Left Ventricular Systolic and Diastolic Function in Normotensive Type 1 Diabetic Patients With or Without Autonomic Neuropathy

Abstract

OBJECTIVE -To investigate the relation between diabetic autonomic neuropathy (DAN) and left ventricular (LV) function in type 1 diabetic patients. RESEARCH DESIGN AND METHODS-A total of 57 type 1 diabetic patients free of coronary artery disease and arterial hypertension were studied. Diagnosis of DAN was established by autonomic nervous function (ANF) tests, and LV systolic and diastolic functions were assessed by radionuclide ventriculography at rest.RESULTS -There were 24 patients who had definite DAN, established by the presence of two or more abnormal ANF tests, and 33 subjects were without DAN. DAN patients had impaired LV filling pattern, obvious by a reduced peak filling rate (3.1 Ϯ 1.1 vs. 3.7 Ϯ 0.7 end-diastolic volume [EDV]/s, P ϭ 0.011) and first third filling fraction (35.3 Ϯ 19.5 vs. 50.8 Ϯ 16%, P ϭ 0.002) as well as an increased time to peak filling (159.4 Ϯ 45.1 vs. 134.2 Ϯ 33.4 ms, P ϭ 0.02) after correction for age and heart rate. There were no differences between the two groups with regard to ejection fraction, cardiac output, and cardiac index, whereas the peak emptying rate was greater in DAN patients (4.1 Ϯ 0.8 vs. 3.6 Ϯ 0.8 EDV/s, P ϭ 0.019), suggesting LV hypercontractility. DAN patients had an increased heart rate (83.4 Ϯ 11.9 vs. 72.7 Ϯ 9.3 bpm, P ϭ 0.001) and slightly higher systolic blood pressure. As a result, LV working load at rest was higher in DAN patients (11,109 vs. 9,096 bpm ϫ mmHg, P Ͻ 0.001). Moreover, a correlation was found between abnormal LV systolic and diastolic indexes and the number of abnormal ANF tests.CONCLUSIONS -At rest, DAN patients have impaired LV filling pattern, slightly increased LV systolic function, and a higher LV working load, in comparison to non-DAN type 1 diabetic patients. Diabetes Care 26:1955-1960, 2003C linical and epidemiological studies have confirmed that patients with diabetes appear susceptible to heart failure, which is the leading cause of death in these patients (1). Impairment of left ventricular (LV) function is frequent in patients with type 1 diabetes, even in the absence of ischemic, hypertensive, or valvular heart disease (2). Possible mechanisms for a specific diabetic cardiomyopathy include abnormalities of small intramural coronary vessels, deposition of collagen, and lipids and metabolic derangements that alter actomyosin and myosin adenosine triphosphatase activities (3). Although histopathologic and biochemical evidence for a distinct diabetic cardiomyopathy is available, it remains unclear whether these pathologic processes may cause significant LV systolic or diastolic dysfunction. Numerous studies have reported normal LV systolic function at rest in most type 1 diabetic patients (4), whereas others have suggested increased LV systolic function (5,6). Several investigators have shown abnormal LV diastolic function in the majority of type 1 diabetic patients (7-11), whereas others (12) found no evidence of LV diastolic dysfunction at rest in longterm type 1 diabetic patients. It has been suggested that LV dysfunction in type...

Diabetic Cardiovascular Autonomic Neuropathy

“…CAN is associated with LV diastolic dysfunction (LVDD) at rest, both in patients with long-term type 2 58 or type 1 diabetes. 10,59 LVDD may progress to heart failure, mainly with preserved LV systolic function (diastolic heart failure), which is also related to high morbidity and mortality rates. 60,61 The pathophysiology of LVDD includes delayed relaxation, impaired LV filling, and/or increased stiffness.…”

Cardiac Abnormalities in Diabetic Patients With Neuropathy

“…Because this study was intended to address the benefit of ARI treatment in patients without overt CAD, we excluded subjects with evidence of ischemia based on myocardial perfusion imaging, as has been done in prior studies (6,10,(15)(16)(17). Although myocardial perfusion imaging detects significant CAD and has prognostic importance (45), it does not entirely exclude the presence of mild CAD, microvascular ischemia, or endothelial dysfunction (46).…”

“…Both LV systolic and diastolic function are also modulated by autonomic influences. Cardiac autonomic dysfunction is common in diabetes (14) and has been associated with low diastolic peak filling rates (PFR) (6,15) and impaired augmentation of LVEF during exercise (10,16,17). Patients with type 1 diabetes with abnormal LVEF responses during exercise have intact inotropic responses to dobutamine (16) and postextrasystolic potentiation (17), indicating the importance of extrinsic factors, including autonomic function, in determining the cardiac response to exercise.…”

Predictors and diagnosis of cardiac autonomic nervous dysfunction in patients with type 1 and type 2 diabetes mellitus

“…считают, что необходимо раз-граничивать понятия кардиомиопатии и кардиальной нейропатии, основываясь на анализе соотношения структурных и нейровегетативных нарушений сердечной деятельности при СД [15].…”