Congestive heart failure positive inotropics

Resident Survival Guide

File:Critical Pathways.gif

Congestive Heart Failure Microchapters
Home
Patient Information
Overview
Historical Perspective
Classification
Pathophysiology Systolic Dysfunction Diastolic Dysfunction HFpEF HFrEF
Causes
Differentiating Congestive heart failure from other Diseases
Epidemiology and Demographics
Risk Factors
Screening
Natural History, Complications and Prognosis
Diagnosis
Clinical Assessment
History and Symptoms
Physical Examination
Laboratory Findings
Electrocardiogram
Chest X Ray
Cardiac MRI
Echocardiography
Exercise Stress Test
Myocardial Viability Studies
Cardiac Catheterization
Other Imaging Studies
Other Diagnostic Studies
Treatment
Invasive Hemodynamic Monitoring
Medical Therapy:
Summary
Acute Pharmacotherapy
Chronic Pharmacotherapy in HFpEF
Chronic Pharmacotherapy in HFrEF Diuretics ACE Inhibitors Angiotensin receptor blockers Aldosterone Antagonists Beta Blockers Ca Channel Blockers Nitrates Hydralazine Positive Inotropics Anticoagulants Angiotensin Receptor-Neprilysin Inhibitor Antiarrhythmic Drugs Nutritional Supplements Hormonal Therapies Drugs to Avoid Drug Interactions Treatment of underlying causes Associated conditions
Exercise Training
Surgical Therapy: Biventricular Pacing or Cardiac Resynchronization Therapy (CRT) Implantation of Intracardiac Defibrillator Ultrafiltration Cardiac Surgery Left Ventricular Assist Devices (LVADs) Cardiac Transplantation
ACC/AHA Guideline Recommendations Initial and Serial Evaluation of the HF Patient Hospitalized Patient Patients With a Prior MI Sudden Cardiac Death Prevention Surgical/Percutaneous/Transcather Interventional Treatments of HF Patients at high risk for developing heart failure (Stage A) Patients with cardiac structural abnormalities or remodeling who have not developed heart failure symptoms (Stage B) Patients with current or prior symptoms of heart failure (Stage C) Patients with refractory end-stage heart failure (Stage D) Coordinating Care for Patients With Chronic HF Quality Metrics/Performance Measures
Implementation of Practice Guidelines
Congestive heart failure end-of-life considerations
Specific Groups: Special Populations Patients who have concomitant disorders Obstructive Sleep Apnea in the Patient with CHF NSTEMI with Heart Failure and Cardiogenic Shock
Congestive heart failure positive inotropics On the Web
Most recent articles
Most cited articles
Review articles
CME Programs
Powerpoint slides
Images
Ongoing Trials at Clinical Trials.gov
US National Guidelines Clearinghouse
NICE Guidance
FDA on Congestive heart failure positive inotropics
CDC on Congestive heart failure positive inotropics
Congestive heart failure positive inotropics in the news
Blogs on Congestive heart failure positive inotropics
Directions to Hospitals Treating Congestive heart failure positive inotropics
Risk calculators and risk factors for Congestive heart failure positive inotropics

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-In-Chief: Lakshmi Gopalakrishnan, M.B.B.S. [2]

Overview

Positive inotropes are agents that increase myocardial contractility, and are used to support cardiac function in conditions such as decompensated congestive heart failure, cardiogenic shock, septic shock, myocardial infarction, cardiomyopathy, etc. Examples of positive inotropes include digoxin, dobutamine, dopamine and phosphodiesterase-III inhibitors like amrinone and milrinone.

Inotropics

Pharmacologic Mechanisms

1. Agents that increase intracellular cAMP
   • Alpha-adrenergic agonists
   • Phosphodiesterase inhibitors
2. Agents that affect sarcolemmal ion pumps/channels
   • Digoxin
3. Agents that modulate intracellular calcium mechanisms by either:
   • Release of sarcoplasmic reticulum calcium (IP3)
   • Increased sensitization of the contractile proteins to calcium
4. Drugs having multiple mechanisms of action
   • Pimobendan
   • Vesnarinone

Digoxin

• Inhibits Na,K+-ATPase resulting in an increase in intracellular Na+, extracellular Ca2+ exchange increasing the velocity and extent of sarcomere shortening.
• ACC/AHA recommend digoxin for symptomatic patients with left ventricular systolic dysfunction.
• Commonly used in patients with heart failure and atrial fibrillation to reduce the ventricular response rate.
• Mortality has not been shown to be improved with use of digoxin, but the use of digoxin has been associated with a reduction in hospitalization in the RALES study.
• There is no need to load a CHF patient with digoxin. For the majority of patients with normal renal function, a daily dose of 0.25 mg of digoxin is usually adequate. In the older patient or in those patients with renal impairment, a dose of 0.125 mg per day may be adequate.
• Drugs that increase the concentration of digoxin include antibiotics and anticholinergic agents as well as amiodarone, quinidine and verapamil.
• In the RALES study, a level of < 1 ng/ml was associated with efficacy. Levels above 1 ng/ml were not associated with greater efficacy and were associated with higher mortality.

Dobutamine

• Activates beta-1 receptors resulting in enhanced cardiac contractility.
• Long-term dobutamine infusions are arrhythmogenic and increase mortality.
• Dobutamine also slightly reduces afterload

Dopamine

Dopamine is associated with a dose dependent mechanism of action:

• At low doses: (≤2 µg/kg/min), selectively dilate splanchnic and renal arterial beds and increase renal perfusion.
• At intermediate doses: (2 to 10 µg/kg/min), increase norepinephrine secretion and result in increased cardiac contractility, heart rate and systemic vascular resistance.
• At higher doses: (5 to 20 µg/kg/min), result in direct alpha-adrenergic receptor stimulation and increases systemic vascular resistance.

Milrinone

• Phosphodiesterase-III inhibitor that enhances cardiac contractility by increasing intracellular cyclic adenosine monophosphate (cAMP).
• Potent pulmonary vasodilator that may benefit some patients with pulmonary hypertension.
• Unlike dobutamine, milrinone is beneficial in decompensated heart failure patients who are on beta-blocker therapy.
• Long term milrinone infusions are arrhythmogenic, and increase mortality.

2009 ACC/AHA Focused Update and 2005 Guidelines for the Diagnosis and Management of Chronic Heart Failure in the Adult (DO NOT EDIT)

Positive Inotropics in Patients Presenting With Heart Failure (DO NOT EDIT)

Class III (No Benefit)

"'1. Long-term use of an infusion of a positive inotropic drug may be harmful and is not recommended for patients with current or prior symptoms of heart failure and reduced left ventricular ejection fraction (LVEF), except as palliation for patients with end-stage disease who cannot be stabilized with standard medical treatment. (Level of Evidence: C) "

Digitalis in Patients Presenting With Heart Failure (DO NOT EDIT)

Class IIa

"1. Digitalis can be beneficial in patients with current or prior symptoms of heart failure and reduced left ventricular ejection fraction (LVEF) to decrease hospitalizations for heart failure. (Level of Evidence: B) "

References

Template:WikiDoc Sources