Left ventricular filling patterns and its relation to left ventricular untwist in patients with type 1 diabetes and normal ejection fraction

BACKGROUND: We evaluated young patients with type 1 diabetes (T1DM) who had normal left ventricular (LV) ejection fraction and used speckle tracking echocardiography to assess changes in LV untwisting. We used cardiac magnetic resonance imaging (MRI) to assess the LV filling patterns in these subjects.

METHODS: We recruited 33 T1DM patients and 32 age-matched healthy controls (HC) into the study. Study participants underwent echocardiography, cardiac MRI and metabolic exercise testing.

RESULTS: The early peak LV untwisting rate (E) was similar in T1DM and HC (-11.9 ± 4.6 0/cm/s vs -11.3 ± 4.7 0/cm/s, P=0.29) but the late peak LV untwisting rate (A) was significantly increased in T1DM (-6.2 ± 3 0/cm/s vs -4.9 ± 3.9 0/cm/s, P<0.05). The time to early peak untwisting rate was not different (50.9 ± 9.6% vs 48.4 ± 7.3%, P=0.12) but the time to late peak untwisting rate was significantly delayed in T1DM patients (80.4 ± 12.5% vs 72.7 ± 14.6%, P<0.05). The LV filling patterns demonstrated a significantly increased left atrial (LA) contribution to LV filling in T1DM. On linear regression peak late filling rate (r=0.60, P<0.000), trans-mitral A wave (r=0.25, P<0.05) and A' (r=0.30, P<0.01) were predictors of LA contribution to LV filling.

CONCLUSION: We demonstrate for the first time using speckle tracking that LV untwisting rate E is preserved and untwisting rate A is increased and delayed in young patients with uncomplicated T1DM. The LA contribution to LV filling is increased in these patients and is directly related to increases in other indices of LA function like peak late filling rate, trans-mitral A wave and A'.