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Disturbances in Heart Rhythm

Disturbances 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...

Dysrhythmias III: Characteristics of Dysrhythmias

Dysrhythmias 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...

Mechanism of Cardiac Arrhythmias

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.

Dysrhythmias IV: Characteristics of Bradyarrhythmias

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...

Increased pulse rate

Increased pulse rate

Tachycardia is a condition marked by an abnormally fast or irregular heart rate, surpassing the typical resting rate. In adults, tachycardia is characterized by a pulse rate ranging from 100 to 180 beats per minute. The increased heart rate can result in inadequate blood flow to various body parts, ultimately diminishing the oxygen supply to organs and tissues.
Many factors can elevate the risk of developing tachycardia. These include advanced age, a family history of arrhythmias, and an...

Decreased pulse rate

Decreased pulse rate

Bradycardia is a medical condition in which the heart rate is slower than normal. It occurs when the heart's natural pacemaker, the sinus node, generates slower electrical impulses than the standard rhythm. In adults, bradycardia is diagnosed when the pulse rate falls below 60 beats per minute, indicating a deviation from the normal heart rate range.
There are specific risk factors that can elevate the likelihood of developing bradycardia. Advanced age is a significant factor, with...

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Optimization of Transesophageal Atrial Pacing to Assess Atrial Fibrillation Susceptibility in Mice

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A sudden change in pacing rate: Normal or malfunction?

Yiru Han¹, Yubin Zhang², Tong Liu³

¹Department of Healthcare, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.

Annals of Noninvasive Electrocardiology : the Official Journal of the International Society for Holter and Noninvasive Electrocardiology, Inc

|November 12, 2021

Summary

A rare pacemaker issue, orthodromic pacemaker-mediated arrhythmia (OPMA), caused chest discomfort. This study details the first case of OPMA occurring exclusively in the DDI pacing mode.

Keywords:

auto-mode switch far-field sensing lead dislodgement pacemaker-mediated arrhythmia

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Area of Science:

Cardiology
Biomedical Engineering
Electrophysiology

Background:

Pacemakers are crucial for managing cardiac rhythm disorders.
Pacemaker-mediated arrhythmias (PMAs) are known complications.
Dual-chamber pacing modes offer advanced rate control but can predispose to specific arrhythmias.

Observation:

A patient presented with recurrent chest discomfort and palpitations.
Holter monitoring revealed sudden increases in pacing rate from 60 to 105 bpm, correlating with symptoms.
The episodes were linked to a dislodged ventricular lead causing atrial far-field sensing.

Findings:

The patient experienced orthodromic pacemaker-mediated arrhythmia (OPMA).
This OPMA was triggered and sustained solely in the DDD (dual-chamber, dual-response, inhibited) pacing mode.
This represents the first reported case of OPMA exclusively occurring in the DDI mode.

Implications:

OPMA is a rare but significant pacemaker complication.
Lead integrity and sensing parameters are critical for preventing PMAs.
Clinicians should consider DDI mode-specific OPMA in patients with unexplained pacemaker behavior and symptoms.