Toronto Congenital Cardiac Center for Adults, Peter Munk Cardiac Center, University of Toronto, Toronto General Hospital, Toronto, Ontario, Canada.
Toronto Joint Department of Medical Imaging, University of Toronto, University Health Network, Toronto, Ontario, Canada.
Heart. 2021 Jan;107(2):142-149. doi: 10.1136/heartjnl-2020-316613. Epub 2020 Jul 6.
Although a life-preserving surgery for children with single ventricle physiology, the Fontan palliation is associated with striking morbidity and mortality with advancing age. Our primary objective was to evaluate the impact of non-invasive, external, thoraco-abdominal ventilation on pulmonary blood flow (PBF) and cardiac output (CO) as measured by cardiovascular magnetic resonance (CMR) imaging in adult Fontan subjects.
Adults with a dominant left ventricle post-Fontan palliation (lateral tunnel or extracardiac connections) and healthy controls matched by sex and age were studied. We evaluated vascular flows using phase-contrast CMR imaging during unassisted breathing, negative pressure ventilation (NPV) and biphasic ventilation (BPV). Measurements were made within target vessels (aorta, pulmonary arteries, vena cavae and Fontan circuit) at baseline and during each ventilation mode.
Ten Fontan subjects (50% male, 24.5 years (IQR 20.8-34.0)) and 10 matched controls were studied. Changes in PBF and CO, respectively, were greater following BPV as compared with NPV. In subjects during NPV, PBF increased by 8% (Δ0.20 L/min/m (0.10-0.53), p=0.011) while CO did not change significantly (Δ0.17 L/min/m (-0.11-0.23), p=0.432); during BPV, PBF increased by 25% (Δ0.61 L/min/m (0.20-0.84), p=0.002) and CO increased by 16% (Δ0.47 L/min/m (0.21-0.71), p=0.010). Following BPV, change in PBF and CO were both significantly higher in subjects versus controls (0.61 L/min/m (0.2-0.84) vs -0.27 L/min/m (-0.55-0.13), p=0.001; and 0.47 L/min/m (0.21-0.71) vs 0.07 L/min/m (-0.47-0.33), p=0.034, respectively).
External ventilation acutely augments PBF and CO in adult Fontan subjects. Confirmation of these findings in larger populations with longer duration of ventilation and extended follow-up will be required to determine sustainability of haemodynamic effects.
尽管对于单心室生理的儿童来说，Fontan 姑息术是一种维持生命的手术，但随着年龄的增长，它与显著的发病率和死亡率相关。我们的主要目标是评估非侵入性、外部、胸-腹通气对心血管磁共振（CMR）成像测量的肺血流量（PBF）和心输出量（CO）的影响，在成人 Fontan 患者中。
研究了接受 Fontan 姑息术后具有优势左心室（侧隧道或心外连接）的成年患者和按性别和年龄匹配的健康对照者。我们在自主呼吸、负压通气（NPV）和双相通气（BPV）期间使用相位对比 CMR 成像评估血管流量。在基线和每个通气模式下，在目标血管（主动脉、肺动脉、腔静脉和 Fontan 循环）内进行测量。
研究了 10 名 Fontan 患者（50%为男性，24.5 岁（IQR 20.8-34.0））和 10 名匹配的对照者。与 NPV 相比，BPV 后 PBF 和 CO 的变化更大。在 NPV 期间，PBF 增加了 8%（Δ0.20 L/min/m（0.10-0.53），p=0.011），而 CO 无明显变化（Δ0.17 L/min/m（-0.11-0.23），p=0.432）；在 BPV 期间，PBF 增加了 25%（Δ0.61 L/min/m（0.20-0.84），p=0.002），CO 增加了 16%（Δ0.47 L/min/m（0.21-0.71），p=0.010）。与对照组相比，BPV 后，患者的 PBF 和 CO 变化均显著更高（0.61 L/min/m（0.2-0.84）vs -0.27 L/min/m（-0.55-0.13），p=0.001；0.47 L/min/m（0.21-0.71）vs 0.07 L/min/m（-0.47-0.33），p=0.034）。
外部通气可急性增加成人 Fontan 患者的 PBF 和 CO。需要在具有更长通气时间和更长随访时间的更大人群中确认这些发现，以确定血流动力学效应的可持续性。
