Left ventricular diastolic function in diabetes mellitus type 2 patients: correlation with heart rate and its variability

Aims To assess the prevalence of left ventricular diastolic dysfunction in a population of patients with type 2 diabetes mellitus; to determine correlation of diastolic dysfunction with heart rate and its variability. Methods The study included 202 patients with type 2 diabetes mellitus. Echocardiography was performed with special reference to diastolic function, and heart rate variability was analysed using standard deviation of normal RR intervals, root mean square of successive differences and percentage of successive R-R intervals greater than 50 ms (pNN 50 %) in a 24-h electrocardiogram recording. Results Diastolic dysfunction is present in 79 % of type 2 diabetes mellitus patients: grade 1 in 52 %, grade 2 in 26 % and grade 3 in 1 % of patients. The subjects with grade 1 diastolic dysfunction had a statistically significantly higher heart rate variability compared with those with grade 2 diastolic dysfunction (LSD, post hoc test, p = 0.001). In the group with diastolic dysfunction, grade 2 reduced heart rate variability was recorded in 83 % of patients (37 and 7 % for grade 1 and normal diastolic function). An increase in the severity of diastolic dysfunction was associated with decreased heart rate variability and increased heart rate. Conclusion Progression of diastolic dysfunction is associated with a significantly greater prevalence of reduced heart rate variability, which is accompanied by increased heart rate.