Walley K R, Grover M, Raff G L, Benge J W, Hannaford B, Glantz S A
Circ Res. 1982 Apr;50(4):573-89. doi: 10.1161/01.res.50.4.573.
No approach to describing the heart's dynamic geometry has been widely adopted, probably because all require questionable assumptions of chamber shape, symmetry, or placement of the measuring devices. In other words, these approaches require assumptions about shape to reach conclusions about shape. We present an analysis that avoids such assumptions and provides an objective description of how the left ventricle deforms and rotates during the cardiac cycle. We only assume that the deformation of the left ventricular cavity is homogeneous, and explicitly validate this assumption. Our analysis yields the following new information about the contracting left ventricle: three principal directions of deformation and the relative length change alone these directions: the axis and angle of rotation, and relative volume. All these changes are referenced to the ventricle's configuration at end-diastole. We instrumented 13 dogs with tantalum screws without opening their chests. During systole, the three principal directions of deformation essentially are aligned along apex-base, anterior-posterior, and septum-free wall directions. There is little length change in the apex-base direction. The anterior and septal principal directions do not remain fixed with respect to the heart's anatomy during systole. During isovolumic relaxation and early filling, systolic shape changes are reversed. During slow filling, only small shape changes occur. Opening the pleura or performing a sternotomy and pericardiectomy makes the heart change orientation within the chest, but does not alter the magnitude of shortening, relative to the left ventricle's end-diastolic configuration.
目前尚未有描述心脏动态几何形状的方法被广泛采用，这可能是因为所有方法都需要对腔室形状、对称性或测量设备的放置做出有疑问的假设。换句话说，这些方法需要关于形状的假设才能得出关于形状的结论。我们提出了一种分析方法，该方法避免了此类假设，并提供了关于左心室在心动周期中如何变形和旋转的客观描述。我们仅假设左心室腔的变形是均匀的，并明确验证了这一假设。我们的分析得出了关于收缩期左心室的以下新信息：三个主要变形方向以及沿这些方向的相对长度变化；旋转轴和角度以及相对体积。所有这些变化均以舒张末期心室的形态为参照。我们在13只狗身上植入了钽螺钉，且未打开它们的胸腔。在收缩期，三个主要变形方向基本上沿心尖 - 心底、前后和室间隔 - 游离壁方向排列。在心尖 - 心底方向上长度变化很小。在收缩期，前侧和室间隔主要方向相对于心脏解剖结构并不固定。在等容舒张期和早期充盈期，收缩期的形状变化会逆转。在缓慢充盈期，仅发生很小的形状变化。打开胸膜或进行胸骨切开术和心包切除术会使心脏在胸腔内改变方向，但相对于左心室舒张末期形态，并不会改变缩短的幅度。
