Establishing a safe anesthesia concentration window for Nile tilapia (Oreochromis niloticus) (Linnaeus 1758) by monitoring cardiac activity in eugenol immersion baths.

Nile tilapia, Oreochromis niloticus, is the most cultivated fish species in the world, due to its low cost, high growth rate, environmental adaptability, and resistance to disease and stress. Anesthetics for fish become necessary in management because they minimize mortality during transport and maintenance of ponds, one of the most used anesthetics is clove oil, which has eugenol as the major substance, representing 90-95 % of clove oil. The present study evaluates the effect of eugenol on cardiac activity in Oreochromis niloticus specimens and relates it to behavioral data to determine a concentration window for safe anesthesia. For the comportamental analysis, was used five treatments (50, 75, 100, 125, and 150 µL·L-1) were evaluated and for the eletrocardiographic test was used seven groups (Control, Vehicle, 50, 75, 100, 125, and 150 µL·L-1), n = 9/treatment, totaling 108 animals. Behavioral and electrocardiographic tests were performed on all treatments during induction and recovery. The results of the behavioral tests demonstrated the reversibility of the effects with recovery of the posture reflex, varying according to the concentration. The ECG results showed a slow recovery because, at concentrations above 100 µL·L-1, there was no full reversibility of the cardiac effects in the observed experiment time, which could cause greater changes in the tilapia hemodynamics, which led us to identify a window for safe anesthesia. Eugenol is an effective anesthetic in Nile tilapia juveniles when used in concentrations ranging from 50 to 100 µL·L-1, if there is a need for anesthetic deepening, doses above 100 µL·L-1, however, the animals must be monitored due to hemodynamic changes.

Transient Loss of Consciousness Associated With Severe Hypocalcemia and QT Prolongation Due to Primary Hypoparathyroidism in an Adolescent Girl.

As hypocalcemia is uncommon, serum calcium levels are not routinely measured in many emergency medicine clinics. We report a case of an adolescent girl with a transient loss of consciousness due to hypocalcemia. A 13-year-old healthy girl had a syncopal episode complicated with numbness in the extremities. On admission, she was fully conscious, but hypocalcemia and QT prolongation were noted. After careful consideration of the possible etiologies, the patient was diagnosed with acquired QT prolongation due to primary hypoparathyroidism. The patient's serum calcium levels were controlled by activated vitamin D and calcium supplementation. Primary hypoparathyroidism-associated hypocalcemia can cause QT prolongation and neurological complications, even in previously healthy adolescents.

Transient P' waves in a hyperkalemic cat: artifact or dissociation?

A 15-year-old Sphynx cat was referred for cervical ventroflexion, ataxia, and lethargy associated with hypokalemia. After administration of supplemental potassium, the cat became severely hyperkalemic. Transient P' (vs. pseudo P' waves) were detected on the electrocardiogram. Over the course of hospitalization, the cat's potassium normalized, and the abnormal P' waves did not recur. These images are presented to highlight the differential diagnoses for this type of electrocardiogram. Diagnostic considerations included complete or transient atrial dissociation (as a rare consequence of hyperkalemia), atrial parasystole, and various electrocardiographic artifacts. Definitive diagnosis of atrial dissociation requires an electrophysiologic study or echocardiographic documentation of two independent atrial rhythms with associated mechanical activity, but these were unavailable in this case.

Predictive value of dynamic electrocardiography for myocardial ischemia and arrhythmia in patients with coronary heart disease / 中国基层医药

Objective:To investigate the predictive value of dynamic electrocardiography (ECG) for myocardial ischemia and arrhythmia in patients with coronary heart disease.Methods:A total of 87 patients with coronary heart disease who received treatment in Wenling Hospital of Traditional Chinese Medicine from January 2020 to January 2022 were included in this study. These patients were divided into a conventional ECG group (group A, n = 40) and a dynamic ECG group (group B, n = 47) according to different examination methods. The detection rate of myocardial ischemia in the two groups was determined. The diagnostic efficacy of routine ECG and dynamic ECG for myocardial ischemia was analyzed according to the results of coronary angiography. The detection rate of arrhythmia was determined in each group. Patient satisfaction was compared between the two groups. Results:There was no significant difference in the total detection rate of myocardial ischemia between the two groups ( P = 0.154). The detection rate of asymptomatic myocardial ischemia in group B [25% (25/47)] was significantly higher than that in group A [10% (10/40), χ2 = 5.24, P = 0.020). According to the results of coronary angiography, the detection rates of myocardial ischemia in group A and group B were 68% (27/40) and 87% (41/47), respectively. The sensitivity, specificity, and accuracy of group B in diagnosing myocardial ischemia were 80% (33/41), [67% (4/6), and 74% (35/47), respectively, all of which were significantly higher than 74% (20/27), [46% (6/13), 68% (27/40) in group A ( χ2 = 8.03, 5.89, 5.03, P = 0.003, 0.012, 0.005). The detection rates of premature ventricular contraction in bi-triplet rhythm, frequent paired premature atrial contraction in bi-triplet rhythm, right bundle-branch block, atrioventricular block, supraventricular tachycardia in group B were significantly higher compared with group A ( χ2 = 10.78, P = 0.001). According to the results of coronary angiography, the detection rates of arrhythmia in groups A and B were 65% (26/40) and 79% (37/47), respectively. The sensitivity, specificity, and accuracy of diagnosing arrhythmia in coronary heart disease in group B were 86% (32/37), 40% (4/10), and 81% (38/47), respectively. The sensitivity and accuracy of diagnosing arrhythmia in coronary heart disease in group B were significantly higher than those in group A [58% (15/26), 55% (22/40), χ2 = 7.30, 4.90, P = 0.005, 0.010). Patient satisfaction in group B [87% (41/47)] was significantly higher than that in group A [65% (26/40), χ2 = 6.24, P = 0.044]. Conclusion:Compared with conventional ECG detection, dynamic ECG has substantially higher detection and diagnosis rates of myocardial ischemia and arrhythmia, as well as a higher patient satisfaction rate, in patients with coronary heart disease, in particular in those with asymptomatic myocardial ischemia.

Successful Treatment of Near Fatal Cardiogenic Shock Following Toxic Mushroom Ingestion.

Myocardial injury and hemodynamic compromise following toxic mushroom ingestion is rare. Here we present a case of cardiogenic shock after Amanita proxima ingestion, presenting with severe hemodynamic collapse necessitating mechanical circulatory support. Prompt identification, multidisciplinary clinical decision making, and timely treatment resulted in an outstanding complete clinical resolution. (Level of Difficulty: Intermediate.).

Glucose and Fructose Supplementation and Their Acute Effects on Electrocardiographic Time Intervals during Anaerobic Cycling Exercise in Healthy Individuals: A Secondary Outcome Analysis of a Double-Blind Randomized Crossover-Controlled Trial.

The impact of glucose and fructose supplementation on acute cardiac effects during cardiopulmonary exercise testing (CPET) is a topic that is rarely investigated. The aim of the presented secondary outcome analysis of a double-blind, randomized crossover-controlled trial was to investigate the impact of glucose (Glu), fructose (Fru), glucose and fructose (GluFru), and sucralose on electrocardiogram (ECG), heart rate variability (HRV), premature ventricular complexes (PVCs), and heart rate turn points (HRTP) during CPET. Fourteen healthy individuals (age 25.4 ± 2.5 years, body mass index (BMI) 23.7 ± 1.7 kg/m2, body mass (BM) of 76.3 ± 12.3 kg) participated in this study, of which 12 were included for analysis. Participants received 1 g/kg BM of Glu, 1 g/kg BM of Fru, 0.5 g/kg BM of GluFru (each), and 0.2 g sucralose dissolved in 300 mL 30 min prior to each exercise session. No relevant clinical pathology or significant inter-individual differences between our participants could be revealed for baseline ECG parameters, such as heart rate (HR) (mean HR 70 ± 16 bpm), PQ interval (146 ± 20 ms), QRS interval (87 ± 16 ms) and the QT (405 ± 39 ms), and QTc interval (431 ± 15 ms). We found preserved cardiac autonomic function by analyzing the acute effects of different Glu, Fru, GluFru, or sucralose supplementation on cardiac autonomic function by Schellong-1 testing. SDNN and RMSSD revealed normal sympathetic and parasympathetic activities displaying a balanced system of cardiac autonomic regulation across our participating subjects with no impact on the metabolism. During CPET performance analyses, HRV values did not indicate significant changes between the ingested drinks within the different time points. Comparing the HRTP of the CPET with endurance testing by variable metabolic conditions, no significant differences were found between the HRTP of the CPET data (170 ± 12 bpm), Glu (171 ± 10 bpm), Fru (171 ± 9 bpm), GluFru (172 ± 9 bpm), and sucralose (170 ± 8 bpm) (p = 0.83). Additionally, the obtained time to reach HRTP did not significantly differ between Glu (202 ± 75 s), Fru (190 ± 88 s), GluFru (210 ± 89 s), and sucralose (190 ± 34 s) (p = 0.59). The significance of this study lies in evaluating the varying metabolic conditions on cardiac autonomic modulation in young healthy individuals. In contrast, our participants showed comparable cardiac autonomic responses determined by ECG and CPET.

Cardiac electrophysiology studies in mice via the transjugular route: a comprehensive practical guide.

Cardiac arrhythmias are associated with cardiovascular morbidity and mortality. Cardiac electrophysiology studies (EPS) use intracardiac catheter recording and stimulation for profound evaluation of the heart's electrical properties. The main clinical application is investigation and treatment of rhythm disorders. These techniques have been translated to the murine setting to open opportunities for detailed evaluation of the impact of different characteristics (including genetics) and interventions on cardiac electrophysiology and -pathology. Currently, a detailed description of the technique of murine transjugular EPS (which is the standard route of catheter introduction) is lacking. This article provides detailed information on EPS in mice via the transjugular route. This includes catheter placement, stimulation protocols, intracardiac tracing interpretation, artifact reduction, and surface ECG recording. In addition, reference values as obtained in C57BL/6N mice are presented for common electrophysiological parameters. This detailed methodological description aims to increase accessibility and standardization of EPS in mice. Ultimately, also human research and patient care may benefit from translation of the knowledge obtained in preclinical models using this technique.NEW & NOTEWORTHY Electrophysiology studies (EPS) allow in-depth evaluation of cardiac electrophysiology and -pathology. These techniques have been adapted to the murine setting for (translational) studies, mainly focusing on arrhythmogenesis. Despite the frequent application of EPS via the transjugular route, a thorough description of the technique is currently lacking. This article aims to function as a comprehensive guide, also elaborating (for the first time) on nonsurgical aspects such as catheter positioning, tracing artifacts, stimulation protocols, and reference values.

Mitigating Bias in the Measurement of Heart Rate Variability in Physiological Studies of Spinal Manipulation: A Comparison Between Authentic and Sham Manipulation.

OBJECTIVE: The purpose of this study was to identify sources and strategies for the mitigation of bias in studies of spinal manipulation and heart rate variability. METHODS: A small-scale study compared the effects of a single session of sham and authentic cervical manipulation on heart rate variability as measured by power spectrum analysis. The participants were a sample of 31 healthy young students from the Canadian Memorial Chiropractic College, randomized into 2 study arms. The effectiveness of blinding was evaluated, and 2 alternative methods of data analysis were explored to mitigate risk of bias. Following execution of the study, the stages of implementation and data processing were scored against version 2 of the Cochrane risk-of-bias tool for randomized trials for risk of bias. RESULTS: The risk of bias arising from (1) the randomization process, (2) missing outcome data, and (3) selection of reported results was judged to be low. Risk of bias in (1) deviations from intended interventions (particularly due to the failure of masking) and (2) the measurement of the outcome, for example, through cleaning of the data, were judged to be high. CONCLUSION: The use of power spectrum analysis of heart rate variability based on 5-minute recordings of echocardiogram pre-and post-intervention contained multiple sources of bias that were challenging to mitigate. Based upon these findings, power spectrum analysis of heart rate variability using these parameters may be ill-suited to the study of physiological effects of spinal manipulative therapy.

Severe hypokalemia in the emergency department: A retrospective, single-center study.

Background and Aims: Hypokalemia is one of the most common problems in the emergency department (ED). Severe hypokalemia, defined as a serum potassium level ≤2.5 mEq/L, is a relatively uncommon electrolyte disorder, and few studies have reported its prevalence, etiology, symptoms, and management in the ED. Therefore, we aimed to investigate them in this study. Methods: This retrospective single-center study included adult patients whose serum potassium levels were measured in the ED between 2012 and 2019. Data including age, sex, serum potassium levels, and serum creatinine levels were collected from the electronic medical records. Results: The serum potassium levels of 21,616 adult patients were measured. The median age of these patients was 73 years (range: 57-83 years), and 38% were men. The prevalence of severe hypokalemia was 0.4%. The most common symptom of symptomatic severe hypokalemia was weakness (p = 0.001). Malnutrition, use of Japanese herbal medicine, and use of diuretics were the main causes of severe hypokalemia. Sixty-one patients (70%) underwent electrocardiography. Fifty-nine patients (68%) received treatment for severe hypokalemia within one day of the visit. Conclusion: The management of severe hypokalemia in the ED may be suboptimal. Emergency physicians should be vigilant to avoid missing hypokalemia.

Hypocalcemia-Induced QT Interval Prolongation.

An 87-year-old man with a history of transcatheter aortic valve replacement, pulmonary hypertension, diastolic dysfunction with preserved systolic function, and myelofibrosis had a 12-lead ECG showed a prolonged QT interval of 508 ms with heart-rate correction placing it in the 99th percentile of the population. Reduction in the dose of furosemide and calcium supplementation increased serum calcium and shortened the QT interval. This case provides an opportunity to examine newer concepts for the understanding of the mechanisms by which hypocalcemia might induce QT prolongation. Hypocalcemia likely produces corrected QT interval prolongation primarily through a calcium-dependent inactivation (CDI) mechanism on the L-type calcium channel (LTCC). Lower extracellular calcium leads to a decreased ICaL, subsequently causing intracellular calcium to take longer to reach the critical threshold to induce CDI of the LTCC. The resulting prolonged repolarization of the ventricular myocyte can lead to early after-depolarizations and ensuing life-threatening ventricular arrhythmias. Genetic polymorphisms in Ca2+-binding protein calmodulin which can prolong QT, underscore the role for disturbances of intracellular myocardial calcium handling in arrhythmogenesis. Hypocalcemia is an under-recognized cause of QT prolongation and should be taken into careful consideration in patients presenting with incidental findings of a prolonged QT interval.

Nonsustained Ventricular Tachycardia Is Independently Associated With Sustained Ventricular Arrhythmias in Nonischemic Dilated Cardiomyopathy.

BACKGROUND: Spontaneous nonsustained ventricular tachycardia (NSVT) on Holter, VT inducibility during electrophysiology study, and late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) have been associated with sustained ventricular arrhythmias (SVAs) in nonischemic dilated cardiomyopathy (DCM). This study aimed to analyze whether these parameters carry independent prognostic value for spontaneous SVA in DCM. METHODS: Between 2011 and 2018, patients with the DCM clinical spectrum and documented SVA, suspected SVA, or considered to be at intermediate or high risk for SVA were enrolled in the prospective Leiden Nonischemic Cardiomyopathy Study. Patients underwent a comprehensive evaluation including 24-hour Holter, LGE-CMR, and electrophysiology study. Holters were assessed for the presence of NSVT (≥3 beats; rate, ≥120 bpm; lasting <30 s) and NSVT characteristics (coupling interval, duration, cycle length, morphology, regularity). Patients were followed at 6 to 12 monthly intervals. RESULTS: Of all 115 patients (age, 59±12 years; 77% men; left ventricular ejection fraction, 33±13%; history of SVA, 36%; LGE in 63%; median LGE mass, 13 g; interquartile range, 8-23 g), 62 (54%) had NSVT on Holter, and sustained monomorphic VT was inducible in 34 of 114 patients (30%). NSVT was not associated with LGE on CMR or VT inducibility during electrophysiology study nor were its features (all P>0.05). During 4.0±1.8 years of follow-up, SVA occurred in 39 patients (34%). NSVT (HR, 4.47 [95% CI, 1.87-10.72]; P=0.001) and VT inducibility (HR, 3.08 [95% CI, 1.08-8.81]; P=0.036) were independently associated with SVA during follow-up. A bivariable model including only noninvasively acquired parameters also allowed identification of a high-risk subgroup (ie, those with both NSVT and LGE on CMR). The findings remained similar when only patients without prior SVA were included. CONCLUSIONS: In patients with DCM, NSVT on Holter and VT inducibility during electrophysiology study predict SVA during follow-up independent of LGE on CMR. NSVTs may serve as an initiator, and sustained VT inducibility indicates the presence of the substrate for SVA in DCM. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01940081.

Nuciferine from Nelumbo nucifera Gaertn. attenuates isoproterenol-induced myocardial infarction in Wistar rats.

The study explored the cardioprotective role of the methanolic leaf extract of Nelumbo nucifera and nuciferine against isoproterenol-induced myocardial infarction (MI) in Wistar rats. Pretreatment with leaf extract and nuciferine (200 and 20 mg/kg body weight, respectively) against MI induced by isoproterenol (85 mg/kg body weight) significantly decreased heart weight; levels of cardiac markers such as lactate dehydrogenase and creatine kinase-MB were similar to those in controls. The treatment significantly increased the content of endogenous antioxidants and decreased lipid peroxidation in all treated groups. Treated groups showed a significant reduction in heartbeats per minute as compared with the MI-induced positive control. The MI-induced group showed pathological implications such as tachycardia, left atrial enlargement, and anterolateral ST-elevated MI, which were absent in treated groups. Histology confirmed that the leaf extract and nuciferine prevented structural abnormality and inflammation in heart and liver tissues of treated groups. On in silico analysis, nuciferine showed stronger binding interaction with both ß1 and ß2 adrenergic receptors than isoproterenol. Hence, the leaf extract of N. nucifera and nuciferine could be used as plant-based cardioprotective agents.

Cardioprotective effects of amiodarone in a rat model of epilepsy-induced cardiac dysfunction.

Cardiac dysfunction is one of the leading causes of death in epilepsy. The anti-arrhythmic drug, amiodarone, is under investigation for its therapeutic effects in epilepsy. We aimed to evaluate the possible effects of amiodarone on cardiac injury during status epilepticus, as it can cause prolongation of the QT interval. Five rat groups were enrolled in the study; three control groups (1) Control, (2) Control-lithium and (3) Control-Amio, treated with 150 mg/kg/intraperitoneal amiodarone, (4) Epilepsy model, induced by sequential lithium/pilocarpine administration, and (5) the epilepsy-Amio group. The model group expressed a typical clinical picture of epileptiform activity confirmed by the augmented electroencephalogram alpha and beta spikes. The anticonvulsive effect of amiodarone was prominent, it diminished (p < 0.001) the severity of seizures and hence, deaths and reduced serum noradrenaline levels. In the model group, the electrocardiogram findings revealed tachycardia, prolongation of the corrected QT (QTc) interval, depressed ST segments and increased myocardial oxidative stress. The in-vitro myocardial performance (contraction force and - (df/dt)max ) was also reduced. Amiodarone decreased (p < 0.001) the heart rate, improved ST segment depression, and myocardial contractility with no significant change in the duration of the QTc interval. Amiodarone preserved the cardiac histological structure and reduced the myocardial injury markers represented by serum Troponin-I, oxidative stress and IL-1. Amiodarone pretreatment prevented the anticipated cardiac injury induced during epilepsy. Amiodarone possessed an anticonvulsive potential, protected the cardiac muscle and preserved its histological architecture. Therefore, amiodarone could be recommended as a protective therapy against cardiac dysfunction during epileptic seizures with favourable effect on seizure activity.

Sensitivity and Adjustment Model of Electrocardiographic Signal Distortion Based on the Electrodes' Location and Motion Artifacts Reduction for Wearable Monitoring Applications.

Wearable vital signs monitoring and specially the electrocardiogram have taken important role due to the information that provide about high-risk diseases, it has been evidenced by the needed to increase the health service coverage in home care as has been encouraged by World Health Organization. Some wearables devices have been developed to monitor the Electrocardiographic in which the location of the measurement electrodes is modified respect to the Einthoven model. However, mislocation of the electrodes on the torso can lead to the modification of acquired signals, diagnostic mistakes and misinterpretation of the information in the signal. This work presents a volume conductor evaluation and an Electrocardiographic signal waveform comparison when the location of electrodes is changed, to find a electrodes' location that reduces distortion of interest signals. In addition, effects of motion artifacts and electrodes' location on the signal acquisition are evaluated. A group of volunteers was recorded to obtain Electrocardiographic signals, the result was compared with a computational model of the heart behavior through the Ensemble Average Electrocardiographic, Dynamic Time Warping and Signal-to-Noise Ratio methods to quantitatively determine the signal distortion. It was found that while the Einthoven method is followed, it is possible to acquire the Electrocardiographic signal from the patient's torso or back without a significant difference, and the electrodes position can be moved 6 cm at most from the suggested location by the Einthoven triangle in Mason-Likar's method.

Simple electrophysiological predictor of QRS change induced by cardiac resynchronization therapy: A novel marker of complete left bundle branch block.

BACKGROUND: QRS complex shortening by cardiac resynchronization therapy (CRT) has been associated with improved outcomes. OBJECTIVE: We hypothesized that the absence of QRS duration (QRSd) prolongation by right ventricular mid-septal pacing (RVP) may indicate complete left bundle branch block (cLBBB). METHODS: We prospectively collected 12-lead surface electrocardiograms (ECGs) and intracardiac electrograms during CRT implant procedures. Digital recordings were edited and manually measured. The outcome measure was a change in QRSd induced by CRT (delta CRT). Several outcome predictors were investigated: native QRSd, cLBBB (by using Strauss criteria), interval between the onset of the QRS complex and the local left ventricular electrogram (Q-LV), and a newly proposed index defined by the difference between RVP and native QRSd (delta RVP). RESULTS: One hundred thirty-three consecutive patients were included in the study. Delta RVP was 27 ± 25 ms, and delta CRT was -14 ± 28 ms. Delta CRT correlated with native QRSd (r = -0.65), with the presence of ECG-based cLBBB (r = -0.40), with Q-LV (r = -0.68), and with delta RVP (r = 0.72) (P < .00001 for all correlations). In multivariable analysis, delta CRT was most strongly associated with delta RVP (P < .00001), followed by native QRSd and Q-LV, while ECG-based cLBBB became a nonsignificant factor. CONCLUSION: Baseline QRSd, delta RVP, and LV electrical lead position (Q-LV) represent strong independent predictors of ECG response to CRT. The absence of QRSd prolongation by RVP may serve as an alternative and more specific marker of cLBBB. Delta RVP correlates strongly with the CRT effect on QRSd and outperforms the predictive value of ECG-based cLBBB.

Maintenance Impact of Large Dose of Vitamin C on Proinflammatory Cytokines, Insulin, and Electrocardiographic Parameters of Wistar Rats Following Partial Pancreatectomy.

We investigated serum tumor necrosis factor alpha (TNF-α) and interleukins (IL-6 and IL-8) in rats undergoing pancreatic wound healing after partial pancreatectomy. In addition, we studied the effects of partial pancreatectomy on the insulin and the electrocardiography (ECG). We proposed that vitamin C (VitC) could have maintenance impact on TNF-α, IL-6, IL-8, insulin, and ECG parameters of pancreatic wound healing of Wistar rats that had partial pancreatectomy surgery, if administered in large dose. Thirty-five male adult Wistar rats (180-250 g) were randomized into 7 groups, with 5 rats in each group. Group 1 was control. Groups 2, 3, and 4 (phase 1) received oral 1,000 mg/kg VitC, while groups 5, 6, and 7 (phase 2) received only water and feed ad libitum postoperatively for 14 days. One-quarter (») pancreatectomy was performed in groups 2 and 5, half (½) pancreatectomy was performed in groups 3 and 6, and three-quarter (¾) pancreatectomy was performed in groups 4 and 7. Significant (P < 0.5) decrease in IL-6 was observed in phase 1 when compared with the control. Significant increase in IL-6 was observed when compared with control. Significant increase in IL-8 was observed in phase 1 (groups 2 and 3) and phase 2 when compared with the control. Significant decrease in TNF-α was observed in phase 1 when compared with the control. Significant decrease in TNF-α was observed in phase 2 (groups 6 and 7) when compared with the control. Insulin level decreased and increased insignificantly in phase 2 and phase 1, respectively, when compared with the control. Although atrial fibrillation was recorded in phase 2 (group 7), normal ECG was seen in the control and phase 1 (group 2). Large dose vitC may be helpful in the reduction of proinflammatory cytokines as well as elevation of insulin and normalization of ECG in rats that had undergone partial pancreatectomy.

Algorithm for cavo-tricuspid isthmus flutter on surface ECGs: the ACTIONS study.

OBJECTIVE: Cavo-tricuspid isthmus atrial flutter (CTI-AFL) is an important arrhythmia to recognise because there is a highly effective and relatively low-risk ablation strategy. However, clinical experience has demonstrated that providers often have difficulty distinguishing AFL from atrial fibrillation. METHODS: We developed a novel ECG-based three-step algorithm to identify CTI-AFL based on established CTI flutter characteristics and verified on consecutive ablation cases of typical flutter, atypical flutter and atrial fibrillation. The algorithm assesses V1/inferior lead F-wave concordance, consistency of P-wave morphology and the presence of isoelectric intervals in the inferior leads. In this observation study, the algorithm was validated on a cohort of 50 second-year medical students. Students were paired in a control and experimental group, and each pair received 10 randomly selected ECGs (from a pool of 50 intracardiac electrogram-proven CTI-AFL and 50 AF or atypical AFL cases). The experimental group received a cover sheet with the CTI algorithm, and the control group received no additional guidance. RESULTS: There was a statistically significant difference in the mean number of correctly identified ECGs among the students in the experimental and control groups (8.12 vs 5.68, p<0.001). Students who used the algorithm correctly identified 2.44 more ECGs as being CTI-AFL or not CTI-AFL. Using the electrophysiology study as the gold standard, the algorithm had an accuracy of 81%, sensitivity of 81%, specificity of 82%, positive predictive value of 78% and negative predictive value of 84% in identifying CTI-AFL. CONCLUSION: We developed a three-step ECG algorithm that provides a simple, sensitive, specific and accurate tool to identify CTI-AFL.

Functional assessment of myocardial ischaemia by intracoronary ECG.

INTRODUCTION: In patients with chronic coronary syndrome, percutaneous coronary intervention targets haemodynamically significant stenoses, that is, those thought to cause ischaemia. Intracoronary ECG (icECG) detects ischaemia directly where it occurs. Thus, the goal of this study was to test the accuracy of icECG during pharmacological inotropic stress to determine functional coronary lesion severity in comparison to the structural parameter of quantitative angiographic per cent diameter stenosis (%S), as well as to the haemodynamic indices of fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR). METHOD: The primary study endpoint of this prospective trial was the maximal change in icECG ST-segment shift during pharmacological inotropic stress induced by dobutamine plus atropine obtained within 1 min after reaching maximal heart rate(=220 - age). IcECG was acquired by attaching an alligator clamp to the angioplasty guidewire positioned downstream of the stenosis. For the pressure-derived stenosis severity ratios, coronary perfusion pressure and simultaneous aortic pressure were continuously recorded. RESULTS: There was a direct linear relation between icECG ST-segment shift and %S: icECG=-0.8+0.03*%S (r2=0.164; p<0.0001). There were inverse linear correlations between FFR and %S: FFR=1.1-6.1*10-3*%S (r2=0.494; p<0.0001), and between iFR and %S: iFR=1.27-8.6*10-3*%S (r2=0.461; p<0.0001). Using a %S-threshold of ≥50% as the reference for structural stenosis relevance, receiver operating characteristics-analysis of absolute icECG ST-segment shift during hyperemia showed an area under the curve (AUC) of 0.678±0.054 (p=0.002; sensitivity=85%, specificity=50% at 0.34 mV). AUC for FFR was 0.854±0.037 (p<0.0001; sensitivity=64%, specificity=96% at 0.78), and for iFR it was 0.816±0.043 (p<0.0001;sensitivity=62%, specificity=96% at 0.83). CONCLUSIONS: Hyperaemic icECG ST-segment shift detects structurally relevant coronary stenotic lesions with high sensitivity, while they are identified highly specific by FFR and iFR.

The utility of electrocardiography and echocardiography in copper deficiency-induced cardiac damage in goats.

Copper deficiency (CuD) is a common mineral disorder in ruminants, which causes histomorphological changes in the heart due to disturbances in copper-dependent metalloenzymes. However, alterations in the measurable cardiac parameters during CuD have not been studied in ruminants, especially in goats. Therefore, the current study aimed to investigate longitudinally the potential role of electrocardiography (ECG) and echocardiography to detect the CuD-induced cardiac damage at different time intervals and concomitantly highlighting the impact of CuD on specific hemato-biochemical parameters and histological cardiac disruption in goats. Eight Shiba goats were included and divided into two equal groups; copper adequate (CuA) as a control and copper-deficient (CuD) that supplemented with copper-chelating agents (sulfur 3 g/kg DM and molybdenum 40 mg/kg DM). The hemato-biochemical analysis, ECG assessment at the base apex lead, and right-side echocardiography were performed just before the experimental onset (T0), and later on at two-time intervals after existing of CuD, at the fifth (T5) and seventh (T7) months. Necropsy and histopathological examination of the heart were performed at the end of the experiment. In the CuD group, the heart dimensions at T5 and T7 showed significant increase in QRS duration, ST-segment duration, the left atrial area in systole, left ventricular diameter and volume in diastole, stroke volume, and cardiac output compared with CuA (P < 0.05). Also, myocardial degeneration, necrosis, and fibrosis were evidenced with a concurrent increase of plasma creatine kinase, lactate dehydrogenase, aspartate aminotransferase, and cardiac troponin I (P < 0.05). In conclusion, CuD disturbs hemato-biochemical parameters and results in myocardial damage and cardiac dilatation that increases some ECG and echocardiographic parameters without development of systolic dysfunction. The ECG and echocardiography can potentially detect cardiac changes in long-lasting CuD in goats.

Efficacy of Nicorandil in the treatment of unstable angina pectoris in 30 patients / 中国基层医药

Objective:To investigate the efficacy of Nicorandil in the treatment of unstable angina pectoris.Methods:Sixty patients with unstable angina pectoris who received treatment in Department of Cardiovascular Disease, Suixi Hospital of Traditional Chinese Medicine, China during January-July 2020 were included in this study. They were randomly assigned to receive either conventional treatment including antiplatelet, increasing coronal blood flow velocity, lipid-lowering treatment and stabilization of atherosclerotic plaque (control group, n = 30) or Nicorandil treatment and conventional treatment (observation group, n = 30). Clinical efficacy was compared between the two groups. Angina attack, electrocardiogram changes and adverse reactions in each group were analyzed before and after treatment. Results:Total effective rate in the observation group was significantly higher than that in the control group [88.67% (26/30) vs. 53.33% (16/30), χ2 = 7.937, P = 0.005]. The frequency and duration of angina pectoris in the observation group were (1.53 ± 0.62) times/week, (1.93 ± 0.78) minutes, which were significantly lower or shorter than those in the control group [(1.97 ± 0.71) times /week, (2.60 ± 1.00) minutes, t = -2.359, -3.162, P = 0.025, 0.004). The total effective rate of electrocardiogram in the observation group was significantly higher than that in the control group [70.00% (22/30) vs. 43.34% (13/30), χ2 = 5.554, P = 0.018]. There was no significant difference in the incidence of adverse drug reactions such as nausea, dizziness and palpitation between the two groups (all P > 0.05). Conclusion:Based on conventional treatment, Nicorandil treatment for unstable angina pectoris can improve the clinical symptoms and electrocardiogram changes, exhibit remarkable efficacy, and therefore deserve clinical promotion.