Nonspecific intraventricular conduction delay: Definitions, prognosis, and implications for cardiac resynchronization
Romain Eschalier1, Sylvain Ploux2, Philippe Ritter2
1Hôpital Cardiologique du Haut-Lévêque, CHU Bordeaux, Université Bordeaux, IHU LIRYC, Bordeaux, France; Clermont Université, Université d'Auvergne, Cardio Vascular Interventional Therapy and Imaging, Image Science for Interventional Techniques, UMR6284, and CHU Clermont-Ferrand, Cardiology Department, F-63003 Clermont-Ferrand, France.
Heart Rhythm
|January 24, 2015
Summary
Cardiac resynchronization therapy (CRT) shows mixed results for heart failure patients with nonspecific intraventricular conduction delay (NICD). More research is needed to identify which NICD patients benefit from CRT.
Area of Science:
- Cardiology
- Electrophysiology
- Heart Failure Management
Background:
- Cardiac resynchronization therapy (CRT) treats heart failure with reduced ejection fraction and wide QRS, aiming to correct electrical dyssynchrony.
- Nonspecific intraventricular conduction delay (NICD) presents a challenge, as CRT outcomes are contradictory in this patient group.
- Current guidelines for CRT in NICD patients are based on limited subgroup analyses, necessitating further investigation.
Purpose of the Study:
- To evaluate the efficacy of CRT in heart failure patients with nonspecific intraventricular conduction delay (NICD).
- To address the lack of prospective studies and contradictory results regarding CRT in NICD patients.
- To explore the potential of ECG and noninvasive electrical activation studies in identifying CRT responders within the NICD population.
Main Methods:
- Analysis of existing data and subgroup findings related to CRT in heart failure patients.
- Review of guidelines based on small sample size analyses.
- Proposal for dedicated prospective studies incorporating detailed ECG and noninvasive ventricular electrical activation assessments.
Main Results:
- CRT outcomes in patients with NICD are contradictory, with a seemingly neutral overall trend.
- Existing evidence is derived from subgroup analyses of limited sample sizes.
- Prospective studies are lacking, hindering definitive conclusions.
Conclusions:
- The efficacy of CRT in patients with nonspecific intraventricular conduction delay remains uncertain.
- A dedicated prospective study is warranted to properly assess CRT benefits in this population.
- Identifying NICD patients who will respond to CRT may be improved through advanced ECG and noninvasive electrical activation analysis.
Related Concept Videos
01:30Cardiomyopathy II: Dilated Cardiomyopathy
807
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,...
807
01:29Cardiomyopathy V: Interprofessional Care
724
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...
724
01:30Heart Failure IV: Classification and Diagnostic Evaluation
631
Heart failure can be classified in various ways, with the most common classifications based on physical activity limitations, disease progression, severity, and treatment strategies.The Functional Classification of Heart Failure divides patients into four categories based on physical activity limitation due to symptom burden.Class I: Patients in this class have cardiac disease but no physical activity limitations. Ordinary activities like walking, climbing stairs, or routine tasks do not cause...
631
01:29Cardiomyopathy IV: Restrictive Cardiomyopathy
924
Restrictive cardiomyopathy (RCM) is a rare heart muscle disease characterized by impaired ventricular filling due to stiffened ventricular walls, leading to significant diastolic dysfunction.EtiologyRestrictive cardiomyopathy can arise from both inherited and acquired diseases, many of which are systemic. It is categorized into four main types: infiltrative, storage, non-infiltrative, and endomyocardial diseases.Infiltrative diseases, such as amyloidosis, lead to RCM by depositing amyloid...
924
01:30Cardiac Action Potential
11.4K
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
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
11.4K
01:18Dysrhythmias IV: Characteristics of Bradyarrhythmias
845
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...
845