Iriarte M M, Perez Olea J, Sagastagoitia D, Molinero E, Murga N
University of the Basque Country Institute of Cardiology, Bilbao (Bizkaia), Spain.
Am J Cardiol. 1995 Nov 2;76(13):43D-47D. doi: 10.1016/s0002-9149(99)80491-3.
Left ventricular (LV) diastolic dysfunction is the first discernible manifestation of heart disease in hypertensive patients. Arterial hypertension with LV hypertrophy leads to reduced preload followed by impaired cardiac output (systolic dysfunction stemming from primary diastolic dysfunction). Diastolic dysfunction leads more often than systolic dysfunction to hypertensive heart failure and is in many cases clearly distinguishable from heart failure with low ejection fraction (EF). Mortality due to heart failure from impaired inotropism is higher than mortality due to diastolic dysfunction, but morbidity is lower. Hypertensive cardiomyopathies can be divided into 4 ascending categories, according to the pathophysiologic and clinical impact of hypertension on the heart: Degree I: LV diastolic dysfunction with no associated LV hypertrophy Degree II: LV diastolic dysfunction with echocardiographic LV hypertrophy Degree IIA: Normal exercise capacity in terms of maximal oxygen consumption Degree IIB: Impaired exercise capacity in terms of maximal oxygen consumption Degree III: Congestive heart failure (severe dyspnea and radiographically determined pulmonary edema with normal (> or = 50%) EF Degree IIIA: LV mass/volume ratio > 1.8 with little or no myocardial ischemia Degree IIIB: LV mass/volume ratio < 1.8 with significant myocardial ischemia Degree IV: Profile of dilated cardiomyopathy; LV hypertrophy and impaired EF (< 50%).
左心室舒张功能障碍是高血压患者心脏病最早可察觉的表现。伴有左心室肥厚的动脉高血压会导致前负荷降低,继而心输出量受损(原发性舒张功能障碍引起的收缩功能障碍)。舒张功能障碍比收缩功能障碍更常导致高血压性心力衰竭,并且在许多情况下与射血分数降低(EF)的心力衰竭明显不同。因心肌收缩力受损导致的心力衰竭死亡率高于舒张功能障碍导致的死亡率,但发病率较低。根据高血压对心脏的病理生理和临床影响,高血压性心肌病可分为4个递进类别:I度:左心室舒张功能障碍,无相关左心室肥厚;II度:左心室舒张功能障碍,超声心动图显示左心室肥厚;IIA度:最大摄氧量方面运动能力正常;IIB度:最大摄氧量方面运动能力受损;III度:充血性心力衰竭(严重呼吸困难,影像学检查显示肺水肿,射血分数正常(≥50%));IIIA度:左心室质量/容积比>1.8,几乎无心肌缺血;IIIB度:左心室质量/容积比<1.8,有明显心肌缺血;IV度:扩张型心肌病表现;左心室肥厚,射血分数受损(<50%)。