Cardiovascular Autonomic Neuropathy

Abstract

Cardiovascular autonomic neuropathy often goes unrecognized. We present a case of a 22-year-old man with multiple manifestations of this disease, including weakness, dizziness, fatigue, tachycardia, abnormal QTc, and orthostasis, which occurred 2 years after his type 1 diabetes diagnosis. He exhibited parasympathetic denervation with resting tachycardia and exercise intolerance but also had evidence of orthostatic hypotension, which suggests sympathetic denervation. He did not have complete cardiovascular autonomic reflex testing, which would have been helpful, but improved with aggressive diabetes treatment and the increase of beta-blockade. It is important to identify these patients to understand their signs and symptoms and consider appropriate therapies. C ardiovascular autonomic neuropathy (CAN) is a serious and common complication of diabetes mellitus (DM) that is often not recognized. Diabetes mellitus aff ects more than 26 million people in the United States. Prevalence rates of CAN increase with age and duration of DM. Th e Diabetes Control and Complication Trial reported rates as high as 35% in type 1 DM and 44% in type 2 DM, with a prevalence rate of up to 60% in longstanding diabetics ( 1 ). Th e presence of CAN is associated with increased cardiovascular mortality and is the cause of cardiac dysfunction and multiple clinical symptoms, including resting tachycardia, exercise intolerance, postural hypotension, silent ischemia, cardiomyopathy, and perioperative instability ( 1 -4 ). CASE REPORTA 22-year-old African American man with a 2-year history of type 1 DM presented to the clinic with complaints of fatigue, decreased exercise tolerance, palpitations, and persistent tachycardia. He was 6' tall and 147 lb. His blood pressure and heart rate recorded supine, sitting, and standing after 3 minutes were 138/80 mm Hg/105 beats per minute (bpm), 130/88 mm Hg/122 bpm, and 98/72 mm Hg/126 bpm, respectively. His exam revealed the presence of peripheral neuropathy with numbness and tingling extending bilaterally to the shin. A Holter monitor recorded a marked decrease in his heart rate variability (HRV), with HRV of 20 bpm over each hour and an average of 118 bpm with no dipping during sleep. His thyroid function was normal. An electrocardiogram exhibited sinus

Orthostatic Hypotension in Asymptomatic Patients with Chronic Kidney Disease

“…This therapeutic scheme common in the treatment of CKD appears to be an evident pathophysiological mechanism leading to OH since diuretics and dehydration activate the RAA system, thus augmenting the effects of ACE-I and β-blockers. This is confirmed by findings from other studies [4,5,6]. It should be stressed that polypharmacy and drug interactions are the most frequent risk factors for the development of OH [36].…”

“…Its clinical manifestation has a wide spectrum, ranging from very mild symptoms, i.e., weakness, dizziness and fainting, to serious conditions accompanied by loss of consciousness. Within the spectrum of civilization diseases, OH coexists with arterial hypertension (AH), metabolic disorders like diabetes, chronic kidney disease (CKD), dialysis therapy, or toxemia with secondary damage to the ANS (long-term alcohol-dependence, long-term drug use, drug induced damage), and electrolyte imbalance [5,6,7]. A model disease that illustrates this problem is diabetes, and the coexistence of OH and AN in diabetic patients has been quite thoroughly researched [5,8,9].…”

“…Diabetic autonomic neuropathy is a serious and common complication of diabetes, and cardiovascular autonomic neuropathy (CAN) is its most studied and clinically important form, since it is associated with an increased risk of mortality due to cardiovascular (CV) causes. The determination of the presence of CAN is usually based on a battery of the ANS function tests, and consequently this condition frequently remains undiagnosed [6]. At present, a battery of three tests is recommended: heart rate variability (HRV), the Valsalva maneuver, and postural blood pressure testing [10].…”

Cardiovascular autonomic neuropathy in diabetes: Pathophysiology, clinical assessment and implications

“…However, there is no universal standard method for detecting CAN, and it is suggested that more than one test should be conducted to enhance the sensitivity and reliability of CAN diagnosis [ 19 ]. In this setting, several tests with different degrees of accuracy, such as CARTs, HRV, and nuclear imaging, are available[ 61 , 69 , 81 , 82 ].…”

Electrocardiographic Findings of Leprosy

“…These disorders that develop in the autonomic system are explained by the neurotropic effects of the leprosy bacilli that infiltrate the sympathetic and parasympathetic fibers. The autonomic and intrinsic cardiac involvement affects ventricular repolarization and prolongs QTc and Tp-e intervals (14,15). It is now well known that QT and QTc prolongation causes life-threatening arrhythmias, and it has also started to be realized that LAH is important regarding cardiac comorbidities.…”