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Left ventricular torsion is increased and cardiac energetics are reduced in uncomplicated type 1 diabetes mellitus (T1DM). Our aim was to determine the relationships of these abnormalities to cardiovascular autonomic neuropathy (CAN) in subjects with T1DM. A cross-sectional study was conducted in 20 subjects with T1DM free of known coronary heart disease attending an outpatient clinic. Cardiovascular autonomic neuropathy was assessed using heart rate variability studies and the continuous wavelet transform method. Left ventricular function was determined by speckle tracking echocardiography. Magnetic resonance spectroscopy and stress magnetic resonance imaging were used to measure cardiac energetics and myocardial perfusion reserve index, respectively. Twenty subjects (age, 35 ± 8 years; diabetes duration, 16 ± 9 years; hemoglobin A(1c), 8.0% ± 1.1%) were recruited. Forty percent of the subjects exhibited definite or borderline CAN. Log peak radial strain was significantly increased in subjects with CAN compared with those without (1.56 ± 0.06 vs 1.43 ± 0.14, respectively; P = .011). Data were adjusted for log duration of diabetes, and log left ventricular torsion correlated (r = 0.593, P = .01) with log low-frequency to high-frequency ratio during the Valsalva maneuver. Log isovolumic relaxation time correlated significantly with log Valsalva ratio and log proportion of differences in consecutive RR intervals of normal beats greater than 50 milliseconds during deep breathing. However, CAN did not correlate with cardiac energetics or myocardial perfusion reserve index. Spectral analysis of low-frequency to high-frequency ratio power during the Valsalva maneuver is associated with altered left ventricular torsion in subjects with T1DM. Parasympathetic dysfunction is closely associated with diastolic deficits. Cardiovascular autonomic neuropathy is not however the principal cause of impaired cardiac energetics. The role of CAN in the development of cardiomyopathy warrants further evaluation., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Background: Using speckle-tracking imaging (STI), the aims of this study were to assess dyssynchrony and quantify the myocardial energy wasted by contractility in delayed segments by determining the longitudinal strain delay index (LSDi) in patients with heart failure with preserved ejection fraction (HFpEF)., Method: Thirty-eight patients with HFpEF and 33 matched controls were recruited. All subjects underwent clinical examinations, 12-lead electrocardiography, pulmonary function tests, echocardiography, and metabolic exercise tests. LSDi was determined, the magnitude of which is a measure of the amount of wasted energy. Global and segmental systolic and diastolic dyssynchrony was assessed by STI., Results: LSDi was significantly higher in patients with HFpEF than controls (-14.36 +/- 8.24% vs -10.73 +/- 5.62%, P < .05). Patients with HFpEF exhibited left ventricular (LV) systolic and diastolic dyssynchrony, with the LV anterior wall displaying the most delayed motion., Conclusion: Patients with HFpEF exhibited increased myocardial contractile inefficiency. They also exhibited LV systolic and diastolic dyssynchrony, with the LV anterior wall displaying the most delayed motion., (Copyright 2010 American Society of Echocardiography. Published by Mosby, Inc. All rights reserved.)

Background: The role of left atrial (LA) function on exercise remains poorly understood in heart failure with preserved ejection fraction (HfpEF) despite its key role in optimizing left ventricular (LV) diastolic function. We used resting and exercise radionuclide ventriculography to investigate the role of LA function in the pathophysiology of HfpEF., Methods and Results: A total of 25 patients with HfpEF and 15 age- and gender-matched controls were recruited. All subjects underwent resting echocardiogram, metabolic exercise testing to peak effort, and radionuclide ventriculography (at rest and exercise [to 35% of heart rate reserve]). At rest LA and LV function were similar in patients and controls. During exercise, HfpEF patients had lower left ventricular ejection fraction (69 +/- 9% vs. 73 +/- 10%, P < .05) and lower peak early filling rate (387 +/- 109 end-diastolic count/sec vs. 561 +/- 156 end-diastolic count/sec, P < .001). During exercise, the atrial contribution to LV filling was significantly higher in patients than controls (46 +/- 11% vs. 30 +/- 9%, P < .001). Atrial contribution to LV filling correlated negatively with peak early filling rate during exercise (r = -0.6, P < .001). Peak early filling rate correlated positively with peak oxygen consumption (r = 0.485, P = .004) and negatively with minute/carbon dioxide production (r = -0.423, P = .013)., Conclusion: Patients with HfpEF have increased atrial contribution to LV filling as a compensatory response to impaired early LV filling during cycle exercise.

Objective: We used speckle tracking echocardiography to study the early changes in left ventricular (LV) torsion in young patients with uncomplicated type 1 diabetes and stress magnetic resonance imaging (MRI) to assess its interrelationships with coronary microangiopathy., Research Design and Methods: We recruited 33 asymptomatic subjects with type 1 diabetes and 32 age-matched healthy control subjects. All subjects underwent echocardiograms. Stress MRIs were performed in 30 subjects (8 healthy control subjects) to compute myocardial perfusion reserve index (MPRI)., Results: A significant increase in LV torsion (2 +/- 0.7 vs. 1.4 +/- 0.7 degrees /cm, P < 0.05) was identified in longer-term and retinopathy-positive type 1 diabetic subjects (1.9 +/- 0.7 vs. 1.4 +/- 0.7 degrees /cm, P < 0.05) as compared with the healthy control subjects. The MPRI was independently associated with increased LV torsion., Conclusions: We demonstrate that LV torsion is increased in young patients with uncomplicated type 1 diabetes and that coronary microvascular disease may play a key pathophysiological role in the development of increased LV torsion.

Aims: We used speckle tracking echocardiography (STE) to make a comparison between the effects of ageing and of heart failure with normal ejection fraction (HfnEF) on left ventricular (LV) torsion and strain patterns., Methods and Results: Forty patients with HfnEF, 27 young controls and 26 older controls, were prospectively recruited. All subjects underwent clinical examination, 12-lead electrocardiogram, pulmonary function test, echocardiogram, and metabolic exercise test. LV torsion increases with advancing age (older controls vs. young controls, 2.2 +/- 0.9 vs. 1.4 +/- 0.8 degrees /cm; P = 0.03). Circumferential strain was enhanced in patients with HfnEF (-24.7 +/- 4.7 vs. -20.0 +/- 4.9%; P = 0.003). Rotational deformation delay (time difference between peak basal rotation and peak apical rotation), global circumferential strain, E-velocity deceleration time, and LV end-diastolic volume index were independent predictors of LV torsion. LV torsion and body mass index were independent predictors of LV untwist rate., Conclusion: Ageing is associated with increased LV torsion secondary to reduced rotational deformation delay and increased peak basal rotation. LV torsion and strain patterns in patients with HfnEF are similar to age-related changes apart from circumferential strain, which is enhanced in patients with HfnEF.