PR Interval Research Articles

The Role of Electrocardiographic Markers for Predicting Atrial Fibrillation in Patients with Acute Ischemic Stroke: Data from the BIOSIGNAL Cohort Study.

P-wave abnormalities in the 12-lead electrocardiogram (ECG) have been associated with a higher risk of acute ischemic stroke (AIS) as well as atrial fibrillation (AF). This study aimed to assess pre-determined ECG criteria during sinus rhythm in unselected AIS patients and their value for predicting newly diagnosed atrial fibrillation (NDAF) after hospital admission. P-wave alterations were measured on 12-lead ECG on admission in all consecutively enrolled patients without known AF between October 2014 and 2017. The outcome of interest was NDAF, identified by prolonged electrocardiographic monitoring within one year after the index AIS. Univariable and multivariable logistic regression was applied to assess the magnitude and independence of the association between pre-selected ECG markers and NDAF. The discriminatory accuracy was evaluated with the area under the receiver operating characteristic curve (AUC), and the incremental prognostic value was estimated with the net reclassification index. NDAF was detected in 87 (10%) of 856 patients during a follow-up of 365 days. Out of the pre-selected ECG parameters, advanced interatrial block (aIAB) and PR interval in lead II were independently associated with NDAF in univariable regression analysis. Only aIAB remained a significant predictor in multivariable analysis. Adding aIAB to the best-performing multivariable regression model improved the discriminatory accuracy to predict NDAF from an AUC of 0.78 (95%-CI 0.77-0.80) to 0.81 (95%-CI 0.80-0.83, p < 0.001). aIAB is independently and highly associated with NDAF in patients with AIS, has high inter-rater reliability, and therefore may be helpful to refine diagnostic work-up to search for AF in AIS.

Ozanimod Therapy in Patients With COVID-19 Requiring Oxygen Support: A Randomized Open-Label Pilot Trial

BackgroundSphingosine-1-phosphate receptor ligands (SRLs) dampen immunopathological damages in models of viral pneumonia. Research QuestionIs it feasible to administer an SRL therapy, here ozanimod, to acutely ill SARS-CoV-2-infected patients? Study Design and MethodsThe prospective, randomized, open-label, COVID-19 Ozanimod Intervention (COZI) pilot trial was conducted in three Canadian hospitals. Patients admitted for COVID-19 requiring oxygen were eligible. Randomization was stratified for risk factors of poor outcome and oxygen needs at inclusion. Participants were allocated to standard of care (SOC), or to standard of care plus ozanimod (OZA). Ozanimod (oral, once daily, incremental dosage) was administered for a maximum of 14 days. Primary endpoint investigated for size effect and variance over time was the assessment of safety and efficacy, evaluated by the daily score on the WHO-adapted 6-points ordinal scale for clinical improvement analyzed under the intention-to-treat principle. ResultsTwenty-three patients were randomized to SOC arm and 20, in the OZA arm from September 2020 to February 2022. Evaluation of efficacy showed non-significant reductions of median duration of respiratory support (6 (3-10) vs 9 (4-12) days, P=0.34), median duration of hospitalization (9 (6-12) vs 10 (6-18) days, P=0.20) and median time to clinical improvement (4 (3-7) vs 7 (3-11) days, P=0.12) for OZA compared to SOC. Heart rate was significantly lower with ozanimod (65 (63-67) vs. 71 (69-72) bpm, P<0.0001). However, QT and PR intervals were not affected. No severe adverse drug reaction was reported. InterpretationSRLs utility in severe pneumonia had never been tested in patients. We show for the first time that this new pharmacological agent can safely be administered to patients hospitalized for viral pneumonia, with potential clinical benefits. Bradycardia was frequent but well tolerated. Clinical Trial RegistrationClinicalTrials.gov number NCT04405102

Cardiometabolic sex differences in adults born small for gestational age.

This study aimed to assess the cardiometabolic sex similarities and differences in adults born small for gestational age. This study was an ambispective cohort study from a birth registry in Barcelona, Spain, including 523 adult participants (20-40 years-old) subdivided as born small for gestational age (SGA, if birth weight <10th centile) or adequate fetal growth for gestational age (AGA). Cardiometabolic health was assessed by echocardiography, electrocardiogram, blood pressure measurement, vascular ultrasound, anthropometric measurements, and serum glycemia and lipid profile. Stratified analyses by sex were performed by estimation of adjusted absolute difference (AAD) using inverse probability weighting. Compared with AGA, the stratified analyses by sex showed a more pronounced reduction in ejection fraction [AAD: female -1.73 (95% CI -3.2 to -0.28) vs. male -1.33 (-3.19 to 0.52)] and increment in heart rate [female 3.04 (0.29-5.8) vs. male 2.25 (-0.82 to 5.31)] in SGA females compared with SGA males. In contrast, a more pronounced reduction in PR interval [female -1.36 (-6.15 to 3.42) vs. male -6.61 (-11.67 to -1.54)] and an increase in systolic blood pressure [female 0.06 (-2.7 to 2.81) vs. male 2.71 (-0.48 to 5.9)] and central-to-peripheral fat ratio [female 0.05 (-0.03 to 0.12) vs. male 0.40 (0.17-0.62)] were mainly observed in SGA male compared with SGA female. Sex differences were observed in the effect of SGA on cardiometabolic endpoints with female being more prone to cardiac dysfunction and male to electrocardiographic, vascular, and metabolic changes. Future research including sex-stratification data is warranted.

Twelve-Lead ECG, Holter Monitoring Parameters, and Genetic Testing in Brugada Syndrome: Insights from Analysis of Multigenerational Family with a History of Sudden Cardiac Arrest during Physical Activity.

Brugada syndrome (BrS) is an arrhythmogenic disorder increasing the risk of syncopal episodes and sudden cardiac death. BrS usually runs through families with reduced penetrance and variable expression. We analyzed the multigenerational family of a patient who died after sudden cardiac arrest with post-mortem diagnosis of BrS. We analyzed clinical history, comprehensive arrhythmic risk, genetic findings, and additional tests, including electrocardiogram (ECG), detailed 24-hour Holter ECG results, and standard echocardiography findings, and followed up the patients in the ambulatory clinic. We analyzed a pedigree of 33 members of four generations of the family (19 male and 14 female patients). In this family, we identified 7 patients with BrS (median Modified Shanghai Score and Sieira model: 4.5 (4-6) and 1 (0-4) points, respectively), including both parents of the deceased patient, and 8 relatives with negative sodium channel blocker drug challenge test. Genetic testing revealed a novel mutation in sodium voltage-gated channel alpha subunit 5 (SCN5A) c.941A>G, (p.Tyr314Cys) inherited from the father of the proband. Patients with BrS were characterized by longer P-wave duration (120 (102-155) vs. 92.5 (88-110) ms, p = 0.013) and longer PR intervals (211.3 ±26.3 vs. 161.6 ± 18.9 ms, p = 0.001), along with more frequent positive aVR sign, but did not differ in terms of QRS duration or T-wave characteristics in resting ECGs. BrS patients were characterized by lower mean, minimal, and maximal (for all p ≤ 0.01) heart rates obtained from Holter ECG monitoring, while there was no difference in arrhythmias among investigated patients. Moreover, visual diurnal variability of ST segment changes and fragmented QRS complexes were observed in patients with BrS in Holter ECG monitoring. There were no major arrhythmic events during median follow-up of 68.7 months of alive BrS patients. These results suggest ECG features which may be associated with a diagnosis of BrS and indicate a novel SCN5A variant in BrS patients. Twelve-lead Holter ECG monitoring, with modified precordial leads placement, may be useful in BrS diagnostics and risk stratification in personalized medicine.

Prolonged PR intervals are associated with epicardial adipose tissue and recurrence after catheter ablation in persistent atrial fibrillation.

Epicardial adipose tissue (EAT) has been reported to promote myocardial fibrosis and to affect intracardiac conduction. The PR interval reflects the conduction from the atria to the Purkinje fibers and may be associated with the EAT volume, especially in persistent atrial fibrillation (AF) patients. We aimed to investigate the relationship between the EAT and PR interval in patients with persistent AF. We enrolled 268 persistent AF patients who underwent catheter ablation (CA) and divided the patients into two groups: the normal PR interval group (PR interval less than 200ms: Group N) and long PR interval group (PR interval 200ms or more: Group L). We then analyzed the association between the total EAT volume around the heart and PR interval and calculated the ratio of the duration of the P wave (PWD) to the PR interval (PWD/PR interval). Moreover, we investigated whether a long PR interval was associated with the outcomes after ablation. The total EAT volume was significantly larger in Group L than Group N (Group N: 131.4 ± 51.8ml vs. Group L: 151.3 ± 63.3ml, p = 0.039). A positive correlation was also observed between the PWD/PR interval and EAT volume in Group L (r = 0.345, p = 0.039). A multivariate analysis also revealed that a long PR interval was independently associated with AF recurrence after CA (hazard ratio [HR] 2.071, p = 0.032). The total EAT volume was associated with a long PR interval, and a long PR interval was a significant risk factor for recurrence after ablation in persistent AF patients.

Hepatorenal and renocardial syndrome in young patients with acute glomerulonephritis

In this paper we discuss classical types of acute glomerulonephritis in young adults, when the intake of paracetamol and diclofenac led to a dysfunctional and organic liver injury, at the same time it negatively affected the course of acute glomerulonephritis. To study the characteristics of the development of acute reno-cardial syndrome (ARCS) Goal: Assessment of cause and effect relations of renal, hearts and liver injuries in young adults in acute post-streptococcal glomerulonephritis (APSG). With acute nephritic syndrome (ANS) complicated by acute kidney injury (AKI) and without it, to identify the role of the etiological factor on the course of APSG. Methods and Material: 220 male patients with APSG with ANS aged 18-20 were examined. The patients were divided into 2 groups based on the functional state of kidneys. The first group included 140 patients with APSG without ANS, the second group included 80 patients with AKI. Results: Out 66 patients had subclinical liver injury, which resulted from the effect of antipyretic hepatotoxic drugs taken in the initial stage of the disease. Due to the toxic and immunological liver injury, levels of transaminases increase, and albumin levels decrease. These changes occur along with the development of APSG and are correlated with some laboratory values. Impairment of cardiovascular function was observed in all 220 patients. ECG and Echocardiography studies conducted during the cardiac asthma attacks occurred as a decrease of voltage, broadening of the P wave, lengthening of the PQ interval, broadening of the QRS complex, dilatations of the right and left atrium. The severity of clinical manifestations of AKI and ARCS correlates with the degree of macrohematuria, GFR decrease, complement C3 fraction, monocyte. Conclusion. In APSG liver injury has a toxicoallergic character. Frequency of liver injury depends on specific features of a particular organism, it does not depend on the dose of the taken drug. In case of any type of acute glomerulonephritis it is necessary to assess the functional state of liver and after the treatment of the main disease hepatologist follow-up of patients is recommended. Thus in the development of acute reno-cardial syndrome (ARCS) the degree of manifestation of hypervolemia with hypertension, as a result of active immune inflammation of the glomerular apparatus with the development of AKI, plays the main role in the development of ARCS with APSG.. As a rule ARCS in case of APSG with ANS in young adults has a successful outcome.

Evidence for the cardiodepressive effects of the plasticizer di-2-ethylhexyl phthalate.

Di-2-ethylhexyl phthalate (DEHP) is commonly used in the manufacturing of plastic materials, including intravenous bags, blood storage bags, and medical-grade tubing. DEHP can leach from plastic medical products, which can result in inadvertent patient exposure. DEHP concentrations were measured in red blood cell units stored between 7 and 42 days (17-119 μg/ml). Using these concentrations as a guide, Langendorff-perfused rat heart preparations were acutely exposed to DEHP. Sinus activity remained stable with lower doses of DEHP (25-50 μg/ml), but sinus rate declined by 43% and sinus node recovery time (SNRT) prolonged by 56.5% following 30-min exposure to 100 μg/ml DEHP. DEHP exposure also exerted a negative dromotropic response, as indicated by a 69.4% longer PR interval, 108.5% longer Wenckebach cycle length (WBCL), and increased incidence of atrioventricular (AV) uncoupling (60-min exposure). Pretreatment with doxycycline partially rescued the effects of DEHP on sinus activity, but did not ameliorate the effects on AV conduction. DEHP exposure also prolonged the ventricular action potential and effective refractory period, but had no measurable effect on intracellular calcium transient duration. Follow-up studies using human-induced pluripotent stem cell-derived cardiomyocytes confirmed that DEHP slows electrical conduction in a time (15 min-3 h) and dose-dependent manner (10-100 μg/ml). Previous studies have suggested that phthalate toxicity is specifically attributed to metabolites of DEHP, including mono-2-ethylhexylphthalate. This study demonstrates that DEHP exposure also contributes to cardiac dysfunction in a dose- and time-dependent manner. Future work is warranted to investigate the impact of DEHP (and its metabolites) on human health, with special consideration for clinical procedures that employ plastic materials.

Association of preoperative electrocardiographic markers with sepsis in elderly patients after general surgery

BackgroundElectrocardiographic markers, as surrogates for sympathetic excitotoxicity, are widely predictive of cardiovascular adverse events, but whether these markers can predict postsurgical sepsis (SS) is unclear.MethodsWe retrospectively analyzed patients who underwent abdominal surgery from March 2013 to May 2023. We collected basic data, comorbidities, blood samples, echocardiology, electrocardiogram, and surgical data, as well as short-term outcome. The primary endpoints were postsurgical SS, in which logistic regression analyses can identify independent risk factors. The optimal cut-off value predictive postsurgical SS both P wave and PR interval were calculated in the receiver operating characteristic curve (ROC).ResultsA total of 1988 subjects were analyzed, and the incidence of postsurgical SS was 3.8%. The mean age at enrollment was 68.6 ± 7.1 years, and 53.2% of the participants were men. In the ROC analysis, the areas under the curve (AUC) for P wave and PR interval predictive postsurgical SS were 0.615 (95%CI, 0.548–0.683; p = 0.001) and 0.618 (95%CI, 0.554–0.682; p = 0.001), respectively. The P wave and PR interval predicted postoperative sepsis with optimal discrimination of 103 and 157 ms, with a sensitivity of 0.744 and 0.419, and a specificity of 0.427 and 0.760. P-wave less than 103 ms or PR interval less than 157 ms associated with a 2.06 or 2.33 fold increase occurred risk postsurgical SS.ConclusionsShorter P-wave and PR intervals were both independently associated with postsurgical SS. These preoperative electrophysiological markers could have potential useful for early recognition of postoperative SS.

Isolated Left Atrium Morphofunctional Study of an Experimental Pulmonary Hypertension Model in Rats.

The high incidence of atrial arrhythmias in pulmonary hypertension (PH) might be associated with poor prognosis, and the left atrium (LA) may play a role in this. An important finding in PH studies is that LA remodeling is underestimated. This study investigated LA morphology and mechanical function, as well as the susceptibility to develop arrhythmias in a monocrotaline-induced PH (MCT-PH) model. Wistar rats aged 4 weeks received 50 mg/kg of MCT. Electrocardiography and histology analysis were performed to evaluate the establishment of the MCT-PH model. The tissue was mounted in an isolated organ bath to characterize the LA mechanical function. Compared with the control group (CTRL), the MCT-PH model presented LA hypertrophy and changes in cardiac electrical activity, as evidenced by increased P wave duration, PR and QT interval in MCT-PH rats. In LA isolated from MCT-PH rats, no alteration in inotropism was observed; however, the time to peak contraction was delayed in the experimental MCT-PH group. Finally, there was no difference in arrhythmia susceptibility of LA from MCT-PH animals after the burst pacing protocol. The morphofunctional remodeling of the LA did not lead to increased susceptibility to ex vivo arrhythmia after application of the burst pacing protocol.

Giant U Wave: Tanda Bahaya yang Harus Dikenali dalam Praktik Klinik Primer

Introduction: Detection of hypokalaemia by ECG accompanied by detailed history and physical examination will greatly facilitate diagnosis, initiate potassium correction therapy, and prevent further complications due to various cardiac arrhythmias and neurological dysfunctions. Case: A 40-year-old man with weakness in both leg muscles since last night, starting from the legs up to the thighs. Initial ECG showed sinus rhythm with a heart rate at 80 bpm, first-degree heart block (PR interval 240 ms); Q wave in III lead; “apparent” prolonged QTc interval at 551 ms; ST segment depression in I, II, and V3-V6 leads; ST segment elevation in aVR lead; T-wave inseparable from large U wave formed giant U wave that remarkedly seen in V2-V4 leads. Laboratory tests revealed very low serum potassium at 1.94 mmol/L Conclusion: In severe hypokalaemia, T and U waves will merge and form a giant U wave. Emergency and primary physicians should be familiar with the ECG changes of hypokalaemia, especially the giant U wave.

Knowing Your Heart Condition Anytime

Electrocardiogram (ECG) monitoring has been widely explored in detecting and diagnosing cardiovascular diseases due to its accuracy, simplicity, and sensitivity. However, medical- or commercial-grade ECG monitoring devices can be costly for people who want to monitor their ECG on a daily basis. These devices typically require several electrodes to be attached to the human body which is inconvenient for continuous monitoring. To enable low-cost measurement of ECG signals with off-the-shelf devices on a daily basis, in this paper, we propose a novel ECG sensing system that uses acceleration data collected from a smartphone. Our system offers several advantages over previous systems, including low cost, ease of use, location and user independence, and high accuracy. We design a two-tiered denoising process, comprising SWT and Soft-Thresholding, to effectively eliminate interference caused by respiration, body, and hand movements. Finally, we develop a multi-level deep learning recovery model to achieve efficient, real-time and user-independent ECG measurement on commercial mobile phones. We conduct extensive experiments with 30 participants (with nearly 36,000 heartbeat samples) under a user-independent scenario. The average errors of the PR interval, QRS interval, QT interval, and RR interval are 12.02 ms, 16.9 ms, 16.64 ms, and 1.84 ms, respectively. As a case study, we also demonstrate the strong capability of our system in signal recovery for patients with common heart diseases, including tachycardia, bradycardia, arrhythmia, unstable angina, and myocardial infarction.

PRIME score for prediction of permanent pacemaker implantation after transcatheter aortic valve replacement.

We sought to produce a simple scoring system that can be applied at clinical visits before transcatheter aortic valve replacement (TAVR) to stratify the risk of permanent pacemaker (PPM) after the procedure. Atrioventricular block is a known complication of TAVR. Current models for predicting the risk of PPM after TAVR are not designed to be applied clinically to assist with preprocedural planning. Patients undergoing TAVR at the University of Colorado were split into a training cohort for the development of a predictive model, and a testing cohort for model validation. Stepwise and binary logistic regressions were performed on the training cohort to produce a predictive model. Beta coefficients from the binary logistic regression were used to create a simple scoring system for predicting the need for PPM implantation. Scores were then applied to the validation cohort to assess predictive accuracy. Patients undergoing TAVR from 2013 to 2019 were analyzed: with 483 included in the training cohort and 123 included in the validation cohort. The need for a pacemaker was associated with five preprocedure variables in the training cohort: PR interval > 200 ms, Right bundle branch block, valve-In-valve procedure, prior Myocardial infarction, and self-Expandable valve. The PRIME score was developed using these clinical features, and was highly accurate for predicting PPM in both the training and model validation cohorts (area under the curve 0.804 and 0.830 in the model training and validation cohorts, respectively). The PRIME score is a simple and accurate preprocedural tool for predicting the need for PPM implantation after TAVR.

Electrophysiological basis of cardiac arrhythmia in a mouse model of myotonic dystrophy type 1.

Introduction: Myotonic dystrophy type 1 (DM1) is a multisystemic genetic disorder caused by the increased number of CTG repeats in 3' UTR of Dystrophia Myotonia Protein Kinase (DMPK) gene. DM1 patients experience conduction abnormalities as well as atrial and ventricular arrhythmias with increased susceptibility to sudden cardiac death. The ionic basis of these electrical abnormalities is poorly understood. Methods: We evaluated the surface electrocardiogram (ECG) and key ion currents underlying the action potential (AP) in a mouse model of DM1, DMSXL, which express over 1000 CTG repeats. Sodium current (INa), L-type calcium current (ICaL), transient outward potassium current (Ito), and APs were recorded using the patch-clamp technique. Results: Arrhythmic events on the ECG including sinus bradycardia, conduction defects, and premature ventricular and atrial arrhythmias were observed in DMSXL homozygous mice but not in WT mice. PR interval shortening was observed in homozygous mice while ECG parameters such as QRS duration, and QTc did not change. Further, flecainide prolonged PR, QRS, and QTc visually in DMSXL homozygous mice. At the single ventricular myocyte level, we observed a reduced current density for Ito and ICaL with a positive shift in steady state activation of L-type calcium channels carrying ICaL in DMSXL homozygous mice compared with WT mice. INa densities and action potential duration did not change between DMSXL and WT mice. Conclusion: The reduced current densities of Ito, and ICaL and alterations in gating properties in L-type calcium channels may contribute to the ECG abnormalities in the DMSXL mouse model of DM1. These findings open new avenues for novel targeted therapeutics.

Complete heart block is a significant predictor of mortality in immune checkpoint inhibitor myocarditis

BackgroundImmune checkpoint inhibitor (ICI) myocarditis is associated with significant mortality risk. Electrocardiogram (ECG) changes in ICI myocarditis have strong prognostic value. However the impact of complete heart block (CHB) is not well defined. This study sought to evaluate the impact of CHB on mortality in ICI myocarditis, and to identify clinical predictors of mortality and CHB incidence.MethodsWe conducted a retrospective cohort study of patients with ICI myocarditis at three Mayo Clinic sites from 1st January 2010 to 31st September 2022 to evaluate mortality rates at 180 days. Clinical, laboratory, ECG, echocardiographic, and cardiac magnetic resonance imaging (CMR) characteristics were assessed. Cox and logistic regression were performed for associations with mortality and CHB respectively.ResultsOf 34 identified cases of ICI myocarditis, 7 (20.6%) had CHB. CHB was associated with higher mortality (HR 7.41, p = 0.03, attributable fraction 86.5%). Among those with CHB, troponin T (TnT) < 1000 ng/dL, low white blood cell count and high ventricular rate at admission were protective. There was trend towards increased survival among patients who underwent permanent pacemaker insertion (p = 0.051), although most experienced device lead complications. Factors associated with development of CHB included prolonged PR and QRS intervals and low Sokolow Lyon Index. Where these were normal and TnT was < 1000 ng/dL, no deaths occurred. Impaired myocardial longitudinal strain was sensitive for ICI myocarditis but was not prognostically significant.ConclusionThere is a strong temporal association between CHB and early mortality in people with ICI myocarditis. Focusing on arrhythmogenic complications can be helpful in predicting outcomes for this group of critically ill individuals.

Sedation Quality and Cardiorespiratory, Echocardiographic, Radiographic and Electrocardiographic Effects of Intramuscular Alfaxalone and Butorphanol in Spanish Greyhound Dogs.

The quality of sedation and changes in cardiorespiratory variables after the intramuscular administration of alfaxalone and butorphanol in Spanish greyhound dogs were evaluated. Twenty-one adult dogs were included. The dogs received alfaxalone (2 mg/kg) and butorphanol (0.2 mg/kg) intramuscularly. Sedation scoring, cardiorespiratory parameters (including blood gas analysis), echocardiography, thoracic radiography and electrocardiography were performed before sedation and 30 min after drug administration. Moderate sedation was observed, and side effects, such as tremors, nystagmus and auditory hyperesthesia, were noticed. Statistically significant changes in heart rate, invasive blood pressure, pH, arterial saturation of O2 and partial pressure of O2 and CO2 were found. Echocardiographic variables, including end-diastolic volume, left ventricular diameter in diastole, aortic and pulmonic flow, diastolic transmitral flow and left atrial/aortic ratio, and electrocardiography parameters, including PQ interval and QT interval, showed statistically significant changes. In conclusion, the intramuscular administration of alfaxalone and butorphanol to healthy dogs produced moderate sedation with mild cardiorespiratory, echocardiographic and electrocardiographic changes, without alterations in cardiac size on radiographic images.

IR-based device to acquire real-time online heart ECG signals of fish (Cyprinus carpio) to evaluate the water quality

Water quality monitoring is a challenging task due to continuous pollution. The rapid development of engineering technologies has paved the way for the development of efficient and convenient computer-based online continuous water-quality assessment techniques. Techniques based on biological-responses are gaining attention, worldwide. Different biosensors have been developed in recent years to monitor real-time biological responses to evaluate water-quality. The survival and function of various organs of the organism depends on the cardiac system. Alterations in the cardiac system could signify the occurrence/initiation of stress in the organism. We developed a real-time online cardiac function assessment system-OCFAS to acquire fish ECG-signals. We obtained P-wave, R-wave, T-wave, PR-intervals, QT-intervals and QRS-complex continuously, which did not affect the normal activities of carp. We exposed Cyprinus carpio to different concentrations (National Environmental Quality Standards) of ammonia for 48 h. Our OCFAS has precisely acquired the required ECG-signals. A real-time dataset reveals sensitivity to ammonia in carp ECG-indexes. Compared with the control group the P-wave, R-wave and T-wave were weaker in ammonia-treated groups. In contrast, the PR-intervals, QT-intervals and QRS-complex were prolonged in the ammonia-treatment groups. The self-organizing map signifies that the PR-intervals, the QRS-complex and the QT-intervals are consistent with environmental stress. Linear regression analysis also quantitatively signifies that the PR interval has the highest R2 value and the lowest SSE-value, followed by the QRS complex and the QT interval. A concentration-related effect was observed in the ammonia treated groups. The integrated biomarker response (IBRv2) index was used to determine the overall stress of ammonia on carp heart ECG-indexes. IBRv2 also supports the real-time response of carp to ammonia stress. Ammonia levels in the aquaculture and water environment require special attention to avoid its adverse effects on the health of aquatic biota. Our study emphasizes the importance of online real-time fish ECG for water-quality assessment.

Index of cardio-electrophysiological balance and Parkinson disease.

Neurodegeneration of the autonomic nervous systems due to Parkinson disease (PD) may lead to increase in the QT duration. In recent years, a new parameter index of cardio-electrophysiological balance (ICEB) was found. ICEB is a significant parameter of medicine related dysrhythmia. The purpose of this research is to assess ICEB in PD. Twenty-eight PD cases and 26 controls participated in our investigation. First diagnosed PD patients were registered in the research. The symptom progression of PD was assessed Modified Hoehn and Yahr Scale. Analyzed ECG variables are QRS, PR, QT, corrected QT (QTc) interval, ICEB and corrected index of cardio-electrophysiological balance (ICEBc). All cases had sinus rhythm. ICEB was analyzed by the ratio of QT/QRS. ICEBc was analyzed by the ratio of QTc/QRS. Twenty-eight PD cases participated in this research. Among PD cases, 15 patients were female (53.5%). The mean age of PD patients are 59.03 ± 9.94 years. There was no important difference between groups with respect to the clinical variables. The Modified Hoehn and Yahr Scale was appreciably higher in the PD group than the Control group. The heart rate of the PD group was significantly lower than that of the control group. PR intervals and QRS duration were similar in both groups. QT and QTc duration were significantly longer in PD patients. Also, the ICEB and ICEBc variables were appreciably higher in PD cases. The findings of our investigation suggest that ICEB is related to PD. ICEB can help to evaluate arrhythmia risk in patients with PD.

Prognostic significance of quantitative electrocardiographic parameters in patients with non-high-risk pulmonary embolism

BackgroundElectrocardiogram (ECG) abnormalities indicating right ventricular strain have been reported to have prognostic value in severe cases of acute pulmonary embolism (PE). We aimed to analyze the prognostic significance of other quantitative ECG parameters in non-high-risk acute PE. MethodsConsecutive patients with non-high-risk acute PE were prospectively enrolled. The following baseline ECG parameters were collected: rhythm, heart rate, QRS axis, right bundle branch block (RBBB) pattern, S1Q3T3 pattern, T-wave inversion, ST-segment elevation, Qr in lead V1, PR Interval, QRS complex duration, QT interval, P-wave amplitude and duration, R- and S-wave amplitudes. The primary endpoint was early discharge within three days. Associations between ECG parameters and early discharge were analyzed. ResultsOverall, 383 patients were enrolled (median age: 67 years, 57% female): 277 (72.3%) with low-risk and 106 (27.7%) with intermediate-risk. The two groups of patients differed in several ECG signs of right ventricular strain and many other quantitative parameters like R- and S-wave amplitudes. In the multivariate logistic regression analysis, the S-wave depth in lead V5 (S-V5) was the only independent prognostic factor for early discharge (odds ratio = 0.137, 95% confidence interval = 0.031-0.613, p = 0.009). The optimum cutoff value of S-V5 for predicting early discharge derived from the receiver operative characteristic curve was 0.15 mv (c-statistic = 0.66, p =0.003). ConclusionsSeveral ECG signs of right ventricular strain and many other quantitative parameters were associated with disease severity in non-high-risk acute PE. An S-V5 lesser than 0.15 mv was predictive for early discharge in these patients.

Unusual manifestation of atypical type I second degree atrioventricular block.

A 25year-old woman exhibited atypical type I second degree atrioventricular block characterized by constant PR intervals except the PR interval of the beat after the block. This was attributed to vagally induced AV block with failure of the vagal effect to depress the sinus node.

Association between cardiac atrioventricular conduction and antibodies to Chlamydia pneumoniae in fibromyalgia patients.

Fibromyalgia patients may complain of cardiovascular symptoms, including chest pain and palpitations. It has been proposed that infection by Chlamydia pneumoniae might be common in fibromyalgia. Chlamydia pneumoniae infection has also been hypothesized to be a causative factor in cardiac disease. This study aims to test the hypothesis that there is an association between atrioventricular conduction and antibodies to Chlamydia pneumoniae in fibromyalgia. Thirteen female fibromyalgia patients underwent serum Chlamydia pneumoniae IgG assays and 12-lead electrocardiography in a cross-sectional study. None of the patients was taking medication which might affect atrioventricular conduction, and none suffered from hypothyroidism, renal disease, hepatic disease, or carotid hypersensitivity. There was a significant positive correlation between the PR interval duration and the serum Chlamydia pneumoniae IgG level (r = 0.650; P = 0.016). This study supports the hypothesis of an association between atrioventricular conduction and antibodies to Chlamydia pneumoniae in fibromyalgia patients. It suggests that the higher the level of such antibodies, the greater the electrocardiographic PR interval, and therefore the slower the atrioventricular conduction. Potential pathophysiological mechanisms include a chronic inflammatory response to Chlamydia pneumoniae and the action of the bacterial lipopolysaccharide. The latter may involve stimulators of interferon genes, activation of the cardiac NOD-like receptor protein 3 inflammasomes, and downregulation of fibroblast growth factor 5 in the heart.