von Roeder Maximilian, Rommel Karl-Philipp, Kowallick Johannes Tammo, Blazek Stephan, Besler Christian, Fengler Karl, Lotz Joachim, Hasenfuß Gerd, Lücke Christian, Gutberlet Matthias, Schuler Gerhard, Schuster Andreas, Lurz Philipp
From the Department of Internal Medicine/Cardiology (M.v.R., K.-P.R., S.B., C.B., K.F., G.S., P.L.) and Department of Radiology (C.L., M.G.), University of Leipzig, Heart Center, Germany; Department of Cardiology and Pneumology (G.H., A.S.) and Institute for Diagnostic and Interventional Radiology (J.T.K., J.L.), Georg-August University, Göttingen, Germany; and DZHK (German Centre for Cardiovascular Research), Berlin, Germany (J.T.K., J.L., G.H., A.S.).
Circ Cardiovasc Imaging. 2017 Apr;10(4). doi: 10.1161/CIRCIMAGING.116.005467.
Although left atrial (LA) dysfunction is common in heart failure with preserved ejection fraction (HFpEF), its functional implications beyond the reflection of left ventricular (LV) pathology are not well understood. The aim of this study was to further characterize LA function in HFpEF patients.
We performed cardiac magnetic resonance myocardial feature tracking in 22 patients with HFpEF and 12 patients without HFpEF. LA reservoir strain, LA conduit strain, and LA booster pump strain were quantified. Peak oxygen uptake (VO2max) was determined. Invasive pressure-volume loops were obtained to evaluate LV diastolic properties. LV early filling was determined from LV volume-time curves as derived from cardiac magnetic resonance. LA reservoir and conduit strain were significantly lower in HFpEF (LA reservoir strain, 22±7% versus 29±6%, =0.04; LA conduit strain, -9±5% versus -15±4%, <0.01). Patients with HFpEF showed lower oxygen uptake (17±6 versus 29±8 mL/(kg min); <0.01). Strain measurement for LA conduit function was strongly associated with VO2max (=0.80; <0.01). On multivariable regression analysis, LA conduit strain emerged as strongest predictor for VO2max even after inclusion of LV stiffness and relaxation time (β=0.80; <0.01). LA conduit strain correlated with the volume of early ventricular filling (=0.67; <0.01), but not LV stiffness constant β (-0.34; =0.051) or relaxation constant τ (=-0.33; =0.06).
Cardiac magnetic resonance myocardial feature tracking-derived conduit strain is significantly impaired in HFpEF and associated with exercise intolerance. Impaired conduit function is associated with impaired early ventricular filling, as potential mechanism leading to impaired oxygen uptake. Our results propose that impaired LA conduit function represents a distinct feature of HFpEF, independent of LV stiffness and relaxation.
URL: http://www.clinicaltrials.gov. Unique identifier: NCT02459626.
虽然左心房（LA）功能障碍在射血分数保留的心力衰竭（HFpEF）中很常见，但其在反映左心室（LV）病理之外的功能意义尚未得到充分理解。本研究的目的是进一步描述HFpEF患者的左心房功能。
我们对22例HFpEF患者和12例无HFpEF患者进行了心脏磁共振心肌特征追踪。对左心房储备应变、左心房管道应变和左心房增压泵应变进行了量化。测定了峰值摄氧量（VO2max）。获取有创压力-容积环以评估左心室舒张特性。从心脏磁共振得出的左心室容积-时间曲线确定左心室早期充盈。HFpEF患者的左心房储备和管道应变显著降低（左心房储备应变，22±7%对29±6%，P = 0.04；左心房管道应变，-9±5%对-15±4%，P < 0.01）。HFpEF患者的摄氧量较低（17±6对29±8 mL/（kg·min）；P < 0.01）。左心房管道功能的应变测量与VO2max密切相关（r = 0.80；P < 0.01）。在多变量回归分析中，即使纳入左心室僵硬度和舒张时间后，左心房管道应变仍是VO2max的最强预测因子（β = 0.80；P < 0.01）。左心房管道应变与心室早期充盈量相关（r = 0.67；P < 0.01），但与左心室僵硬度常数β（-0.34；P = 0.051）或舒张常数τ（r = -0.33；P = 0.06）无关。
心脏磁共振心肌特征追踪得出的管道应变在HFpEF中显著受损，并与运动不耐受相关。管道功能受损与心室早期充盈受损相关，这是导致摄氧量受损的潜在机制。我们的结果表明，左心房管道功能受损代表了HFpEF的一个独特特征，独立于左心室僵硬度和舒张功能。
