Late potentials in an ovine model of acute transmural myocardial infarction

1992 ◽  
Vol 73 (3) ◽  
pp. 841-846 ◽  
Author(s):  
G. Kreiner ◽  
C. D. Gottlieb ◽  
S. Furukawa ◽  
M. B. Simson ◽  
G. S. Tyson ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Ventricular Arrhythmias ◽  
Additional Data ◽  
Late Potentials ◽  
Qrs Complex ◽  
Ovine Model ◽  
Slow Conduction ◽  
Before And After ◽  
Qrs Duration ◽  
Low Amplitude

The development of slow conduction during the first hours of acute transmural myocardial infarction (ATMI) was studied by signal-averaged electrocardiograms (SAE) in 19 adult anesthetized sheep. SAEs were recorded before and after intravenous infusions of lidocaine and bretylium were begun and 10, 30, and 60 min after ATMI produced by ligation of the left anterior descending and second diagonal coronary arteries. Four sheep died promptly of ventricular tachyarrhythmias; two others developed sustained ventricular arrhythmias, which precluded additional data. Biphasic changes in QRS duration, root mean square voltage of the terminal 40 ms of the QRS complex, and duration of terminal low-amplitude (less than 30 microV) signal were observed. Peak changes in conduction occurred 30 min after infarction and regressed toward baseline thereafter. At 30 min, all animals developed late potentials, which were defined as signals that exceeded both after-drug QRS duration and duration of terminal low-amplitude signal less than 30 microV by more than two standard deviations. At 60 min, only 3 of 13 (23%) animals had late potentials. Conduction is slowest 30 min after ATMI in sheep but may not be related to development of ventricular arrhythmias. In five of six sheep (83%), ventricular arrhythmias occurred within 15 min of infarction before peak slowing was observed by SAE.

Recognition and Management of Cardiac Arrhythmias: Part II. Ventricular Arrhythmias and Bradyarrhythmias

1998 ◽  
Vol 13 (2) ◽  
pp. 68-77
Author(s):  
Simon Chakko ◽  
Raul Mitrani
Keyword(s):  
Myocardial Infarction ◽  
Heart Failure ◽  
Congestive Heart Failure ◽  
Ventricular Tachycardia ◽  
Ventricular Fibrillation ◽  
Cardiac Arrhythmias ◽  
Ventricular Arrhythmias ◽  
Qrs Complex ◽  
Implantable Defibrillators

This review discusses the treatment of ventricular arrhythmias and bradyarrhythmias. Recent studies addressing the management of nonsustained ventricular arrhythmias in patients with congestive heart failure and those recovering from myocardial infarction are discussed. Determination of the origin of wide QRS complex tachycardia is usually possible at the bedside and the diagnostic criteria are provided. Therapy to prevent recurrent ventricular tachycardia or ventricular fibrillation is difficult and controversial. A widely accepted approach based on electrophysiologic testing and implantable defibrillators appears to be the most effective. Recognition and management of common bradyarrhythmias including the indications for pacemakers are discussed.

scholarly journals High-resolution electrocardiography in the diagnosis of arrhythmogenic right ventricular cardiomyopathy in Boxer dogs

2013 ◽  
Vol 43 (6) ◽  
pp. 1102-1106
Author(s):  
Evandro Zacché Pereira ◽  
Thais Cristine Alves Assumpção ◽  
Ana Paula Gering ◽  
Fábio Nelson Gava ◽  
Edna Mireya Gómez Ortiz ◽  
...  
Keyword(s):  
High Resolution ◽  
Right Ventricular ◽  
Ventricular Arrhythmias ◽  
Arrhythmogenic Right Ventricular Cardiomyopathy ◽  
Systolic Dysfunction ◽  
Qrs Complex ◽  
Ventricular Cardiomyopathy ◽  
Echocardiographic Examination ◽  
Qrs Duration ◽  
Boxer Dogs

To evaluate the reliability of high-resolution electrocardiography in the diagnosis of arrhythmogenic right ventricular cardiomyopathy in Boxers, 20 dogs with no structural cardiac alterations at echocardiographic examination were grouped on the basis of frequency of ventricular arrhythmias, evaluated by 24-hour ambulatory ECG, and undergoing a high-resolution electrocardiography. High frequency QRS duration, duration of terminal QRS complex less than 40µV (LAS40) and root mean square voltage of the terminal 40 milliseconds of the QRS complex (RMS40) were measured. Differences in high-resolution ECG variables were not observed between groups. Therefore, the results of this investigation suggest that high-resolution electrocardiography is not a useful method for the diagnosis of arrhythmogenic right ventricular cardiomyopathy in Boxers without detectable myocardial alterations or systolic dysfunction.

scholarly journals PERANAN DURASI QRS DAN SKOR QRS SELVESTER DALAM KEBERHASILAN REPERFUSI MIOKARD

2016 ◽  
Vol 38 (4) ◽  
pp. 218
Author(s):  
Yose Ramda Ilhami
Keyword(s):  
Infarct Size ◽  
Cellular Level ◽  
Dynamic Parameters ◽  
Myocardial Cells ◽  
Qrs Complex ◽  
St Segment Elevation ◽  
T Wave ◽  
St Segment ◽  
Before And After ◽  
Qrs Duration

AbstrakPerubahan gambaran elektrokardiogram (EKG) terjadi pada fase akut IMA EST baik berupa perubahan repolarisasi ataupun perubahan depolarisasi. Skor QRS Selvester dan pemanjangan kompleks QRS merupakan parameter yang digunakan untuk memperkirakan luas infark dan penilaian iskemia. Tujuan penulisan ini adalah untuk mengetahui mekanisme perubahan durasi QRS dan skor QRS Selvester setelah reperfusi yang optimal. Penulisan artikel ini berdasarkan studi kepustakaan yang terkait dengan peranan durasi QRS dan skor QRS Selvester serta keberhasilan reperfusi miokard. Iskemia mengakibatkan perubahan gambaran listrik sel miokard normal, sehingga terjadi perubahan gambaran EKG yaitu meliputi perubahan gelombang T, elevasi segmen ST dan distorsi dengan pemanjangan kompleks QRS. Penilaian luas infark dapat dilakukan dengan menilai skor QRS Selvester. Iskemia juga mengakibatkan pemanjangan kompleks QRS melalui pemanjangan konduksi purkinye dan blok peri-infark. Reperfusi optimal dapat mengakibatkan regresi gelombang Q dan penurunan durasi kompleks QRS. Perubahan skor QRS selama reperfusi masih kontroversial. Perubahan pada durasi QRS dan skor QRS Selvester sebelum dan setelah reperfusi menandakan bahwa parameter ini merupakan parameter dinamis yang akan berubah ketika terjadinya reperfusi yang optimal pada tingkat seluler.AbstractChanges in Electro Cardiogram (ECG) occur in acute phase of STEMI either as repolarization or depolarization change. Selvester QRS score and lengthening of QRS complex duration are parameters that is used to predict infarct size and to analyze ischemia. The purpose of this literature review is to understand the mechanism of change in QRS duration and Selvester QRS score after optimal reperfusion. Ischemia causes changes in the electrical feature of normal myocardial cells including changes in the T wave, ST segment elevation and distortion with prolongation QRS complex. Assessment of infarct size can be done by assessing Selvester QRS score. Ischemia also resulted in prolongation of the QRS complex with elongation of Purkinje conduction and peri-infarction block. Optimal reperfusion may lead to regression of the Q wave and a decrease in the duration of the QRS complex. QRS score changes during reperfusion remains controversial. Changes in QRS duration and Selvester QRS score before and after reperfusion indicates that these parameters are dynamic parameters that will change when the optimal reperfusion occurs at the cellular level.

Fragmented QRS complex and ventricular arrhythmias in patients with myocardial infarction

2021 ◽  
Vol 8 (2) ◽  
pp. 83
Author(s):  
Tamer Sayed MohamedAbdel Mawla ◽  
Asmaa MizarAbdel Hameed ◽  
SherifHamed Zaky ◽  
KhaledAhmed El khashab
Keyword(s):  
Myocardial Infarction ◽  
Ventricular Arrhythmias ◽  
Qrs Complex ◽  
Fragmented Qrs
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