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.

The Value of Electrocardiographic Changes in Evaluating the Prognosis of Acute ST-Elevation Myocardial Infarction (STEMI) After PCI

2021 ◽  
Vol 7 (5) ◽  
pp. 1435-1442
Author(s):  
Yang Yang ◽  
Xiuyu Liang ◽  
Yuzhe Fan ◽  
Gendong Zhou ◽  
Xiaohong Zhang
Keyword(s):  
Myocardial Infarction ◽  
Evaluation Method ◽  
St Elevation Myocardial Infarction ◽  
Control Group ◽  
Observation Group ◽  
St Segment Elevation ◽  
St Segment ◽  
Thrombolytic Effect ◽  
St Elevation ◽  
The Difference

To explore the relationship between the changes of ECG indexes and the prognosis after PCI in patients with acute ST-elevation myocardial infarction (STEMI), and to develop the evaluation method and analyze the advantages and characteristics. 420 patients with acute myocardial infarction (AMI) were admitted to our hospital from March 2017 to April 2020. They were divided into the observation group (ST segment elevation type) with 220 patients and control group (non-ST segment elevation type) with 200 patients according to whether ST segment elevation was or not. ECG was detected before and 1 hour after operation, evaluation of thrombolytic effect, 6-minute walking test and echocardiography were performed 3 months after operation. Compared with the control group, the ECG of the observation group showed St Compared with the control group, the thrombolytic effect of the observation group was significantly improved, and the difference was statistically significant (P < 0.05); compared with the control group, the thrombolysis effect of the observation group was significantly improved, the difference was statistically significant (P < 0.05); ECG index can effectively reflect the recovery of cardiac function after PCI in patients with acute STEMI, and can effectively indicate the improvement of symptoms in patients with AMI, which is worthy of clinical application.

Increased ventricular repolarization heterogeneity in patients with ventricular arrhythmia vulnerability and cardiomyopathy: a human in vivo study

2006 ◽  
Vol 290 (1) ◽  
pp. H79-H86 ◽  
Author(s):  
Vijay S. Chauhan ◽  
Eugene Downar ◽  
Kumaraswamy Nanthakumar ◽  
John D. Parker ◽  
Heather J. Ross ◽  
...  
Keyword(s):  
Ventricular Arrhythmia ◽  
Ventricular Arrhythmias ◽  
Conduction Block ◽  
Left Ventricular ◽  
Ventricular Repolarization ◽  
Similar Patient ◽  
T Wave Alternans ◽  
Activation Times ◽  
Unipolar Electrograms

Increased repolarization heterogeneity can provide the substrate for reentrant ventricular arrhythmias in animal models of cardiomyopathy. We hypothesized that ventricular repolarization heterogeneity is also greater in patients with cardiomyopathy and ventricular arrhythmia vulnerability (inducible ventricular tachycardia or positive microvolt T wave alternans, VT/TWA) compared with a similar patient population without ventricular arrhythmia vulnerability (no VT/TWA). Endocardial and epicardial repolarization heterogeneity was measured in patients with ( n = 12) and without ( n = 10) VT/TWA by using transvenous 26-electrode catheters placed along the anteroseptal right ventricular endocardium and left ventricular epicardium. Local activation times (AT), activation-recovery intervals (ARI), and repolarization times (RT) were measured from unipolar electrograms. Endocardial RT dispersion along the apicobasal ventricle was greater ( P < 0.005) in patients with VT/TWA than in those without VT/TWA because of greater ARI dispersion ( P < 0.005). AT dispersion was similar between the two groups. Epicardial RT dispersion along the apicobasal ventricle was greater ( P < 0.05) in patients with VT/TWA than in those without VT/TWA because of greater ARI dispersion ( P < 0.05). AT dispersion was similar between the two groups. A plot of AT as a function of ARI revealed an inverse linear relationship for no VT/TWA such that progressively later activation was associated with progressively shorter ARI. The AT-ARI relationship was nonlinear in VT/TWA. In conclusion, patients with cardiomyopathy and VT/TWA have greater endocardial and epicardial repolarization heterogeneity than those without VT/TWA without associated conduction slowing. The steep repolarization gradients in VT/TWA may provide the substrate for functional conduction block and reentrant ventricular arrhythmias.

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.

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.

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.

Validation of a simple model for the morphology of the T wave in unipolar electrograms

2009 ◽  
Vol 297 (2) ◽  
pp. H792-H801 ◽  
Author(s):  
Mark Potse ◽  
Alain Vinet ◽  
Tobias Opthof ◽  
Ruben Coronel
Keyword(s):  
Theoretical Model ◽  
Simple Model ◽  
Action Potential ◽  
Normal Tissue ◽  
T Wave ◽  
Simple Theoretical Model ◽  
Wave Morphology ◽  
The Difference ◽  
Unipolar Electrograms ◽  
T Waves

Local unipolar electrograms (UEGs) permit assessment of local activation and repolarization times at multiple sites simultaneously. However, UEG-based indexes of local repolarization are still debated, in particular for positive T waves. Previous experimental and computer modeling studies have not been able to terminate the debate. In this study we validate a simple theoretical model of the UEG and use it to explain how repolarization statistics in the UEG relate to those in the action potential. The model reconstructs the UEG by taking the difference between an inverted local action potential and a position-independent remote signal. In normal tissue, this extremely simple model predicts T-wave morphology with surprising accuracy while explaining in a readily understandable way why the instant of repolarization is always related to the steepest upstroke of the UEG, both in positive and negative T waves, and why positive T waves are related to early repolarizing sites, whereas negative T waves are related to late repolarizing sites.

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 -374-EFFECTS OF CALCIUM ANTAGONISTS ON VENTRICULAR ARRHYTHMIAS AND ELECTRICAL ALTERNANS OF ST SEGMENT DURING ACUTE CORONARY OCCLUSION IN DOGS

1986 ◽  
Vol 50 (6) ◽  
pp. 571
Author(s):  
Daiju Morishita ◽  
Takayuki lkeda ◽  
Toshisuke Terakawa ◽  
Akira Higashino ◽  
Satoshi Hirota ◽  
...  
Keyword(s):  
Calcium Antagonists ◽  
Ventricular Arrhythmias ◽  
Coronary Occlusion ◽  
Acute Coronary Occlusion ◽  
St Segment ◽  
Electrical Alternans

scholarly journals Cardiogenic shock and radial access in patients with an acute ST elevation myocardial infarction

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
R Zahn ◽  
M Hochadel ◽  
B Schumacher ◽  
M Pauschinger ◽  
C Stellbrink ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Hospital Mortality ◽  
Cardiogenic Shock ◽  
St Elevation Myocardial Infarction ◽  
Strong Variation ◽  
Access Site ◽  
Femoral Access ◽  
Radial Access ◽  
St Elevation ◽  
The Difference

Abstract Background Cardiogenic shock (CS) in patients (pts) with acute ST elevation myocardial infarction (STEMI) is the strongest predictor of hospital mortality. Radial in contrast to femoral access in STEMI pts might be associated with a lower mortality. However, little is known on radial access in CS pts. Methods We retrospectively analysed all STEMI pts between 2009 and 2015 who sufferend from CS and who were included into the ALKK PCI registry. Pts treated via a radial access were compared to those treated via a femoral access. Results Between 2009 and 2015 23796 STEMI pts were included in the registry. 1763 (7.4%) of pts were in CS. The proportion of radial access was 6.6%: in 2009 4.0% and in 2015 19.6%, p for trend &lt;0.0001 with a strong variation between the participating centres (0% to 37%). Conclusions Radial access was only used in 6.6% of STEMI pts presenting in CS. However, a significant increase in the use of radial access was observed over time (2009: 4%, 2015 19.6%, p&lt;0.001), with a great variance in its use between the participating hospitals. Despite similar pt characteristics the difference in hospital mortality according to access site has to be interpretated with caution. Funding Acknowledgement Type of funding source: None

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