Device therapies in the post-myocardial infarction patient with left ventricular dysfunction
Alan H Kadish1, James A Reiffel, Gerald V Naccarelli
1Division of Cardiology, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, USA. a-kadish@northwestern.edu
The American Journal of Cardiology
|October 3, 2008
Summary
Prophylactic implantable cardioverter defibrillators (ICDs) improve survival in high-risk patients post-myocardial infarction (MI) with left ventricular dysfunction (LVD). ICD therapy is the standard of care, offering benefits beyond optimal pharmacologic treatment for sudden cardiac death prevention.
Area of Science:
- Cardiology
- Electrophysiology
- Medical Devices
Background:
- Patients post-myocardial infarction (MI) with left ventricular dysfunction (LVD) face a significant risk of sudden cardiac death due to ventricular arrhythmias.
- A depressed left ventricular ejection fraction in post-MI patients is a key indicator of high risk for life-threatening arrhythmias.
Purpose of the Study:
- To evaluate the survival benefits of prophylactic implantable cardioverter defibrillators (ICDs) in high-risk post-MI patients with LVD.
- To establish ICD therapy as the standard of care for selected post-MI patients with systolic dysfunction.
- To explore the role of cardiac resynchronization therapy (CRT) in improving quality of life for symptomatic heart failure patients with QRS prolongation.
Main Methods:
- Analysis of data from recent device trials focusing on prophylactic ICD placement in post-MI patients.
- Inclusion of patients selected based on left ventricular systolic dysfunction post-MI.
- Consideration of cardiac resynchronization therapy for symptomatic heart failure patients with specific electrocardiographic criteria (QRS prolongation).
Main Results:
- Prophylactic ICD implantation significantly improves survival rates in high-risk post-MI patients with LVD and depressed ejection fraction.
- The survival benefits of ICDs are additive to those provided by optimal pharmacologic therapy.
- Cardiac resynchronization therapy offers quality of life improvements beyond drug therapy alone in select heart failure patients.
Conclusions:
- Implantable cardioverter defibrillator therapy is the standard of care for high-risk post-MI patients with left ventricular dysfunction.
- Further research into risk stratification for post-MI LVD patients may enhance the cost-effectiveness of ICD therapy.
- Cardiac resynchronization therapy should be considered for improving quality of life in symptomatic heart failure patients with QRS prolongation.
Related Concept Videos
01:22Heart Failure VI: Adjunct Therapies
Additional therapies for treating patients with heart failure (HF) may include procedural interventions, supplemental oxygen, the management of sleep disorders, and nutritional therapy.Procedural InterventionsImplantable Cardioverter-Defibrillator: For patients at risk of life-threatening arrhythmias due to severe left ventricular dysfunction, an Implantable Cardioverter-Defibrillator (ICD) can detect and terminate these arrhythmias, preventing sudden cardiac death and improving survival rates.
01:29Cardiomyopathy 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...
01:30Cardiomyopathy 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,...
01:30Heart Failure V: Medical Management
Medical Management of Acute Decompensated Heart Failure (ADHF)The primary goals of therapy for patients hospitalized with acute decompensated heart failure (ADHF) include:Relieving symptomsOptimizing volume statusSupporting oxygenation and ventilationMaintaining cardiac output (CO) and end-organ perfusionIdentifying and addressing the cause of ADHFPreventing complicationsProviding patient education on factors precipitating HF exacerbationPlanning for dischargeOngoing monitoring and assessment...
01:14Myocarditis III: Medical Management
Myocarditis: Comprehensive Medical ManagementMyocarditis, the heart muscle inflammation, requires a comprehensive medical management strategy that addresses the underlying cause, provides supportive care, manages symptoms, and reduces cardiac workload.Infections and Autoimmune CausesAdminister appropriate antimicrobial therapy when an infectious agent causes myocarditis. For instance, penicillin treats infections caused by Group A Streptococcus. In cases where autoimmune processes are...
01:26Heart Failure Drugs: Inotropic Agents
Positive inotropic agents are commonly used as the first line of treatment for heart failure. One such agent is digoxin, derived from the genus Digitalis, which has been known for centuries but effectively utilized since 1785. However, these cardiac glycosides can have potentially toxic effects due to their mechanism of action, which involves inhibiting Na+/K+-ATPase and increasing contractility. Digoxin is absorbed orally and distributed in various tissues, including the CNS. It has a long...