扩张型心肌病患者左心室扩大的无症状亲属的心肺运动变量异常。

Abnormal cardiopulmonary exercise variables in asymptomatic relatives of patients with dilated cardiomyopathy who have left ventricular enlargement.

作者信息

Mahon N G, Sharma S, Elliott P M, Baig M K, Norman M W, Barbeyto S, McKenna W J

机构信息

Department of Cardiological Sciences, St George's Hospital Medical School, Cranmer Terrace, London SW17 ORE, UK.

出版信息

Heart. 2000 May;83(5):511-7. doi: 10.1136/heart.83.5.511.

DOI:10.1136/heart.83.5.511

PMID:10768898

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC1760817/

Abstract

BACKGROUND

Left ventricular enlargement with normal systolic function is common in asymptomatic relatives of patients with familial dilated cardiomyopathy, many of whom progress to overt dilated cardiomyopathy at follow up.

OBJECTIVE

To examine maximal and submaximal gas exchange variables of cardiopulmonary exercise testing in asymptomatic relatives with left ventricular enlargement.

DESIGN AND SETTING

Controlled evaluation of metabolic exercise performance of patients with dilated cardiomyopathy and asymptomatic relatives with left ventricular enlargement identified through prospective family screening in a cardiomyopathy outpatient clinic.

METHODS

23 relatives with left ventricular enlargement, 33 normal controls, 29 patients with dilated cardiomyopathy, and 10 elite athletes with echocardiographic criteria of left ventricular enlargement ("physiological" enlargement) underwent symptom limited upright cycle ergometry using a ramp protocol.

RESULTS

Peak oxygen consumption (pVO(2); mean (SD)) was significantly reduced in relatives with left ventricular enlargement (78 (16.3)%) v normal controls (96%, p < 0.01) and athletes (152%, p < 0.001), but was higher than in patients with dilated cardiomyopathy (69%, p < 0.01). pVO(2) was less than 80% of predicted in 75% of patients, 58% of relatives, 22% of controls, and none of the athletes. Oxygen pulse (pVO(2)/heart rate) was less than 80% of predicted in 69% of patients, 35% of relatives, 6% of controls, and none of the athletes. The slope of minute ventilation v CO(2) production (DeltaVE/DeltaVCO(2)) was > 30 in 68% of patients, 50% of relatives, and in none of the controls or athletes. Anaerobic threshold, occurring in relatives at 37 (14)% of the predicted VO(2), was higher than in the patients (32%, p < 0.01) and lower than in the controls (45%, p < 0.05) or in the athletes (55%, p < 0.001).

CONCLUSIONS

Maximal and submaximal cardiopulmonary exercise test variables are abnormal in asymptomatic relatives with left ventricular enlargement, in spite of normal systolic function. This provides further evidence that left ventricular enlargement represents subclinical disease in relatives of patients with dilated cardiomyopathy. Metabolic exercise testing can complement echocardiography in identifying relatives at risk for the development of dilated cardiomyopathy.

摘要

背景

左心室扩大但收缩功能正常在家族性扩张型心肌病患者的无症状亲属中很常见，其中许多人在随访中进展为明显的扩张型心肌病。

目的

研究左心室扩大的无症状亲属心肺运动试验的最大和次最大气体交换变量。

设计与场所

在心肌病门诊通过前瞻性家族筛查确定的扩张型心肌病患者和左心室扩大的无症状亲属的代谢运动表现的对照评估。

方法

23名左心室扩大的亲属、33名正常对照者、29名扩张型心肌病患者和10名符合左心室扩大超声心动图标准（“生理性”扩大）的精英运动员采用斜坡方案进行症状限制直立自行车运动试验。

结果

左心室扩大的亲属的峰值耗氧量（pVO₂；均值（标准差））显著低于正常对照者（78（16.3）%对96%，p<0.01）和运动员（152%，p<0.001），但高于扩张型心肌病患者（69%，p<0.01）。75%的患者、58%的亲属、22%的对照者和所有运动员的pVO₂均低于预测值的80%。69%的患者、35%的亲属、6%的对照者和所有运动员的氧脉搏（pVO₂/心率）低于预测值的80%。68%的患者、50%的亲属的分钟通气量与二氧化碳产生量的斜率（ΔVE/ΔVCO₂）>30，而对照者和运动员均无此情况。亲属的无氧阈出现在预测VO₂的37（14）%，高于患者（32%，p<0.01），低于对照者（45%，p<0.05）或运动员（55%，p<0.001）。