Cardiac Resynchronization Therapy: Difference between revisions

Jump to navigation Jump to search
No edit summary
No edit summary
Line 38: Line 38:
#LV pacing under direct visualization using cardiac surgical approach
#LV pacing under direct visualization using cardiac surgical approach
#Transvenous via transseptal approach
#Transvenous via transseptal approach
#Direct approach to surface of left ventricle without thoracostomy
#Direct approach to surface of left ventricle without thoracostomy<br>


The first step in pacing the LV is cannulation of lead into coronary sinus.Fluoroscopy is mostly performed in LAO position which helps in guiding the lead in best location in the coronary sinus.
#The first step is formation of pocket between the fascia and the muscle.The pocket is formed by anesthetizing the patient and blunt and sharp dissection.Usually the non-dominant side of patient is used.The size should be enough to adjust the device but not large enough to allow it to move.
#Most common routes of venous access are :1)Subclavian cutdown  2)Cephalic stick<br>
Other routes of access are Internal or External Jugular vein, Iliofemoral vein or Axillary vein.





Revision as of 15:21, 19 April 2011

WikiDoc Resources for Cardiac Resynchronization Therapy

Articles

Most recent articles on Cardiac Resynchronization Therapy

Most cited articles on Cardiac Resynchronization Therapy

Review articles on Cardiac Resynchronization Therapy

Articles on Cardiac Resynchronization Therapy in N Eng J Med, Lancet, BMJ

Media

Powerpoint slides on Cardiac Resynchronization Therapy

Images of Cardiac Resynchronization Therapy

Photos of Cardiac Resynchronization Therapy

Podcasts & MP3s on Cardiac Resynchronization Therapy

Videos on Cardiac Resynchronization Therapy

Evidence Based Medicine

Cochrane Collaboration on Cardiac Resynchronization Therapy

Bandolier on Cardiac Resynchronization Therapy

TRIP on Cardiac Resynchronization Therapy

Clinical Trials

Ongoing Trials on Cardiac Resynchronization Therapy at Clinical Trials.gov

Trial results on Cardiac Resynchronization Therapy

Clinical Trials on Cardiac Resynchronization Therapy at Google

Guidelines / Policies / Govt

US National Guidelines Clearinghouse on Cardiac Resynchronization Therapy

NICE Guidance on Cardiac Resynchronization Therapy

NHS PRODIGY Guidance

FDA on Cardiac Resynchronization Therapy

CDC on Cardiac Resynchronization Therapy

Books

Books on Cardiac Resynchronization Therapy

News

Cardiac Resynchronization Therapy in the news

Be alerted to news on Cardiac Resynchronization Therapy

News trends on Cardiac Resynchronization Therapy

Commentary

Blogs on Cardiac Resynchronization Therapy

Definitions

Definitions of Cardiac Resynchronization Therapy

Patient Resources / Community

Patient resources on Cardiac Resynchronization Therapy

Discussion groups on Cardiac Resynchronization Therapy

Patient Handouts on Cardiac Resynchronization Therapy

Directions to Hospitals Treating Cardiac Resynchronization Therapy

Risk calculators and risk factors for Cardiac Resynchronization Therapy

Healthcare Provider Resources

Symptoms of Cardiac Resynchronization Therapy

Causes & Risk Factors for Cardiac Resynchronization Therapy

Diagnostic studies for Cardiac Resynchronization Therapy

Treatment of Cardiac Resynchronization Therapy

Continuing Medical Education (CME)

CME Programs on Cardiac Resynchronization Therapy

International

Cardiac Resynchronization Therapy en Espanol

Cardiac Resynchronization Therapy en Francais

Business

Cardiac Resynchronization Therapy in the Marketplace

Patents on Cardiac Resynchronization Therapy

Experimental / Informatics

List of terms related to Cardiac Resynchronization Therapy

Cardiology Network

Discuss Cardiac Resynchronization Therapy further in the WikiDoc Cardiology Network
Adult Congenital
Biomarkers
Cardiac Rehabilitation
Congestive Heart Failure
CT Angiography
Echocardiography
Electrophysiology
Cardiology General
Genetics
Health Economics
Hypertension
Interventional Cardiology
MRI
Nuclear Cardiology
Peripheral Arterial Disease
Prevention
Public Policy
Pulmonary Embolism
Stable Angina
Valvular Heart Disease
Vascular Medicine

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Associate Editor: Cafer Zorkun, M.D., Ph.D. [2] Assistant Editor: Atif Mohammad, MD

Introduction

Cardiac resynchronization therapy is a relatively new mode of therapeutic modality currently being used particularly in patients with advanced heart failure.Bi-ventricular pacing or pacing one of the ventricles with bundle branch block is referred to as Cardiac Resynchronization Therapy.

Currently CRT has been approved in patients with advanced HF patients benefit from simultaneous pacing of both ventricles (biventricular or BiV pacing) or of one ventricle in patients with bundle branch block. This approach is referred to as cardiac resynchronization therapy (CRT) . CRT can be achieved with a device designed only for pacing or can be incorporated into a combination device with an ICD.

Cardiac Resynchronization therapy has been approved for patients with advanced heart failure NYHA class III,IIV or patients with LVEF <35% and with QRS delay >120 ms.It has gain FDA approval for patients with NYHA class I OR II heart failure in the setting of QRS delay.

Mechanism of Benefit

CRT in Heart Failure

CRT has been known to benefit patients with left ventricular dyssynchrony.The mechanism is till unclear but it is known to improve contractile performance of cardiac chambers and hence result in reverse remodeling improving functional capacity and decreasing clinical outcomes of mortality and repeat hospitalizations.Basically, CRT causes improved cardiac myocyte depolarization as a result of cardiac resynchronization which improves cardiac systolic function causing contraction of the left ventricle and thus reducing wall stress and mitral regurgitation.This also improves ventricular remodeling .

Improved contractility of LV in patients with HF associated with IVCD or LBBB is known to reduce myocardial energy demands and oxygen consumption.

CRT has shown to cause reverse ventricular remodeling.A study conducted in Hong Kong showed long term clinical improvement in patients treated with CRT. But it is still not clear whether,clinical improvement and ventricular remodeling correlate with each other or ventricular remodeling is necessary for reduction in clinical signs and symptoms.

CRT in Afib

Cardiac resynchronization Therapy is mostly used in Chronic Afib in patients with a node ablation indication.CRT has shown to increases peak oxygen consumption and increased exercise duration as compared to standard RV pacing.It has shown to reduce atrial size and activation along with reduction in degrees of mitral regurgitation.It has also known to improve LVEF in patients with chronic Afib.
It is still not clearly known to benefit in patients in Afib with heart failure.
Observational studies have shown significant improvement when CRT is combined with AV node ablation.But there is not enough data to show benefits with other modes of therapy like pulmonary vein isolation.

Major Society Guidelines

Therefore, common indications for CRT implantation according to the recent guidelines of the American Heart Association/American College of Cardiology/Heart Rhythm Society (AHA/ACC/HRS),HFSA,

  1. It is recommended for patients with LVEF ≤35 percent, a QRS duration ≥120 msec, and NYHA functional class III or ambulatory class IV symptoms with optimal medical therapy
  2. Itis reasonable for patients with LVEF ≤35 percent with NYHA functional class III or ambulatory class IV symptoms who are receiving optimal recommended medical therapy and who have frequent dependence on ventricular pacing
  3. It may be considered for patients with LVEF ≤35 percent with NYHA functional class I or II symptoms who are receiving optimal recommended medical therapy and who are undergoing implantation of a permanent pacemaker and/or ICD with anticipated frequent ventricular pacing

The American Society of Echocardiography made a consensus statement that patients who meet accepted criteria for CRT should not have their treatment kept on hold because of dyssynchrony results on Echocardiography.

Procedure Technique

Prior to implantation of LV leads for pacing, basic clinical knowledge of techniques common to all ICDS and pacemakers is necessary.In addition,facilities with various types of vascular access and alternative sites of lead placements is important.
There are 4 approaches

  1. Transvenous approach
  2. LV pacing under direct visualization using cardiac surgical approach
  3. Transvenous via transseptal approach
  4. Direct approach to surface of left ventricle without thoracostomy
  1. The first step is formation of pocket between the fascia and the muscle.The pocket is formed by anesthetizing the patient and blunt and sharp dissection.Usually the non-dominant side of patient is used.The size should be enough to adjust the device but not large enough to allow it to move.
  2. Most common routes of venous access are :1)Subclavian cutdown 2)Cephalic stick

Other routes of access are Internal or External Jugular vein, Iliofemoral vein or Axillary vein.








Please Take Over This Page and Apply to be Editor-In-Chief for this topic: There can be one or more than one Editor-In-Chief. You may also apply to be an Associate Editor-In-Chief of one of the subtopics below. Please mail us [3] to indicate your interest in serving either as an Editor-In-Chief of the entire topic or as an Associate Editor-In-Chief for a subtopic. Please be sure to attach your CV and or biographical sketch.


Template:SIB

Template:WikiDoc Sources Template:Mdr