ECG SIGNAL GENERATION AND HEART RATE VARIABILITY SIGNAL EXTRACTION: SIGNAL PROCESSING, FEATURES DETECTION, AND THEIR CORRELATION WITH CARDIAC DISEASES

The sum total of millions of cardiac cell depolarization potentials can be represented by an electrocardiogram (ECG). Inspection of the P–QRS–T wave allows for the identification of the cardiac bioelectrical health and disorders of a subject. In order to extract the important features of the ECG signal, the detection of the P wave, QRS complex, and ST segment is essential. Therefore, abnormalities of these ECG parameters are associated with cardiac disorders. In this work, an introduction to the genesis of the ECG is given, followed by a depiction of some abnormal ECG patterns and rhythms (associated with P–QRS–T wave parameters), which have come to be empirically correlated with cardiac disorders (such as sinus bradycardia, premature ventricular contraction, bundle-branch block, atrial flutter, and atrial fibrillation). We employed algorithms for ECG pattern analysis, for the accurate detection of the P wave, QRS complex, and ST segment of the ECG signal. We then catagorited and tabulated these cardiac disorders in terms of heart rate, PR interval, QRS width, and P wave amplitude. Finally, we discussed the characteristics and different methods (and their measures) of analyting the heart rate variability (HRV) signal, derived from the ECG waveform. The HRV signals are characterised in terms of these measures, then fed into classifiers for grouping into categories (for normal subjects and for disorders such as cardiac disorders and diabetes) for carrying out diagnosis.

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Changes in the Electrocardiogram and Achilles Reflex Test during Treatment of Hypothyroidism

Scottish Medical Journal ◽

10.1177/003693306901400206 ◽

1969 ◽

Vol 14 (2) ◽

pp. 59-63 ◽

Cited By ~ 1

Author(s):

R. J. Weir ◽

J. A. Young ◽

J. B. McGuinness

Keyword(s):

P Wave ◽

Qrs Complex ◽

T Wave ◽

St Segment ◽

Pr Interval ◽

Myocardial Muscle ◽

Reflex Time

In 10 patients with hypothyroidism, the electrocardiogram and Achilles reflex test have been recorded before and during treatment with l-thyroxine sodium. Aspects of the electrocardiogram affected by hypothyroidism are the rate, duration of PR interval, height of P-wave, of QRS complex and of T-wave and the ST segment. Each of these improved with therapy, the earliest and most sensitive change being the height of the QRS complex. The Achilles reflex time as recorded by the photomotograph also showed a parallel decrease with therapy but this is considered to be less reliable as an isolated test. The prolongation of the PR interval is briefly discussed and a correlation between the changes in skeletal and myocardial muscle is suggested.

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Electrocardiogram Changes with Acute Alcohol Intoxication: A Systematic Review

The Open Cardiovascular Medicine Journal ◽

10.2174/1874192401812010001 ◽

2018 ◽

Vol 12 (1) ◽

pp. 1-6 ◽

Cited By ~ 4

Author(s):

Hitesh Raheja ◽

Vinod Namana ◽

Kirti Chopra ◽

Ankur Sinha ◽

Sushilkumar Satish Gupta ◽

...

Keyword(s):

Cardiac Arrhythmias ◽

Alcohol Intoxication ◽

P Wave ◽

Acute Alcohol Intoxication ◽

Qrs Complex ◽

Qtc Prolongation ◽

Ecg Changes ◽

T Wave ◽

St Segment ◽

Electrocardiogram Ecg

Background: Acute alcohol intoxication has been associated with cardiac arrhythmias but the electrocardiogram (ECG) changes associated with acute alcohol intoxication are not well defined in the literature. Objective: Highlight the best evidence regarding the ECG changes associated with acute alcohol intoxication in otherwise healthy patients and the pathophysiology of the changes. Methods: A literature search was carried out; 4 studies relating to ECG changes with acute alcohol intoxication were included in this review. Results: Of the total 141 patients included in the review, 90 (63.8%) patients had P-wave prolongation, 80 (56%) patients had QTc prolongation, 19 (13.5%) patients developed T-wave abnormalities, 10 (7%) patients had QRS complex prolongation, 3 (2.12%) patients developed ST-segment depressions. Conclusion: The most common ECG changes associated with acute alcohol intoxication are (in decreasing order of frequency) P-wave and QTc prolongation, followed by T-wave abnormalities and QRS complex prolongation. Mostly, these changes are completely reversible.

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Electrocardiogram of Clinically Healthy Mithun (Bos frontalis): Variation among Strains

Veterinary Medicine International ◽

10.4061/2010/790310 ◽

2010 ◽

Vol 2010 ◽

pp. 1-8 ◽

Cited By ~ 1

Author(s):

Sagar Sanyal ◽

Pradip Kumar Das ◽

Probal Ranjan Ghosh ◽

Kinsuk Das ◽

Kezha V. Vupru ◽

...

Keyword(s):

Heart Rate ◽

Respiration Rate ◽

Rectal Temperature ◽

The Other ◽

P Wave ◽

Qrs Complex ◽

T Wave ◽

Genetic Strains ◽

The Mean ◽

Bovine Species

A study was conducted to establish the normal electrocardiogram in four different genetic strains of mithun (Bos frontalis). Electrocardiography, cardiac electrical axis, heart rate, rectal temperature and respiration rate were recorded in a total of 32 adult male mithun of four strains ( each). It was found that the respiration and heart rates were higher () in Manipur than other three strains. Amplitude () and duration of P wave and QRS complex differed () among the strains. Mizoram strain had the highest amplitude and duration of P wave and QRS complex. On the other hand, higher () amplitude and duration of T wave were recorded in Arunachalee and Mizoram strains. The mean electrical axis of QRS complex that were recorded for Arunachalee and Manipur strains were similar to that reported for other bovine species; whereas the electrical axis of QRS for Nagamese and Mizoram strains were more close to feline and caprine species, respectively. In conclusion, electrocardiogram of mithun revealed that the amplitude and duration of P wave, QRS complex and T wave were different among four different genetic strains of mithun and the electrical axis of QRS complex for Nagamese and Mizoram mithuns are dissimilar to bovine species.

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Characteristics of the reindeer electrocardiogram

Rangifer ◽

10.7557/2.2.2.412 ◽

1982 ◽

Vol 2 (2) ◽

pp. 36

Author(s):

Jouni Timisjärvi ◽

Mauri Nieminen ◽

Sven Nikander

Keyword(s):

Heart Rate ◽

Indirect Evidence ◽

Frontal Plane ◽

Heart Beat ◽

P Wave ◽

Qrs Complex ◽

Single Plane ◽

T Wave ◽

Wide Range ◽

Electrocardiogram Ecg

The electrocardiogram (ECG) provides reliable information about heart rate, initiation of heart beat and also, to some degree, indirect evidence on the functional state of the heart muscle. A wide range of such information is readily obtainable from conventional scalar leads, even if the records are limited to a single plane. The present investigation deals with the normal reindeer ECG in the frontal plane. The technique used is the scalar recording technique based on the Einthovenian postulates. The P wave was positive in leads II, III and aVF, negative in lead aVL and variable in leads I and aVR. The direction of the P vector was 60 to 120°. The QRS complex was variable. The most common forms of QRS complex were R and rS in leads I and aVR; R, Rs and rS in lead aVL and Qr or qR in other leads. The most common direction of the QRS vector was 240 to 300°. The T wave was variable. The duration of various intervals and deflection depended on heart rate.Elektrokardiogram på ren.Abstract in Swedish / Sammandrag: Elektrokardiogramet (EKG) ger tillförlitliga uppgifter om hjärtfrekvens, retledning och, indirekt, delvis även om hjärtmuskelns funktionell tillstånd. Största delen av denna information fås med normal skalar koppling även om registrering sker i ett plan. I detta arbete har renens normala EKG i frontalplanet undersökts. Kopplingarna har baserats på Einthovs postulat. P-vågen var riktad uppåt i koppling II, III och aVF, nedåt i koppling aVL och den varierade i koppling I och aVR. P-vektorns riktning var 60 - 120°. QRS-komplexet varierade. De vanligaste formerna var R och rS i koppling I och aVR; R, Rs och rS i koppling aVL och Qr eller qR i andra kopplingar. Vanligen var QRS-vektorns riktning 240 - 300°. T-vågen varierade. Awikelserna och intervallernas längd var beroende av hiärtfrekvenssen.Poron sydänsähkökäyrän ominaisuuksia.Abstract in Finnish / Yhteenveto: Sydänsähkökäyrästä saadaan luotettavaa tietoa sydämen syketiheydestä, sähköisestä johtumisesta ja välillisesti jossain määrin myös sydänlihaksen toiminnallisesta tilasta. Suurin osa tämänkaltaista tietoa voidaan saada tavanomaisia skalaarisia kytkentöjäkäyttäen, ja usein yhdessä tasossa tapahtuva rekisteröinti on riittävä. Tässä työssä on tutkittu porojen normaalia sydänsähkökäyrää ja sen eri poikkeamien suuntautumista frontaalitasossa, kun rekisteröinnissä on käytetty Einthovenin postulaattien mukaisia raajakytkentöjä. P aalto suuntautui ylöspäin kythkennöissä II, III ja aVF, alaspäin kytkennässä aVL ja vaihteli kytkennöissä I ja aVR. P vektorin suunta oli 60 - 120°. QRS kompleksi vaihteli. Tavallisimmat muodot olivat R ja rS kytkennöissä I ja aVR; R, Rs ja rS kytkennässä aVL ja Qr tai qR muissa kytkennöissä. Tavallisin QRS vektorin suunta oli 240 - 300°. T aalto vaihteli. Poikkeaminen ja intervallien kesto riippui sydämen syketiheydestä.

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Electrocardiographic changes in awassi diarrheic suckling lambs in Iraq

The Iraqi Journal of Veterinary Medicine ◽

10.30539/iraqijvm.v43i1.467 ◽

2019 ◽

Vol 43 (1) ◽

pp. 26-33

Author(s):

Islam Jawad . Alkhafaji

Keyword(s):

P Wave ◽

Qrs Complex ◽

Sinus Arrhythmia ◽

T Wave ◽

St Depression ◽

St Segment ◽

Electrocardiographic Changes ◽

Qrs Duration ◽

Awassi Lambs ◽

T Waves

This study was done to investigate the electrocardiographic changes in 90 diarrheic nursed Awassi lambs, in comparison with 10 clinically healthy lambs of the same breed. Their ages were ranged from 5 days to 2 months, in Karbala City-Iraq, from November 2015 to April 2016. The diarrheic lambs showed significant (P≤0.05) decreased duration of P-wave (0.039±0.0000001 ms and shorter QRS wave amplitudes 0.6 0±0.042 mV with duration 0.041±0.0008 ms , higher T wave amplitude and duration ( 0.25±0.034 mV and 0.070±0.002 ms) , prolonged QT (0.21±0.004 ms) but ST-segment ( 0.17±0.004 ms) were its observed sinus arrhythmia with tachycardia in lead-II in diarrheic lambs were recorded compared with non-diarrheic lambs group which their QRS duration and amplitude were it was (0.04±0.000001ms and 0.65±0.026 mV ) , T waves duration and amplitude were ( 0.076±0.004 ms and 0.21±0.012 mV ) QT interval (0.20±0.011 ms) and ST-segment ( 0.16±0.011 ms) .The morphological abnormal of ECG changes in diarrheic suckling lambs characterized by a widening or flattening, bifid(mitral) and pulmonale (tall) shape of P wave, increased P-R interval, increased duration of QRS complex and QT-prolongation, ST-depression or elevation .Inverted or board (slurring) tall, symmetric, peaked shape of T waves. These abnormal shapes appeared alternately in lead I, II, III, aVR, aVL and aVF. Conclusively the diarrheic lambs showed serious abnormal changes of electrocardiography..

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LABVIEW BASED ECG SIGNAL ACQUISITION AND ANALYSIS

International Journal of Engineering Applied Sciences and Technology ◽

10.33564/ijeast.2021.v05i09.046 ◽

2021 ◽

Vol 5 (9) ◽

Author(s):

Shila Dhande

Keyword(s):

Heart Rate ◽

Research Work ◽

Heart Rhythm ◽

The Body ◽

P Wave ◽

Signal Acquisition ◽

Ecg Signal ◽

Qrs Complex ◽

Ecg Signals ◽

Rr Interval

The system “LabVIEW based ECG signal acquisition and analysis” is developed to assist patients and doctors in health care. An arrhythmia is an abnormal heart rhythm. It may be so brief that it doesn’t change the overall heart rate, but it can cause the heart rate to be too slow or too fast. When arrhythmias are severe or last long enough, the heart may not be able to pump enough blood to the body. This can cause the patient to feel tired, lightheaded or may make him pass out. It can also cause death. Before treatment, it’s important for the doctor to know where an arrhythmia starts in the heart and whether it’s abnormal. An electrocardiogram (ECG) is often used to diagnose arrhythmias. “LabVIEW based ECG signal acquisition and analysis” is meant to acquire ECG signals from the patient and analyze it to detect and classify its anomalies and abnormalities. This is achieved by extracting amplitudes and durations of parameters of ECG waveform such as P wave, QRS complex, RR interval, and PR durations. These parameters are compared with the normal values to determine the type of abnormality- Tachycardia or Bradycardia. The database of the patient is maintained for further use by the doctor. The objective of LabVIEW based ECG signal acquisition and analysis aims at acquiring and analyzing temporal parameters of ECG signal such as P wave, QRS complex, RR interval, PR durations and amplitudes of the P wave, ST wave, identification of cardiac arrhythmia using LabVIEW. The research work has helped us to explore various features of LabVIEW like signal processing and automated database generation.

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Circulatory Phenomena During Anoxia in the Newborn Lamb

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1958.193.2.269 ◽

1958 ◽

Vol 193 (2) ◽

pp. 269-271

Author(s):

Herbert S. Harned ◽

Ira K. Brandt ◽

Robert E. Cooke

Keyword(s):

Heart Rate ◽

Qt Interval ◽

Heart Block ◽

P Wave ◽

Qrs Complex ◽

T Wave ◽

Aortic Blood ◽

Blood Pressures ◽

Definition Of ◽

Umbilical Cords

Newborn lambs were delivered by hysterotomy, their respiratory passages occluded, and their umbilical cords ligated. Lead II electrocardiographs and aortic blood pressures were taken during the increasing asphyxia. Precipitous fall in heart rate resulting from heart block occurred within two minutes of cord ligation. Thereafter progressive fall in heart rate, systolic blood pressure, and pulse pressure occurred. In sequence, the electrocardiogram revealed heart block, return of slow sinus rhythm, lowering of T wave and shortening of QT interval, and terminal loss of P wave with development of bizarre broad QRS complex, low ST takeoff and loss of definition of the QS endpoint.

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Autoencoder-Based Extrasystole Detection and Modification of RRI Data for Precise Heart Rate Variability Analysis

Sensors ◽

10.3390/s21093235 ◽

2021 ◽

Vol 21 (9) ◽

pp. 3235

Author(s):

Koichi Fujiwara ◽

Shota Miyatani ◽

Asuka Goda ◽

Miho Miyajima ◽

Tetsuo Sasano ◽

...

Keyword(s):

Heart Rate ◽

Heart Rate Variability ◽

Mean Squared Error ◽

False Positive Rate ◽

Premature Ventricular Contraction ◽

Heart Rate Variability Analysis ◽

Unified Framework ◽

Atrial Contraction ◽

Premature Atrial Contraction ◽

Positive Rate

Heart rate variability, which is the fluctuation of the R-R interval (RRI) in electrocardiograms (ECG), has been widely adopted for autonomous evaluation. Since the HRV features that are extracted from RRI data easily fluctuate when arrhythmia occurs, RRI data with arrhythmia need to be modified appropriately before HRV analysis. In this study, we consider two types of extrasystoles—premature ventricular contraction (PVC) and premature atrial contraction (PAC)—which are types of extrasystoles that occur every day, even in healthy persons who have no cardiovascular diseases. A unified framework for ectopic RRI detection and a modification algorithm that utilizes an autoencoder (AE) type of neural network is proposed. The proposed framework consists of extrasystole occurrence detection from the RRI data and modification, whose targets are PVC and PAC. The RRI data are monitored by means of the AE in real time in the detection phase, and a denoising autoencoder (DAE) modifies the ectopic RRI caused by the detected extrasystole. These are referred to as AE-based extrasystole detection (AED) and DAE-based extrasystole modification (DAEM), respectively. The proposed framework was applied to real RRI data with PVC and PAC. The result showed that AED achieved a sensitivity of 93% and a false positive rate of 0.08 times per hour. The root mean squared error of the modified RRI decreased to 31% in PVC and 73% in PAC from the original RRI data by DAEM. In addition, the proposed framework was validated through application to a clinical epileptic seizure problem, which showed that it correctly suppressed the false positives caused by PVC. Thus, the proposed framework can contribute to realizing accurate HRV-based health monitoring and medical sensing systems.

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Characteristics of heart rate variability in patients with acute coronary syndrome without ST segment elevation in comparison with clinical and biochemical parameters

I P Pavlov Russian Medical Biological Herald ◽

10.17816/pavlovj35173 ◽

2021 ◽

Vol 29 (3) ◽

pp. 369-378

Author(s):

Aleksej A. Nizov ◽

Aleksej I. Girivenko ◽

Mihail M. Lapkin ◽

Aleksej V. Borozdin ◽

Yana A. Belenikina ◽

...

Keyword(s):

Heart Rate ◽

Heart Rate Variability ◽

Acute Coronary Syndrome ◽

Creatine Phosphokinase ◽

Spectral Power ◽

Low Frequency ◽

Heart Rhythm ◽

St Segment Elevation ◽

Coronary Syndrome ◽

St Segment

BACKGROUND: The search for rational methods of primary, secondary, and tertiary prevention of coronary heart disease. To date, there are several publications on heart rate variability in ischemic heart disease. AIM: To study the state of the regulatory systems in the organism of patients with acute coronary syndrome without ST segment elevation based on the heart rhythm, and their relationship with the clinical, biochemical and instrumental parameters of the disease. MATERIALS AND METHODS: The open comparative study included 76 patients (62 men, 14 women) of mean age, 61.0 0.9 years, who were admitted to the Emergency Cardiology Department diagnosed of acute coronary syndrome without ST segment elevation. On admission, cardiointervalometry was performed using Varicard 2.51 apparatus, and a number of clinical and biochemical parameters were evaluated RESULTS: Multiple correlations of parameters of heart rate variability and clinical, biochemical and instrumental parameters were observed. From this, a cluster analysis of cardiointervalometry was performed, thereby stratifying patients into five clusters. Two extreme variants of dysregulation of the heart rhythm correlated with instrumental and laboratory parameters. A marked increase in the activity of the subcortical nerve centers (maximal increase of the spectral power in the very low frequency range with the underlying reduction of SDNN) in cluster 1 was associated with reduction of the left ventricular ejection fraction: cluster 147.0 [40.0; 49.0], cluster 260.0 [58.0; 64.0], cluster 360.0 [52.5; 64.5] % (the data are presented in the form of median and interquartile range; Me [Q25; Q75], p 0,05). Cluster 5 showed significant reduction in SDNN (monotonous rhythm), combined with increased level of creatine phosphokinase (CPC): cluster 5446,0 [186.0; 782.0], cluster 4141.0 [98.0; 204.0] IU/l; Me [Q25; Q75], p 0.05) and MВ-fraction of creatine phosphokinase; cluster 532.0 [15.0; 45.0], 4 cluster 412.0 [9.0; 18.0] IU/l; Me [Q25; Q75], p 0.05). CONCLUSIONS: In patients with acute coronary syndrome without ST segment elevation, cluster analysis of parameters of heart rate variability identified different peculiarities of regulation of the heart rhythm. Pronounced strain of the regulatory systems of the body was found to be associated with signs of severe pathology: the predominance of VLF (spectral power of the curve enveloping a dynamic range of cardiointervals in the very low frequency range) in spectral analysis with an underlying reduced SDNN is characteristic of patients with a reduced ejection fraction, and a monotonous rhythm is characteristic of patients with an increased level of creatine phosphokinase and MB-fraction of creatine phosphokinase.

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Physiological ECG Value for Polish Half-Bred Anglo-Arab Horses

Bulletin of the Veterinary Institute in Pulawy ◽

10.2478/v10213-012-0111-4 ◽

2012 ◽

Vol 56 (4) ◽

pp. 631-635 ◽

Cited By ~ 1

Keyword(s):

Heart Rate ◽

P Wave ◽

P Waves ◽

T Wave ◽

Duration Time ◽

Qt Intervals ◽

Electrocardiographic Examination ◽

Electrocardiographic Findings ◽

Almost All ◽

T Waves

Abstract The electrocardiographic examination was performed in 33 training horses (2-16 years of age, 11 males and 22 females). Einthoven and precordial leads (I, II, III, aVR, aVL, aVF, CV1, CV2, CV4) were used. The ECG was performed in resting horses and immediately after exercise (10 min walk, 15 min trot, 10 min canter) using a portable Schiller AT-1 3-channel electrocardiograph, with a paper speed of 25 mm sec-1 and a sensitivity of 10 mm.mV-1. The heart rate, wave amplitudes, and duration time were estimated manually. All horses presented a significant increase in heart rate after exercise (rest 43.83 ±10.33 vs. exercise 73.2 ±14.8). QT intervals were significantly shortened in most of the leads. In resting horses, all P waves in the lead I were positive and almost all II, III and CV4 leads were positive. Simple negative P wave dominated in aVR and only simple negative T wave was found in the leads I. The biphasic shape was observed. After exercise, the amplitude of P and T waves rose, however, clear changes were not observed in wave polarisation and form. In the absence of specific racial characteristics of the electrocardiogram in the Polish Anglo- Arabians, electrocardiographic findings can be interpreted according to ECG standards adopted for horses.

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