Trikas A, Tentolouris K, Katsimaklis G, Antoniou J, Stefanadis C, Toutouzas P
Department of Cardiology, University of Athens Medical School, Athens, Greece.
Am Heart J. 1998 Dec;136(6):988-90. doi: 10.1016/s0002-8703(98)70154-1.
The objective of this study was to examine the association between exercise capacity and echocardiographic indexes of atrial and ventricular function and size in patients with beta-thalassemia major.
In patients with beta-thalassemia major, the assessment of cardiac function with echocardiography alone does not always correspond to their functional status. Peak oxygen uptake and anaerobic threshold, on the other hand, constitute 2 objective and reproducible determinants of exercise capacity in patients with heart failure.
Forty consecutive patients (22 women and 18 men, 18 to 30 years old) who were in stable condition while receiving regular transfusions and 30 age- and sex-matched control subjects were studied. At 2 to 3 days after the last transfusion, each subject underwent complete echocardiographic study followed by cardiopulmonary exercise testing. Left atrial volumes (maximal [Vmax], at onset of atrial systolic [Vp], and minimal [Vmin]) and left ventricular volumes were measured with the biplane area-length method, and left atrial active emptying fraction (ACTEF) and left ventricular ejection (LVEF) fraction were calculated. Peak oxygen uptake (Vo 2 max) and anaerobic threshold (AT) were also estimated. After transfusion, patients with beta-thalassemia major had reduced Vo 2 max and AT and greater left atrial volume in comparison with control subjects. Also, ACTEF and LVEF were significantly lower in the patient group. Moreover, Vo2 max and AT were inversely related to Vmax (r = -0.74 and r = -0.80, respectively) and directly related to ACTEF (r = 0.85 and r = 0.82, respectively) in beta-thalassemia major, whereas they were poorly related to LVEF (r = 0.50 and r = 0. 53, respectively). In the control group, Vo 2 max and AT parameters were related to Vmax and ACTEF in a similar way to that in the beta-thalassemia group.
In patients with beta-thalassemia major, exercise capacity does not correlate with left ventricular dimensions and function. On the contrary, left atrial size and systolic dysfunction are probably predictors of decreased exercise capacity.
本研究旨在探讨重型β地中海贫血患者运动能力与心房和心室功能及大小的超声心动图指标之间的关联。
在重型β地中海贫血患者中，仅通过超声心动图评估心脏功能并不总是与其功能状态相符。另一方面，峰值摄氧量和无氧阈值是心力衰竭患者运动能力的两个客观且可重复的决定因素。
对40例连续的患者（22例女性和18例男性，年龄18至30岁）进行研究，这些患者在接受定期输血时病情稳定，另外选取30例年龄和性别匹配的对照者。在最后一次输血后2至3天，每位受试者接受完整的超声心动图检查，随后进行心肺运动测试。采用双平面面积长度法测量左心房容积（最大[Vmax]、心房收缩开始时[Vp]和最小[Vmin]）和左心室容积，并计算左心房主动排空分数（ACTEF）和左心室射血分数（LVEF）。还估算了峰值摄氧量（Vo₂max）和无氧阈值（AT）。输血后，重型β地中海贫血患者的Vo₂max和AT降低，左心房容积增大，与对照组相比，患者组的ACTEF和LVEF也显著降低。此外，在重型β地中海贫血患者中，Vo₂max和AT与Vmax呈负相关（r分别为-0.74和-0.80），与ACTEF呈正相关（r分别为0.85和0.82），而它们与LVEF的相关性较差（r分别为0.50和0.53）。在对照组中，Vo₂max和AT参数与Vmax和ACTEF的关系与重型β地中海贫血组相似。
在重型β地中海贫血患者中，运动能力与左心室大小和功能无关。相反，左心房大小和收缩功能障碍可能是运动能力下降的预测因素。
