Related Experiment Video
Updated: Jul 23, 2025

Electrocardiogram Recordings in Anesthetized Mice using Lead II
Published on: June 20, 2020
Corrected QT interval in electrocardiogram recordings in patients treated with calcium channel blockers
Małgorzata Wołek1,2, Katarzyna Matusiak1, Patryk Machoczek3
1Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, Krakow, Poland.
Introduction:
One of the most popular tests of the heart is the electrocardiogram (ECG). The physical basis of this study has been known for over 200 years. However, the way an ECG is performed and the interpretation of the obtained results have undergone considerable evolution over time.
Aim:
To analyze the ECG recordings regarding the QTc interval in patients taking calcium channel blockers.
Material And Methods:
The publicly available PhysioNet signals database was used to analyze the effect of selected drugs on the heart rhythm and QTc interval. To automate the QTc assessment, the database was processed in MATLAB. First, QTc was assessed using four formulas; then the results were compared in terms of methodology and medications taken.
Results:
In the group of patients taking dihydropyridine blockers, the QTc interval assessed by the Bazett formula (mean: 478.87 ms; SD: 73.10) is longer than in patients taking non-dihydropyridine blockers (mean: 446.54 ms, SD: 88.07, p = 0.2123) and in patients not taking calcium channel blockers (mean: 436.33 ms, SD: 49.94, p = 0.0319). The same significant differences were obtained regardless of the QTc assessment method used. However, the QTc result obtained with the Bazett formula is significantly lower than in the case of using the other three formulas used for the presented analysis.
Conclusions:
Automatic ECG analysis is possible; however, it should be used carefully, considering the possibility of obtaining incorrect results. Taking calcium channel blockers may affect the QTc interval. QTc results significantly depend on the formula based on which we evaluate this parameter.
Related Concept Videos
Antiarrhythmic Drugs: Class I Agents as Sodium Channel Blockers
Class 1A Antiarrhythmic Drugs: These drugs work by moderately blocking sodium channels,...
Electrocardiogram
Three major waveforms are present in a typical ECG recording: the P wave, the QRS complex, and...
Antiarrhythmic Drugs: Class IV Agents as Calcium Channel Blockers
Verapamil, a calcium channel blocker, inhibits calcium movement across myocardial cell membranes and vascular smooth muscle. This results in the dilation of coronary and...
ECG Interpretation of Arrhythmias II: Atrial, Junctional and Ventricular Arrhythmias
Antiarrhythmic Drugs: Class III Agents as Potassium Channel Blockers
Disturbances in Heart Rhythm
Arrhythmias are categorized by their speed, rhythm, and origin. A slow...

