Related Experiment Video
Updated: May 3, 2026

Confirmation of Myocardial Ischemia and Reperfusion Injury in Mice Using Surface Pad Electrocardiography
Published on: November 24, 2016
J wave and fragmented QRS formation during the hyperacute phase in Takotsubo cardiomyopathy
Masato Shimizu1, Mitsuhiro Nishizaki, Noriyoshi Yamawake
1Department of Cardiology, Yokohama Minami Kyosai Hospital.
Background:
The J wave and fragmented QRS (fQRS) on electrocardiography are suggested to be closely related to cardiac arrhythmogenesis. Takotsubo cardiomyopathy (TTC) occasionally causes fatal cardiac conditions including life-threatening ventricular arrhythmia. There has been, however, only 1 case report describing the J wave in TTC, and fQRS has not been reported thus far in relation to clinical courses and prognosis.
Methods And Results:
J wave and fQRS formation were investigated in 31 consecutive patients with TTC. Nine patients (29%) had J waves and/or fQRS (group A), whereas the remaining 22 did not (group B). The J wave (4 patients), fQRS (4 patients), or both (1 patient) appeared transiently during the hyperacute phase. Left ventricular ejection fraction was significantly lower in group A. Summed defect score of single-photon emission computed tomography using iodine 123 beta-methyl-p-iodophenyl-pentadecanoic acid, and creatine kinase MB isozyme (CKMB) were significantly higher in group A. On multivariate analysis CKMB was a significant indicator of J wave or fQRS. Moreover, the J wave was a significant indicator for cardiac death and/or ventricular tachyarrhythmia (odds ratio, 11.5; P=0.026).
Conclusions:
Patients with TTC frequently had J waves and/or fQRS during the hyperacute phase, and which were associated with myocardial damage. J wave was also an indicator for cardiac death and/or ventricular tachyarrhythmia. J waves and fQRS may be useful markers for myocardial damage.
More Related Videos
18:11A Research Method For Detecting Transient Myocardial Ischemia In Patients With Suspected Acute Coronary Syndrome Using Continuous ST-segment Analysis
Published on: December 28, 2012
08:19Transthoracic Echocardiography to Assess Post-Resuscitation Left Ventricular Dysfunction After Acute Myocardial Infarction and Cardiac Arrest in Pigs
Published on: July 12, 2022
Related Concept Videos
Acute Coronary Syndrome II: Pathophysiology and Clinical Manifestations
Correlation between ECG and Cardiac Cycle
A cardiac action potential originates in the SA node and spreads throughout the atria and the AV node in approximately 0.03 seconds. This results in the P wave in an ECG and triggers atrial contraction. The action potential is then briefly slowed at the AV node, allowing the atria to contract and fill the ventricles with blood before...
Cardiac Action Potential
The cardiac action potential process involves a series of phases characterized by the movement of ions across the cardiac cell membranes, leading to the depolarization and repolarization of the cardiac myocytes.
Ionic Basis of Cardiac Action Potentials
Electrocardiogram Fundamentals
An electrocardiogram (ECG) is a diagnostic tool for identifying cardiac conditions such as arrhythmias, conduction abnormalities, and myocardial ischemia.
Definition
An electrocardiogram (ECG) visualizes the heart's electrical activity by tracing the electrical movement associated with each heartbeat on a graph or monitor. As the heart beats, an electrical wave passes through it, correlating with the cardiac cycle events.
Parts of an ECG
An ECG utilizes electrodes on the skin...
Disturbances in Heart Rhythm
Arrhythmias are categorized by their speed, rhythm, and origin. A slow heart...
Dysrhythmias IV: Characteristics of Bradyarrhythmias