Related Experiment Video
Updated: Jul 16, 2026
08:05
Optimization of Transesophageal Atrial Pacing to Assess Atrial Fibrillation Susceptibility in Mice
Published on: June 29, 2022
Microvolt T-wave alternans during atrial and ventricular pacing
Alaa A Shalaby1, Andrew Voigt, Aiman El-Saed
1Veterans Affairs Pittsburgh Healthcare System, Pittsburgh, Pennsylvania, USA. Alaa.Shalaby@med.va.gov
Pacing and Clinical Electrophysiology : PACE
|February 17, 2007
Summary
Ventricular pacing (VP) enables more microvolt T-wave alternans (MTWA) assessments than atrial pacing (AP), showing good concordance. VP yields higher amplitudes and noise, increasing non-negative results for sudden cardiac death risk evaluation.
Area of Science:
- Cardiology
- Electrophysiology
- Biomedical Engineering
Background:
- Microvolt T-wave alternans (MTWA) assessment using spectral analysis (SA) requires stable heart rates.
- Ventricular pacing (VP) can achieve the necessary heart rate stability for MTWA-SA.
- Atrial pacing (AP) is an alternative method for heart rate control during MTWA-SA.
Purpose of the Study:
- To compare the feasibility and diagnostic performance of MTWA-SA using short-term VP versus AP.
- To evaluate the concordance, sensitivity, specificity, and predictive values of MTWA-VP compared to MTWA-AP.
- To analyze differences in MTWA amplitude and noise levels between VP and AP.
Main Methods:
- Invasive electrophysiologic study in 42 patients undergoing risk evaluation for sudden cardiac death.
- Comparison of MTWA-SA results obtained during VP and AP.
- Evaluation of concordance (kappa statistic), sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV).
- Analysis of maximum MTWA amplitude (MValt) and noise levels in both pacing modes.
Main Results:
- MTWA-SA was completed in 40 patients with VP versus 32 patients with AP.
- VP-MTWA-SA demonstrated a sensitivity of 93%, specificity of 71%, NPV of 92%, and PPV of 72%.
- Results were concordant in 80% of patients (kappa = 0.62, P < 0.001).
- Noise levels were significantly higher during VP (1.4 ± 0.8) compared to AP (1 ± 0.8, P < 0.01).
- A trend towards higher MTWA amplitude was observed during VP (10.7 ± 5.3) versus AP (7.8 ± 3.9, P = 0.058).
Conclusions:
- MTWA-SA is more frequently completed using VP than AP.
- There is overall concordance between MTWA-VP and MTWA-AP.
- VP results in higher MTWA amplitudes and noise levels, leading to a greater proportion of non-negative findings.
More Related Videos
Related Concept Videos
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.
01:25ECG 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...
01:29Disturbances 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...
01:18Dysrhythmias IV: Characteristics of Bradyarrhythmias
Bradyarrhythmias are cardiac rhythm disorders characterized by a slower-than-normal heart rate, typically defined as fewer than 60 beats per minute. Some of which are discussed here:Sinus BradycardiaSinus bradycardia presents a heart rate lower than 60 beats per minute, with a regular rhythm originating from the SA node. The ECG typically shows normal P waves preceding each QRS complex, a normal PR interval (0.12 to 0.20 seconds), and a normal QRS duration (0.06 to 0.10 seconds).First-Degree AV...
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
01:19Electrophysiology 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...