Electrocardiographic interpretation of the nasopharyngealresponse in conscious rabbits

The present study was conducted to recognize by part, the cardiovascular events of the nasopharyngeal reflex, through electrocardiographic interpretations. ECG patterns were traced in twelve clinically normal and healthy New Zealand White rabbits of both sexes, weighing between 2-3 kg and aged between 1-3 years with inhalant irritants. Immediately after induction of formaldehyde vapour, the heart rate fell by 69% from a mean of 192 ± 7.310 bpm to 60 ± 1.296 bpm, whereas exposure with cigarette smoke caused a fall in heart rate by 74% from a mean of 205 ± 9.605 bpm to 53 ± 3.065 bpm. With both irritants, P wave becomes smaller and totally disappeared, indicating an increased vagal activity inducing a sinoatrial node arrest. The amplitude of QRS complex also significantly decreased; and so did the duration of P wave and PR interval, presumably due to junctional escape. T wave duration decreased with slow ventricular repolarization. Bradycardia was also evident with increased QT interval. However, there was no change in QRS complex or ventricular depolarization, mediated perhaps via compensatory sympathetic influence on the ventricular myocardium. The study demonstrates that both formaldehyde and cigarette smoke provoked a similar protective response of rabbits against noxious fumes.

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

Journal of Mechanics in Medicine and Biology ◽

10.1142/s021951941240012x ◽

2012 ◽

Vol 12 (04) ◽

pp. 1240012 ◽

Cited By ~ 4

Author(s):

GOUTHAM SWAPNA ◽

DHANJOO N. GHISTA ◽

ROSHAN JOY MARTIS ◽

ALVIN P. C. ANG ◽

SUBBHURAAM VINITHA SREE

Keyword(s):

Heart Rate ◽

Heart Rate Variability ◽

Sinus Bradycardia ◽

Premature Ventricular Contraction ◽

P Wave ◽

Ecg Signal ◽

Qrs Complex ◽

T Wave ◽

St Segment ◽

Cardiac Disorders

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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Cardiac changes during arousals from non-REM sleep in healthy volunteers

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00642.2006 ◽

2007 ◽

Vol 292 (3) ◽

pp. R1320-R1327 ◽

Cited By ~ 16

Author(s):

Eugene Nalivaiko ◽

Peter G. Catcheside ◽

Amanda Adams ◽

Amy S. Jordan ◽

Danny J. Eckert ◽

...

Keyword(s):

Heart Rate ◽

Neural Control ◽

Cardiac Pacemaker ◽

Ventricular Myocardium ◽

Rapid Eye Movement Sleep ◽

Sleep Studies ◽

Cardiac Responses ◽

Pr Interval ◽

Consistent Change ◽

Ventricular Filling

Our aim was to evaluate cardiac changes evoked by spontaneous and sound-induced arousals from sleep. Cardiac responses to spontaneous and auditory-induced arousals were recorded during overnight sleep studies in 28 young healthy subjects (14 males, 14 females) during non-rapid eye movement sleep. Computerized analysis was applied to assess beat-to-beat changes in heart rate, atrio-ventricular conductance, and ventricular repolarization from 30 s before to 60 s after the auditory tone. During both types of arousals, the most consistent change was the increase in the heart rate (in 62% of spontaneous and in 89% of sound-induced arousals). This was accompanied by an increase or no change in PR interval and by a decrease or no change in QT interval. The magnitude of all cardiac changes was significantly higher for tone-induced vs. spontaneous arousals (mean ± SD for heart rate: +9 ± 8 vs. +13 ± 9 beats per min; for PR prolongation: 14 ± 16 vs. 24 ± 22 ms; for QT shortening: −12 ± 6 vs. −20 ± 9 ms). The prevalence of transient tachycardia and PR prolongation was also significantly higher for tone-induced vs. spontaneous arousals (tachycardia: 85% vs. 57% of arousals, P < 0.001; PR prolongation: 51% vs. 25% of arousals, P < 0.001). All cardiac responses were short-lasting (10–15 s). We conclude that cardiac pacemaker region, conducting system, and ventricular myocardium may be under independent neural control. Prolongation of atrio-ventricular delay may serve to increase ventricular filling during arousal from sleep. Whether prolonged atrio-ventricular conductance associated with increased sympathetic outflow to the ventricular myocardium contributes to arrhythmogenesis during sudden arousal from sleep remains to be evaluated.

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The ECG changes in various comorbidities with hypertension and without hypertension

International Journal of Research in Medical Sciences ◽

10.18203/2320-6012.ijrms20201323 ◽

2020 ◽

Vol 8 (4) ◽

pp. 1351

Author(s):

Metta Anil Kumar ◽

J. Muralikrishna ◽

Anand Acharya

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Systolic Blood Pressure ◽

Diastolic Blood Pressure ◽

P Wave ◽

Study Group ◽

Qtc Interval ◽

Epidemiologic Transition ◽

Mortality And Morbidity ◽

Pr Interval

Background: Hypertension is the commonest cardiovascular disorder posing a challenge to the societies in socioeconomic and epidemiologic transition. In India, Cardiovascular Diseases (CVDs) are estimated to be responsible for 1.5 million deaths annually. Indeed, it is estimated that by 2020, CVDs will be the largest cause of mortality and morbidity in India. To present study is designed to evaluate the variation of blood pressure and ECG wave forms among people hypertension with co morbidities (study group) and controls.Methods: The study included 50 people comorbidities with hypertension and 50 controls, each between ages 30-40 years from general population, and also from Medicine outpatient department, KIMS and RF Amalapuram. Detailed history from subjects, blood pressure (sitting position) and electrocardiogram was recorded during resting state in supine position. The ECG results were evaluated for various parameters like heart rate, P wave, PR interval, QRS complex etc.Results: There was significant increase in heart rate, systolic blood pressure as well as diastolic blood pressure in study group when compared to controls. Decrease in PR interval, decrease in QT interval, decrease in QTc interval, decrease in QRS axis in smokers when compared to controls.Conclusions: There was significant increase in heart rate in study group (smokers, diabetic) when compared to controls. There was significant increase in systolic blood pressure as well as diastolic blood pressure in study group (smokers, diabetics) when compared to controls. There was significant decrease in PR interval in smokers when compared to controls. There was significant decrease in QT and QTc interval in smokers when compared to controls.

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Electrocardiographic patterns of Mangalarga Marchador horses before and after implementation of the marcha gait

Ciência Rural ◽

10.1590/0103-8478cr20150873 ◽

2016 ◽

Vol 46 (5) ◽

pp. 915-920 ◽

Cited By ~ 4

Author(s):

Clarisse Simões Coelho ◽

Gabriella Agra de Omena e Silva ◽

Luiz Antonio Trindade Oliveira Junior ◽

Vanessa Sartor Moraes ◽

Laura Monteiro de Castro Conti ◽

...

Keyword(s):

Qt Interval ◽

P Wave ◽

Qrs Complex ◽

Sinus Arrhythmia ◽

Qt Intervals ◽

Pr Interval ◽

Before And After ◽

Kolmogorov Smirnov ◽

Electrocardiographic Parameters ◽

T Waves

ABSTRACT: The aim of this study was to evaluate the electrocardiographic parameters in Mangalarga Marchador horses submitted to marcha exercise. Twenty-four Mangalarga Marchador horses, thirteen females and eleven males, 6.4±2.7 years old with a mean weight of 428.3±24.7kg, were used. Electrocardiograms were recorded in two different moments: rest and immediately after exercise (40 minutes of aerobic exercise, marcha gait). The electrocardiographic variables analyzed were cardiac rhythm, heart rate (HR), duration of P wave, QRS complex, PR and QT intervals, amplitudes of P, R and T waves, and analysis of QT corrected (QTc) according to Bazett's formula (QT/√RR). Variables were analyzed for normality with Kolmogorov-Smirnov test and paired t-test, considering P<0.05. Rhythm analysis revealed 91.7% of sinus rhythm and 8.3% of sinus arrhythmia in rest, with mean HR of 45.7±12.7 beats minute-1, and 100% of sinus tachycardia, with mean HR of 77.3±13.5 beats minute-1 after exercise (P<0.0001). In post-exercise, it was possible to observe decreases in P wave duration (P=0.0121), PR interval (P=0.0007) and QT interval (P<0.0001) and increase of QTc (P=0.0039) and R wave amplitude (P=0.0033). There were no significant differences for amplitude of P and T waves and QRS complex related to atrioventricular enlargement. Although QT interval decreased after exercise, there was an increase on QTc after exercise, indicating changes in ventricular repolarization. It was possible to conclude that the imposed exercise (marcha gait) led to electrocardiographic alterations without causing pathological arrhythmias.

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Electrocardiographic Evaluation in Patients With Spinal Muscular Atrophy: A Case-Control Study

Journal of Child Neurology ◽

10.1177/0883073818767170 ◽

2018 ◽

Vol 33 (7) ◽

pp. 487-492 ◽

Cited By ~ 4

Author(s):

Raffaele Falsaperla ◽

Giovanna Vitaliti ◽

Ausilia Desiree Collotta ◽

Chiara Fiorillo ◽

Alfredo Pulvirenti ◽

...

Keyword(s):

Heart Rate ◽

Spinal Muscular Atrophy ◽

Cardiac Tissue ◽

Muscular Atrophy ◽

P Wave ◽

Cardiac Conduction ◽

Control Group ◽

Qrs Complex ◽

P Waves ◽

Spinal Muscular Atrophy Type

Background: This study aimed to show the impairment of autonomic cardiac conduction causing bradycardia and/or electrocardiographic alterations in children affected by spinal muscular atrophy type 1 and 2 (SMA 1 and 2). Methods: We included 25 spinal muscular atrophy patients, admitted from November 2016 to May 2017. All patients underwent an electrocardiographic examination and we studied PR and QRS intervals, P-waves and QRS amplitudes, and heart rate in spinal muscular atrophy patients compared to a control group. Results: In all patients, we found longer PRi and QRSi ( P < .05), lower P-wave and QRS complex amplitudes ( P < .01), and a decreased heart rate ( P < .01) with respect to controls. When we divided our patients into SMA1 and SMA2 subgroups, we found that statistical differences were maintained for P-wave and QRS complex amplitudes and heart rate, but not for PRi and QRSi with respect to controls. Conclusion: We suggest the hypothesis of SMN expression on cardiac tissue condition and/or autonomic cardiac conduction.

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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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The autonomic balance predicts cardiac responses after the first dose of fingolimod

Multiple Sclerosis Journal ◽

10.1177/1352458514538885 ◽

2014 ◽

Vol 21 (2) ◽

pp. 206-216 ◽

Cited By ~ 19

Author(s):

S Rossi ◽

C Rocchi ◽

V Studer ◽

C Motta ◽

B Lauretti ◽

...

Keyword(s):

Valsalva Maneuver ◽

P Wave ◽

Cardiac Response ◽

Vagal Activity ◽

Deep Breathing ◽

Autonomic Balance ◽

Cardiac Side Effects ◽

Dose Monitoring ◽

Pr Interval ◽

Normalized Units

Background: Predictive markers of cardiac side effects would be helpful for the stratification and individualized monitoring of multiple sclerosis (MS) patients prescribed with fingolimod. Objective: To test whether the autonomic balance predicts a cardiac response after the first dose of fingolimod. Methods: A total of 55 consecutive relapsing–remitting MS (RRMS) patients underwent ‘head-up tilt’, Valsalva maneuver, deep breathing and handgrip tests before their first dose of fingolimod. The normalized unit of the high frequency (HF) component (HF normalized units; HFnu), reflecting mostly vagal activity; and the low frequency (LF) component (LF normalized units; LFnu) reflecting mostly sympathetic activity, were considered for the analysis of heart rate (HR) variability. The patients’ HR and electrocardiographic parameters ((the interval between P wave and ventricular depolarization (PR); the interval between Q and T waves (QT)) were recorded during 6-hour post-dose monitoring. Results: We found significant correlations between measures of parasympathetic function and fingolimod-induced bradycardia. Subjects with higher Valsalva ratio and HR variation during deep breathing had, in fact, nadir HR ≤ 50 beats/minute (bpm) after the first fingolimod dose. Conversely, significant negative correlations were found between measures of sympathetic function and fingolimod-induced PR interval increase. Subjects with lower LFnu at rest and less increase of blood pressure on the handgrip test showed a PR interval increase > 20 ms after fingolimod. Conclusions: Assessing autonomic control of cardiovascular functions can be useful to predict cardiac effects after the first fingolimod dose.

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Autonomic cardiovascular control during submergence and emergence in bullfrogs

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1979.237.3.r210 ◽

1979 ◽

Vol 237 (3) ◽

pp. R210-R216

Author(s):

R. S. Lillo

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Vagal Tone ◽

Systemic Blood Pressure ◽

Vagal Activity ◽

Adrenergic Blockade ◽

Systemic Blood ◽

Heart Rates ◽

Heart Rate Decrease ◽

Sympathetic Influence

Unanesthetized bullfrogs were involuntarily submerged for 25 min in air-saturated water at 21 degrees C. Significant bradycardia was observed while systemic blood pressure was maintained or slightly elevated. Upon emergence, heart rates immediately returned to presubmergence levels or higher. Similar responses were observed in frogs allowed to make voluntary dives in an experimental tank. Heart rates of vagal-blocked (atropine) frogs did not change during submergence or emergence. beta-Adrenergic blockade (propranolol) had little effect on the magnitude of heart rate decrease during submergence or its increase upon emergence. After alpha-adrenergic blockade (phentolamine), frogs developed diving bradycardia while undergoing a fall in systemic blood pressure. It is concluded that, in bullfrogs, 1) bradycardia during submergence is entirely due to increased vagal activity, 2) the immediate cardiac rate increase upon emergence apparently results from a decrease in vagal tone; and 3) there appears to be no substantial reciprocal sympathetic influence on heart rate during alterations in vagal tone.

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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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