Repolarization spatial-time current abnormalities in patients with coronary heart disease
Kuniomi Ogata1, Akihiko Kandori, Yasushi Watanabe
1Advanced Research Laboratory, Hitachi Ltd., Higashi-Koigakubo, Kokubunji, Tokyo, Japan. kuniomi.ogata.fb@hitachi.com
Pacing and Clinical Electrophysiology : PACE
|April 2, 2009
Summary
Magnetocardiography (MCG) current distribution parameters (CDPs) can identify coronary heart disease (CHD) abnormalities. A scoring system using maximum and total current vectors during repolarization shows promise for diagnosing CHD.
Area of Science:
- Biophysics
- Cardiology
- Medical Imaging
Background:
- Magnetocardiography (MCG) visualizes myocardial current distribution.
- Current distribution parameters (CDPs) assess spatial-time current abnormalities in coronary heart disease (CHD).
- Standardized criteria for CDP-based CHD abnormality scoring remain under development.
Purpose of the Study:
- To evaluate the effectiveness of CDPs in distinguishing between normal controls and CHD patients.
- To develop and validate a scoring method for CHD abnormalities using CDPs.
Main Methods:
- MCG signals were acquired from 101 controls and 56 CHD patients.
- Analyzed CDPs including maximum current vector (MCV) and total current vector (TCV) during ventricular repolarization.
- Calculated areas under the receiver operating characteristic curve (A(z)) and developed a total score (0-4) based on four high-A(z) CDPs.
Main Results:
- MCV and TCV angles at T-wave peak, and TCV angular differences, showed high diagnostic accuracy (A(z)).
- The averaged total score was significantly higher in triple-vessel disease patients (2.67) than controls (0.53).
- A total score >1 yielded 85.7% sensitivity and 74.3% specificity for suspected CHD.
Conclusions:
- A scoring system using MCV and TCV during repolarization effectively reflects lesion areas in CHD.
- This scoring method can indicate time changes in electrical activation dispersion due to ischemia.
- The proposed criteria and scoring offer a promising approach for diagnosing CHD using MCG.
Related Concept Videos
01:30Cardiac Action Potential
Cardiac action potentials are essential for proper heart function, enabling the rhythmic contractions needed for adequate blood circulation. Nodal cells and Purkinje fibers, specialized for electrical conduction, generate these action potentials.
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
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
01:30Acute Coronary Syndrome III: Diagnostic Studies
Diagnosing acute coronary syndrome or ACS begins with a thorough patient history. Notable symptoms include central, crushing chest pain radiating to the left arm, neck, jaw, or back, along with shortness of breath, sweating (diaphoresis), nausea, vomiting, dizziness, and palpitations.It is crucial to note any history of cardiac illnesses and assess risk factors, including age, gender, smoking, hypertension, diabetes, hyperlipidemia, and a sedentary lifestyle.During physical examination, vital...
01:19Electrophysiology of Normal Cardiac Rhythm
The normal cardiac rhythm is a synchronized electrical activity that facilitates the regular and coordinated contraction of the heart muscle. This process is essential for efficient blood circulation throughout the body. The fundamental elements involved in establishing and maintaining this rhythm include the unique electrical properties of cardiac muscle cells, the sinoatrial (SA) node's pacemaker function, the specialized conducting system, and the ionic mechanisms underlying each phase of...
01:19Acute Coronary Syndrome II: Pathophysiology and Clinical Manifestations
The pathophysiology of Acute Coronary Syndrome [ACD] involves several key processes:The main underlying cause of ACD is atherosclerosis, a chronic inflammatory disease characterized by the buildup of lipid-laden plaques within the coronary arteries.As the atherosclerotic plaque grows in the coronary artery, it may become unstable due to the formation of a lipid-rich core and a thin fibrous cap. Inflammatory cells within the plaque, such as macrophages, secrete enzymes that degrade the...
01:25Correlation between ECG and Cardiac Cycle
The electrical signals recorded on an electrocardiogram (ECG) occur before the mechanical processes of contraction and relaxation during the 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...
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...
01:29Electrocardiogram
An electrocardiogram (ECG or EKG) is a critical diagnostic tool that records the electrical signals produced by the heart during each heartbeat. This recording is achieved through electrodes placed strategically on the arms, legs, and chest. The electrocardiograph amplifies these signals and produces 12 distinct tracings, offering a comprehensive understanding of the heart's electrical activity.
Three major waveforms are present in a typical ECG recording: the P wave, the QRS complex, and the T...
Three major waveforms are present in a typical ECG recording: the P wave, the QRS complex, and the T...