高血压成年人的心肌机械-能量效率

Myocardial mechano-energetic efficiency in hypertensive adults.

作者信息

de Simone Giovanni, Chinali Marcello, Galderisi Maurizio, Benincasa Margherita, Girfoglio Daniela, Botta Ilaria, D'Addeo Gianpaolo, de Divitiis Oreste

机构信息

Department of Clinical and Experimental Medicine, Federico II University Hospital, Naples, Italy.

出版信息

J Hypertens. 2009 Mar;27(3):650-5. doi: 10.1097/hjh.0b013e328320ab97.

DOI:10.1097/hjh.0b013e328320ab97

PMID:19330923

Abstract

BACKGROUND

Myocardial mechanical efficiency can be measured as the ratio between systolic work and energy consumption. We evaluated the relation between myocardial mechanical efficiency and left ventricular (LV) mass in untreated hypertensive patients.

METHODS

Myocardial work was estimated in 256 normotensive (35 +/- 12 years) and 306 hypertensive patients (47 +/- 10 years) with normal ejection fraction, as stroke work in gram-meters (stroke work = BPs x SV x 0.0144, where BPs is systolic blood pressure, SV is echocardiographic stroke volume). Myocardial O2 consumption was estimated as the product of heart rate (HR) x BPs (eMVO2). Myocardial mechanical efficiency was estimated as the ratio of stroke work/eMVO2, which can be simplified and expressed as ml/s.

RESULTS

LV mass was greater in hypertensive than in normotensive patients (46 +/- 13 vs. 38 +/- 11 g/m2.7, P < 0.0001), but myocardial mechanical efficiency was identical (85 +/- 23 vs. 86 +/- 26 ml/s). Relations between myocardial mechanical efficiency and LV mass were close (both P < 0.0001), but more scattered among hypertensive patients because of 56 patients exhibiting low myocardial mechanical efficiency relative to the magnitude of LV mass. At comparable age and body size, these patients had higher HR, BPs, and pulse pressure than those with normal myocardial mechanical efficiency (all P < 0.001). After adjusting for age and sex, hypertensive patients with low myocardial mechanical efficiency showed greater relative wall thickness and lower ejection fraction and midwall shortening than those with normal myocardial mechanical efficiency (all P < 0.001). Low myocardial mechanical efficiency was also associated with inappropriately high LV mass (P < 0.0001).

CONCLUSION

In some hypertensive patients the left ventricle works inefficiently with a high energy wasting, at the same level of LV mass as hypertensive patients with normal myocardial mechanical efficiency. Those patients feature a high cardiovascular risk phenotype, with concentric LV geometry, systolic dysfunction, and indirect signs of more severe vascular impairment.

摘要

背景

心肌机械效率可通过收缩期功与能量消耗的比值来衡量。我们评估了未经治疗的高血压患者中心肌机械效率与左心室（LV）质量之间的关系。

方法

在256名射血分数正常的血压正常者（35±12岁）和306名高血压患者（47±10岁）中估计心肌功，以克 - 米为单位的每搏功（每搏功 = 收缩压×每搏量×0.0144，其中收缩压为收缩期血压，每搏量为超声心动图测得的每搏量）。心肌耗氧量通过心率（HR）×收缩压（eMVO2）来估计。心肌机械效率通过每搏功/eMVO2的比值来估计，可简化并表示为毫升/秒。

结果

高血压患者的左心室质量高于血压正常者（46±13 vs. 38±11 g/m2.7，P < 0.0001），但心肌机械效率相同（85±23 vs. 86±26毫升/秒）。心肌机械效率与左心室质量之间的关系密切（均P < 0.0001），但在高血压患者中更为分散，因为有56名患者相对于左心室质量的大小表现出低心肌机械效率。在年龄和体型相当的情况下，这些患者的心率、收缩压和脉压高于心肌机械效率正常的患者（均P < 0.001）。在调整年龄和性别后，心肌机械效率低的高血压患者比心肌机械效率正常的患者表现出更大的相对室壁厚度、更低的射血分数和室壁中层缩短率（均P < 0.001）。低心肌机械效率还与左心室质量过高有关（P < 0.0001）。