tran hoang hai - Academia.edu (original) (raw)

Papers by tran hoang hai

this modulation is usually assessed by the well-known study of heart rate variability (HRV), whic... more this modulation is usually assessed by the well-known study of heart rate variability (HRV), which means an analysis of spontaneous and induced fluctuations that occur in HR (or in the electrocardiographic RR interval) as a result of ANS sympathetic and parasympathetic activities on sinus node automaticity. Most patients with diabetic polyneuropathy (PNP) show some degree of autonomic dysfunction. Patients with predominant autonomic signs and symptoms are considered as having diabetic autonomic neuropathy (DAN). Although this may affect any organ system, it usually starts in the skin neurovascular system (foot microcirculation) and in the cardiovascular system (CAN). Furthermore, it affects the gastrointestinal system (gastroparesis, constipation and diarrhea) and genitourinary system (urinary incontinence, neurogenic bladder and erectile dysfunction). CAN is one of the major complications of DM since its presence is associated with worsening prognosis and patient's poorer life quality. The following clinical manifestations are associated with CAN: resting tachycardia, severe orthostatic hypotension (OH), syncope, exercise intolerance (due to chronotropic and inotropic response block), perioperative instability, asymptomatic myocardial ischemia and infarction, left ventricular (LV) diastolic and systolic dysfunction, and increased risk of renal diseases, chronic renal failure (CRF), stroke, and sudden cardiac death (SCD). Despite the potential negative impact on the quality of life of patients with CAN, this disease falls among the least understood and least frequently diagnosed complications of individuals with DM. This type of neuropathy can usually be found in approximately 25% of the patients with type-1 diabetes mellitus (DM1) and in 34% of those with type-2 diabetes mellitus (DM2). The prevalence of CAN progressively increases in a direct proportion to age, duration of DM and poor glycemic control 1. CAN may be subdivided into subclinical (in which functional and reversible alterations are predominant) and clinical (when structural neuronal alterations are already present): the first one is only diagnosed by tests and may occur as soon as the diagnosis of certain types of DM are diagnosed, or in the first years of the disease; the second form, as the name suggests, is symptomatic and occurs in more advanced stages 2. Autonomic fibers are compromised in the several clinical subtypes of diabetic neuropathies. The most common type (classical PNP: symmetric, distal, and predominantly sensitive), shows a strong correlation between the progressive lesion of both somatic and autonomic fibers, i.e., nowadays we know that 50% of the diabetic patients with PNP have asymptomatic Summary Cardiovascular autonomic neuropathy (CAN) is one of the most clinically significant complications of diabetes mellitus (DM), but one of the least frequently diagnosed. In this review, we discuss the major risk factors for the development and progression of CAN in patients with DM, the natural history of autonomic neuropathy and its impact on cardiovascular disease in DM, as well as the tests for the early diagnosis and staging of CAN in the clinical practice. The bibliographic research was based on two databases: Medline and Tripdatabase, with the following descriptors: diabetic cardiovascular autonomic neuropathy and cardiovascular autonomic neuropathy and diabetes. We selected English and German articles, written between 1998 and 2007. In its initial stages (early and intermediate), CAN may be diagnosed and reversed. However, in advanced cases (severe stage), the only treatment that remains is a symptomatic one. CAN is associated with higher cardiovascular morbidity and mortality rates and poor quality of life in diabetic individuals.