The Effect of Diabetes Mellitus on the P-Wave Dispersion

Abstract

-wave dispersion (PD) is defined as the difference between the minimum (P min) and maximum (P max) P-wave durations on standard 12-lead electrocardiography (ECG). PD is a measure of heterogeneity of atrial refractoriness and prolongation of PD shows the intra-atrial and inter-atrial non-uniform conduction. 1 In previous studies it was shown that PD prolongation is an independent risk factor for development of atrial fibrillation (AF). 2,3 AF is the most frequently encountered rhythm disturbance in clinical practice and its frequency increases 2-fold in every decade after 55 years old. 4 Although AF is often associated with structural heart diseases, there is no detectable heart disease in a substantial portion of the cases. 5 It was shown in epidemiological studies that the rate of development of AF in diabetic cases is higher than normal cases. 6 The pathological mechanisms related to initiation and maintainance of AF in patients with diabetes mellitus (DM) has not been well described. In diabetic cases it is thought that myocardial ischemia as a result of coronary microcirculation disorders or metabolic stress on atrium can play a role. Hypertension and coronary artery diseases, which are important factors in development of AF, often accompany DM. No study evaluating PD in diabetic cases without hypertension and coronary artery disease has yet been published.In the current study we planned to investigate PD in noncomplicated diabetic patients. MethodsSeventy-six diabetic patients who had no coronary artery disease or hypertension (group1; mean age 48±9 years) and 40 healthy volunteer individuals (group2; mean age 46±13 years) were enrolled in the study. Patients with DM history, taking anti-diabetic medicine and patients whose fasting glucose level is 126mg/dl or above were accepted as diabetic. 7 Of the diabetic cases, 25 (33%) were receiving insulin (mean 26±6U/day) and 51 (67%) of the cases were receiving oral anti-diabetic treatment. The cases whose fundus examination showed retinopathy were not included in the study. Cases with history of myocardial infarction, angina pectoris or other clinical findings of coronary artery diseases were not included in the study. Resting 12-lead ECG and maximal treadmill exercise test (according to Bruce protocol) were performed in every case. Cases who had right bundle-branch block, left bundle-branch block, Wolff-Parkinson-White syndrome, intraventricular conduction defect in resting ECG and anginal chest pain or ischemic ECG changes during the exercise test were excluded from the study. Patients with a history of AF, having a permanent pacemaker, taking anti-arrhythmic medicine, having a thyroid disease, left ventricular hypertrophy, and/or left ventricular dysfunction were also excluded. The 24-h Holter ECG records of the cases were obtained. Holter WIN-PV plus program was used for these records.We paid attention to the patient's renal and hepatic functions and monitored the levels so they were kept in normal Background P-wave dispersion (PD), a measure of heterogeneit...

Early electrocardiographic evaluation of atrial fibrillation risk in beta-thalassemia major patients

“…PD is a noninvasive indicator of intra-atrial conduction heterogeneity producing substrate for reentry, which is a pathophysiological mechanism of atrial fibrillation [16,17]. PD has been studied in some other conditions such as hypertension [18], obesity [19], diabetes mellitus [20], metabolic syndrome [21], dilated cardiomyopathy [22], myocardial infarction [23], atrial septal defect [24], hypertrophic cardiomyopathy [25], obstructive sleep apnea [26] and Wilson's disease [27]. The exact mechanism of PD prolongation in these clinical conditions is not well known, but it is thought that structural and electrophysiological changes in the atrial myocardium caused by elevated plasma volume [28], ventricular diastolic dysfunction [29] and enhanced neurohormonal activation [30], that accompany these diseases, may contribute to left atrial enlargement and electrical instability.…”

Physiological Values of P-Wave Dispersion in Silesian Breed Horses and Polish Primitive Horses

“…The speed of the impulse conduction in the myocardium depends on the activity of the immune system and the presence of ischaemia (4,6). Additional factors that can increase P d and that should be taken into account while interpreting results related with atrial conduction include endocrine disease, such as diabetes, thyroid hyperfunction, and the terminal stadium of renal failure (2,5,10,(21)(22)(23)25). In people, changes of Pwave dispersion were also observed during changes in the tension of the autonomic nervous system, for example while conducting the Valsalva maneuver (1) or in connection with panic attacks (24).…”

Spinal Palsy Augments Electrophysiological Dispersion

“…Patients with uncontrolled hypertension exhibit a significantly prolonged P-wave duration and increased P-wave dispersion as compared to controls and patients with controlled hypertension (2,3). Likewise, patients with diabetes display a significantly prolonged Pwave duration and increased P-wave dispersion compared to normal controls (4). Individuals with obesity also have a significantly prolonged P-wave duration and increased Pwave dispersion compared with control s (5, 6).…”