A Comprehensive Algorithm for the Analysis of ECG Waveforms

2012 ◽  
Author(s):  
Abdul Jaleel Palliyali ◽  
Reza Tafreshi ◽  
Nasreen Mohsin ◽  
Leyla Tafreshi
Keyword(s):  
Curve Fitting ◽  
Clinical Judgment ◽  
Qrs Complex ◽  
Average Accuracy ◽  
St Segment ◽  
Reliable Performance ◽  
Adaptive Thresholds ◽  
St Elevation ◽  
Automate Diagnosis ◽  
T Waves

This paper presents a comprehensive approach for the detailed analysis of ECG waveforms including various morphologies to aid clinical diagnosis. Clinical judgment is often based on observing various features which may occur simultaneously on the ECG. Thus, to automate diagnosis, a comprehensive tool capable of detecting all these features is required. Parabolic curve fitting, adaptive thresholds and synchronicity across leads are utilized to detect the various waves of the QRS complex namely Q,R,S,R’ and S’. Onset of the QRS complex and the J point are detected using a ‘modified second derivative’ approach. The isoelectric level is detected using linearity and slope conditions. P and T waves are detected using ‘area under curve’ approach. Measurements such as peak-to-peak intervals and ST elevation/depression are numerically calculated from the points obtained. Curve fitting and change in slope are utilized for obtaining morphology of the ST segment. Presence of significant Q waves and abnormal T waves are inferred using clinical guidelines and numerical calculations. The performance of the algorithm is validated on 40 sample patient data — 20 healthy and 20 with Myocardial Infarction. Average accuracy shown in detecting all points of interest is 98.5%. All measurements are successfully calculated from these points. Along with this reliable performance, the approach proves to be simple and computationally fast.

Opposite effects of lidocaine and diltiazem on electrophysiologic alterations in acutely ischemic porcine myocardium

1989 ◽  
Vol 67 (7) ◽  
pp. 697-703 ◽  
Author(s):  
René Cardinal ◽  
D. Leigh Carson ◽  
Chantal Lambert ◽  
Jafar Shenasa ◽  
Robert Parent ◽  
...  
Keyword(s):  
Ventricular Arrhythmias ◽  
St Segment ◽  
St Elevation ◽  
The Difference ◽  
Activation Times ◽  
Electrical Alternans ◽  
Transmembrane Currents ◽  
Ischemic Arrhythmias ◽  
Unipolar Electrograms ◽  
T Waves

To investigate the actions of lidocaine and diltiazem on the ischemic alterations associated with the onset of acute ischemic arrhythmias, the left anterior descending coronary artery was occluded for 6-min periods separated by 30 min of reperfusion, under control conditions and after injection of lidocaine (2.4–3.8 μg/mL of plasma) or diltiazem (390–510 ng/mL) in open–chest anesthetized pigs. Sixty-one unipolar electrograms were continuously recorded in the ischemic zone. Isochronal maps and isopotential maps were determined by computer analysis. The magnitude of beat-to-beat alternation of unipolar waveforms was described by the difference between the time integrals subtended by electrograms of consecutive beats. Activation times were prolonged by ischemia and the ST segment became elevated. Delay and ST elevation developed at a faster rate in the presence of lidocaine than under control conditions, but were reduced by diltiazem. ST-T alternation was not significantly different between control and lidocaine occlusions, but the incidence of negative T waves and that of ventricular tachycardia degenerating to fibrillation were higher in lidocaine occlusions than in control occlusions. In contrast, unipolar waveform alternation and negative T waves were virtually abolished by diltiazem, even at fast pacing rates (180–210 beats/min) at which diltiazem did not reduce ST elevation. Ventricular arrhythmias also were abolished by diltiazem. Thus, lidocaine and diltiazem produce opposite effects on the ischemic alterations most closely associated with the initiating mechanism of tachycardia. This could be related to differences between these drugs with regard to their actions on transmembrane currents during repolarization.Key words: acute myocardial ischemia, lidocaine, diltiazem, ventricular arrhythmias, electrical alternans.

scholarly journals De Winter ECG Pattern Can Be A Temporary ECG Phenomenon Related To Severe Stenosis of The Left Circumflex Coronary Artery: A Case Report

2021 ◽  
Author(s):  
Jian Wang ◽  
Faming Ding ◽  
Jingsen Li ◽  
Huipu Xu
Keyword(s):  
Case Report ◽  
Coronary Artery ◽  
Circumflex Coronary Artery ◽  
Severe Stenosis ◽  
Left Circumflex Coronary Artery ◽  
St Segment ◽  
St Elevation ◽  
T Waves

Abstract The de Winter ECG pattern consisting of ST-segment depression and tall symmetrical T waves on ECG, known as an ST elevation equivalent, accounts for approximately 2% of patients with occlusion of the proximal left anterior descending coronary artery (LAD). These patterns are considered static and persistent and are, on average, recorded 1.5 hours after onset. Here, we describe a case of the de Winter ECG pattern as a temporary ECG phenomenon associated with left circumflex coronary artery (LCX) stenosis.

scholarly journals Atypical electrocardiographic presentations of myocardial infarction with ST elevation - ST elevation myocardial infarction equivalents

2018 ◽  
Vol 71 (7-8) ◽  
pp. 241-246
Author(s):  
Jadranka Dejanovic ◽  
Anastazija Stojsic-Milosavljevic ◽  
Milos Trajkovic ◽  
Tanja Popov ◽  
Aleksandra Ilic
Keyword(s):  
Myocardial Infarction ◽  
Clinical Symptoms ◽  
Coronary Artery Occlusion ◽  
Reperfusion Therapy ◽  
Artery Occlusion ◽  
St Elevation Myocardial Infarction ◽  
St Segment Elevation ◽  
St Segment ◽  
St Elevation ◽  
T Waves

Introduction. Some patients with clinical symptoms and signs of acute myocardial and coronary artery occlusion have atypical electrocardiographic presentations - ST elevation myocardial infarction equivalents. Rapid recognition of these patterns is imperative, because the condition requires prompt reperfusion therapy following actual guidelines. De Winter pattern. Diagnostic criteria are: tall, prominent, symmetrical T-waves in the precordial leads, upsloping ST segment depression > 1 mm at the J-point in the precordial leads, absence of ST elevation in the precordial leads, ST segment elevation (0.5 mm - 1 mm) in aVR. ST Elevation in aVR. Electrocardiographic criteria include ST segment elevation in aVR ? 1 mm, ST segment elevation in aVR ? V1, and diffuse ST segment depression in lateral leads. Wellens syndrome. Wellens syndrome describes deeply inverted or bi?phasic T-waves in leads V2 - V3, highly specific for significant stenosis of the left anterior descending artery. Posterior infarction. Posterior infarction is confirmed with ST segment depression ? 0,5 mm in leads V1 - 3 and ST segment elevation ? 0.5 mm in posterior leads (V7 - V9). Conclusion. There are many electrocardiographic patterns that physicians should promptly recognize as clinical myocardial infarction with ST segment elevation equivalents in order to perform urgent reperfusion therapy for better prognosis and survival in these patients.

scholarly journals Electrocardiographic surrogates of structural myocardial alterations in the Dorper sheep heart

2005 ◽  
Vol 72 (4) ◽  
Author(s):  
J. Ker ◽  
E.C. Webb
Keyword(s):  
Qrs Complex ◽  
Premature Ventricular Complexes ◽  
Cardiac Memory ◽  
St Segment ◽  
Electrocardiographic Markers ◽  
Dorper Sheep ◽  
Myocardial Pathology ◽  
T Waves

In this study we evaluated the validity of well-known human electrocardiographic markers of myocardial pathology in Dorper sheep. These markers include: the duration of the QRS complex of premature ventricular complexes (PVCs), the presence of notching of the QRS complex of PVCs and change of the ST-segment of PVCs. It was shown that these three electrocardiographic phenomena correlate with myocardial pathology in the hearts of Dorper sheep. We also describe a new electrocardiographic indicator of myocardial pathology, namely an increase in the frequency of cardiac memory T waves as a new electrocardiographic surrogate for myocardial pathology in the hearts of Dorper sheep.

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..

scholarly journals Electrocardiographic surrogates of structural myocardial alterations in the Dorper sheep heart

2005 ◽  
Vol 72 (4) ◽  
pp. 273-277 ◽  
Author(s):  
J. Ker ◽  
E.C. Webb
Keyword(s):  
Qrs Complex ◽  
Premature Ventricular Complexes ◽  
Cardiac Memory ◽  
St Segment ◽  
Electrocardiographic Markers ◽  
Dorper Sheep ◽  
Myocardial Pathology ◽  
T Waves

In this study we evaluated the validity of well-known human electrocardiographic markers of myocardial pathology in Dorper sheep. These markers include: the duration of the QRS complex of premature ventricular complexes (PVCs), the presence of notching of the QRS complex of PVCs and change of the ST-segment of PVCs. It was shown that these three electrocardiographic phenomena correlate with myocardial pathology in the hearts of Dorper sheep. We also describe a new electrocardiographic indicator of myocardial pathology, namely an increase in the frequency of cardiac memory T waves as a new electrocardiographic surrogate for myocardial pathology in the hearts of Dorper sheep.

scholarly journals The association between T wave inversion in leads with ST-elevation and patency of the infarct-related artery

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Abdolmohammad Ranjbar ◽  
Bahram Sohrabi ◽  
Seyyed-Reza Sadat-Ebrahimi ◽  
Samad Ghaffari ◽  
Babak Kazemi ◽  
...  
Keyword(s):  
Therapeutic Interventions ◽  
Tertiary Referral Hospital ◽  
St Segment Elevation ◽  
T Wave ◽  
Wave Inversion ◽  
St Segment ◽  
Infarct Related Artery ◽  
St Elevation ◽  
Time Of Admission ◽  
T Waves

Abstract Background Up to over half of the patients with ST-segment elevation myocardial infarction (STEMI) are reported to undergo spontaneous reperfusion without therapeutic interventions. Our objective was to evaluate the applicability of T wave inversion in electrocardiography (ECG) of patients with STEMI as an indicator of early spontaneous reperfusion. Methods In this prospective study, patients with STEMI admitted to a tertiary referral hospital were studied over a 3-year period. ECG was obtained at the time of admission and patients underwent a PPCI. The association between early T wave inversion and patency of the infarct-related artery was investigated in both anterior and non-anterior STEMI. Results Overall, 1025 patients were included in the study. Anterior STEMI was seen in 592 patients (57.7%) and non-anterior STEMI in 433 patients (42.2%). Among those with anterior STEMI, 62 patients (10.4%) had inverted T and 530 (89.6%) had positive T waves. In patients with anterior STEMI and inverted T waves, a significantly higher TIMI flow was detected (p value = 0.001); however, this relationship was not seen in non-anterior STEMI. Conclusion In on-admission ECG of patients with anterior STEMI, concomitant inverted T wave in leads with ST elevation could be a proper marker of spontaneous reperfusion of infarct related artery.

scholarly journals Usefulness of ECG to differentiate apical hypertrophic cardiomyopathy from non-ST elevation acute coronary syndrome

2020 ◽  
Author(s):  
Yirao Tao ◽  
Jing Xu ◽  
Samira Yerima Bako ◽  
Xiaobo Yao ◽  
Donghui Yang
Keyword(s):  
Acute Coronary Syndrome ◽  
Hypertrophic Cardiomyopathy ◽  
Maximal Amplitude ◽  
Apical Hypertrophic Cardiomyopathy ◽  
Coronary Syndrome ◽  
T Wave ◽  
St Segment ◽  
St Elevation ◽  
Elevation Acute Coronary Syndrome ◽  
T Waves

Abstract Objective: Apical hypertrophic cardiomyopathy (ApHCM) is a phenotypic variant of nonobstructive HCM. ApHCM is characterized by left ventricular hypertrophy involve the distal apex. The electrocardiographic character of ApHCM can mimic non-ST elevation acute coronary syndrome (NSTEACS) which triggers a series of studies and treatments that may be unnecessary. This study aimed to clarify the ECG differences between the two diseases.Methods: Initial electrocardiogram (ECG) recordings of 41 patients with ApHCM and 72 patients with NSTEACS were analyzed retrospectively. We analyzed the voltage of negative T (neg T) wave, R wave and the change of ST-segment in the 12-lead ECGs as well as the number of leads with neg T waves.Results: Across the 12-lead ECGs, the magnitude of R wave significantly differed between ApHCM and NSTEACS in 10 leads excluding leads aVR and V1. ApHCM was associated with a greater maximal amplitude of R wave in lead V5 (3.13±1.08 vs. 1.38±0.73, P=0.000). The magnitude of T wave significantly differed between ApHCM and NSTEACS in 10 leads excluding leads II and V1. ApHCM was associated with a greater maximal amplitude of neg T wave in lead V4 (0.85±0.69 vs. 0.35±0.23, P=0.000). The frequency of giant neg T (1mv or more) wave was higher in ApHCM (36.5% vs. 0%, P=0.000). The magnitude of ST-segment deviation significantly differed between ApHCM and NSTEACS in 10 leads excluding leads aVF and V2. ApHCM was associated with a greater maximal amplitude of ST-segment depression in lead V5 (0.19±0.07 vs. 0.03±0.06, P=0.000). The number of leads with neg T waves also differed between ApHCM and NSTEACS (6.75±1.42 vs. 6.08±1.51, P=0.046). The sum of R wave in lead V5, neg T wave in lead V6 and ST-segment depression in lead V4>2.585 mV identified ApHCM with 90.2% sensibility and 87.5% specificity, representing the highest diagnostic accuracy.Conclusions: Compared with NSTEACS patients, ApHCM patients presented higher R waves and neg T wave voltage as well as a greater ST-segment depression in the 12-lead ECGs.

scholarly journals Management of ST Elevation Myocardial Infarction (STEMI) in Different Settings

2021 ◽  
Author(s):  
Rod Partow-Navid ◽  
Narut Prasitlumkum ◽  
Ashish Mukherjee ◽  
Padmini Varadarajan ◽  
Ramdas G. Pai
Keyword(s):  
Myocardial Infarction ◽  
Treatment Strategies ◽  
Management Process ◽  
St Segment Elevation ◽  
Segment Elevation Myocardial Infarction ◽  
Multiple Factors ◽  
St Segment ◽  
Threatening Condition ◽  
Life Threatening ◽  
St Elevation

AbstractST-segment elevation myocardial infarction (STEMI) is a life-threatening condition that requires emergent, complex, well-coordinated treatment. Although the primary goal of treatment is simple to describe—reperfusion as quickly as possible—the management process is complicated and is affected by multiple factors including location, patient, and practitioner characteristics. Hence, this narrative review will discuss the recommended management and treatment strategies of STEMI in the circumstances.

scholarly journals Cerebral embolism due to left atrial myxoma in a patient presenting with chest pain and ST-segment elevation: a case report

2020 ◽  
Author(s):  
António Fontes ◽  
Nuno Dias-Ferreira ◽  
Anabela Tavares ◽  
Fátima Neves
Keyword(s):  
Myocardial Infarction ◽  
Chest Pain ◽  
Magnetic Resonance ◽  
Left Atrial ◽  
Left Ventricular ◽  
Atrial Myxoma ◽  
Left Atrial Myxoma ◽  
St Segment ◽  
Wide Range ◽  
St Elevation

Abstract Background Myocarditis is an uncommon, potentially life-threatening disease that presents with a wide range of symptoms. In acute myocarditis, chest pain (CP) may mimic typical angina and also be associated with electrocardiographic changes, including an elevation of the ST-segment. A large percentage (20–56%) of myxomas are found incidentally. Case summary A 62-year-old female presenting with sudden onset CP and infero-lateral ST-elevation in the electrocardiogram. The diagnosis of ST-elevation myocardial infarction was presumed and administered tenecteplase. The patient was immediately transported to a percutaneous coronary intervention centre. She complained of intermittent diplopia during transport and referred constitutional symptoms for the past 2 weeks. Coronary angiography showed normal arteries. The echocardiogram revealed moderate to severe left ventricular systolic dysfunction due to large areas of akinesia sparing most of the basal segments, and a mobile mass inside the left atrium attached to the septum. The cardiac magnetic resonance (CMR) suggested the diagnosis of myocarditis with concomitant left atrial myxoma. The patient underwent resection of the myxoma. Neurological evaluation was performed due to mild vertigo while walking and diplopia in extreme eye movements. The head magnetic resonance imaging identified multiple infracentimetric lesions throughout the cerebral parenchyma compatible with an embolization process caused by fragments of the tumour. Discussion Myocarditis can have various presentations may mimic acute myocardial infarction and CMR is critical to establish the diagnosis. Myxoma with embolic complications requires emergent surgery. To the best of our knowledge, this is the first case reported in the applicable literature of a myxoma diagnosed during a myocarditis episode.

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