左束支传导阻滞患者机械和代谢失同步与 18 氟脱氧葡萄糖正电子发射断层扫描的关系：非缺血性心力衰竭患者的评估。

Relationship between mechanical and metabolic dyssynchrony with left bundle branch block: evaluation by 18-fluorodeoxyglucose positron emission tomography in patients with non-ischemic heart failure.

机构信息

División Enfermedades Cardiovasculares; Departamento Medicina Nuclear, Facultad de Medicina, Pontificia Universidad Católica, Santiago, Chile.

出版信息

J Heart Lung Transplant. 2012 Oct;31(10):1096-101. doi: 10.1016/j.healun.2012.07.002.

DOI:10.1016/j.healun.2012.07.002

PMID:22975099

Abstract

BACKGROUND

Ventricular dyssynchrony is a common finding in patients with heart failure (HF), especially in the presence of conduction delays. The loss of ventricular synchrony leads to progressive impairment of contractile function, which may be explained in part by segmental abnormalities of myocardial metabolism. However, the association of these metabolic disarrangements with parameters of ventricular dyssynchrony and electrocardiography (ECG) findings has not yet been studied.

METHODS

Our aim was to determine the correlation between the presence of left bundle branch block (LBBB) with left ventricular (LV) mechanical synchrony assessed by multiple-gated acquisition scan (MUGA) and with patterns of 18-fluorodeoxyglucose (18FDG) uptake in patients with non-ischemic heart failure. Twenty-two patients with non-ischemic cardiomyopathy, LV ejection fraction (LVEF) ≤45% and New York Heart Association (NYHA) Functional Class II or III symptoms under standard medical therapy were included, along with 10 healthy controls matched for age and gender. A 12-lead ECG was obtained to measure the length of the QRS. Mechanical LV synchrony was assessed by MUGA using phase analysis. All patients and controls underwent positron emission tomography with 18FDG to determine the distribution of myocardial glucose uptake. The standard deviation of peak (18)FDG uptake was used as an index of metabolic heterogeneity. Student's t-test and Pearson's correlation were used for statistical analysis.

RESULTS

The mean age of the patients with HF was 54 ± 12 years and 72% were male. The length of the QRS was 129 ± 31 milliseconds and LBBB was present in 9 patients. Patients with HF had decreased LV 18FDG uptake compared with controls (7.56 ± 3.36 vs. 11.63 ± 4.55 standard uptake value; p = 0.03). The length of the QRS interval correlated significantly with glucose uptake heterogeneity (r = 0.62; p = 0.002) and mechanical dyssynchrony (r = 0.63; p = 0.006). HF patients with LBBB showed marked glucose uptake heterogeneity compared with HF patients without LBBB (41.4 ± 10 vs 34.7 ± 4.9 ml/100 g/min, respectively; p = 0.01).

CONCLUSIONS

Patients with non-ischemic heart failure exhibit a global decrease in myocardial glucose uptake. Within this group, subjects who also have LBBB exhibit a marked heterogeneity in segmental glucose uptake, which directly correlates with QRS duration.

摘要

背景

心室不同步是心力衰竭（HF）患者的常见表现，尤其是在存在传导延迟的情况下。心室同步性的丧失导致收缩功能进行性受损，这部分可以用心肌代谢的节段异常来解释。然而，这些代谢紊乱与心室不同步和心电图（ECG）发现的参数之间的关系尚未得到研究。

方法

我们的目的是确定左束支传导阻滞（LBBB）患者左心室（LV）机械同步性与 18-氟脱氧葡萄糖（18FDG）摄取模式之间的相关性，这些患者患有非缺血性心力衰竭。22 名非缺血性心肌病患者，LV 射血分数（LVEF）≤45%，纽约心脏协会（NYHA）功能分类 II 或 III 级症状，在标准药物治疗下，以及 10 名年龄和性别匹配的健康对照者，均接受了多门控采集扫描（MUGA）评估的 LV 机械同步性和 18FDG 正电子发射断层扫描（PET），以确定心肌葡萄糖摄取分布。使用标准偏差来确定代谢异质性。采用 Student's t 检验和 Pearson 相关分析进行统计学分析。

结果

HF 患者的平均年龄为 54±12 岁，72%为男性。QRS 波的长度为 129±31 毫秒，9 名患者存在 LBBB。HF 患者的 LV 18FDG 摄取量低于对照组（7.56±3.36 与 11.63±4.55 标准摄取值；p=0.03）。QRS 间隔的长度与葡萄糖摄取异质性（r=0.62；p=0.002）和机械不同步（r=0.63；p=0.006）显著相关。与无 LBBB 的 HF 患者相比，LBBB 的 HF 患者的葡萄糖摄取异质性显著增加（分别为 41.4±10 与 34.7±4.9 ml/100 g/min；p=0.01）。