相关实验视频

Updated: Jun 13, 2025

Electrocardiogram Recordings in Anesthetized Mice using Lead II
04:16

Electrocardiogram Recordings in Anesthetized Mice using Lead II

Published on: June 20, 2020

12.7K

已知高风险的p.R190Q KCNQ1变体需要第二次检测QTc延长

Anton Karabinos1, Drahomira Schwartzova2, Renata Zemjarova Mezenska3

  • 1Laboratory of Clinical Genetics, Medirex, Inc., Magnezitarska 2/C, 04013, Kosice, Slovak Republic.

Journal of electrocardiology
|April 3, 2025
PubMed
概括

在长QT综合征 (LQTS) 中常见的KCNQ1 p.R190Q突变通常单独显示低风险. 然而,与其他因素相结合,它可以引发危险的QTc延长和心律失常.

关键词:
节律失常 (arrhythmia) 是一种心律失常.遗传学 是一个遗传学.KCNQ1 一个国家.长时间QT综合征这是SCN5A.

更多相关视频

Determining the Likelihood of Variant Pathogenicity Using Amino Acid-level Signal-to-Noise Analysis of Genetic Variation07:15

Determining the Likelihood of Variant Pathogenicity Using Amino Acid-level Signal-to-Noise Analysis of Genetic Variation

Published on: January 16, 2019

11.0K
Isolation and Kv Channel Recordings in Murine Atrial and Ventricular Cardiomyocytes11:33

Isolation and Kv Channel Recordings in Murine Atrial and Ventricular Cardiomyocytes

Published on: March 12, 2013

13.4K

相关概念视频

Antiarrhythmic Drugs: Class III Agents as Potassium Channel Blockers01:12

Antiarrhythmic Drugs: Class III Agents as Potassium Channel Blockers

Class III antiarrhythmic drugs are a group of medications that can prolong action potentials in the heart. They achieve this by blocking potassium channels or enhancing inward currents from sodium channels. However, these drugs have a unique property of "reverse use-dependence," which is most pronounced at slower heart rates and can lead to torsades de pointes—a specific type of arrhythmia. However, it is essential to note that excessive QT interval prolongation—a measure of...
933
Antiarrhythmic Drugs: Class I Agents as Sodium Channel Blockers01:22

Antiarrhythmic Drugs: Class I Agents as Sodium Channel Blockers

Class I antiarrhythmic drugs are used to treat various types of arrhythmias or irregular heart rhythms. These drugs block the sodium (Na+) channels in the cardiac cells, thereby affecting the movement of electrical impulses across the heart. Class I antiarrhythmic drugs are divided into three subgroups: Class IA, Class IB, and Class IC, each with distinct mechanisms of action and effects on the heart.
Class 1A Antiarrhythmic Drugs: These drugs work by moderately blocking sodium channels,...
1.3K
Cardiac Action Potential01:30

Cardiac 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
1.1K
Antiarrhythmic Drugs: Class IV Agents as Calcium Channel Blockers01:20

Antiarrhythmic Drugs: Class IV Agents as Calcium Channel Blockers

Class IV antiarrhythmic drugs, such as verapamil and diltiazem, block calcium channels. They primarily affect the heart, slowing the conduction in calcium-dependent tissues like the SA and AV nodes. These drugs manage reentrant supraventricular tachycardia (SVT) and reduce ventricular rate in atrial flutter/fibrillation.
Verapamil, a calcium channel blocker, inhibits calcium movement across myocardial cell membranes and vascular smooth muscle. This results in the dilation of coronary and...
796
Antiarrhythmic Drugs: Class II Agents as β-Adrenergic Blockers01:24

Antiarrhythmic Drugs: Class II Agents as β-Adrenergic Blockers

Adrenergic stimulation generally impacts cardiac rate and rhythm. Specifically, stimulation of the β-adrenoceptors triggers an increase in intracellular calcium ion influx and pacemaker currents, which may cause arrhythmias. Catecholamines like adrenaline also demonstrate β2-adrenoceptor-mediated hypokalemia, impacting cardiac action potential and disrupting the normal cardiac rhythm. Class II antiarrhythmic drugs are β-adrenoceptor antagonists or β-blockers, which...
719
Electrocardiogram01:29

Electrocardiogram

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...
2.2K