Resting Left Ventricular Dyssynchrony and Mechanical Reserve in Asymptomatic Normotensive Subjects with Early Type 2 Diabetes Mellitus

Abstract

Background: Most diabetic patients have silent ischemia and cardiac dysfunction that is usually observed in the late phase of the disease when it becomes clinically obvious. We hypothesized that left ventricular dyssynchrony (LVdys) (or dispersion) is an early marker of myocardial involvement in asymptomatic early type 2 diabetes mellitus (T2DM) patients. Therefore, we aimed to detect early markers of myocardial dysfunction in early T2DM using LVdys and left ventricular mechanical reserve (LVMR). Methods: We examined 91 consecutive subjects with early T2DM with speckle tracking imaging to evaluate LVdys and with dobutamine stress to evaluate LVMR (defined as left ventricular mechanical reserve global longitudinal strain [LVMR GLS ] ≥2%). Our patients were divided into two groups according to LVdys: group 1 with LVdys (n = 49), and group 2 without LVdys (n = 42). Results: We found that 49 (54%) subjects in our cohort had resting LVdys (standard deviation of tissue synchronization of the 12 left ventricular segments [Ts-SD-12] ≥34.2 ms). GLS and strain rate were comparable at rest between patients with and without LVdys. On the other hand, LVMR was blunted in those with LVdys (p < 0.001). We found that HbA1c, high-sensitivity C-reactive protein, and left atrial volume index were inversely correlated with LVMR. Multivariate analysis showed that LVdys was the strongest predictor (p < 0.001) of blunted LVMR. Using receiver operating characteristic curve analysis, we found that a Ts-SD-12 ≥36.5 ms was the best cutoff value to predict blunted LVMR (area under the curve = 0.89, p < 0.001). Conclusion: The LVdys (Ts-SD-12) cutoff ≥36.5 ms was the optimal value for prediction of impaired LVMR and might be an early marker of subclinical cardiac dysfunction and risk stratification of subjects with asymptomatic early T2DM with preserved left ventricular ejection fraction.

Comparing left ventricular mechanical dyssynchrony between diabetic and non-diabetic patients with normal gated SPECT MPI

“…They also claimed that HbA1c, high-sensitivity C-reactive protein and left atrial volume index were inversely correlated with LVMR. This is in line with our study to show the importance of early detection of ventricular dyssynchrony in early stages to detect those diabetic patients who would bene t from early resynchronization therapy (25).…”

“…Divergences(increased PBW) in left ventricular contractibility has been mentioned as the main pathophysiology of LVMD in diabetic patients in the recent studies (24). Many evidences indicate that LVMD is an independent risk factor for further cardiac complications in the diabetic patients (25), therefore, it necessitates detection of LVMD in patients by phase analysis. Despite the fact, phase analysis ability would be much more than the current de nition of LVMD based on QRS width, as 12.5% of our patients had a normal QRS width but an abnormal phase analysis.…”

Left ventricular subclinical systolic myocardial dysfunction assessed by speckle-tracking in patients with Cushing’s syndrome

“…In addition, we also found that after CS patients achieve biochemical remission, ventricular hypertrophy and systolic function will be partially reversed, but will not return to normal levels. That is, changes in cardiac morphology and function in CS patients can be reversed to a certain extent after biochemical remission of cortisol levels, which is consistent with the conclusion of AHacioglu's team [21] Through in-depth exploration, we found that LVSD, another sensitive index used by STE to evaluate myocardial contractile function, showed signi cant differences between the inactive group and the control group. Since changes in overall left ventricular cardiac function are related to myocardial contractile reserve, as shown by typical contractile reserve markers such as LVEF and GLS, we speculate that CS patients with early subclinical cardiac dysfunction have normal myocardial contractile reserve but abnormal mechanical reserve.…”

“…Since changes in overall left ventricular cardiac function are related to myocardial contractile reserve, as shown by typical contractile reserve markers such as LVEF and GLS, we speculate that CS patients with early subclinical cardiac dysfunction have normal myocardial contractile reserve but abnormal mechanical reserve. Left ventricular systolic asynchrony can lead to ineffective ventricular pressure work, which in the long run can lead to overall left ventricular systolic dysfunction [21]. Similarly, LVSD can also be present in T2DM patients with normal LVEF and normal myocardial perfusion, and has been shown to be a novel imaging marker for early assessment of myocardial injury [14].…”