D flow in atrial fibrillation (AF) and sinus rhythm (SR). Methods Eighty-six subjects (SR, n = 64; AF, n = 22) with wide-ranging stroke risk (CHA2DS2VASc 0–6) underwent LA 4D flow assessment of peak and mean velocity, vorticity, vortex volume, and stasis. Eighty-five (99%) underwent a second acquisition within the same session, and 74 (86%) also returned at 30 (27–35) days for an interval scan. We assessed variability attributable to manual contouring (intra- and inter-observer), and subject repositioning and reacquisition of data, both within the same session (same-day scan–rescan), and over time (interval scan). Within-subject coefficients of variation (CV) and bootstrapped 95% CIs were calculated and compared. Results Same-day scan–rescan CVs were 6% for peak velocity, 5% for mean velocity, 7% for vorticity, 9% for vortex volume, and 10% for stasis, and were similar between SR and AF subjects (all p > 0.05). Interval-scan variability was similar to same-day scan–rescan variability for peak velocity, vorticity, and vortex volume (all p > 0.05), and higher for stasis and mean velocity (interval scan CVs of 14% and 8%, respectively, both p < 0.05). Longitudinal changes in heart rate and blood pressure at the interval scan in the same subjects were associated with significantly higher variability for LA stasis (p = 0.024), but not for the remaining flow parameters (all p > 0.05). SR subjects showed significantly greater interval-scan variability than AF patients for mean velocity, vortex volume, and stasis (all p < 0.05), but not peak velocity or vorticity (both p > 0.05). Conclusions LA peak velocity and vorticity are the most reproducible and temporally stable novel LA 4D flow biomarkers, and are robust to changes in heart rate, blood pressure, and differences in heart rhythm.

scholarly journals Increased Serum Uric Acid Levels Are Correlated with Decreased Left Atrial Appendage Peak Flow Velocity in Patients with Atrial Fibrillation

2015 ◽  
Vol 24 (3) ◽  
pp. 263-268 ◽  
Author(s):  
Murat Celik ◽  
Emre Yalcinkaya ◽  
Uygar Cagdas Yuksel ◽  
Yalcin Gokoglan ◽  
Baris Bugan ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Uric Acid ◽  
Flow Velocity ◽  
Serum Uric Acid ◽  
Left Atrial ◽  
Left Atrial Appendage ◽  
Peak Flow ◽  
Atrial Appendage ◽  
Peak Flow Velocity

A Stunning Left Atrial Appendage Thrombus

Cardiology ◽  
2016 ◽  
Vol 134 (4) ◽  
pp. 394-397
Author(s):  
Sajid Ali ◽  
Justin Ugwu ◽  
Yousuf Kanjwal
Keyword(s):  
Atrial Fibrillation ◽  
Sinus Rhythm ◽  
Atrial Flutter ◽  
Pulmonary Vein ◽  
Left Atrial ◽  
Left Atrial Appendage ◽  
Thrombus Formation ◽  
Atrial Appendage ◽  
Transesophageal Echocardiogram ◽  
Left Atrial Appendage Thrombus

Background: Left atrial appendage thrombus formation is a known major complication of atrial fibrillation and atrial flutter which increases the risk of embolism and stroke. This risk of thrombosis is greatly increased with a lack of anticoagulation. After conversion to a normal sinus rhythm in these arrhythmias, the risk of thrombus formation in the left atrium persists through a phenomenon termed atrial myocardial stunning. Case: We present the case of a patient who previously underwent successful pulmonary vein isolation and was found to be in typical isthmus-dependent atrial flutter with a questionable recurrence of atrial fibrillation. The decision was made to return for atrial flutter ablation and for evaluation of prior pulmonary vein isolation. Initially, a transesophageal echocardiogram showed a normal ejection fraction, biatrial enlargement and no left atrial appendage thrombus. Ablation of the cavotricuspid isthmus was successfully accomplished with documented bidirectional block. A transesophageal echocardiogram probe was still in place prior to planned transseptal puncture for the evaluation of pulmonary veins. A large thrombus was now observed filling the left atrial appendage. Conclusion and Objective: Atrial stunning is a transient atrial contractile dysfunction that occurs whether sinus rhythm is restored spontaneously, electrically, pharmacologically or by ablation. We know after conversion that there is higher propensity to increased spontaneous echogenic contrast and decreased velocities; however, we do not have documented knowledge of exactly how soon after the conversion to a sinus rhythm a thrombus may be seen. We demonstrate a case of acute left atrial appendage thrombus formation immediately following the successful ablation of isthmus-dependent atrial flutter. Our report validates the belief that strategies of not interrupting anticoagulation prior to the conversion of these arrhythmias should be implemented.

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