Heart failure
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
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
Cardiac resynchronization therapy
According to a systematic review, cardiac resynchronization therapy can reduce morbiity and mortality if the ejection fraction is less than 35%.[7] 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.[8]
References
- ↑ National Library of Medicine. Heart Failure, Congestive. Retrieved on 2007-10-19.
- ↑ 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]
- ↑ 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]
- ↑ 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]
- ↑ 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]
- ↑ 6.0 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
- ↑ 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
- ↑ 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.