Related Experiment Video

Updated: Jun 24, 2026

Microelectrode Array Recording of Sinoatrial Node Firing Rate to Identify Intrinsic Cardiac Pacemaking Defects in Mice
09:20

Microelectrode Array Recording of Sinoatrial Node Firing Rate to Identify Intrinsic Cardiac Pacemaking Defects in Mice

Published on: July 5, 2021

Progression of conduction system disease in a paced patient with Kearns-Sayre syndrome

Murat Yeşil1, Serdar Bayata, Nursen Postaci

  • 1Department of Cardiology, Atatürk Teaching Hospital, Izmir, Turkey.

Clinical Cardiology
|March 24, 2009
PubMed

Insights

Kearns-Sayre syndrome can lead to heart problems, requiring pacemakers. This rare condition may cause a complete loss of natural heart rhythm over time.

Area of Science:

  • Neurology
  • Cardiology
  • Genetics

Background:

  • Kearns-Sayre syndrome (KSS) is a rare mitochondrial disorder.
  • KSS presents with a triad of symptoms: progressive external ophthalmoplegia, pigmentary degeneration of the retina, and cardiac conduction defects.

Observation:

  • This case report details a patient diagnosed with Kearns-Sayre syndrome.
  • The patient required a permanent pacemaker due to cardiac conduction abnormalities.

Findings:

  • Over the course of long-term follow-up, the patient experienced a complete cessation of spontaneous cardiac impulse formation.
  • This indicates a progressive decline in the heart's natural electrical activity.

Implications:

  • This case highlights the potential for complete heart block in KSS patients, necessitating vigilant cardiac monitoring.
  • Understanding the progression of cardiac involvement in KSS is crucial for patient management and prognosis.
  • Further research into the mechanisms of cardiac conduction failure in mitochondrial diseases is warranted.

More Related Videos

Preclinical Cardiac Electrophysiology Assessment by Dual Voltage and Calcium Optical Mapping of Human Organotypic Cardiac Slices09:35

Preclinical Cardiac Electrophysiology Assessment by Dual Voltage and Calcium Optical Mapping of Human Organotypic Cardiac Slices

Published on: June 16, 2020

Related Concept Videos

Conduction System of the Heart01:19

Conduction System of the Heart

Autorhythmicity is a term that refers to the heart's inherent ability to generate electrical signals and instigate muscle contractions. This self-regulating conduction system within the heart consists of two key components: the pacemaker cells and specialized conducting cells.
The pacemaker cells are located in two primary nodes: the sinoatrial (SA) node and the atrioventricular (AV) node. The SA node pacemaker cells can autonomously depolarize, triggering an action potential that leads to the...
Conduction System of the Heart01:20

Conduction System of the Heart

The cardiac conduction system produces and transmits electrical impulses that prompt myocardial contraction, ensuring efficient heart function. This intricate system ensures that the heart beats in a coordinated and efficient manner, beginning with the atria and then the ventricles. The conduction system optimizes cardiac output by maintaining this precise sequence, which is crucial for adequate blood circulation.
This system relies on the unique properties of nodal and Purkinje cells:...
Dysrhythmias IV: Characteristics of Bradyarrhythmias01:18

Dysrhythmias 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...
Mechanism of Cardiac Arrhythmias01:28

Mechanism 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.
Electrophysiology of Normal Cardiac Rhythm01:19

Electrophysiology 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...
Dysrhythmias I: Introduction01:15

Dysrhythmias I: Introduction

Dysrhythmias refers to abnormalities in the heart's rhythm. They result from disruptions in the heart's electrical conduction system, which includes the sinoatrial(SA)node, atrioventricular(AV) node, the bundle of His, bundle branches, and Purkinje fibers.Definition and PathophysiologyDysrhythmias result from disorders of impulse formation, impulse conduction, or both. The heart contains specialized cells in the sinoatrial node, atrioventricular node, and the bundle of His and Purkinje fibers...