Heart failure

From Citizendium
Revision as of 01:52, 14 November 2007 by imported>Robert Badgett (→‎Medications)
Jump to navigation Jump to search
This article is developing and not approved.
Main Article
Discussion
Related Articles  [?]
Bibliography  [?]
External Links  [?]
Citable Version  [?]
 
This editable Main Article is under development and subject to a disclaimer.

Congestive heart failure is defined as "defective cardiac filling and/or impaired contraction and emptying, resulting in the heart's inability to pump a sufficient amount of blood to meet the needs of the body tissues or to be able to do so only with an elevated filling pressure".[1]

Classification

Systolic dysfunction

Diastolic dysfunction

Diagnosis

History and physical examination

The best findings for detecting increased filling pressure are jugular venous distention and radiographic redistribution. The best findings for detecting systolic dysfunction are abnormal apical impulse, radiographic cardiomegaly, and q waves or left bundle branch block on an electrocardiogram. [2]

Echocardiogram

The fractional shortening can estimate the left ventricular ejection fraction.[3][4][5]

Treatment

Medications

Angiotensin-converting enzyme inhibitors

Angiotensin-converting enzyme inhibitors (ACE inhibitors) should not be used if:[6]

  • Baseline serum potassium is < 5.5 mmol per liter.
  • No prior life-threatening adverse reactions (angioedema or anuric renal failure) during previous exposure to the drug
  • They are not pregnant
  • Systolic blood pressure less than 80 mm Hg
  • Serum levels of creatinine greater than 3 mg per dL
  • Bilateral renal artery stenosis is not present

Angiotensin-converting enzyme inhibitors combined with angiotensin-receptor blockers

This combination should be avoided due to increased azotemia, hyperkalemia, and symptomatic hypotension.[7]

Aldosterone antagonists

Aldosterone antagonists, initial dose of spironolactone 12.5 mg or eplerenone 25 mg, may be used as long as:[6]

  • Serum creatinine 1.6 mg per dL or less and glomerular filtration rate or creatinine clearance exceeds 30 mL per minute.
  • Baseline serum potassium is < 5.0 mEq per liter

Risk of hyperkalemia is increased if the following drugs are used:[6]

  • Higher doses of ACE inhibitors (captopril greater than or equal to 75 mg daily; enalapril or lisinopril greater than or equal to 10 mg daily).
  • Nonsteroidal anti-inflammatory drugs and cyclo-oxygenase-2 inhibitors
  • Potassium supplements

After starting aldosterone antagonists:[6]

  • Potassium levels and renal function should be checked in 3 days
  • Potassium levels and renal function should be checked at 1 week
  • Potassium levels and renal function should be checked monthly for the first 3 months.
  • Diarrhea or other causes of dehydration should be addressed emergently

Implantable devices

Several implantable devices may help; however, it is not clear that implantable cardioverter-defibrillators (ICD) add benefit over cardiac resynchronisation therapy (CRT).[8]

Cardiac resynchronization therapy

According to a systematic review, cardiac resynchronization therapy (CRT), which is biventricular pacing, can reduce morbiity and mortality if the ejection fraction is less than 35%.[9] 30 patients must be treated to avoid one death (number needed to treat is 30). Cardiac resynchronization should only be used for patients with a QRS duration of at least 120 msec.[10]

Implantable cardioverter-defibrillator

Implantable cardioverter-defibrillators (ICD) can reduce mortality in patients who have an ejection fraction of less than 35%.[11]

Left ventricular assist devices

Left ventricular assist devices (LVADs) may be an option for patients with end stage heart failure.[12]

References

  1. National Library of Medicine. Heart Failure, Congestive. Retrieved on 2007-10-19.
  2. Badgett RG, Lucey CR, Mulrow CD (1997). "Can the clinical examination diagnose left-sided heart failure in adults?". JAMA 277 (21): 1712-9. PMID 9169900[e]
  3. Tortoledo FA, Fernandez GC, Quinones MA (1983). "An accurate and simplified method to calculate angiographic left ventricular ejection fraction". Catheterization and cardiovascular diagnosis 9 (4): 357-62. PMID 6627386[e]
  4. Quinones MA, Waggoner AD, Reduto LA, et al (1981). "A new, simplified and accurate method for determining ejection fraction with two-dimensional echocardiography". Circulation 64 (4): 744-53. PMID 7273375[e]
  5. Erbel R, Schweizer P, Krebs W, Meyer J, Effert S (1984). "Sensitivity and specificity of two-dimensional echocardiography in detection of impaired left ventricular function". Eur. Heart J. 5 (6): 477-89. PMID 6745290[e]
  6. 6.0 6.1 6.2 6.3 Hunt SA, Abraham WT, Chin MH, et al (2005). "ACC/AHA 2005 Guideline Update for the Diagnosis and Management of Chronic Heart Failure in the Adult: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Update the 2001 Guidelines for the Evaluation and Management of Heart Failure): developed in collaboration with the American College of Chest Physicians and the International Society for Heart and Lung Transplantation: endorsed by the Heart Rhythm Society". Circulation 112 (12): e154–235. DOI:10.1161/CIRCULATIONAHA.105.167586. PMID 16160202. Research Blogging. National Guidelines Clearinghouse
  7. Phillips CO, Kashani A, Ko DK, Francis G, Krumholz HM (2007). "Adverse effects of combination angiotensin II receptor blockers plus angiotensin-converting enzyme inhibitors for left ventricular dysfunction: a quantitative review of data from randomized clinical trials". Arch. Intern. Med. 167 (18): 1930–6. DOI:10.1001/archinte.167.18.1930. PMID 17923591. Research Blogging.
  8. Lam SK, Owen A (2007). "Combined resynchronisation and implantable defibrillator therapy in left ventricular dysfunction: Bayesian network meta-analysis of randomised controlled trials". BMJ 335 (7626): 925. DOI:10.1136/bmj.39343.511389.BE. PMID 17932160. Research Blogging.
  9. McAlister FA, Ezekowitz J, Hooton N, et al (2007). "Cardiac resynchronization therapy for patients with left ventricular systolic dysfunction: a systematic review". JAMA 297 (22): 2502–14. DOI:10.1001/jama.297.22.2502. PMID 17565085. Research Blogging. ACPJC summary
  10. Beshai JF, Grimm RA, Nagueh SF, et al (2007). "Cardiac-Resynchronization Therapy in Heart Failure with Narrow QRS Complexes". DOI:10.1056/NEJMoa0706695. PMID 17986493. Research Blogging.
  11. Bardy GH, Lee KL, Mark DB, et al (2005). "Amiodarone or an implantable cardioverter-defibrillator for congestive heart failure". N. Engl. J. Med. 352 (3): 225–37. DOI:10.1056/NEJMoa043399. PMID 15659722. Research Blogging.
  12. Delgado RM, Radovancevic B (2007). "Symptomatic relief: left ventricular assist devices versus resynchronization therapy". Heart failure clinics 3 (3): 259–65. DOI:10.1016/j.hfc.2007.05.004. PMID 17723934. Research Blogging.