Screening and assessment of cardiac autonomic neuropathy in long-standing type 2 diabetic women

Abstract

Abstract Background Patients with long-standing diabetes mellitus undergoing surgical interventions are under considerable risk, hence posing a surgical challenge, as they may have cardiovascular and/or cardiac autonomic neuropathy (CAN). CAN is serious, often overlooked and underdiagnosed, with possible arrhythmias and silent ischemia that may be life threatening. Objectives The aim of this study was to screen for one of the underdiagnosed high-risk problems by assessment of CAN in long-standing type 2 diabetic women undergoing stressful situations. Study design Cross-sectional study. Patients and methods Hundred type 2 diabetic women scheduled for major surgery were assessed by autonomic function tests. CAN was assessed by analyzing heart rate variations during three standard tests (deep breathing, lying to standing, and the valsalva maneuver). Sympathetic functions were assessed by checking orthostatic hypotension. The CAN score of each patient was analyzed. Continuous 24 h ECG monitoring was performed to evaluate arrhythmia, corrected QT (QTc), and QT dispersion (QTd). Transthoracic Doppler echocardiography, with a focus on left ventricular hypertrophy, diastolic, and systolic dysfunctions, was carried out. Patients were classified as having mild (with only one abnormal test) or severe CAN when two or more abnormal function tests were present. Exclusion criteria included any systemic illness that could affect the results of the study or the autonomic functions, smoking, hypertension, and patients with evident ischemia. Results CAN was detected in 70% of the patients studied, and 70% of them had a severe case of CAN. Postural hypotension was detected in 34% of the patients studied. QTc prolongation and QTd were frequent. ECG and Doppler echocardiography changes of left ventricular hypertrophy were more prevalent among patients with CAN. Diabetics with CAN were significantly older, had a longer duration of diabetes mellitus, and higher HbA1-c, higher pulse pressure, triglyceride, uric acid, and urinary albumin excretion rate. They also had a significantly increased left ventricular mass index and diastolic dysfunction. Conclusion Middle-aged women with long-standing diabetes are vulnerable to CAN with postural hypotension and prolonged QTc intervals, QTd, and increased left ventricular mass index. Identification of CAN is crucial to prevent the hazards of cardiovascular insults during stressful situations, and cases with severe CAN may require coronary artery disease screening preoperatively.