Time Course of ECG Depolarization and Repolarization Changes during Ischemia in PTCA Recordings

Summary Objectives: In this work we studied the temporal evolution of changes in the electrocardiogram (ECG) as a consequence of the induced ischemia during prolonged coronary angioplasty, comparing the time course of indexes reflecting depolarization and those reflecting repolarization. Methods: We considered both local (measured at specific points of the ECG) and global (obtained from the Karhunen-Loève transform) indexes. In particular, the evolution of Q, R and S wave amplitudes during ischemia was analyzed with respect to classical indexes such as ST level. As a measurement of sensitivity we used an Ischemic Changes Sensor (ICS), which reflects the capacity of an index to detect changes in the ECG. Results: The results showed that, in leads with low-amplitude ST-T complexes, the S wave amplitude was more sensitive in detecting ischemia than was the commonly used index ST60. It was found that in such leads the S wave amplitude initially exhibited a delayed response to ischemia when compared to ST60, but its performance was better from the second minute of occlusion. The global indexes describing the ST-T complex were, in terms of the ICS, superior to the S wave amplitude for ischemia detection. Conclusions: Ischemic ECG changes occur both at repolarization and depolarization, with alterations in the depolarization period appearing later in time. Local indexes are less sensitive to ischemia than global ones.

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Can Changes in S Wave Amplitude be Used to Detect Ischaemia during Ambulatory ECG Monitoring?

Clinical Science ◽

10.1042/cs070001pa ◽

1986 ◽

Vol 70 (s13) ◽

pp. 1P-1P

Author(s):

J.J. Glazier ◽

S. Chierchia ◽

A. Maseri

Keyword(s):

Wave Amplitude ◽

Ecg Monitoring ◽

S Wave ◽

Ambulatory Ecg ◽

Ambulatory Ecg Monitoring

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Postoperative ‘STEMI’ in Intracerebral Hemorrhage due to Arteriovenous Malformation: A Case Report and Review of Literature

Case Reports in Critical Care ◽

10.1155/2019/9048239 ◽

2019 ◽

Vol 2019 ◽

pp. 1-5

Author(s):

Ravinder Datt Bhanot ◽

Jasleen Kaur ◽

Shitiz Sriwastawa ◽

Kendall Bell ◽

Kushak Suchdev

Keyword(s):

Myocardial Infarction ◽

Intracerebral Hemorrhage ◽

Arteriovenous Malformation ◽

Cardiac Biomarkers ◽

Review Of Literature ◽

Fibrinolytic Agents ◽

Intraparenchymal Hemorrhage ◽

Ecg Changes ◽

St Segment ◽

Electrocardiogram Ecg

Electrocardiogram (ECG) changes suggestive of cardiac ischemia are frequently demonstrated in patients with ischemic stroke and subarachnoid hemorrhage. However, little is known of such changes particularly acute ST segment myocardial infarction (STEMI) in patients with intracerebral hemorrhage (ICH), especially after neurosurgery. We present a patient with intraparenchymal hemorrhage due to cerebral arteriovenous malformation (AVM) who exhibited acute STEMI after neurosurgery. Serial cardiac biomarkers and echocardiograms were performed which did not reveal any evidence of acute myocardial infarction. The patient was managed conservatively from cardiac stand point with no employment of anticoagulants, antiplatelet therapy, fibrinolytic agents, or angioplasty and recovered well with minimal neurological deficit. This case highlights that diffuse cardiac ischemic signs on the ECG can occur in the setting of an ICH after neurosurgery, potentially posing a difficult diagnostic and management conundrum.

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Improved constraints on the πOπO S-wave amplitude

Nuclear Physics B ◽

10.1016/0550-3213(72)90404-x ◽

1972 ◽

Vol 41 (2) ◽

pp. 474-484 ◽

Cited By ~ 2

Author(s):

P. Grassberger

Keyword(s):

Wave Amplitude ◽

S Wave

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Application of instantaneous rotations to S‐wave vertical seismic profiling

Geophysics ◽

10.1190/1.1444240 ◽

1997 ◽

Vol 62 (5) ◽

pp. 1365-1368

Author(s):

M. Boulfoul ◽

Doyle R. Watts

Keyword(s):

High Amplitude ◽

Seismic Profile ◽

P Wave ◽

Petroleum Exploration ◽

S Wave ◽

Amplitude Variation With Offset ◽

Seismic Profiling ◽

Vertical Seismic Profiling ◽

Seismic Models ◽

Low Amplitude

The petroleum exploration industry uses S‐wave vertical seismic profiling (VSP) to determine S‐wave velocities from downgoing direct arrivals, and S‐wave reflectivities from upgoing waves. Seismic models for quantitative calibration of amplitude variation with offset (AVO) data require S‐wave velocity profiles (Castagna et al., 1993). Vertical summations (Hardage, 1983) of the upgoing waves produce S‐wave composite traces and enable interpretation of S‐wave seismic profile sections. In the simplest application of amplitude anomalies, the coincidence of high amplitude P‐wave reflectivity and low amplitude S‐wave reflectivity is potentially a direct indicator of the presence of natural gas.

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Relationship Between the s-wave Amplitude of the Multifocal Electroretinogram and the Retinal Nerve Fiber Layer Thickness in Glaucomatous Eyes

Japanese Journal of Ophthalmology ◽

10.1007/s10384-005-0236-6 ◽

2005 ◽

Vol 49 (6) ◽

pp. 481-490 ◽

Cited By ~ 3

Author(s):

Junfuku Nitta ◽

Yutaka Tazawa ◽

Ken-ichi Murai ◽

Isao Egawa ◽

Takashi Nabeshima ◽

...

Keyword(s):

Nerve Fiber ◽

Layer Thickness ◽

Retinal Nerve Fiber Layer ◽

Wave Amplitude ◽

Multifocal Electroretinogram ◽

S Wave ◽

Fiber Layer ◽

Nerve Fiber Layer ◽

Nerve Fiber Layer Thickness ◽

Retinal Nerve Fiber

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Does Prior Surgery Affect Total Ankle Complication and Failure Rates?

Foot & Ankle Orthopaedics ◽

10.1177/2473011420s00345 ◽

2020 ◽

Vol 5 (4) ◽

pp. 2473011420S0034

Author(s):

Luigi Manzi ◽

Federico Giuseppe Usuelli ◽

Alexander Caughman ◽

Christopher E. Gross

Keyword(s):

Functional Outcome ◽

Repeated Measures ◽

Functional Outcomes ◽

Time Course ◽

Temporal Evolution ◽

Consecutive Series ◽

Exact Test ◽

Time Points ◽

Significant Difference ◽

Pain Outcomes

Category: Ankle Arthritis; Ankle Introduction/Purpose: Given that most ankle replacements are post-traumatic in origin, it is important to investigate if prior interventions can affect a patient’s functional outcome or the possibility of having a complication. Prior surgeries create scar, incisions, and possible affect bone health that could interfere with healing. The purpose of the study is to assess the pain and functional temporal outcomes of patients with and without prior surgeries in the ipsilateral ankle. We hypothesize that those with a previous ipsilateral ankle procedure will not have an increased complication rate or worse functional outcomes. Methods: We retrospectively identified a consecutive series of 100 primary TARs with a prior procedure who were followed for a minimum of 3 years. The follow-up time points considered were 0, 6, 12, and 36 months. Outcomes were measured using AOFAS, VAS, SF12, and range of motion scores. The mean patient age was 56.5 +- 13.4 years. Sixty-four patients had previous interventions which included osteosynthesis (49), arthroscopy (11), hardware removal (25), arthrodesis (3), prosthesis (1), open fracture (9), and other open surgery (12). Within-group comparisons were performed using one-way repeated-measures ANOVA (1-w rANOVA), analyzing temporal course of clinical data (comparisons between different time points) between the groups. To compare the time course of clinical measures between the two groups, 2-w rANOVAs were performed. Data and statistical analysis were conducted using Matlab (MathWorks, Natick, MA). Results: For each type of intervention, every outcome was compared to test whether presurgery interventions have an influence on the temporal evolution of the outcomes. The two groups did not show any difference on the temporal evolution of the outcomes. The type of intervention did have a weak effect on outcomes. Treatment of previous open fractures was the only pre- surgical intervention that showed a statistically significant difference in temporal evolution of functional and pain outcomes between intervention and non-intervention groups. No significant correlations were found between all outcomes and the time between the last intervention and prosthesis. Using Fisher’s-exact test, there was not a significant association between the those who had previous surgery and those who did not and the rate of complication and revision (p =0.10). Conclusion: A pre-operative discussion should center on potential complications and predicted functional outcomes. The presence, type, and timing of an intervention prior to an ankle replacement does not strongly affect the temporal outcomes of pain and functional outcome scores. Furthermore, the complication or revision rate is not affected by prior surgeries.

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Electrocardiogram (ECG) Changes and Cardiac Biomarker Abnormalities Among Two Marathon Runners

Journal of Emergency Medicine ◽

10.1016/j.jemermed.2008.05.015 ◽

2010 ◽

Vol 38 (2) ◽

pp. 159-161 ◽

Cited By ~ 4

Author(s):

Alicia B. Minns ◽

Richard F. Clark

Keyword(s):

Ecg Changes ◽

Marathon Runners ◽

Cardiac Biomarker ◽

Electrocardiogram Ecg

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Sequential changes in rat liver nuclear tri-iodothyronine receptors and mitochondrial α-glycerophosphate dehydrogenase activity after administeration of tri-iodothyronine

Biochemical Journal ◽

10.1042/bj1820377 ◽

1979 ◽

Vol 182 (2) ◽

pp. 377-382 ◽

Cited By ~ 14

Author(s):

Hirotoshi Nakamura ◽

Satoshi Hamada ◽

Hiroo Imura

Keyword(s):

Dehydrogenase Activity ◽

Nuclear Receptors ◽

Nuclear Receptor ◽

Rat Liver ◽

Time Course ◽

Delayed Response ◽

Histone Proteins ◽

Glycerophosphate Dehydrogenase ◽

Receptor Concentration ◽

Hormonal Modulation

The dynamics of the induction of nuclear tri-iodothyronine receptors and mitochondrial α-glycerophosphate dehydrogenase were studied in rat liver after a single injection of tri-iodothyronine. The maximal binding capacity (Cmax.) and association constant (Ka) of the nuclear receptors were determined by Scatchard analyses with and without correction for the endogenous tri-iodothyronine measured by radioimmunoassay. The administration of tri-iodothyronine induced sequential increases in the concentration of nuclear receptors and α-glycerophosphate dehydrogenase activity in the liver. The nuclear-receptor concentration was increased to 2.5 times that in the hypothyroid rat 1 day after the administration of hormone, and then decreased, with a half-life of about 2 days. α-Glycerophosphate dehydrogenase activity changed in parallel with the nuclear-receptor concentration, showing a delayed response. The total amount of non-histone protein in the liver was significantly increased 3 days after the administration. It seems likely therefore that the tri-iodothyronine-induced increase in nuclear-receptor concentration is responsible, at least in part, for the induction of this enzyme. The possibility is also suggested that nuclear receptors may be one of the non-histone proteins selectively synthesized at an early stage of the hormonal stimulation. Throughout the time course, the Ka values of the nuclear receptors for tri-iodothyronine remained unchanged, when corrected for endogenous tri-iodothyronine bound to the non-histone proteins, although they were apparently changed when the correction was not made. The results obtained provide further evidence for hormonal modulation of the nuclear receptors which is closely linked with the hormonal effect.

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