Determinants of postinfarction ventricular tachycardia
Thomas Crawford1, Jennifer Cowger, Benoit Desjardins
1University of Michigan Medical Center, Ann Arbor, Mich 48109-5853, USA.
Circulation. Arrhythmia and Electrophysiology
|October 13, 2010
Summary
Postinfarction ventricular tachycardia (VT) is linked to specific scar characteristics. Larger infarct size and distinct electrical potentials within scar tissue correlate with inducible VT, aiding in risk stratification.
Area of Science:
- Cardiology
- Cardiac Electrophysiology
- Medical Imaging
Background:
- Postinfarction ventricular tachycardia (VT) development is influenced by unclear structural factors.
- Understanding infarct architecture is crucial for managing VT post-myocardial infarction.
Purpose of the Study:
- To analyze infarct architecture and electrogram characteristics in patients with and without inducible VT.
- To identify structural and electrical correlates of postinfarction VT.
Main Methods:
- Delayed-enhanced MRI (DE-MRI) to assess infarct size and architecture.
- Electrophysiological mapping to evaluate scar tissue characteristics and VT inducibility.
- Comparison of scar area, voltage mapping, and isolated potentials (IPs) between groups.
Main Results:
- Patients with inducible VT had significantly larger subendocardial infarct areas (43 cm² vs 8 cm²).
- Lower unipolar and bipolar voltages were observed in patients with inducible VT.
- Distinct sites with isolated potentials (IPs) were more prevalent in patients with inducible VT (13.2% vs 1.1%).
- An infarct volume >14% accurately identified patients with inducible VT (AUC 0.94).
Conclusions:
- Scar tissue in postinfarction patients with inducible VT exhibits distinct quantitative and qualitative differences.
- Infarct scar size and the presence of isolated potentials are significant correlates of VT inducibility.
More Related Videos
09:37Permanent Ligation of the Left Anterior Descending Coronary Artery in Mice: A Model of Post-myocardial Infarction Remodelling and Heart Failure
Published on: December 2, 2014
14:35Post-Myocardial Infarction Heart Failure in Closed-chest Coronary Occlusion/Reperfusion Model in Göttingen Minipigs and Landrace Pigs
Published on: April 17, 2021
Related Concept Videos
01:28Dysrhythmias II: Classification of Tachyarrhythmias
Tachyarrhythmias are a type of dysrhythmia where the heart rate exceeds 100 beats per minute. Here are some common types of tachyarrhythmias:Sinus TachycardiaSinus tachycardia originates from increased impulses from the sinus node, leading to an elevated heart rate. It is often triggered by stress, fever, or exercise.Patients may experience palpitations, a sensation of a racing heart, dizziness, and chest discomfort.Causes and Risk Factors: Common causes include physical exertion, emotional...
01:29Dysrhythmias III: Characteristics of Dysrhythmias
Dysrhythmias, also known as arrhythmias, are irregular heart rhythms that result from abnormal electrical activity in the heart, affecting its ability to circulate blood efficiently. Tachyarrhythmias, a subset of dysrhythmias, are characterized by abnormally fast heart rates exceeding 100 beats per minute. Here are some types of tachyarrhythmias with their distinct ECG features:Sinus Tachycardia:Sinus tachycardia presents a regular heart rhythm with an increased rate of 101-180 beats per minute.
01:29Pathophysiology of Cardiac Performance
Typical heart performance is influenced by heart rate, rhythm, myocardial contraction, and metabolism or blood flow. The cardiac muscle exhibits distinct electrophysiological features, including pacemaker activity and calcium channel control, which play a vital role in the heart's response to various drugs. The autonomic nervous system, comprising the sympathetic and parasympathetic branches, regulates heart rate. Sympathetic activation increases heart rate, while parasympathetic activation...
01:25ECG Interpretation of Arrhythmias II: Atrial, Junctional and Ventricular Arrhythmias
Arrhythmia is a condition characterized by an irregular heart rhythm, with ECG changes that differ based on its origin and nature. The types of arrhythmias discussed below include atrial, junctional, and ventricular arrhythmias.Atrial ArrhythmiasPremature Atrial Complexes (PACs): PACs are early atrial beats caused by stress, caffeine, alcohol, electrolyte imbalances, hypoxia, hyperthyroidism, or certain medications (e.g., bronchodilators and decongestants). The ECG shows early P waves with an...
01:28Mechanism of Cardiac Arrhythmias
Arrhythmias are irregular heart rhythms occurring when the heart's electrical impulses become abnormal. These disturbances can lead to various symptoms, depending on their severity and the underlying cause. Some common factors contributing to arrhythmias include hypoxia, ischemia, electrolyte imbalances, excessive catecholamine exposure, drug toxicity, and muscle overstretching. Arrhythmias can be classified into two main types based on the rate and site of origin of abnormal heart rhythms.
01:29Disturbances in Heart Rhythm
Arrhythmia or dysrhythmia refers to an abnormal heart rhythm caused by a defect in the heart's conduction system. It can cause the heart to beat irregularly, too quickly, or too slowly, leading to symptoms like chest pain, shortness of breath, and fainting. Factors such as stress, caffeine, alcohol, nicotine, cocaine, certain drugs, congenital defects, diseases, and electrolyte abnormalities can trigger arrhythmias.
Arrhythmias are categorized by their speed, rhythm, and origin. A slow heart...
Arrhythmias are categorized by their speed, rhythm, and origin. A slow heart...