Researchers from the School of Biomedical Engineering & Imaging Sciences proposed a new metric, curvature of the left ventricular endocarium to characterise anatomical changes in the left ventricle related to high blood pressure in early stages of the disease. The new marker helps clinicians choose the most effective drugs, which can stop or reverse the changes in cardiac morphology, improving the working of the heart and patient quality of life.
The research published in the Journal of Hypertension investigates what is known as basal septal hypertrophy (BSH) a local thickening of the upper interventricular septum (the partition between the left and right ventricle) and constitutes a marker of an undesirable anatomical changes in patients with hypertension. Aside from the increased risk of cardiac events and weaker cardiac function having the BSH may impact the quality of life, cause shortness of breath, and continuous fatigue.
According to different studies, it occurs in about 15 to 20 percent of hypertensive cases, at various stages of the disease. Previous studies suggest the usage of Beta-blockade drugs in patients with BSH, which slow down the heart rate and lowers the force that the heart contracts against. Typically, it is not the first choice for hypertension treatment and may even be combined with other medicine for high blood pressure.
As a symptom of hypertension, it requires more caution and a tailored treatment for patients. Improper treatment may increase the risk of severe cardiac incidents, like heart failure. However, BSH remains understudied, due to lack of clear detection guidelines.
The new research has proposed a marker, called average septal curvature, defined as the inverse of the radius adjacent to each point of the endocardial contour along the basal and mid inferoseptal segments of the left ventricle. In other words, the metric measures how much the normally uncurled septum deviates from being straight, which directly translates to BSH detection.
Lead researcher Maciej Marciniak at the School of Biomedical Engineering & Imaging Sciences said the aim is to use the new metric to quantify the visual assessment performed when clinicians diagnose patients with the basal septal hypertrophy.
In normal clinical practice, this morphological feature is diagnosed based on the echocardiographic images of the heart. A doctor looks at these images and decides whether a patient should be diagnosed with BSH or not. This makes the diagnostic process very subjective.– Mr Maciej Marciniak
Mr Marciniak said attempts have been made to clarify the definition of BSH, with measurements of the heart’s wall thickness and ratios between these measurements, which are currently used in the medical literature.
However, these ratios are inconsistent among different research groups and suffer from low reproducibility due to technical issues and lack of clear protocols on performing the wall thickness measurements in these cases.
“The results of our experiments on 220 patients, including 59 healthy controls and 161 hypertensive patients, with 32 cases with diagnosed BSH, have shown that the metric that we proposed is significantly more reproducible and less prone to technical issues and expert subjective opinions,” Mr Marciniak said.
“It also correlates better with various metrics of cardiac health, how efficient it is in pumping the blood, and how effectively it contracts.”
Mr Marciniak said the marker may serve as a complementary measurement in other diseases that affect the anatomy of the heart, such as aortic stenosis or hypertrophic cardiomyopathy, especially in diagnoses based on the wall thickness measurements.
“The strength of this marker is that it is based on another tool used in everyday analysis by cardiologists in the hospitals, a two-dimensional strain measurement, and could be easily implemented into the workflow, without the need for additional measurements,” he said.