The detection of left ventricular diastolic dysfunction in patients with type 2 diabetes mellitus by tissue Doppler imaging

Abstract

Background: The left ventricular diastolic dysfunction in asymptomatic patients with type 2 diabetes mellitus (T2DM) has been documented by tissue Doppler echocardiography.Objectives: The aim of this study was to look for the value of tissue Doppler imaging (TDI) in detecting LV diastolic dysfunction in type 2 diabetic patients.Patients and methods: This study is conducted by the department of physiology, college of medicine, Al-Mustansiriryah University in cooperation with the unit of Echocardiography at Al-Yarmouk Teaching Hospital in Baghdad during the period from November 2013 to July 2014. A randomized controlled non-invasive echocardiography. A total number of 92 subjects were included in this study, about fourty six healthy subjects (control group) (with mean age of 47.07±7.6 years) and fourty six patients with T2DM (with mean age of 49.39±5.7 years). Pulsed wave blood flow Doppler and tissue Doppler imaging (TDI) were used in estimating (LV) diastolic dysfunction.Results: 69.6% of the 46 diabetic patients (41% were male and 59% were female) showed evidence of LV diastolic dysfunction through impairment in mitral valve annular velocities and in the filling velocities of LV. By TDI the ratio of early filling velocity to the average early mitral annular velocity (E/E` ratio) was significantly increased in diabetic patients compared with the control subjects (7.4±1.7 versus 6.4±1.3) (P<0.04), the ratio of early (E`) mitral annular velocity to the late (A`) mitral annular velocity (E`/A` ratio) was significantly reduced in diabetic patients compared with control subjects (0.8±0.3 versus 1.02±0.3) (P<0.004). The E` average velocity was significantly reduced in diabetic patients (8.9±1.9 cm/sec) versus (10.7±1.6 cm/sec) in control group (P<0.0001). While by pulsed wave Doppler the ratio of the peak early (E) filling velocity to the late (A) filling velocity (E/A ratio) was significantly reduced in diabetic patients (0.9±0.3) versus (1.17±0.4) in control group (P<0.0001), and lower E velocity in diabetic patients (63.7±13.4 cm/sec) versus (72±19.9cm/sec) in control subjects (P<0.01). By TDI the study revealed that 69.6% of the asymptomatic type 2 diabetic patients have LV diastolic dysfunction, while by pulsed wave Doppler echo there was only 56.5% of diabetic patients have LV diastolic dysfunction. This would allow us to detect diastolic abnormalities in 12 subjects (13% of this sample study and 22.6% of LV diastolic dysfunction patients diagnosed by TDI) who would otherwise have been classified as normal by pulsed wave Doppler flow analysis alone. The mean duration of DM was 7.6±6.4 year. The study also revealed that the duration of DM was positively correlated with A velocity (r=0.29, p=0.048), fasting blood sugar (FBS) was negatively correlated with A velocity (r=-0.39, p=0.008).Conclusion: LV diastolic dysfunction can be evidenced by TDI in type 2 diabetic patients, even in the presence of a normal cardiac function with conventional echocardiography and asymptomatic diabetic patients. TDI is a valuable tool and it is more sensitive and more specific in detecting LV diastolic dysfunction in asymptomatic normotensive diabetic patients with non significant features on conventional echocardiography.