Echo Research and Practice最新文献

Echocardiography is the key to the detection and initial assessment of valve disease. The examination helps differentiate severe from moderate disease if this is unclear from the echocardiogram, but is less useful than echocardiography for surveillance. However, the history is extremely important because symptoms are an indication for surgery in all types of valve disease. In aortic stenosis, the mortality rises soon after the onset of exertional breathlessness or chest tightness. Exercise testing is an extension of the history and may reveal symptoms in apparently asymptomatic patients. This article discusses the history, examination and exercise testing in patients either newly referred or under routine follow-up in a specialist valve clinic.

The prevalence of heart valve disease is increasing as the population ages. A series of studies have shown current clinical practice is sub-optimal. Some patients are referred for surgery at advanced stages of disease with impaired ventricular function or not even considered for surgery. Valve clinics seek to improve patient outcomes by providing an expert-led, patient-centred framework of care designed to provide an accurate diagnosis with active surveillance of valve pathology and timely referral for intervention at guideline directed trigger points. A range of different valve clinic models can be adopted depending on local expertise combining the skill set of cardiologist, physiologist/scientist and nurses. Essential components to all clinics include structured clinical review, echocardiography to identify disease aetiology and severity, patient education and access to both additional diagnostic testing and a multi-disciplinary meeting for complex case review. Recommendations for training in heart valve disease are being developed. There is a growing evidence base for heart valve clinics providing better care with increased adherence to guideline recommendations, more timely referral for surgery and better patient education than conventional care.

Objective: Due to its circular shape, the area of the proximal left ventricular tract (PLVOT) adjacent to aortic valve can be derived from a single linear diameter. This is also the location of flow acceleration (FA) during systole, and pulse wave Doppler (PWD) sample volume in the PLVOT can lead to overestimation of velocity (V₁) and the aortic valve area (AVA). Therefore, it is recommended to derive V₁ from a region of laminar flow in the elliptical shaped distal LVOT (away from the annulus). Besides being inconsistent with the assumptions of continuity equation (CE), spatial difference in the location of flow and area measurement can result in inaccurate AVA calculation. We evaluated the impact of FA in the PLVOT on the accuracy of AVA by continuity equation (CE) in patients with aortic stenosis (AS).

Methods: CE-based AVA calculations were performed in patients with AS once with PWD-derived velocity time integral (VTI) in the distal LVOT (VTI_LVOT) and then in the PLVOT to obtain a FA velocity profile (FA-VTI_LVOT) for each patient. A paired sample t-test (P < 0.05) was conducted to compare the impact of FA-VTI_LVOT and VTI_LVOT on the calculation of AVA.

Result: There were 46 patients in the study. There was a 30.3% increase in the peak FA-VTI_LVOT as compared to the peak VTI_LVOT and AVA obtained by FA-VTI_LVOT was 29.1% higher than obtained by VTI_LVOT.

Conclusion: Accuracy of AVA can be significantly impacted by FA in the PLVOT. LVOT area should be measured with 3D imaging in the distal LVOT.

Despite 3D echocardiography (3DE) acquiring significantly greater data than standard 2D echocardiography (2DE), it is underutilized in assessing cardiac anatomy and physiology. A key advantage is the ability of a single 3DE acquisition to be post-processed to generate volume rendered 3D models and an unlimited number of multiplanar reconstruction (MPR) images. We describe the case of a highly anxious patient with life-threatening complex aortic valve endocarditis and aortic root abscess, refusing transesophageal echocardiography (TOE) under general anaesthesia with tachycardia, breathlessness and acute kidney injury precluding accurate or safe gated (computed tomography) CT, who was comprehensively assessed with a rapid 3DE-TOE under sedation. This led to timely surgery and an excellent outcome for the patient.

Cardiovascular MRI and CT are useful imaging modalities complimentary to echocardiography. This review article describes the common indications and consideration for the use of MRI and CT in the management of congenital heart disease.