Costello Benedict T, Voskoboinik Aleksandr, Qadri Abdul M, Rudman Murray, Thompson Mark C, Touma Ferris, La Gerche Andre, Hare James L, Papapostolou Stavroula, Kalman Jonathan M, Kistler Peter M, Taylor Andrew J
Baker Heart & Diabetes Institute, Melbourne, Australia; Heart Centre, The Alfred Hospital, Melbourne, Australia; Department of Cardiology, St Vincent's Hospital, Australia.
Baker Heart & Diabetes Institute, Melbourne, Australia; Heart Centre, The Alfred Hospital, Melbourne, Australia; Department of Cardiology, Royal Melbourne Hospital, Melbourne, Australia.
Int J Cardiol. 2020 Sep 15;315:45-50. doi: 10.1016/j.ijcard.2020.05.012. Epub 2020 May 19.
Paroxysmal atrial fibrillation (PAF) is associated with cardioembolic risk, however events may occur during sinus rhythm (SR). 4D-flow cardiac magnetic resonance (CMR) imaging allows visualisation of left atrial blood flow, to determine the residence time distribution (RTD), an assessment of atrial transit time.
To determine if atrial transit time is prolonged in PAF patients during SR, consistent with underlying atrial stasis.
91 participants with PAF and 18 healthy volunteers underwent 4D flow analysis in SR. Velocity fields were produced RTDs, calculated by seeding virtual 'particles' at the right upper pulmonary vein and counting them exiting the mitral valve. An exponential decay curve quantified residence time of particles in the left atrium, and atrial stasis was expressed as the derived constant (RTD) based on heartbeats. The RTD was evaluated within the PAF group, and compared to healthy volunteers.
Patients with PAF (n = 91) had higher RTD compared with gender-matched controls (n = 18) consistent with greater atrial stasis (1.68 ± 0.46 beats vs 1.51 ± 0.20 beats; p = .005). PAF patients with greater thromboembolic risk had greater atrial stasis (median RTD of 1.72 beats in CHA₂DS₂-VASc≥2 vs 1.52 beats in CHA₂DS₂-VASc<2; p = .03), only female gender and left ventricular ejection fraction contributed significantly to the atrial RTD (p = .006 and p = .023 respectively).
Atrial stasis quantified by 4D flow is greater in PAF, correlating with higher CHA₂DS₂-VASc scores. Female gender and systolic dysfunction are associated with atrial stasis. RTD offers an insight into atrial flow that may be developed to provide a personalised assessment of thromboembolic risk.
阵发性心房颤动（PAF）与心脏栓塞风险相关，然而事件可能在窦性心律（SR）期间发生。4D流心脏磁共振（CMR）成像可使左心房血流可视化，以确定停留时间分布（RTD），这是一种对心房传输时间的评估。
确定PAF患者在SR期间心房传输时间是否延长，这与潜在的心房淤滞一致。
91名PAF患者和18名健康志愿者在SR期间接受了4D流分析。通过在右上肺静脉处植入虚拟“粒子”并计算它们从二尖瓣流出的数量来生成速度场和RTD。一条指数衰减曲线量化了粒子在左心房的停留时间，心房淤滞表示为基于心跳得出的常数（RTD）。在PAF组内评估RTD，并与健康志愿者进行比较。
与性别匹配的对照组（n = 18）相比，PAF患者（n = 91）的RTD更高，这与更大的心房淤滞一致（1.68±0.46次心跳对1.51±0.20次心跳；p = 0.005）。血栓栓塞风险更高的PAF患者有更大的心房淤滞（CHA₂DS₂-VASc≥2的患者中位RTD为1.72次心跳，而CHA₂DS₂-VASc<2的患者为1.52次心跳；p = 0.03），只有女性性别和左心室射血分数对心房RTD有显著影响（分别为p = 0.006和p = 0.023）。
通过4D流量化的心房淤滞在PAF中更大，与更高的CHA₂DS₂-VASc评分相关。女性性别和收缩功能障碍与心房淤滞有关。RTD提供了对心房血流的深入了解，可能会发展为提供个性化的血栓栓塞风险评估。
