Esophageal electrocardiography in acute cardiac care. Efficacy and diagnostic value of a new technique

Esophageal electrocardiography can detect atrial electrical activity during tachyarrhythmias when P waves are not evident by surface electrocardiography. However, patient discomfort, the difficulty of accurately interpreting cardiac signals against a background of electrical noise, and the complexity of use have limited widespread application. In this study, esophageal electrocardiography was used in 48 acutely ill patients with a new "pill electrode" system, consisting of a bipolar electrode pair (3 by 20 mm) attached to 0.5 mm diameter Teflon wires contained in a standard gelatin capsule. The capsule with enclosed electrodes was voluntarily swallowed, and the recording electrodes were positioned posterior to the left atrium. A preamplifier system with a low-frequency filter and a standard three-channel electrocardiographic recorder were used. Esophageal "pill" electrocardiographic recordings were made in 48 of 50 eligible study patients (96 percent) with tachyarrhythmias and absent or equivocal atrial activity on surface electrocardiography. In these patients, a high-quality esophageal electrocardiographic recording was obtained within one to 10 minutes with minimal patient discomfort. In 25 of 48 study patients (52 percent), the original diagnosis, based on the surface electrocardiographic recording, was incorrect after review of the esophageal recording. Results of esophageal recording altered management in 19 of 48 (40 percent) patients. This new and simple technique facilitates diagnosis and management of perplexing tachyarrhythmias in acutely ill patients by physicians with minimal training in the technique.     

An Analysis of Beat-By-Beat Recording of Late Potentials and His-Purkinje Signals in a Hospital Environment

Beat-by-Beat Recording of Low-Level Potentials. Due to the excessive electrical and magnetic noise in a hospital environment, the utility of low-amplitude electrocardiographic signals has been greatly impeded. In order to record surface ventricular late potentials and His-Purkinje potentials on a beat-by-beat basis outside a shielded environment, a new system was implemented with a microcomputer. In the case of late potential recording, six bipolar orthogonal leads (two along each axis) were high-pass filtered, spatially averaged, and finally combined into vectormagnitude complexes on an every beat basis. Bidirectional filters and finite impulse response filters with linear phase response were used to prevent filter ringing in the terminal QRS. Late potentials were recorded on a heat-by-beat hasis in patients who exhibited late potentials in the signal-averaged electrocardiogram (ECG). His-Purkinje potentials were recorded using spatial averaging and channel selection algorithms that discriminate the signal from noise. All the recordings were performed in a clinical environment without using a shielded room. Magnetic fields of 60 Hz and its harmonics were the major sources of interference, and interference-free recordings could he obtained if the field was smaller than 6.6 × 10^?8 Tesla (T) at 60 Hz. The study indicates that with appropriate instrumentation and care during acquisition, it is feasible to acquire high quality data and analyze late potentials and His-Purkinje potentials on a beat-hy-heat hasis in a clinical environment. Interested investigators are cautioned against basing clinical decisions on marginal quality and noisy data. (J Cardiovasc Elec-trophysiol. Vol. 1, pp. 486–495 December 1990)     

Asymptomatic coronary artery disease in diabetes: relation to common risk factors,lipoproteins, apoproteins and apo E polymorphism

The risk factors for asymptomatic coronary artery disease (CAD) were examined in 138 diabetic patients. Following non-invasive screening examinations (exercise electrocardiography, dynamic thallium scintigraphy, 24-h electrocardiographic recording), CAD was confirmed angiographically in 21 symptom-free diabetic subjects with an ischaemic finding in at least one of the non-invasive tests. The prevalence of asymptomatic CAD in this cohort of diabetic patients was 21/132 (16%), which may be an underestimation because 6 patients refused angiography. Risk factors (age, diabetes, smoking, hypertension, serum lipoproteins, apoproteins and apo E phenotypes) were analysed according to the presence or absence of CAD. Multivariate logistic stepwise analysis did not show any definite changes of serum lipids, lipoproteins and apoproteins in type 1 (n=72) and type 2 (n=66) diabetic patients with or without asymptomatic CAD. The only factors associated with asymptomatic CAD were the duration of diabetes (P<0.005) and the age of the patient (P<0.05). These results suggest that in diabetic patients the major risk factor for premature coronary atherosclerosis is diabetes itself. Assessment of other risk factors does not seem to define any subgroup with asymptomatic CAD.     

Transtelephonic electrocardiography for managing out-of-hospital chest pain emergencies

Background

Some healthcare facilities lack professionals qualified to interpret electrocardiograms. We aimed to assess the usefulness of transtelephonic electrocardiography in combination with patients' clinical histories in the diagnosis and management of patients with acute chest pain in out-of-hospital healthcare facilities with personnel without expertise in cardiology or electrocardiography.

Methods

Data from 506 consecutive patients (53.9 ± 16.2 years old) referred from 55 healthcare facilities without professionals specialized in cardiology or electrocardiography form the basis of analysis. Patients were classified into 2 groups according to the results of transtelephonic electrocardiography: (A) patients without electrocardiographic abnormalities (n = 445) and (B) patients who presented abnormalities suggesting a cardiac origin (n = 61) of the chest pain. The presence of risk factors was evaluated by multivariate analysis.

Results

The following risk factors were independent predictors of electrocardiographic abnormalities: male gender (P = .006), diabetes mellitus (P = .0001), and dyslipidemia (P = .001). The multivariate analysis yielded a high degree of specificity (99.6%). Follow-up visits confirmed the noncardiac origin of pain in 432 patients (97%) in group A and the cardiac origin of pain in 59 patients (97%) in group B.

Conclusions

Transtelephonic electrocardiography combined with awareness of the risk factors of patients presenting with chest pain is useful for the diagnostic management of these patients in health care facilities without the means to interpret electrocardiograms.     

心电图电压指标与老年高血压患者心肌几何形态的临床分析

目的观察心电图各项电压指标对老年高血压患者心肌肥厚以及心肌肥厚不同几何形态的诊断价值。方法选择入住本院及门诊老年高血压患者86例,根据心脏超声检查结果,将患者分为4组:正常几何形态组(N组,28例)、向心性重构组(CR组,11例)、向心性肥厚组(CH组,25例)和离心性肥厚组(EH,22例)。观察各项心电图电压指标的阳性率。结果各种心电图电压指标均能明显区分正常及异常心脏几何形态,而12导联中,各导联QRS高度之和175 mm和ⅠR+S12 mm在CR组(63.6%、54.5%)和CH组(56.0%、72.0%)中的阳性率明显高于EH组(36.4%、31.8%,P0.05);继发性ST-T改变,CR组(72.7%)和CH组(80.0%)的阳性率明显高于EH组(45.5%,P0.05)。结论心电图电压指标12导联电压之和175 mm和Ⅰ R+S12 mm以及继发性ST-T改变可较好鉴别高血压不同类型心肌肥厚。     

Recording of abnormal late ventricular activity by high-resolution magnetocardiography

High-resolution magnetocardiography (HR-MCG) is a new noninvasive technique for detection of very low-amplitude magnetic fields generated by the electric activity of the heart. We studied 11 patients with documented sustained ventricular tachycardia after myocardial infarction (VT group), 11 patients with old myocardial infarction without ventricular tachycardia (MI group) and 11 normal controls (N group) with HR-MCG and high-resolution electrocardiography (HR-ECG). After averaging and high-pass filtering (25 Hz, 40 Hz, 60 Hz and 80 Hz) the XYZ leads of HR-ECG were combined to vector magnitude and the magnetic recordings from 3 × 3 grid locations were enveloped with Hilbert transformation. Then the QRS duration and the root-mean-square (RMS) amplitude of the last 40 ms, 50 ms and 60 ms of the QRS were calculated. The QRS duration was significantly longer in the VT group compared to the MI and the N group both in HR-MCG and HR-ECG. Also the RMS values were clearly smaller in the VT group with both methods. There were no significant differencies in the diagnostic power of these two methods. The 25 Hz high-pass filtering separated best the VT group from the MI group and the N group. In conclusion HR-MCG is a new non-invasive method for identification of patients at risk of malignant ventricular arrhythmias after myocardial infarction.Abbreviations HR-ECG high-resolution electrocardiography - HR-MCG high-resolution magnetocardiography - LAS low amplitude signal - LF late fields - LP late potentials - MI myocardial infarction - RMS root-mean-square - VT ventricular tachycardia     

Power Batteries Health Monitoring: A Magnetic Imaging Method Based on Magnetoelectric Sensors

With the popularity of electric vehicles, the ever-increasing demand for high-capacity batteries highlights the need for monitoring the health status of batteries. In this article, we proposed a magnetic imaging technique (MIT) to investigate the health status of power batteries nondestructively. This technique is based on a magnetic sensor array, which consists of a 16-channel high-performance magnetoelectric sensor, and the noise equivalent magnetic induction (NEB) of each channel reaches 3–5 pT/Hz^1/2@10 Hz. The distribution of the magnetic field is imaged by scanning the magnetic field variation of different positions on the surface. Therefore, the areas of magnetic anomalies are identified by distinguishing different magnetic field abnormal results. and it may be possible to classify the battery failure, so as to put forward suggestions on the use of the battery. This magnetic imaging method expands the application field of this high-performance magnetoelectric sensor and contributes to the battery’s safety monitoring. Meanwhile, it may also act as an important role in other nondestructive testing fields.     

Clinical study of interference with cardiac pacemakers by a magnetic field at power line frequencies

OBJECTIVES: This study examined the risk of interference by high magnetic flux density with permanent pacemakers. BACKGROUND: Several forms of electromagnetic energy may interfere with the functions of implanted pacemakers. No clinical study has reported specific and relevant information pertaining to magnetic fields near power lines or electrical appliances. METHODS: A total of 250 consecutive tests were performed in 245 recipients of permanent pacemakers during 12-lead electrocardiographic monitoring. A dedicated exposure system generated a 50-Hz frequency and maximum 100-microT flux density, while the electrical field was kept at values on the order of 0.10 V/m. RESULTS: A switch to the asynchronous mode was recorded in three patients with devices programmed in the unipolar sensing configuration. A sustained mode switch was followed by symptomatic pacing inhibition in one patient. No effect on devices programmed in bipolar sensing was observed, except for a single interaction with a specific capture monitoring algorithm. CONCLUSIONS: The overall incidence of interaction by a magnetic field was low in patients tested with a wide variety of conventionally programmed pacemaker models. A magnetic field pulsed at power frequency can cause a mode switch and pacing inhibition in patients with devices programmed in the unipolar sensing configuration. The risk of interference appears negligible in patients with bipolar sensing programming.     

Effect of Heat Treatments under High Isostatic Pressure on the Transport Critical Current Density at 4.2 K and 20 K in Doped and Undoped MgB2 Wires

Annealing undoped MgB₂ wires under high isostatic pressure (HIP) increases transport critical current density (J_tc) by 10% at 4.2 K in range magnetic fields from 4 T to 12 T and significantly increases J_tc by 25% in range magnetic fields from 2 T to 4 T and does not increase J_tc above 4 T at 20 K. Further research shows that a large amount of 10% SiC admixture and thermal treatment under a high isostatic pressure of 1 GPa significantly increases the J_tc by 40% at 4.2 K in magnetic fields above 6 T and reduces J_tc by one order at 20 K in MgB₂ wires. Additionally, our research showed that heat treatment under high isostatic pressure is more evident in wires with smaller diameters, as it greatly increases the density of MgB₂ material and the number of connections between grains compared to MgB₂ wires with larger diameters, but only during the Mg solid-state reaction. In addition, our study indicates that smaller wire diameters and high isostatic pressure do not lead to a higher density of MgB₂ material and more connections between grains during the liquid-state Mg reaction.     

Peripherally Inserted Central Catheter Thrombosis After Placement via Electrocardiography vs Traditional Methods

BackgroundPeripherally inserted central catheter tip placement at the cavoatrial junction is associated with reduced catheter-related deep vein thrombosis. Electrocardiographic tip confirmation purportedly improves accuracy of tip placement, but whether this approach can reduce deep vein thrombosis is unknown.MethodsProspectively collected data from patients that received peripherally inserted central catheters at 52 Michigan hospitals were analyzed. The method used to confirm tip confirmation at insertion and deep vein thrombosis outcomes were extracted from medical records. Multivariate models (accounting for the clustered nature of the data) were fitted to assess the association between peripherally inserted central catheter-related deep vein thrombosis and method of tip confirmation (electrocardiographic vs radiographic imaging).ResultsA total of 42,687 peripherally inserted central catheters (21,098 radiology vs 21,589 electrocardiographic) were included. Patients receiving electrocardiographic-confirmed peripherally inserted central catheters had fewer comorbidities compared with those that underwent placement via radiology. Overall, deep vein thrombosis occurred in 594 (1.3%) of all peripherally inserted central catheters. Larger catheter size (odds radio [OR] 1.32; 95% confidence interval [CI], 0.93-1.90 per unit increase in gauge), history of deep vein thrombosis, and cancer were associated with increased risk of deep vein thrombosis (OR 2.00; 95% CI, 1.65-2.43 and OR 1.62; 95% CI, 1.16-2.26, respectively) using logistic regression. Following adjustment, electrocardiographic guidance was associated with a significant reduction in peripherally inserted central catheter-related deep vein thrombosis compared with radiographic imaging (OR 0.74; 95% CI, 0.58-0.93; P = .0098).ConclusionThe use of electrocardiography to confirm peripherally inserted central catheter tip placement at the cavoatrial junction was associated with significantly fewer deep vein thrombosis events than radiographic imaging. Use of this approach for peripherally inserted central catheter insertion may help improve patient safety, particularly in high-risk patients.     

Epidemiological and clinical study of subjects occupationally exposed to noise

The role of occupational exposure to noise as a cardiovascular risk factor has not been established sufficiently. The present study investigated the blood pressure (BP) and electrocardiographic (ECG) changes in subjects exposed to different degrees of noise. The first group, comprising 105 males with a mean working life of 20.9 years, was occupationally exposed to mean 93 db(A). The second group, comprising 311 subjects, with a mean working life of 20.2 years, was occupationally exposed to a lower level of noise (15% on average). A control group included 150 clerical workers with a mean working life of 19.7 years not exposed to noise at work. The prevalence of hypertension in differences are statistically significant (p <0.02). The prevalence of orthostatic hypotension was significantly higher in the noise-exposed groups than in the controls (p<0.05). The incidence of electrocardiographic abnormalities in the three groups was 21.9%, 10.9%, and 7.9%, respectively, (p<0.01). These data demonstrate that subjects occupationally exposed to noise are at higher risk for developing certain cardiovascular disorders. The noise-related risk correlates with the intensity of noise and the duration of exposure.Presented at the 33rd Annual Meeting, International College of Angiology, Singapore, June 1991     

Takotsubo cardiomyopathy: A known unknown foe of asthma

Introduction: Patients with uncontrolled asthma are at a greater risk of asthma attacks requiring emergency room visits or hospital admissions. Takotsubo cardiomyopathy is potentially a significant complication in a course of status asthmaticus. Case study: We describe a 43-year-old female patient who presented with status asthmaticus that was further complicated with takotsubo cardiomyopathy. Results: Recognizing apical ballooning syndrome is challenging in patients with a history of respiratory disease because the symptoms of the last entity may complicate the diagnostic approach. It is difficult to distinguish clinically apical ballooning syndrome from the acute airway exacerbation itself. Both asthma and takotsubo cardiomyopathy share the same clinical presentation with dyspnea and chest tightness. In our patient, the electrocardiographic abnormalities, the rapidly reversible distinctive characteristics of echocardiography, and the modest elevation of serum cardiac biomarkers levels, in combination with the presence of a stress trigger (severe asthma attack), strongly supported the diagnosis of broken heart syndrome. Conclusions: Clinicians should re-evaluate asthma management and be aware of the complications associated with asthma attacks such as stress-induced cardiomyopathy.     

Prevention of stroke in patients with atrial fibrillation

Purpose  

Cardiac pacemaker malfunction due to exposure to magnetic fields may cause serious problems in some work environments for workers having cardiac pacemakers. The aim of this study was to find the magnetic field interference thresholds for several commonly used pacemaker models.     

Common electrocardiographic artifacts mimicking arrhythmias in ambulatory monitoring

Background Ambulatory electrocardiographic monitoring is used in clinical practice as a means of detecting cardiac arrhythmias during daily activities. Current equipment provides analysis for the detection of arrhythmias, ST-segment deviation, and more sophisticated analyses (late potentials, Q-T behavior, and heart-rate variability). However, despite the system used, a number of artifacts could mislead diagnosis. Methods and Results We prospectively searched for artifacts during ambulatory electrocardiography in patients referred for monitoring to our institution, a tertiary referral center. Patients were ambulatory at home, work, school, or within the hospital. We divided artifacts according to Krasnow and Bloomfield's classification (pseudoarrhythmia, nonarrhythmia), and we added a new category, artifacts in patients with pacemakers. Artifacts encountered mimicked sinus arrest, supraventricular arrhythmias, ventricular arrhythmias, and aberrancy. Examples of each one and diagnostic clues are provided to recognize these artifacts properly. Conclusions A substantial amount of invalid data (false-positive findings because of electrocardiographic artifacts) were identified during ambulatory electrocardiographic monitoring that can lead to inappropriate interpretation and may result in severe diagnostic errors. (Am Heart J 2002;144:187-97.)     

Safety of Implantable Pacemakers and Cardioverter Defibrillators in the Magnetic Field of a Novel Remote Magnetic Navigation System

Safety of Pacemakers and ICDs . Introduction: Electromagnetic interference with pacemaker and implantable cardioverter defibrillator (ICD) systems may cause temporary or permanent system malfunction of implanted devices. The aim of this study was to evaluate potential interference of a novel magnetic navigation system with implantable rhythm devices. Methods: A total of 121 devices (77 pacemakers, 44 ICDs) were exposed to an activated NIOBE II® Magnetic Navigation System (Stereotaxis, St. Louis, MO, USA) at the maximal magnetic field strength of 0.1 Tesla and evaluated in vitro with respect to changes in parameter settings of the device, changes of the battery status/detection of elective replacement indication, or alterations of data stored in the device. Results: A total of 115 out of 121 (95%) devices were free of changes in parameter settings, battery status, and internally stored data after repeated exposition to the electromagnetic field of the remote magnetic navigation system. Interference with the magnetic navigation field was observed in 6 pacemakers, resulting in reprogramming to a power‐on‐reset mode with or without detection of the elective replacement indication in 5 devices and abnormal variance of battery status in one device. All pacemakers could be reprogrammed to the initial modes and the battery status proved to be normal some minutes after the pacemakers had been removed from the magnetic field. Conclusion: Interference of a remote magnetic navigation system (at maximal field strength) with pacemakers and ICDs not connected to leads with antitachycardic detection and therapies turned off is rare. Occurring functional abnormalities could be reprogrammed in our sample. An in vitro study will give information about interference of devices connected to leads. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1136‐1141)     

A NEW PRINCIPLE FOR ELECTROMAGNETIC CATHETER FLOW METERS

An electromagnetic catheter flow meter is described in which the magnetic field is generated by two parallel bundles of wire carrying equal currents in opposite directions. The electrodes are fixed centrally to the insulated wire bundles that generate the magnetic field. The flow sensor is flexible, resembling a split catheter. The flow transducer is designed to constrict as it is introduced through a branch artery and to expand in the main artery over the span of its diameter. The principle is suitable for branch flow measurement as well as for measurement of flow in a major artery or vein by the same transducer. A special method of guiding the electrode wires results in a zero base line at zero flow for the entire range of diameters accommodating the field generating coil. The electrodes could be used in this configuration with a magnetic field generated by coils external to the patient for blood flow measurements with a catheter of reduced gauge. The transducer can be made smaller in circumference than those employed in other electromagnetic flow measuring catheter devices. This feature is of special value for envisaged clinical uses (percutaneous introduction) to minimize surgical intervention.

The velocity sensitivity of the flow transducer is a logarithmic function of the tube diameter. The flow throughout the entire tube cross section contributes to the flow signal. It is sufficient to calibrate the transducer by one measurement in a dielectric conduit of less than maximum diameter. The sensitivity at other diameters follows from a logarithmic plot. The diameter of the blood vessel is outlined by the transducer in radiograms, thus obviating the need for radiopaque materials. The principle was demonstrated by measurements in vitro. Experiments in vivo, derivation of equations, and construction details will be published elsewhere.

     

Effect of magnetic resonance imaging on DDD pacemakers

A previous study suggested the safety of exposing patients with certain pacemakers models to magnetic resonance imaging (MRI). However, the function of a variety of more advanced DDD pacemakers and the effect of higher magnetic and radio-frequency (rf) field strengths has not been reported. In the present study 4 different DDD pacemakers (Cordis 233F, Intermedic 283-01, Medtronic 7000A, and Pacesetter 283) were tested in a saline phantom under several conditions and with various imaging sequences. Pacemaker output was monitored using electrocardiographic telemetry. All units paced normally in the static magnetic field. However, during imaging, all units malfunctioned, with total inhibition of atrial and ventricular output in 3 of the pacemakers. In the fourth pacemaker, ventricular backup pacing was activated at high rf pulse repetition rates. However, the MRI scanner could trigger atrial output in this pacemaker at rates of up to 800/minute. All malfunctions were a result of rf interference, whereas gradient and static magnetic fields had no effect. Thus, despite magnetic fields had no effect. Thus, despite magnetic field strengths adequate to close pacemaker reed switches, rf interference during MRI may cause total inhibition of atrial and ventricular output in DDD pacemakers, and can also cause dangerous atrial pacing at high rates. MRI should be avoided in patients with these DDD pacemakers.     

Left ventricle in Noonan's syndrome. Electro-vecto-echo and angiocardiographic aspects

The electrocardiographic features of Noonan's syndrome have been known for several years, but the discordance between these electrical findings and the underlying haemodynamic disorders remains unexplained. In an attempt to elucidate the genesis of electrical abnormalities, we present here a retrospective study of 14 children with Noonan's disease, aged from a few days to 16 years and evaluated by electrocardiography, vectography, one- or two-dimensional echocardiography, angiography and His bundle electrophysiology. The electrocardiographic abnormalities observed concerned ventricular depolarization and intracardiac electric conduction with, notably, a QRS axis directed towards the right upper part of the electric field and a first degree infra-hisian atrioventricular block (His bundle potentials). Vectography showed in some cases an image of inferior pseudo-necrosis due to the absence of initial inferior forces; this image is highly characteristic. In other cases the QRS loop showed an image of left segmental block which is unusual in this type or cardiac pathology (pulmonary stenosis with or without atrial septal defect of the ostium secundum type).     

Cardiovascular screening with electrocardiography and echocardiography in collegiate athletes

Background

Current guidelines for preparticipation screening of competitive athletes in the US include a comprehensive history and physical examination. The objective of this study was to determine the incremental value of electrocardiography and echocardiography added to a screening program consisting of history and physical examination in college athletes.

Methods

Competitive collegiate athletes at a single university underwent prospective collection of medical history, physical examination, 12-lead electrocardiography, and 2-dimensional echocardiography. Electrocardiograms (ECGs) were classified as normal, mildly abnormal, or distinctly abnormal according to previously published criteria. Eligibility for competition was determined using criteria from the 36^th Bethesda Conference on Eligibility Recommendations for Competitive Athletes with Cardiovascular Abnormalities.

Results

In 964 consecutive athletes, ECGs were classified as abnormal in 334 (35%), of which 95 (10%) were distinctly abnormal. Distinct ECG abnormalities were more common in men than women (15% vs 6%, P < .001) as well as black compared with white athletes (18% vs 8%, P < .001). Echocardiographic and electrocardiographic findings initially resulted in exclusion of 9 athletes from competition, including 1 for long QT syndrome and 1 for aortic root dilatation; 7 athletes with Wolff-Parkinson-White patterns were ultimately cleared for participation. (Four received further evaluation and treatment, and 3 were determined to not need treatment.) After multivariable adjustment, black race was a statistically significant predictor of distinctly abnormal ECGs (relative risk 1.82, 95% confidence interval, 1.22-2.73; P = .01).

Conclusions

Distinctly abnormal ECGs were found in 10% of athletes and were most common in black men. Noninvasive screening using both electrocardiography and echocardiography resulted in identification of 9 athletes with important cardiovascular conditions, 2 of whom were excluded from competition. These findings offer a framework for performing preparticipation screening for competitive collegiate athletes.     

P wave dispersion in patients with rheumatoid arthritis: its relation with clinical and echocardiographic parameters

P wave dispersion (PWD) is a sign for the prediction of atrial fibrillation (AF). The aim of this study was to assess P wave dispersion and its relation with clinical and echocardiographic parameters in patients with rheumatoid arthritis (RA). Thirty RA patients (mean age 49 ± 10 years) and 27 healthy controls (mean age 47 ± 8 years) were included in the study. We performed electrocardiography and Doppler echocardiography on patients and controls. Maximum and minimum P wave duration were obtained from electrocardiographic measurements. PWD defined as the difference between maximum and minimum P wave duration was also calculated. Maximum P wave duration and PWD was higher in RA patients than controls (P = 0.031 and P = 0.001, respectively). However, there was no significant difference in minimum P wave duration between the two groups (P = 0.152). There was significant correlation between PWD and disease duration (r = 0.375, P = 0.009) and isovolumetric relaxation time (r = 0.390, P = 0.006). P wave duration and PWD was found to be higher in RA patients than healthy control subjects. PWD is closely associated with disease duration and left ventricular (LV) diastolic dysfunction.