Dernellis J M, Stefanadis C I, Zacharoulis A A, Toutouzas P K
First Cardiology Department, Amalia Fleming Hospital, University of Athens, Greece.
Am J Cardiol. 1998 May 1;81(9):1138-43. doi: 10.1016/s0002-9149(98)00134-9.
Left atrial (LA) adaptation during the development of left ventricular (LV) dysfunction is not fully understood. We performed echocardiographic assessment of LA volumes simultaneously with recordings of pulmonary wedge pressures in 60 patients. Twenty patients had no structural or functional LV abnormalities, 20 had a recent myocardial infarction with LV dysfunction, and 20 suffered from congestive heart failure (CHF). Pressure-volume loops were obtained at baseline and during increases in LA pressure produced by normal saline infusion. LA afterload was estimated by the effective LV elastance (E(LV)). Atrioventricular coupling was calculated by the E(LV)/E(es) ratio (where E(es) is the end-systolic elastance). E(es) increased in patients with myocardial infarction (0.80 +/- 0.09 mm Hg/ml, p <0.001), whereas it decreased in patients with CHF (0.22 +/- 0.05 mm Hg/ml, p <0.001) compared with controls (0.61 +/- 0.07 mm Hg/ml). Similarly, stroke workload increased in patients with myocardial infarction (60.7 +/- 7.3 mm Hg x ml, p <0.001), whereas it decreased in patients with CHF (25.4 +/- 2.2 mm Hg x ml, p <0.001) compared with controls (44.8 +/- 5.5 mm Hg x ml). In all patients LA stiffness (slope of the relation of the filling portion of the pressure-volume loop) was increased compared with controls (controls: 0.13 +/- 0.04, patients with myocardial infarction: 0.22 +/- 0.05, and patients with CHF: 0.27 +/- 0.05 mm Hg/ml, p <0.001 for both comparisons). Moreover, the E(LV)/E(es) ratio increased gradually as LV function deteriorated (controls: 1.06 +/- 0.10, patients with myocardial infarction: 1.35 +/- 0.16, and patients with CHF: 6.90 +/- 0.84, p <0.001). Thus, early in heart failure, LA pump function is augmented but LA stiffness increases and work mismatch occurs. With further progression of LV dysfunction, LA pump function decreases as a result of increased afterload imposed on the LA myocardium.
左心室（LV）功能障碍发展过程中左心房（LA）的适应性变化尚未完全明确。我们对60例患者进行了超声心动图评估左心房容积，并同步记录肺楔压。20例患者无左心室结构或功能异常，20例近期发生心肌梗死并伴有左心室功能障碍，20例患有充血性心力衰竭（CHF）。在基线状态以及通过输注生理盐水增加左心房压力期间获取压力-容积环。通过有效左心室弹性（E(LV)）估算左心房后负荷。通过E(LV)/E(es)比值计算房室耦联（其中E(es)为收缩末期弹性）。与对照组（0.61±0.07 mmHg/ml）相比，心肌梗死患者的E(es)升高（0.80±0.09 mmHg/ml，p<0.001），而CHF患者的E(es)降低（0.22±0.05 mmHg/ml，p<0.001）。同样，与对照组（44.8±5.5 mmHg×ml）相比，心肌梗死患者的每搏功增加（60.7±7.3 mmHg×ml，p<0.001），而CHF患者的每搏功降低（25.4±2.2 mmHg×ml，p<0.001）。与对照组相比，所有患者的左心房僵硬度（压力-容积环充盈部分关系的斜率）均增加（对照组：0.13±0.04，心肌梗死患者：0.22±0.05，CHF患者：0.27±0.05 mmHg/ml，两组比较p均<0.001）。此外，随着左心室功能恶化，E(LV)/E(es)比值逐渐升高（对照组：1.06±0.10，心肌梗死患者：1.35±0.16，CHF患者：6.90±0.84，p<0.001）。因此，在心力衰竭早期，左心房泵功能增强，但左心房僵硬度增加且出现功不匹配。随着左心室功能障碍进一步发展，由于左心房心肌承受的后负荷增加，左心房泵功能降低。
