Displaying publications 61 - 80 of 209 in total

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  1. Performance Evaluation of Time-Frequency Distributions for ECG Signal Analysis
    Hussein AF, Hashim SJ, Aziz AFA, Rokhani FZ, Adnan WAW
    J Med Syst, 2017 Nov 29;42(1):15.
    PMID: 29188389 DOI: 10.1007/s10916-017-0871-8
    The non-stationary and multi-frequency nature of biomedical signal activities makes the use of time-frequency distributions (TFDs) for analysis inevitable. Time-frequency analysis provides simultaneous interpretations in both time and frequency domain enabling comprehensive explanation, presentation and interpretation of electrocardiogram (ECG) signals. The diversity of TFDs and specific properties for each type show the need to determine the best TFD for ECG analysis. In this study, a performance evaluation of five TFDs in term of ECG abnormality detection is presented. The detection criteria based on extracted features from most important ECG signal components (QRS) to detect normal and abnormal cases. This is achieved by estimating its energy concentration magnitude using the TFDs. The TFDs analyse ECG signals in one-minute interval instead of conventional time domain approach that analyses based on beat or frame containing several beats. The MIT-BIH normal sinus rhythm ECG database total records of 18 long-term ECG sampled at 128 Hz have been analysed. The tested TFDs include Dual-Tree Wavelet Transform, Spectrogram, Pseudo Wigner-Ville, Choi-Williams, and Born-Jordan. Each record is divided into one-minute slots, which is not considered previously, and analysed. The sample periods (slots) are randomly selected ten minutes interval for each record. This result with 99.44% detection accuracy for 15,735 ECG beats shows that Choi-Williams distribution is most reliable to be used for heart problem detection especially in automated systems that provide continuous monitoring for long time duration.
    Matched MeSH terms: Electrocardiography/methods*
  2. Evaluation of Wrist-Worn Photoplethysmography Trackers with an Electrocardiogram in Patients with Ischemic Heart Disease: A Validation Study
    Ibrahim NS, Rampal S, Lee WL, Pek EW, Suhaimi A
    Cardiovasc Eng Technol, 2024 Feb;15(1):12-21.
    PMID: 37973701 DOI: 10.1007/s13239-023-00693-z
    PURPOSE: Photoplethysmography measurement of heart rate with wrist-worn trackers has been introduced in healthy individuals. However, additional consideration is necessary for patients with ischemic heart disease, and the available evidence is limited. The study aims to evaluate the validity and reliability of heart rate measures by a wrist-worn photoplethysmography (PPG) tracker compared to an electrocardiogram (ECG) during incremental treadmill exercise among patients with ischemic heart disease.

    METHODS: Fifty-one participants performed the standard incremental treadmill exercise in a controlled laboratory setting with 12-lead ECG attached to the patient's body and wearing wrist-worn PPG trackers.

    RESULTS: At each stage, the absolute percentage error of the PPG was within 10% of the standard acceptable range. Further analysis using a linear mixed model, which accounts for individual variations, revealed that PPG yielded the best performance at the baseline low-intensity exercise. As the stages progressed, heart rate validity decreased but was regained during recovery. The reliability was moderate to excellent.

    CONCLUSIONS: Low-cost trackers AMAZFIT Cor and Bip validity and reliability were within acceptable ranges, especially during low-intensity exercise among patients with ischemic heart disease recovering from cardiac procedures. Though using the tracker as part of the diagnosis tool still requires more supporting studies, it can potentially be used as a self-monitoring tool with precautions.

    Matched MeSH terms: Electrocardiography
  3. Fulltext Novel impedance measurement technique for soluble solid content determination of banana
    Ibrahim, N.U.A., Abd Aziz, S., Nawi, N.M.
    Pertanika Journal of Science & Technology, 2017;25(2):519-526.
    MyJurnal
    Soluble solid content (SSC) is one of the important traits that indicate the ripeness of banana fruits.
    Determination of SSC for banana often requires destructive laboratory analysis on the fruit. An impedance measurement technique was investigated as a non-destructive approach for SSC determination of bananas. A pair of electrocardiogram (ECG) electrode connected to an impedance analyser board was used to measure the impedance value of bananas over the frequency of 19.5 to 20.5 KHz. The SSC measurement was conducted using a pocket refractometer and data was analysed to correlate SSC with impedance values. It was found that the mean of impedance, Z decreased from 10.01 to 99.93 KΩ at the frequency of 20 KHz, while the mean value of SSC increased from 0.58 to 4.93 % Brix from day 1 to day 8. The best correlation between impedance and SSC was found at 20 KHz, with the coefficient of determination, R2 of 0.87. This result indicates the potential of impedance measurement in predicting SSC of banana fruits.
    Matched MeSH terms: Electrocardiography
  4. Real-time signal processing for fetal heart rate monitoring
    Ibrahimy MI, Ahmed F, Mohd Ali MA, Zahedi E
    IEEE Trans Biomed Eng, 2003 Feb;50(2):258-62.
    PMID: 12665042
    An algorithm based on digital filtering, adaptive thresholding, statistical properties in the time domain, and differencing of local maxima and minima has been developed for the simultaneous measurement of the fetal and maternal heart rates from the maternal abdominal electrocardiogram during pregnancy and labor for ambulatory monitoring. A microcontroller-based system has been used to implement the algorithm in real-time. A Doppler ultrasound fetal monitor was used for statistical comparison on five volunteers with low risk pregnancies, between 35 and 40 weeks of gestation. Results showed an average percent root mean square difference of 5.32% and linear correlation coefficient from 0.84 to 0.93. The fetal heart rate curves remained inside a +/- 5-beats-per-minute limit relative to the reference ultrasound method for 84.1% of the time.
    Matched MeSH terms: Electrocardiography, Ambulatory/methods*
  5. Deep Deterministic Learning for Pattern Recognition of Different Cardiac Diseases through the Internet of Medical Things
    Iqbal U, Wah TY, Habib Ur Rehman M, Mujtaba G, Imran M, Shoaib M
    J Med Syst, 2018 Nov 05;42(12):252.
    PMID: 30397730 DOI: 10.1007/s10916-018-1107-2
    Electrocardiography (ECG) sensors play a vital role in the Internet of Medical Things, and these sensors help in monitoring the electrical activity of the heart. ECG signal analysis can improve human life in many ways, from diagnosing diseases among cardiac patients to managing the lifestyles of diabetic patients. Abnormalities in heart activities lead to different cardiac diseases and arrhythmia. However, some cardiac diseases, such as myocardial infarction (MI) and atrial fibrillation (Af), require special attention due to their direct impact on human life. The classification of flattened T wave cases of MI in ECG signals and how much of these cases are similar to ST-T changes in MI remain an open issue for researchers. This article presents a novel contribution to classify MI and Af. To this end, we propose a new approach called deep deterministic learning (DDL), which works by combining predefined heart activities with fused datasets. In this research, we used two datasets. The first dataset, Massachusetts Institute of Technology-Beth Israel Hospital, is publicly available, and we exclusively obtained the second dataset from the University of Malaya Medical Center, Kuala Lumpur Malaysia. We first initiated predefined activities on each individual dataset to recognize patterns between the ST-T change and flattened T wave cases and then used the data fusion approach to merge both datasets in a manner that delivers the most accurate pattern recognition results. The proposed DDL approach is a systematic stage-wise methodology that relies on accurate detection of R peaks in ECG signals, time domain features of ECG signals, and fine tune-up of artificial neural networks. The empirical evaluation shows high accuracy (i.e., ≤99.97%) in pattern matching ST-T changes and flattened T waves using the proposed DDL approach. The proposed pattern recognition approach is a significant contribution to the diagnosis of special cases of MI.
    Matched MeSH terms: Electrocardiography/methods*
  6. Ventricular bigeminy following a cobra envenomation
    Ismail AK, Weinstein SA, Auliya M, Appareo P
    Clin Toxicol (Phila), 2012 Jul;50(6):518-21.
    PMID: 22702902 DOI: 10.3109/15563650.2012.696119
    Envenoming by some species of cobras (Naja species) may include cardiotoxic effects including various dysrhythmias. However, dysrhythmias leading specifically to ventricular bigeminy have not been previously documented. We report a case of cardiotoxicity and the development of ventricular bigeminy following a cobra envenomation.
    Matched MeSH terms: Electrocardiography
  7. Fulltext Clinical interpretations of the effectiveness of changes in body position during aerobic fitness after neurologic injury
    Izan NF, Salleh SH, Ting CM, Noman F, Sh-Hussain H, Poznanski RR, et al.
    J Integr Neurosci, 2020 Sep 30;19(3):479-487.
    PMID: 33070527 DOI: 10.31083/j.jin.2020.03.222
    The purpose is to estimate the effectiveness of electrocardiograms during resting and active participation by the differentiation between the electrical activity of the heart while standing and sitting in a resting state. The concern is to identify the electrocardiogram parameters that did not show significant changes within these positions. The electrocardiogram parameters can be considered to be a standard marker for medically compromised patients. The electrocardiogram is recorded in the standing and sitting positions focusing on healthy participants using standard electrode placement of lead-I. Combined lead-I patterns (camel-hump or ST-segment prolongation) are usually seen in neurologic injury or hypothermia patients. The pairwise comparisons of a year data are about 454,400 cycles of sitting and 493,470 cycles of standing data. Thus, it is essential to quantify the nature and magnitude of changes seen in the electrocardiogram with a change of posture from sitting to standing in a healthy individual. This makes the findings of electrocardiogram analysis in this paper interesting in which some parameters (i.e., camel-hump patterns in lead-I) are helpful for clinical interpretations and could be suggestive of neurologic injury.
    Matched MeSH terms: Electrocardiography*
  8. Computer-aided diagnosis of congestive heart failure using ECG signals - A review
    Jahmunah V, Oh SL, Wei JKE, Ciaccio EJ, Chua K, San TR, et al.
    Phys Med, 2019 Jun;62:95-104.
    PMID: 31153403 DOI: 10.1016/j.ejmp.2019.05.004
    The heart muscle pumps blood to vital organs, which is indispensable for human life. Congestive heart failure (CHF) is characterized by the inability of the heart to pump blood adequately throughout the body without an increase in intracardiac pressure. The symptoms include lung and peripheral congestion, leading to breathing difficulty and swollen limbs, dizziness from reduced delivery of blood to the brain, as well as arrhythmia. Coronary artery disease, myocardial infarction, and medical co-morbidities such as kidney disease, diabetes, and high blood pressure all take a toll on the heart and can impair myocardial function. CHF prevalence is growing worldwide. It afflicts millions of people globally, and is a leading cause of death. Hence, proper diagnosis, monitoring and management are imperative. The importance of an objective CHF diagnostic tool cannot be overemphasized. Standard diagnostic tests for CHF include chest X-ray, magnetic resonance imaging (MRI), nuclear imaging, echocardiography, and invasive angiography. However, these methods are costly, time-consuming, and they can be operator-dependent. Electrocardiography (ECG) is inexpensive and widely accessible, but ECG changes are typically not specific for CHF diagnosis. A properly designed computer-aided detection (CAD) system for CHF, based on the ECG, would potentially reduce subjectivity and provide quantitative assessment for informed decision-making. Herein, we review existing CAD for automatic CHF diagnosis, and highlight the development of an ECG-based CAD diagnostic system that employs deep learning algorithms to automatically detect CHF.
    Matched MeSH terms: Electrocardiography*
  9. Primary cardiac amyloidosis
    Jeyamalar R, Pathmanathan R, Yap SF, Kannan P
    Ann Acad Med Singap, 1991 Nov;20(6):795-7.
    PMID: 1803972
    Cardiac amyloidosis is an uncommon and often unrecognised cause of cardiac failure. It is an infiltrative disease that may mimic either a restrictive or hypertrophic cardiomyopathy, constrictive pericarditis, coronary artery disease or valvular heart disease. The diagnosis should be suspected in a patient with cardiac failure who has low voltage complexes on the electrocardiogram, in association with increased myocardial mass and echogenicity on the echocardiogram. The definitive diagnosis, however, can only be made by endomyocardial biopsy or biopsy of any involved organ in systemic amyloidosis. Prognosis is poor and treatment ineffective.
    Matched MeSH terms: Electrocardiography
  10. Left bundle branch area pacing for heart failure patients requiring cardiac resynchronization therapy: A meta-analysis
    Jin C, Dai Q, Li P, Lam P, Cha YM
    J Cardiovasc Electrophysiol, 2023 Sep;34(9):1933-1943.
    PMID: 37548113 DOI: 10.1111/jce.16013
    INTRODUCTION: Left bundle branch area pacing (LBBP) is a novel conduction system pacing method to achieve effective physiological pacing and an alternative to cardiac resynchronization therapy (CRT) with biventricular pacing (BVP) for patients with heart failure with reduced ejection fraction (HFrEF). We conduted this meta-analysis and systemic review to review current data comparing BVP and LBBP in patients with HFrEF and indications for CRT.

    METHODS: We searched PubMed/Medline, Web of Science, and Cochrane Library from the inception of the database to November 2022. All studies that compared LBBP with BVP in patients with HFrEF and indications for CRT were included. Two reviewers performed study selection, data abstraction, and risk of bias assessment. We calculated risk ratios (RRs) with the Mantel-Haenszel method and mean difference (MD) with inverse variance using random effect models. We assessed heterogeneity using the I2 index, with I2  > 50% indicating significant heterogeneity.

    RESULTS: Ten studies (9 observational studies and 1 randomized controlled trial; 616 patients; 15 centers) published between 2020 and 2022 were included. We observed a shorter fluoroscopy time (MD: 9.68, 95% confidence interval [CI]: 4.49-14.87, I2  = 95%, p 

    Matched MeSH terms: Electrocardiography
  11. Fulltext Evaluation of cardiac signals using discrete wavelet transform with MATLAB graphical user interface
    John AA, Subramanian AP, Jaganathan SK, Sethuraman B
    Indian Heart J, 2015 Nov-Dec;67(6):549-51.
    PMID: 26702684 DOI: 10.1016/j.ihj.2015.07.017
    To process the electrocardiogram (ECG) signals using MATLAB-based graphical user interface (GUI) and to classify the signals based on heart rate.
    Matched MeSH terms: Electrocardiography
  12. Global variations in the prevalence, treatment, and impact of atrial fibrillation in a multi-national cohort of 153 152 middle-aged individuals
    Joseph PG, Healey JS, Raina P, Connolly SJ, Ibrahim Q, Gupta R, et al.
    Cardiovasc Res, 2021 05 25;117(6):1523-1531.
    PMID: 32777820 DOI: 10.1093/cvr/cvaa241
    AIMS: To compare the prevalence of electrocardiogram (ECG)-documented atrial fibrillation (or flutter) (AF) across eight regions of the world, and to examine antithrombotic use and clinical outcomes.

    METHODS AND RESULTS: Baseline ECGs were collected in 153 152 middle-aged participants (ages 35-70 years) to document AF in two community-based studies, spanning 20 countries. Medication use and clinical outcome data (mean follow-up of 7.4 years) were available in one cohort. Cross-sectional analyses were performed to document the prevalence of AF and medication use, and associations between AF and clinical events were examined prospectively. Mean age of participants was 52.1 years, and 57.7% were female. Age and sex-standardized prevalence of AF varied 12-fold between regions; with the highest in North America, Europe, China, and Southeast Asia (270-360 cases per 100 000 persons); and lowest in the Middle East, Africa, and South Asia (30-60 cases per 100 000 persons) (P 

    Matched MeSH terms: Electrocardiography/trends
  13. Fulltext Atrial septal defect with Crochetage sign presenting with pulmonary artery thrombosis
    Kaisbain N, Lim WJ, Kim HS
    BMJ Case Rep, 2021 Jul 27;14(7).
    PMID: 34315750 DOI: 10.1136/bcr-2021-244180
    Atrial septal defect (ASD) is the most common congenital heart disease observed in adult. Several ECG findings are considered sensitive for the diagnosis of ASD. We describe a 50 years old man who displayed Crochetage sign, incomplete right bundle branch block (IRBBB) and right ventricular strain pattern on ECG. Crochetage sign is highly specific for ASD and it correlates with shunt severity. The diagnostic specificity for ASD increases if the R waves have both Crochetage patterns and IRBBB. It is important not to confuse Crochetage signs with IRBBB abnormalities on ECG. Our patient was ultimately diagnosed with a large ASD measuring 3 cm with bidirectional shunt and concomitant pulmonary thrombosis. This illustrates that high suspicion of the ASD with the use of good-old ECG signs remains relevant in this modern era. This also reminds us that patients with Eisenmenger syndrome are at higher risk for pulmonary thrombosis.
    Matched MeSH terms: Electrocardiography
  14. ECG lead misplacement in the frontal and horizontal plane mimicking A myocardial infarction
    Kaisbain N, Khoo KKL, Lim WJ
    Am J Emerg Med, 2023 Dec;74:196.e1-196.e4.
    PMID: 37863804 DOI: 10.1016/j.ajem.2023.10.009
    BACKGROUND/AIMS: Electrocardiogram (ECG) is an inexpensive, fundamental screening tool used in daily clinical practice. It is essential in the diagnosis of life-threatening conditions, such as acute myocardial infarctions, ventricular arrhythmias etc. However, ECG lead misplacement is a common technical error, which may translate into wrong interpretations, unnecessary investigations, and improper treatments.

    METHODS/RESULTS: We report a case of a multiple ECG lead misplacement made across two different planes of the heart, resulting in a bizarre series of ECG, mimicking an acute high lateral myocardial infarction. Multiple ECGs were done as there were abrupt changes compared to previous ECGS. Patient was pain free and administration of potentially harmful procedures and treatments were prevented.

    CONCLUSION: Our case demonstrated the importance of high clinical suspicion in diagnosing ECG lead misplacement. It is the responsibility of both the healthcare workers who are performing and interpreting the ECG to be alert of a possible lead malposition, to prevent untoward consequences to the patient.

    Matched MeSH terms: Electrocardiography/methods
  15. Based on Real Time Remote Health Monitoring Systems: A New Approach for Prioritization "Large Scales Data" Patients with Chronic Heart Diseases Using Body Sensors and Communication Technology
    Kalid N, Zaidan AA, Zaidan BB, Salman OH, Hashim M, Albahri OS, et al.
    J Med Syst, 2018 Mar 02;42(4):69.
    PMID: 29500683 DOI: 10.1007/s10916-018-0916-7
    This paper presents a new approach to prioritize "Large-scale Data" of patients with chronic heart diseases by using body sensors and communication technology during disasters and peak seasons. An evaluation matrix is used for emergency evaluation and large-scale data scoring of patients with chronic heart diseases in telemedicine environment. However, one major problem in the emergency evaluation of these patients is establishing a reasonable threshold for patients with the most and least critical conditions. This threshold can be used to detect the highest and lowest priority levels when all the scores of patients are identical during disasters and peak seasons. A practical study was performed on 500 patients with chronic heart diseases and different symptoms, and their emergency levels were evaluated based on four main measurements: electrocardiogram, oxygen saturation sensor, blood pressure monitoring, and non-sensory measurement tool, namely, text frame. Data alignment was conducted for the raw data and decision-making matrix by converting each extracted feature into an integer. This integer represents their state in the triage level based on medical guidelines to determine the features from different sources in a platform. The patients were then scored based on a decision matrix by using multi-criteria decision-making techniques, namely, integrated multi-layer for analytic hierarchy process (MLAHP) and technique for order performance by similarity to ideal solution (TOPSIS). For subjective validation, cardiologists were consulted to confirm the ranking results. For objective validation, mean ± standard deviation was computed to check the accuracy of the systematic ranking. This study provides scenarios and checklist benchmarking to evaluate the proposed and existing prioritization methods. Experimental results revealed the following. (1) The integration of TOPSIS and MLAHP effectively and systematically solved the patient settings on triage and prioritization problems. (2) In subjective validation, the first five patients assigned to the doctors were the most urgent cases that required the highest priority, whereas the last five patients were the least urgent cases and were given the lowest priority. In objective validation, scores significantly differed between the groups, indicating that the ranking results were identical. (3) For the first, second, and third scenarios, the proposed method exhibited an advantage over the benchmark method with percentages of 40%, 60%, and 100%, respectively. In conclusion, patients with the most and least urgent cases received the highest and lowest priority levels, respectively.
    Matched MeSH terms: Electrocardiography, Ambulatory
  16. Myocardial infarction in a young Indian grandmultipara
    Kannan P, Raman S, Ramani VS, Jeyamalar R
    Aust N Z J Obstet Gynaecol, 1993 Nov;33(4):424-6.
    PMID: 8179560
    Matched MeSH terms: Electrocardiography
  17. Fulltext Simultaneous electrocardiography and Doppler echocardiography in pulsus alternans
    Khalid Y
    Med J Malaysia, 1994 Jun;49(2):174-5.
    PMID: 8090099
    Pulsus alternans, the alternating strong and week pulses which occur in patients with severe heart failure, was first described by Traube in 1872. Since then various methods, both invasive1,2 and non-invasive3,4, have been used to study this phenomenon. This study demonstrates the utility of using simultaneous electrocardiography (ECG) and Doppler echocardiography to document pulsus alternans, and to differentiate it from other causes of alternating pulses.
    Matched MeSH terms: Electrocardiography*
  18. Fulltext Multimodality registration of two-dimensional echocardiography and cardiac CT for mitral valve diagnosis and surgical planning
    Khalil A, Faisal A, Ng SC, Liew YM, Lai KW
    J Med Imaging (Bellingham), 2017 Jul;4(3):037001.
    PMID: 28840172 DOI: 10.1117/1.JMI.4.3.037001
    A registration method to fuse two-dimensional (2-D) echocardiography images with cardiac computed tomography (CT) volume is presented. The method consists of two major procedures: temporal and spatial registrations. In temporal registration, the echocardiography frames at similar cardiac phases as the CT volume were interpolated based on electrocardiogram signal information, and the noise of the echocardiography image was reduced using the speckle reducing anisotropic diffusion technique. For spatial registration, an intensity-based normalized mutual information method was applied with a pattern search optimization algorithm to produce an interpolated cardiac CT image. The proposed registration framework does not require optical tracking information. Dice coefficient and Hausdorff distance for the left atrium assessments were [Formula: see text] and [Formula: see text], respectively; for left ventricle, they were [Formula: see text] and [Formula: see text], respectively. There was no significant difference in the mitral valve annulus diameter measurement between the manually and automatically registered CT images. The transformation parameters showed small deviations ([Formula: see text] deviation in translation and [Formula: see text] for rotation) between manual and automatic registrations. The proposed method aids the physician in diagnosing mitral valve disease as well as provides surgical guidance during the treatment procedure.
    Matched MeSH terms: Electrocardiography
  19. Occurrences of heart disease in apparently healthy cats in Klang Valley, Malaysia
    Khor KH, Chin MX
    J Adv Vet Anim Res, 2020 Sep;7(3):501-508.
    PMID: 33005676 DOI: 10.5455/javar.2020.g446
    Objective: Annual health screening inclusive of heart workup is recommended for the detection of heart diseases, especially in asymptomatic patients (no clinical signs). This study determined the occurrences of the common heart disease and the risk factors in apparently healthy cats.

    Materials and methods: This prospective study that screened 59 healthy cats and the status of the heart were evaluated based on a combination of findings from physical examination, electrocardiography, blood pressure measurement, routine blood test, urinalysis, and total thyroid level.

    Results: Approximately 40.7% (n = 24/59) of the apparently healthy cats were diagnosed with heart disease hypertrophic cardiomyopathy (62.5%) remains to be the most commonly diagnosed. The mean age was 4.9-year old (age range, 7-month-old to 19-year-old). The prevalence was higher in males (45.0%; n = 17/38) cats, especially the domestic shorthairs (46.0%; n = 11/24). Among the healthy cats with vertebral heart scale (VHS) > 8.0, only 52% (n = 12/23) of them were diagnosed with cardiomyopathy. However, 33% (n = 12/36) of the cats with normal VHS ≤ 7.9 were diagnosed with heart disease. Consistently, all healthy cats with abnormal heart sounds were diagnosed with heart disease. About 31.4% (n = 16/51) of these cats with typical heart sound had cardiomyopathy too.

    Conclusion: The occurrence of cardiomyopathy in apparently healthy cats has no association with the patient's age, sex, and VHS, except for the heart sound. Echocardiography remains the best diagnostic tool, as normal heart size and normal heart sound do not exclude cardiomyopathy in this group of apparently healthy cats.

    Matched MeSH terms: Electrocardiography
  20. Evaluation of a technique to measure heart rate variability in anaesthetised cats
    Khor KH, Shiels IA, Campbell FE, Greer RM, Rose A, Mills PC
    Vet J, 2014 Feb;199(2):229-35.
    PMID: 24321367 DOI: 10.1016/j.tvjl.2013.11.006
    Analysis of heart rate (HR) and heart rate variability (HRV) are powerful tools to investigate cardiac diseases, but current methods, including 24-h Holter monitoring, can be cumbersome and may be compromised by movement artefact. A commercially available data capture and analysis system was used in anaesthetised healthy cats to measure HR and HRV during pharmacological manipulation of HR. Seven healthy cats were subjected to a randomised crossover study design with a 7 day washout period between two treatment groups, placebo and atenolol (1mg/kg, IV), with the efficacy of atenolol to inhibit β1 adrenoreceptors challenged by epinephrine. Statistical significance for the epinephrine challenge was set at P<0.0027 (Holm-Bonferroni correction), whereas a level of significance of P<0.05 was set for other variables. Analysis of the continuous electrocardiography (ECG) recordings showed that epinephrine challenge increased HR in the placebo group (P=0.0003) but not in the atenolol group. The change in HR was greater in the placebo group than in the atenolol group (P=0.0004). Therefore, compared to cats pre-treated with placebo, pre-treatment with atenolol significantly antagonised the tachycardia while not significantly affecting HRV. The increased HR in the placebo group following epinephrine challenge was consistent with a shift of the sympathovagal balance towards a predominantly sympathetic tone. However, the small (but not significant at the critical value) decrease in the normalised high-frequency component (HFnorm) in both groups of cats suggested that epinephrine induced a parasympathetic withdrawal in addition to sympathetic enhancement (increased normalised low frequency component or LFnorm). In conclusion, this model is a highly sensitive and repeatable model to investigate HRV in anaesthetised cats that would be useful in the laboratory setting for short-term investigation of cardiovascular disease and subtle responses to pharmacological agents in this species.
    Matched MeSH terms: Electrocardiography/veterinary
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