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

1969 ◽  
Vol 14 (2) ◽  
pp. 59-63 ◽  
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.

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

2012 ◽  
Vol 12 (04) ◽  
pp. 1240012 ◽  
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.

scholarly journals Electrocardiogram Changes with Acute Alcohol Intoxication: A Systematic Review

2018 ◽  
Vol 12 (1) ◽  
pp. 1-6 ◽  
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.

scholarly journals Electrocardiographic manifestations in severe hypokalemia

2018 ◽  
Vol 48 (1) ◽  
pp. 030006051881105 ◽  
Author(s):  
Xiqiang Wang ◽  
Dan Han ◽  
Guoliang Li
Keyword(s):  
P Wave ◽  
Dynamic Changes ◽  
T Wave ◽  
Electrolyte Disturbances ◽  
St Segment ◽  
Pr Interval ◽  
Wave Morphology ◽  
Life Threatening

Hypokalemia is one of the most common electrolyte disturbances in the clinic and it can increase the risk of life-threatening arrhythmias. Electrocardiographic characteristics associated with hypokalemia include dynamic changes in T-wave morphology, ST-segment depression, and U waves, which are often best seen in the mid-precordial leads (V2–V4). The PR interval can also be prolonged along with an increase in the amplitude of the P wave. We report a case of a patient with hypokalemia (1.31 mmol/L) who showed typical electrocardiographic characteristics of hypokalemia.

scholarly journals Electrocardiographic changes in awassi diarrheic suckling lambs in Iraq

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..

Ventricular coupling induced by anodal or cathodal polarization during continuous direct currents in dog ventricle

1958 ◽  
Vol 196 (1) ◽  
pp. 209-212 ◽  
Author(s):  
Sheppard M. Walker
Keyword(s):  
Direct Current ◽  
Vagal Stimulation ◽  
Ectopic Beat ◽  
T Wave ◽  
Sinus Rate ◽  
St Segment ◽  
Pr Interval ◽  
Ectopic Beats ◽  
Ventricular Beat

Ventricular ectopic beats coupled with preceding normal beats occur during the delivery of direct current when the anode or cathode is on the ventricular epicardium of the dog. These ectopic beats are induced within the T-wave or immediately thereafter during the application of threshold direct current when the anode is on the epicardium. When anodal current is begun in the ST segment of a given cycle, an ectopic beat is induced within or near the T-wave of the same cycle. When the cathode is on the epicardium, coupled ventricular ectopic beats are induced within the PR interval during the application of threshold direct current. Under these conditions marked slowing of sinus rate by vagal stimulation does not alter the interval of coupling between the ectopic beat and the preceding normal beat. Thus it is shown that the abnormal ventricular beat, falling within the PR interval, is ectopic and independent of the auricular impulse.

scholarly journals Electrocardiographic parameters of the American Miniature Horse: influence of age and sex

2016 ◽  
Vol 36 (6) ◽  
pp. 551-558
Author(s):  
Bianca P. Santarosa ◽  
Maria L.G. Lourenço ◽  
Gabriela N. Dantas ◽  
Carla M.V. Ulian ◽  
Marta C.T. Heckler ◽  
...  
Keyword(s):  
Age Groups ◽  
Frontal Plane ◽  
The Elderly ◽  
P Wave ◽  
Sinus Arrhythmia ◽  
T Wave ◽  
St Segment ◽  
Electrocardiographic Parameters ◽  
Electrocardiogram Ecg ◽  
Age And Sex

Abstract: The veterinary cardiology has growing importance in equine medicine. There are studies of standardization of electrocardiographic parameters of many races, according to their stature and ability. However, no studies are in the literature with the American Miniature Horse. To evaluate the electrocardiogram (ECG) tracing configuration of this breed at rest and to verify the influence of age and sex on ECG parameters, 203 horses including 143 females and 60 males were divided into four age groups (foals, yearlings, adults and elderly). Electrocardiographic parameters were performed by computerized electrocardiogram (TEB), and the parameters were evaluated in six leads of frontal plane (Lead I, II, III, aVR, aVL and aVF) and base-apex (BA). Heart rates (HR) decreased with increasing age were higher in males than in females. Sinus tachycardia followed by sinus arrhythmia was dominant in both sexes. The cardiac axis was higher in males and ranged between 120° and 150° for foals, 30° and 60° for yearlings and adults, and 60° and 90° for the elderly. The P wave was bifid in several animals. The P-wave amplitude and T-wave duration from lead II and BA were larger in males than in females. The majority of the animals exhibited ST segment depression and a negative T-wave. The most common QRS complex morphology was Qr. Differences were observed between the electrocardiographic tracings of males and females, and age influenced the ECG parameters. Therefore, this study established the ECG patterns for the American Miniature Horse breed and could be used to determine the influence of age and sex on several of the studied variables.

scholarly journals Research on the duration of electrocardiogram components in pregnant goats

2022 ◽  
Vol 78 (03) ◽  
pp. 6625-2022
Author(s):  
MARIAN GHIȚĂ ◽  
IULIANA CODREANU ◽  
CARMEN PETCU ◽  
ADRIAN RĂDUȚĂ ◽  
DRAGOȘ POPESCU ◽  
...  
Keyword(s):  
Medical Practice ◽  
Electric Activity ◽  
P Wave ◽  
Qrs Complex ◽  
T Wave ◽  
Main Components

The electrocardiogram is a graph recording of heart’s electric activity, so it is used in medical practice mainly in order to observe the heart’s activity. The values of the main components of the electrocardiogram in pregnant goats were determined within the current research. All of these were performed in three different stages of pregnancy (the beginning, the middle and the ending), being focused on the variation of these values during the pregnancy. The gestation diagnosis was confirmed by ultrasound-exam. During the pregnancy, the following values for the duration of the main ECG’s components were found: the P wave (0.045-0.044 s), the P-R segment (0.061-0.048 s), of the P-R range (0.105-0.086 s), of the QRS complex (0.042-0.040 s), of the Q-T range (0.242-0.218 s), of the P-T range (0.377-0.368 s), of the R-R range (0.465-0.431 s), the T wave (0.091-0.104 s) and of the T-P segment (0.097-0.101 s). Our results show that during the pregnancy the duration of: the P wave, the P-R segment, the P-R range, the QRS complex, the Q-T range, the P-T range and the R-R range, decrease, while the duration of the T wave and the T-P segment increase.

Difficulties in ECG diagnosis of myocardial infarction

1993 ◽  
Vol 74 (1) ◽  
pp. 61-62
Author(s):  
V. M. Andreev
Keyword(s):  
Myocardial Infarction ◽  
Qrs Complex ◽  
T Wave ◽  
St Segment

Until now, in the diagnosis of myocardial infarction (MI), the main importance is attached to ECG studies. In the MI focus, an ischemic zone is formed, which is characterized by a change in the repolarization process (T wave), an injury zone manifested by a displacement of the ST segment and a necrosis zone, which is expressed in a change in the QRS complex.

scholarly journals Research on the Values of Amplitudes of Electrocardiographic Waves Depending on Age in Kids

2020 ◽  
Vol 77 (2) ◽  
pp. 80
Author(s):  
Dragos Corneliu COTOR ◽  
Gabriel GAJAILA ◽  
Aurel DAMIAN ◽  
Ana Maria ZAGRAI ◽  
Carmen PETCU ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Electric Activity ◽  
P Wave ◽  
Mechanical Activity ◽  
Qrs Complex ◽  
T Wave ◽  
Electrocardiogram Ecg

The electrocardiogram (ECG) is a graphical recording of the cardiac electric activity during cardiac revolutions. This bio-current triggers and maintains the mechanical activity of the heart. Within this research, the amplitudes values of the electrocardiographic waves were determined in 6 leads: I, II, III, aVL, aVR and aVF. Thus, some electrocardiograms were recorded using limb lead in clinically healthy kids, aged 1 month, 3 months and 5 months, in order to achieve the proposed objectives. Then, the statistical analysis of the obtained results was performed using t (student) test.As a consequence of the interpretation of the obtained results, it was noticed that the limb leads can be used successfully for recording the electrocardiogram in kids because it provides an easy aspect to interpret. The highest amplitude of the electrocardiographic waves is recorded in I lead, in the case of the 1 month old kids (having the following values: 0.115 mV ± 0.010 for P wave; 0.625 mV ± 0.078 for QRS complex; 0.460 mV ± 0.045 for T wave) and in II lead (having the following values for the 3 months old kids: 0.071 mV ± 0.015 for P wave; 0.540 mV ± 0.064 for QRS complex; 0.310 mV ± 0.052 for T wave and having the following values for the 5 months old kids: 0.071 mV ± 0.015 for P wave; 0.455 mV ± 0.028 for QRS complex; 0.430 mV ± 0.026 for T wave). It also found that the lowest amplitude of electrocardiographic waves is recorded in the aVF lead, but this lead cannot be used for ECG recording in kids.

scholarly journals A Fully-Coupled Electro-Mechanical Whole-Heart Computational Model: Influence of Cardiac Contraction on the ECG

2021 ◽  
Vol 12 ◽  
Author(s):  
Robin Moss ◽  
Eike Moritz Wülfers ◽  
Steffen Schuler ◽  
Axel Loewe ◽  
Gunnar Seemann
Keyword(s):  
Body Surface ◽  
In Silico ◽  
Computational Cost ◽  
Cardiac Motion ◽  
The Body ◽  
Cardiac Contraction ◽  
P Wave ◽  
Qrs Complex ◽  
T Wave ◽  
Whole Heart

The ECG is one of the most commonly used non-invasive tools to gain insights into the electrical functioning of the heart. It has been crucial as a foundation in the creation and validation of in silico models describing the underlying electrophysiological processes. However, so far, the contraction of the heart and its influences on the ECG have mainly been overlooked in in silico models. As the heart contracts and moves, so do the electrical sources within the heart responsible for the signal on the body surface, thus potentially altering the ECG. To illuminate these aspects, we developed a human 4-chamber electro-mechanically coupled whole heart in silico model and embedded it within a torso model. Our model faithfully reproduces measured 12-lead ECG traces, circulatory characteristics, as well as physiological ventricular rotation and atrioventricular valve plane displacement. We compare our dynamic model to three non-deforming ones in terms of standard clinically used ECG leads (Einthoven and Wilson) and body surface potential maps (BSPM). The non-deforming models consider the heart at its ventricular end-diastatic, end-diastolic and end-systolic states. The standard leads show negligible differences during P-Wave and QRS-Complex, yet during T-Wave the leads closest to the heart show prominent differences in amplitude. When looking at the BSPM, there are no notable differences during the P-Wave, but effects of cardiac motion can be observed already during the QRS-Complex, increasing further during the T-Wave. We conclude that for the modeling of activation (P-Wave/QRS-Complex), the associated effort of simulating a complete electro-mechanical approach is not worth the computational cost. But when looking at ventricular repolarization (T-Wave) in standard leads as well as BSPM, there are areas where the signal can be influenced by cardiac motion of the heart to an extent that should not be ignored.

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