Exercise-Induced Repolarization Changes in Patients with Isolated Myocardial Bridging.
Gökhan Aksan1, Gökay Nar2, Sinan İnci2
1Deparment of Cardiology, Şişli Hamidiye Etfal Training and Research Hospital, İstanbul, Turkey.
Summary
Exercise significantly alters myocardial repolarization in patients with myocardial bridging (MB), increasing QT dispersion (QTd) and Tp-e intervals. These findings highlight potential risks associated with MB during physical activity.
Area of Science:
- Cardiology
- Electrophysiology
- Exercise Physiology
Background:
- Myocardial bridging (MB) is an angiographic finding, typically benign, but linked to adverse cardiovascular events.
- The impact of exercise on myocardial repolarization in MB patients remains incompletely understood.
Purpose of the Study:
- To investigate the effects of exercise on myocardial repolarization parameters in patients with MB.
- To compare repolarization indexes between MB patients and a control group during exercise stress testing.
Main Methods:
- Coronary angiography diagnosed MB in 50 patients (Group I); 48 controls (Group II) had normal angiography.
- Participants underwent treadmill exercise stress testing (Bruce protocol).
- QT dispersion (QTd) and Tp-e intervals were measured pre- and post-exercise.
Main Results:
- MB patients showed significant increases in QTd, cQTd, Tp-e, and cTp-e intervals with exercise compared to baseline.
- The Tp-e/QT ratio also significantly increased in MB patients during peak exercise.
- The control group did not exhibit significant changes in these repolarization indexes during exercise.
Conclusions:
- Exercise induces significant alterations in myocardial repolarization in MB patients.
- Increased QTd and Tp-e intervals during exercise may indicate heightened cardiac risk in MB patients.
More Related Videos
Related Concept Videos
01:30Cardiac Action Potential
9.4K
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
9.4K
01:18Dysrhythmias IV: Characteristics of Bradyarrhythmias
830
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...
830
01:19Electrophysiology of Normal Cardiac Rhythm
10.4K
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...
10.4K