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Related Concept Videos

Increased pulse rate01:17

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...
Disturbances in Heart Rhythm01:29

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 II: Classification of Tachyarrhythmias01:28

Dysrhythmias II: Classification of Tachyarrhythmias

Tachyarrhythmias are a type of dysrhythmia where the heart rate exceeds 100 beats per minute. Here are some common types of tachyarrhythmias:Sinus TachycardiaSinus tachycardia originates from increased impulses from the sinus node, leading to an elevated heart rate. It is often triggered by stress, fever, or exercise.Patients may experience palpitations, a sensation of a racing heart, dizziness, and chest discomfort.Causes and Risk Factors: Common causes include physical exertion, emotional...
Dysrhythmias III: Characteristics of Dysrhythmias01:29

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 minute.
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...
ECG Interpretation of Arrhythmias II: Atrial, Junctional and Ventricular Arrhythmias01:25

ECG Interpretation of Arrhythmias II: Atrial, Junctional and Ventricular Arrhythmias

Arrhythmia is a condition characterized by an irregular heart rhythm, with ECG changes that differ based on its origin and nature. The types of arrhythmias discussed below include atrial, junctional, and ventricular arrhythmias.Atrial ArrhythmiasPremature Atrial Complexes (PACs): PACs are early atrial beats caused by stress, caffeine, alcohol, electrolyte imbalances, hypoxia, hyperthyroidism, or certain medications (e.g., bronchodilators and decongestants). The ECG shows early P waves with an...

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Related Experiment Video

Updated: Jun 23, 2026

Programmed Electrical Stimulation in Mice
07:29

Programmed Electrical Stimulation in Mice

Published on: May 27, 2010

Efficacy of flecainide in pacing-induced sustained ventricular tachyarrhythmias: correlation to clinical parameters

A Podczeck1, M Borggrefe, K Bartels

  • 1Hospital of the Westfälische Wilhelms-University of Münster, Department of Internal Medicine C (Cardiology and Angiology), West Germany.

European Heart Journal
|October 1, 1989
PubMed
Summary
This summary is machine-generated.

Flecainide effectively reduced inducible ventricular tachycardia (VT) in 32% of patients. This antiarrhythmic drug also slowed VT rates and increased ventricular refractoriness, improving outcomes for VT patients.

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Area of Science:

  • Cardiology
  • Electrophysiology
  • Pharmacology

Background:

  • Sustained ventricular tachycardia (VT) and syncope of unknown origin pose significant clinical challenges.
  • Electrophysiologic evaluation is crucial for diagnosing and managing these conditions.

Purpose of the Study:

  • To evaluate the efficacy of flecainide in patients with inducible sustained ventricular tachycardia (VT) or syncope of unknown origin.
  • To assess flecainide's impact on VT inducibility, rate, and ventricular electrophysiologic properties.

Main Methods:

  • Seventy-two patients underwent electrophysiologic studies before and after flecainide therapy (200-300 mg/day).
  • VT inducibility, VT rate, and right ventricular effective refractory period (ERP) were measured.
  • Factors influencing flecainide response, including left ventricular aneurysm and baseline VT characteristics, were analyzed.

Main Results:

  • Flecainide rendered VT non-inducible in 25% of patients and made it more difficult to induce in an additional 7%, showing overall efficacy in 32%.
  • VT rate decreased significantly (214 to 178 beats/min, P<0.01) and right ventricular ERP increased (251 to 267 ms, P<0.01).
  • Lack of response correlated with left ventricular aneurysm; higher baseline VT rates (>230 beats/min) and induced ventricular fibrillation (VF) predicted better response.

Conclusions:

  • Flecainide is an effective antiarrhythmic agent for a subset of patients with inducible VT, reducing inducibility and slowing VT rates.
  • Baseline electrophysiologic characteristics, particularly VT rate and inducibility of VF, can predict response to flecainide.
  • While generally well-tolerated, flecainide efficacy is limited in patients with left ventricular aneurysms, and side effects may necessitate discontinuation.