Quantitative Assessment of Hypertrophic Obstructive Cardiomyopathy With Intraoperative Three-dimensional Transesophageal Echocardiography Under Provocative Dobutamine Stress Test
The objectives of this study are to determine if the left ventricle outflow tract (LVOT) gradients may be reproduced with dobutamine (DBT) provocation test in obstructive HCM patients under general anesthesia and to analyze the change in anatomic LVOT area and pressure gradients (PG) before and after septal myectomy.
If the DBT stress test can reproduce preoperative gradients in HCM patients during septal myectomy surgery, surgeons will have the opportunity to assess the quality of the surgical procedure depending on the obtained gradients with DBT stress test after surgery when gradients can't be reproduced during general anesthesia after myectomy, and decide if further myectomy is required, saving a re-operation on the patient in the future.
研究概览
地位
条件
详细说明
Hypertrophic cardiomyopathy (HCM) is the most common genetic cardiomyopathy. Echocardiography is the noninvasive method of choice for the evaluation of morphologic and functional abnormalities in HCM. It is of paramount importance to distinguish between obstructive or non-obstructive HCM, based on the presence or absence of left ventricle outflow tract (LVOT) gradient using continuous wave Doppler (CWD), under resting and/or provocable conditions. HCM can then be divided into three different subgroups. When the gradient at rest is ≥ 30 mmHg the HCM is considered obstructive (HOCM); when the gradient is <30 mmHg at rest but ≥ 30 mmHg with provocation, the HCM is considered latent obstructive, and finally, non-obstructive occurs when the gradient is < 30mmHg at rest or with provocation.
The gold standard technique to treat symptomatic HOCM is the surgical transaortic septal myectomy, when the resting gradient or the provocable gradient is ≥50 mmHg. Hemodynamic conditions may change and lead to worsening or improvement in LVOT obstruction during general anesthesia. LVOT gradients during surgery should be measured under reproducible conditions possibly mimicking preoperative hemodynamics.
Dobutamine is a well-known inotropic agent, capable to induce sub-aortic gradients in HOCM. The development of a dynamic LVOT gradient during this test is a pharmacological phenomenon with no clinical significance, not been associated with increased frequency of chest pain, shortness of breath or ischemic wall motion abnormalities, because obstruction resolves after termination of dobutamine (DBT) infusion.
研究类型
注册 (预期的)
阶段
- 第四阶段
联系人和位置
学习联系方式
- 姓名:Azad Mashari, MD
- 电话号码:5164 (416) 340-4800
- 邮箱:azad.mashari@uhn.ca
研究联系人备份
- 姓名:Jo Carroll
- 电话号码:3243 416 340-4800
- 邮箱:jo.carroll@uhn.ca
参与标准
资格标准
适合学习的年龄
接受健康志愿者
有资格学习的性别
描述
Inclusion Criteria:
- HOCM refractory to medical treatment with symptoms like syncope, angina or NYHA functional classes III and IV, with a resting gradient or provocable gradient equal or greater than 50 mmHg, requiring surgical intervention.
- Absence of other cardiac or systemic diseases capable of producing hypertrophy.
- Sinus rhythm.
Exclusion Criteria:
- Patient refusal.
- Patient unable to give consent.
- TEE contraindication.
- Different rhythm than sinus.
- Other systemic diseases capable of producing hypertrophy.
- Severe Aortic or coronary artery pathology.
学习计划
研究是如何设计的?
设计细节
- 主要用途:诊断
- 分配:非随机化
- 介入模型:并行分配
- 屏蔽:无(打开标签)
武器和干预
参与者组/臂 |
干预/治疗 |
---|---|
实验性的:Preoperative Transesophageal Echocardiogram (TEE) PG under anesthesia <50mmHg (Group A)
If LVOT PG post myectomy are >16 mmHg, the surgeon will be advised, for surgical management considerations. |
其他名称:
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实验性的:Preoperative PG under anesthesia ≥ 50mmHg (Group B)
|
其他名称:
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研究衡量的是什么?
主要结果指标
结果测量 |
措施说明 |
大体时间 |
---|---|---|
Analyze if TEE immediate post-myectomy LVOT gradients, may be reproduced with provocation dobutamine test in HOCM patients, when compared to TTE LVOT gradients performed within 6 months post-myectomy, to prove septal myectomy efficacy.
大体时间:Pre-operative up to 6 months, Immediate Intra-operative Pre-myectomy, Immediate Intra-operative Post-myectomy and Post-operative up to 6 months
|
The preoperative gradients obtained by TTE, with and without stress test, within 6 months pre-myectomy, will be compared with the intraoperative TEE pre-myectomy gradients at baseline (before and after DBT stress test). The post-myectomy TEE gradients (before and after DBT stress test), will be compared with the follow up TTE gradients with and without stress test, performed within 6 months post-myectomy, to assess short term outcomes. |
Pre-operative up to 6 months, Immediate Intra-operative Pre-myectomy, Immediate Intra-operative Post-myectomy and Post-operative up to 6 months
|
合作者和调查者
调查人员
- 首席研究员:Jacobo Moreno Garijo, MD、Sunnybrook Health Science Centre
- 首席研究员:Azad Mashari, MD、University Health Network, Toronto
研究记录日期
研究主要日期
学习开始 (预期的)
初级完成 (预期的)
研究完成 (预期的)
研究注册日期
首次提交
首先提交符合 QC 标准的
首次发布 (实际的)
研究记录更新
最后更新发布 (实际的)
上次提交的符合 QC 标准的更新
最后验证
更多信息
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