Heart rate turbulence: an additional parameter in determining the need for mechanical relief of mitral stenosis?

Heart rate turbulence (HRT) is a relatively newer parameter which has predictive value for mortality and severity in a variety of cardiovascular diseases. The study aim was to investigate the relationship between HRT and isolated acquired mitral stenosis (MS) on the basis of symptoms considered important in prognosis and for determining mechanical relief of the stenotic valve.

Among 46 patients with MS undergoing transthoracic echocardiography (TTE), 22 with moderately severe or severe symptoms of MS (NYHA class 3-4) (group 1) were compared with 24 with mild to moderate or no symptoms of MS (NYHA class 1- 2) (group 2). Particular comparison was made with regards to HRT parameters of turbulence onset (TO) and turbulence slope (TS), along with basic clinical and conventional echocardiographic parameters.

Group 1 differed significantly from group 2 in terms of mean mitral valve orifice area (p <0.001), mean transmitral gradient (p <0.001), and left atrial diameter (p <0.05). Among the Holter parameters, TO in group 1 was significantly higher than in group 2. Overall, in MS, an abnormal TO value (> or =0) was found to have sensitivity and specificity of 81.9% and 83.3%, respectively (p <0.05) in distinguishing cases with moderately severe or severe symptoms.

TO, a parameter of HRT, may be useful in the distinction and confirmation of severe symptoms in MS, and may aid in determining the need for mechanical relief of MS, which is especially difficult when discrepancies occur between echocardiographic findings and symptoms.