Tag: aortic stenosis

Categories : Cardiovascular DiseaseTags :

A Simple Low-cost Method to Identify Aortic Valve Stenosis

On By ModernMedia
Source: CC0

In the Journal of Applied Physics, researchers developed a method to identify aortic valve stenosis using complex network analysis that is accurate, simple to use, and low-cost.

Aortic valve stenosis occurs when the aortic valve narrows, constricting blood flow from the heart through the artery and to the entire body. In severe cases, it can lead to heart failure. Identifying the condition can be difficult in remote areas because it requires sophisticated technology, and diagnoses at early stages are challenging to obtain.

“Many rural health centres don’t have the necessary technology for analysing diseases like this,” said author M.S. Swapna, of the University of Nova Gorica and the University of Kerala. “For our technique, we just need a stethoscope and a computer.”

The diagnostic tool works based on the sounds produced by the heart. The organ creates a “lub” noise as it closes the mitral and tricuspid valves, pauses as ventricular relaxation occurs and the blood fills in, then makes a second noise, “dub,” as the aortic and pulmonary valves close.

Swapna and her team used heart sound data, collected over 10 minutes, to form a graph. This was then split into sections, with each part representing with a node on the graph. If the sound in that portion of the data was similar to another section, a line was drawn between the two nodes.

In a healthy heart, the graph showed two distinct clusters of points, with many nodes unconnected. In contrast, a heart with aortic stenosis contained many more correlations and edges.

“In the case of aortic stenosis, there is no separation between the ‘lub’ and ‘dub’ sound signals,” explained Swapna.

The researchers used machine learning to examine the graphs and identify those with and without disease, achieving a classification accuracy of 100%. Their method takes the correlation of each point under consideration, making it more accurate than others that only consider the strength of the signal, and it does so in less than 10 minutes. As such, it could be useful for early-stage diagnoses.

So far, the method has only been tested with data, not in a clinical setting. The authors are developing a mobile application that could be accessed worldwide. Their technique could also be used to diagnose other conditions.

“The proposed method can be extended to any type of heart sound signals, lung sound signals, or cough sound signals,” said Swapna.

Source: American Institute of Physics

Categories : Surgeries & ProceduresTags :

Earlier Valve Replacement Surgery Recommended in Aortic Stenosis

On By ModernMedia
Source: Pixabay CC0

Valve replacement surgery should be performed earlier than conventionally thought for people with aortic stenosis, as shown by new research published in the journal Open Heart.

Aortic stenosis is a common valvular disorder, especially in the elderly population, causing left ventricular outflow obstruction. Aetiologies include congenital (bicuspid/unicuspid), calcific, and rheumatic disease. Symptoms such as exertional dyspnoea or fatigue gradually develop after a long asymptomatic latent period of about 10 to 20 years. But many patients with aortic stenosis do not have symptoms even when they have severe narrowing of the valve and are thus not eligible for valve replacement.

The findings from this study show that these patients would benefit by undergoing a valve replacement – before they suffer irreversible heart muscle damage.

Lead researcher Prof Vassilios Vassiliou, from UEA’s Norwich Medical School, said: “The heart has four valves, which allow the blood to flow in one direction efficiently. With increasing age, one of the valves, the aortic valve, becomes increasingly narrowed or ‘stenosed’.

“A lot of patients with severe aortic stenosis do not have symptoms and therefore are not eligible for valve replacement according to the current guidelines.

“For these patients without symptoms, the guidelines suggest a ‘watchful waiting’ approach and intervention is recommended only when they show symptoms or develop pump failure.

“We wanted to know if it would be better to perform surgery and replace the valve sooner rather than later.”

In a systematic review, researchers compared early intervention versus conservative management in patients with asymptomatic severe aortic stenosis.

They then analysed data from all the available studies which involved a total of 3798 patients, out of which 302 were included in the two largest randomised controlled trials and 3496 in the observational studies.

Prof Vassiliou said: “We found that early intervention, before patients have symptoms, is associated with lower risk of death and hospitalisation for heart failure.

“By the time the patients develop symptoms, there has likely been irreversible damage to the muscle of the heart. This in turn may preclude a worse prognosis and adverse outcomes even after successful intervention.

“The timing of aortic valve intervention is crucial.

“We hope that our findings may herald the beginning of a change in the management of aortic stenosis patients, enabling the intervention to take place more commonly whilst the patients are asymptomatic.

“Ongoing trials investigating this high-risk population are anticipated to shed more light into the matter and in the identification of the optimal time of intervention,” he added.

Source: University of East Anglia