Related Experiment Video

Updated: Oct 4, 2025

A New Single Chamber Implantable Defibrillator with Atrial Sensing: A Practical Demonstration of Sensing and Ease of Implantation
16:40

A New Single Chamber Implantable Defibrillator with Atrial Sensing: A Practical Demonstration of Sensing and Ease of Implantation

Published on: February 28, 2012

26.4K

Experience with a Wearable Cardioverter-defibrillator in 436 Patients

Herbert Nägele1, Eike Groene1, Daniel Stierle1

  • 1Albertinen Cardiovascular Center, Hamburg, Germany.

The Journal of Innovations in Cardiac Rhythm Management
|February 7, 2022
PubMed

Insights

Wearable cardioverter-defibrillators (WCDs) rarely deliver lifesaving shocks under optimal guideline-directed medical therapy (GDMT). Most patients improved significantly, reducing the need for WCDs and permanent defibrillator implantation.

Area of Science:

  • Cardiology
  • Medical Devices
  • Clinical Medicine

Background:

  • Guideline-directed medical therapy (GDMT) has advanced, potentially altering the role of wearable cardioverter-defibrillators (WCDs).
  • Assessing WCD safety and efficacy under current GDMT is crucial for clinical practice.
  • Previous studies may not reflect outcomes with optimized contemporary GDMT.

Purpose of the Study:

  • To evaluate the safety and efficiency of WCDs in patients managed with current GDMT.
  • To determine the positive predictive value (PPV) of WCDs for detecting ventricular tachycardia (VT).
  • To assess the impact of GDMT optimization on left ventricular ejection fraction (LVEF) and WCD necessity.

Main Methods:

  • Retrospective analysis of 436 patients using WCDs between 2014-2020.
  • Validation of automatic arrhythmia alarm (AA) episodes to determine accuracy.
  • Calculation of PPV for VT detection and analysis of patient outcomes including LVEF changes and defibrillator implantation rates.

Main Results:

  • A total of 3,135 AAs were recorded from 206 patients during 23,527 days of wear time.
  • The overall PPV for VT was low (1.21%), with a higher PPV (41%) in patients who actually experienced VT.
  • LVEF significantly improved from 25% to 40% (P < .001), and defibrillator implantation was required in only 27% of patients. No shocks were delivered.

Conclusions:

  • WCDs demonstrated a very low PPV for VT detection under optimal GDMT.
  • Significant LVEF improvement with GDMT reduced the need for WCDs and permanent defibrillator implantation.
  • Current WCDs are rarely needed for lifesaving shocks when GDMT is optimized; algorithm improvements are warranted.

Keywords:
Heart failuresudden cardiac arrestsudden cardiac deathventricular tachycardiawearable cardioverter-defibrillator

More Related Videos

Implantation of Total Artificial Heart in Congenital Heart Disease07:27

Implantation of Total Artificial Heart in Congenital Heart Disease

Published on: July 18, 2014

24.8K
Patient Directed Recording of a Bipolar Three-Lead Electrocardiogram using a Smartwatch with ECG Function05:03

Patient Directed Recording of a Bipolar Three-Lead Electrocardiogram using a Smartwatch with ECG Function

Published on: December 11, 2019

8.8K

Related Concept Videos

Cardiopulmonary Resuscitation III: AED Use01:23

Cardiopulmonary Resuscitation III: AED Use

Introduction to AEDAn Automated External Defibrillator (AED) is a portable medical device that analyzes the heart's rhythm and, if necessary, delivers an electrical shock to help the heart re-establish an effective rhythm during sudden cardiac arrest (SCA). SCA occurs when the heart suddenly and unexpectedly stops beating, leading to a loss of blood flow to the brain and other vital organs. In such emergencies, time is of the essence, and using an AED, combined with Cardiopulmonary...
106
Cardiomyopathy V: Interprofessional Care01:29

Cardiomyopathy V: Interprofessional Care

Managing cardiomyopathy involves addressing underlying or precipitating causes, treating heart failure with medications, and implementing dietary changes and a balanced exercise and rest regimen.Lifestyle ModificationsCardiomyopathy patients should adopt a low-sodium diet to reduce fluid retention and manage heart failure. A personalized exercise and rest plan helps maintain physical fitness without overstraining the heart. Avoiding alcohol and tobacco is essential to prevent further damage to...
56
Dysrhythmias VI: Management of Dysrhythmias01:25

Dysrhythmias VI: Management of Dysrhythmias

Dysrhythmia management involves a multifaceted approach, incorporating pharmacological treatments, medical procedures, surgical interventions, lifestyle modifications, and patient education.Pharmacological ManagementAntiarrhythmic Drugs:Class I (Sodium Channel Blockers): This class includes quinidine and procainamide, which reduce the speed of impulse conduction in the heart, stabilize the cardiac membrane, and control arrhythmias. Quinidine and procainamide are Class IA agents that prolong the...
137
Pulse rhythm01:30

Pulse rhythm

Pulse rhythm refers to the pattern of pulsations within specific intervals, offering valuable insights into the regularity or irregularity of the heart's beats as observed through the pattern of pulsation within specific intervals. A regular pulse exhibits a consistent heart rate with uniform waveforms and pulsation force, variations of which can be classified as normal, weak, or bounding.
Conversely, an irregular pulse pattern is termed dysrhythmia, stemming from disruptions in cardiac...
973
Cardiomyopathy II: Dilated Cardiomyopathy01:30

Cardiomyopathy II: Dilated Cardiomyopathy

Dilated cardiomyopathy, or DCM, is a progressive myocardial disorder characterized by ventricular chamber dilation and contractile dysfunction.EtiologyVarious factors can cause DCM, including hypertension and heavy alcohol intake, which contribute to the weakening and enlargement of the heart muscle. Viral infections, such as Coxsackievirus B, adenoviruses, and influenza, can lead to DCM by causing inflammation and damage to heart tissue. Certain chemotherapeutic agents, including daunorubicin,...
51
Cardiac Catheterization II: Right Heart Catheterization01:21

Cardiac Catheterization II: Right Heart Catheterization

Right Heart Catheterization: An OverviewRight heart catheterization is an invasive diagnostic procedure that measures right-sided cardiac and pulmonary artery pressures, calculates cardiac output, and identifies intracardiac shunts. It provides detailed hemodynamic data essential for diagnosing and managing various cardiovascular conditions, such as pulmonary hypertension.Access SitesCommon access sites for right heart catheterization include the internal jugular vein in the neck region, the...
228