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.

Analysis of six cancer patients with persistent left superior vena cava identified during central venous access device placement via an intracavitary electrocardiogram

2021 ◽  
pp. 112972982110455
Author(s):  
Xinpeng Wang ◽  
Yong Yang ◽  
Jing Dong ◽  
Xiaozheng Wang ◽  
Yuanyuan Zheng ◽  
...  
Keyword(s):  
Body Surface ◽  
Superior Vena ◽  
Central Venous Access ◽  
Vena Cava ◽  
Venous Access ◽  
The Body ◽  
P Wave ◽  
P Waves ◽  
Venous Access Device ◽  
Surface Electrocardiogram

Persistent left superior vena cava (PLSVC) is a rare congenital anomaly. PLSVC can be associated with clinically significant atrial septal defect (ASD) or ventricular septal defect (VSD). It is usually asymptomatic and accidentally detected during invasive procedures or imaging examinations. However, whether central venous access device (CVAD) can be placed and used in patients with PLSVC is controversial. A total of six patients were diagnosed with PLSVC and confirmed by chest CT among 3391 cancer patients who underwent CVAD placement via intracavitary electrocardiogram (IC-EKG) at the Venous Access Center (VAC) from May 2019 to December 2020. The CVADs (peripherally inserted central catheter in four patients and Ports in two patients) of these six patients were left in PLSVC. We analyzed changes in the P-wave in the IC-EKG during CVAD placement and the characteristics of the body surface electrocardiogram in these patients and discussed the catheter tip position in PLSVC. All six patients showed negative P-waves in lead II via IC-EKG from the beginning of catheterization: four patients showed negative P-waves and two showed biphasic P-waves in the body surface electrocardiogram (lead III) before catheterization. CVAD function was normal and no obvious complications were observed during the treatment of these patients. The total retention time of CVADs was 1537 days. For patients with a negative P-wave in lead II via IC-EKG during catheterization, especially in those with a negative or biphasic P-wave in lead III of the body surface electrocardiogram, PLSVC should be considered. CVAD insertion in patients with type I PLSVC is safe under certain conditions, with the proper tip position in the middle to lower part of PLSVC.

Detection of delayed ventricular activation on the body surface in dogs

1981 ◽  
Vol 241 (3) ◽  
pp. H363-H369 ◽  
Author(s):  
M. B. Simson ◽  
D. Euler ◽  
E. L. Michelson ◽  
R. A. Falcone ◽  
J. F. Spear ◽  
...  
Keyword(s):  
Body Surface ◽  
The Body ◽  
Acute Ischemia ◽  
Coronary Artery Ligation ◽  
Qrs Complex ◽  
Signal Averaging ◽  
Artery Ligation ◽  
Bipolar Electrodes ◽  
Ischemic Region ◽  
Ventricular Activation

This study describes a noninvasive method for detecting delayed ventricular activation, caused by ischemia, on the body surface. Signal averaging and a newly developed high-pass digital filter were used. The filter has the property that it does not create an artifact or ring after the QRS complex ends, thereby allowing the detection of microvolt-level potentials that occur immediately after the QRS complex. Eleven dogs were studied before and during acute ischemia induced by coronary artery ligation and latex embolization. The ischemic region was mapped with bipolar electrodes and, after the chest was rapidly closed, signal-averaged recordings were made from the body surface. Repeated cycles of ventricular mapping and signal averaging were performed. In each dog, delayed and fractionated electrograms were recorded directly from the ischemic epicardium that lasted a maximum of 118 +/- 18 ms after QRS onset. The duration of the ventricular electrograms varied with time. Whenever delayed epicardial electrograms were recorded, filtered signal-averaged leads showed microvolt-level potentials early in the S-T segment that were continuous with the QRS complex. The duration of ventricular activation, as measured from the bipolar electrograms and from the filtered signal-averaged leads, correlated well (r = 0.93, P less than 0.001). Because of the absence of filter ringing, low-level potentials could be detected less than 40 ms after the QRS complex ended. This study demonstrates that microvolt-level potentials arising from delayed ventricular activation can be reliably detected on the body surface, even when they occur just after the QRS complex.

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.

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.

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.

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 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.

Pulse Oximetric and ECG changes during continuous infusion of propofol in medetomidine – pentazocine and midazolam – pentazocine premedicated buffalo calves

2015 ◽  
Author(s):  
M. Saibaba ◽  
P. Veena ◽  
N. Dhana Lakshmi ◽  
K. Veera Bramhaiah
Keyword(s):  
Intravenous Infusion ◽  
P Wave ◽  
Continuous Intravenous Infusion ◽  
Qrs Complex ◽  
Normal Range ◽  
Ecg Changes ◽  
Buffalo Calves ◽  
T Wave ◽  
Group I ◽  
Surgical Conditions

Twelve buffalo calves of either sex presented to the clinic with surgical conditions like umbilical hernia, urolithiasis and fractures were utilized to study the effect of continuous intravenous infusion of propofol after premedication with medetomidine – pentazocine and midazolam – pentazocine. The animals were divided into two groups of six animals each. Medetomidine (@ 2.5 μg/kg b.wt.) – pentazocine (@ 0.5 mg/kg b.wt.) and midazolam (@ 0.25 mg/kg b.wt.) – pentazocine (@ 0.5 mg/kg b.wt.) was given intravenously in group I and II respectively. Propofol was given intravenously (@ 4 mg/kg b.wt.) after pre-medication and maintained by continuous intravenous infusion of propofol (@ 0.4 mg/kg b.wt.) in 5 % dextrose normal saline in both groups. Pulse oximetric and electrocardographic changes were recorded at 0, 5,10,15,30 and 60 min. Saturation of oxygen percentage of haemoglobin showed significant (P £ 0.05) difference in both groups but the changes were within the normal range. Electrocardiographic studies did not reveal any abnormalities except slight variations in the amplitude of P wave, T wave and QRS complex in both groups. It is concluded that both anaesthetic drug combinations can be used safely in buffaloes as they did not alter the pulse oximetry and ECG values.

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

2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
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.

Relation of principal components of ECG maps to loci of wall motion abnormality in old myocardial infarction

1994 ◽  
Vol 266 (4) ◽  
pp. H1604-H1609 ◽  
Author(s):  
T. Endo ◽  
M. Yamaki ◽  
H. Ikeda ◽  
I. Kubota ◽  
H. Tomoike
Keyword(s):  
Myocardial Infarction ◽  
Body Surface ◽  
Principal Components ◽  
Potential Distribution ◽  
Principal Component ◽  
Qrs Complex ◽  
T Wave ◽  
Old Myocardial Infarction ◽  
Body Surface Potential ◽  
Z Scores

The purpose of this study was to examine the correlation between body surface potential distribution and the extent of abnormally contracting segments (ACS) of the left ventricle in patients with old myocardial infarction (MI). Body surface potential distribution was quantitatively analyzed using principal component analysis. The first six principal components were extracted from data set obtained from both 25 normal subjects and 100 patients. The z scores (principal component weights) were calculated in a time domain at every 4 or 8 ms in another 81 patients with previous MI. In anterior MI, the second z scores on T wave and the fourth z scores on QRS complex were significantly lower in the presence than in the absence of ACS at the lateral wall. In inferior MI, the first z scores on QRS complex, the second on T wave, and the third on both Q and T represented significant differences between the presence and the absence of ACS at the posterior wall. Minute differences in the extent of ACS were sensitively and noninvasively detected on z scores of principal components.

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