Arrhythmogenic cardiomyopathy is electrocardiographically characterized by right precordial T-wave inversions and epsilonwavesas major criteria. Additionally, terminal activation delay of 55 ms or more serves as a minor criterion. Although ther are more andmore evident pathological data of right ventricles without dilatation or aneurysm, typical fibrofatty abnormalities and myocardialatrophy exist. The ECGs of these patients lack the right precordial T-wave inversion and epsilon waves. Lead aVR and Lead V1 couldbecome more and more relevant. 413 cases with arrhythmogenic cardiomyopathy (292 males, mean age 46. 3 11. 6 years) and a collectiveof normal proband (1496 patients, 859 males with an age range of 18-81 years) were analyzed with regard to ECG appearanceof Lead aVR and the amplitude of inverted T-waves in Lead V1. With a specificity of 99. 9%, a positive predictive value of 99. 7% and anegative predictive value of 98% Lead V1 and aVR were most relevant to diagnose arrhythmogenic cardiomyopathy if an amplitudeof Qwaves of 3mmor more, R waves of 2mmor less, inverted T waves of 2mmor less in Lead aVR and inverted T waves in Lead V1 werepresent. These two Leads appear most relevant to make the diagnosis of arrhythmogenic cardiomyopathy even in cases withoutright ventricular dilatation and right ventricular aneurysms.

Background: In inferior MI, both circumflex (CX) and Right coronary artery (RCA) can be involved. Application of noninvasive paramedical evaluations in predicting of such events is considered to be worthwhile.Objective: Detection of coronary artery (RCA or CX) involvement in inferior myocardial infarction based on aVR change.Methods: In 100 patients with inferior MI, 12-Lead standard ECG was recorded in first 6 hours and ST-T change of aVR evaluated. T-P segment was considered as isoelectric line. Data were analyzed using SPSS-12 and the sensitivity, specificity, positive and negative predictive values evaluated.Findings: RCA disease was seen in 72 patients and CX in 28. Isoelectric ST, ST depression and ST elevation in aVR were seen in 61, 22 and 17 patients, respectively. Positive predictive value (PPV) of isoelectric ST for RCA disease was 78.7% compared with 21.3% for CX. PPV of ST elevation for RCA and CX diseases were 70.6% and 29.4%, respectively. PPP of ST depression for RCA disease was 54.5% compared to 45.5% for CX.Conclusion: Regarding the higher PPV of isoelectric ST, clinicians are suggested to employ this criterion in addition to other findings for RCA involvement prior to invasive procedure.

Introduction: Among the 12 Leads studied in electrocardiography (ECG), Lead aVR can be considered as the most forgotten part of it since no attention is paid to it as the mirror image of other Leads. Therefore, the present study has been designed with the aim of evaluating the prevalence of ST segment changes in Lead aVR and its relationship with the outcome of these patients.Methods: In this retrospective cross sectional study medical profiles of patients who had presented to emergency department with the final diagnosis of myocardial infarction (MI) in a 4-year period were evaluated regarding changes of ST segment in Lead aVR and its relationship with in-hospital mortality, the number of vessels involved, infarct location and cardiac ejection fraction.Results: 288 patients with the mean age of 59.00§ 13.14 (18 – 91) were evaluated (79.2% male).168 (58.3%) patients had the mentioned changes (79.2% male). There was no significant relationship between presence of ST changes in Lead aVR with infarct location (p=0.976), number of vessels involved (p=0.269) and ejection fraction on admission (p =0.801). However, ST elevation¸ 1 mv in Lead aVR had a significant relationship with mortality (Odds=7.72, 95% CI: 3.07 – 19.42, p<0.001). Sensitivity, specificity, positive and negative predictive values and positive and negative likelihood ratios of ST elevation¸ 1 for prediction of in-hospital mortality were 41.66 (95% CI: 22.79 –63.05), 91.53 (95%CI: 87.29 – 94.50), 31.25 (95% CI: 16.74 – 50.13), 94.44 (95% CI: 90.65 – 96.81), 0.45 (95% CI: 0.25– 0.79), and 0.05 (95% CI: 0.03 – 0.09), respectively.Conclusion: Based on the results of the present study, the prevalence of ST segment changes in Lead aVR was estimated to be 58.3%. There was no significant relationship between these changes and the number of vessels involved in angiography, infarct location and cardiac ejection fraction. However, presence of ST elevation ³ 1 in Lead aVR was associated with 8 times increase in in-hospital mortality risk.

Dear Editor: Exercise-induced ST-segment depression, although the most common accepted criterion for detecting coronary artery disease (CAD) has limited sensitivity and is unable to localize ischemic territory. Recently ST-segment elevation in Lead aVR has been studied for the detection of CAD.

In evidence-based medicine, constructing research questions is the most important part of research integration. Formulating a research question is the first step to conducting a credible and valuable research. Patient, intervention, comparison, outcome (PICO) is a specialized framework used by most researchers to formulate a research question and facilitate resource review. In the heart ward of Razi Hospital, Birjand University of Medical Sciences, according to the needs assessments, PICO was implemented during the Journal Club to familiarize students with research and increase their level of knowledge, attitude, as well as clinical reasoning skills. In this article, we explain the case of a 36-year-old woman with typical chest pain for 3 hours due to severe stress, without cardiac risk factors referring to the emergency room. The clinical examination was normal. The ST elevation was observed in the aVR Lead. The question is “, Should we perform an invasive intervention for this patient?

In this paper prediction error measurement (PEM) method is used for online synchronous generator parameters estimation. Unlike the usual off-line standard methods, in the proposed method instead of removing the automatic voltage regulator (aVR) from the circuit and manually disturbing the excitation voltage, a change in the reference signal of the aVR is applied and the parameters are estimated for the aVR-generator interconnected system. To adapt this modeling to real conditions, the input and output signals are mixed with noise. Since the direct application of the PEM method on noisy signals will cause a significant estimation error, the wavelet transform is used as a signal-denoising tool. Using Matlab/Simulink, synchronous generator parameters are estimated under colored noise and white noise conditions. To validate the estimated parameters, the results compare with the standard standstill frequency response (SSFR) test that was applied to the Shahid Rajaee power plant. Moreover, a three-phase short circuit to earth for a period of 2.5 cycles at the generator terminal is simulated and analyzed. The results indicate the proper accuracy of the proposed parameter estimation.

Designing of a PID controller is a very common method for industrial process control and due to its very simple and efficient function; it is used in a wide variety of industrial applications. PID controller to reduce the steady state error and dynamic response of the system is used. PID controller design is an inevitable problem in setting the coefficients need to try a lot of trial and error, therefore the optimization of parameters in this controller is attention of many researcher and there are many methods to find optimal parameters of PID controller. Fast and exactly adjustment of the parameters optimized controller is to create high quality answers. In this paper, an optimized tuning method for PID controller is presented. In this method the PSO algorithm is used to design the parameters of an aVR (Automatic Voltage Regulation) system using various fitness functions. Easy implementation, stable convergence characteristic and high computational efficiency are among advantages of presented method.

BACKGROUND: In this study, we aimed to investigate the prognostic implications of Lead aVR ST-segment elevation in an initial electrocardiogram (ECG) in patients diagnosed with acute coronary syndrome (ACS). Furthermore, we evaluated the association between electrocardiographic changes in Lead aVR and objective measures such as angiographic findings and Syntax score.METHODS: This retrospective cohort study, conducted as a pilot study, encompassing both a retrospective cross-sectional analysis and a longitudinal follow-up, took place at Chamran Hospital from November 2017 to October 2019. A 6-month follow-up was conducted via phone interviews to assess patient outcomes.RESULTS: During the study period, there were 76 admissions with the final diagnosis of acute coronary syndrome and Lead aVR ST-segment elevation on ECG. ARB intake and the severity of right coronary artery stenosis were significantly higher in patients with STE-aVR ≥1.5 mm. The clinical pathway analysis and 6-month follow-up outcomes concerning ST-segment changes in Lead aVR did not reveal statistically significant differences in the distribution of various intervention strategies and clinical events. The overall ST-change was a significant risk factor for 6-month follow-up angiography (OR: 1.10; 95% CI: 1.002 to 1.213) and was also significantly associated with any stenosis in the RCA territory (OR: 1.10; 95% CI: 1.004 to 1.21). There was no significant association between ST-change and other follow-up hospital and angiography outcomes.CONCLUSION: The findings suggest that medication history, particularly with angiotensin receptor blockers, may shape the observed ST-segment changes in Lead aVR. However, further investigation is needed to better understand the clinical implications of these trends.