Cardiac amyloidosis medical therapy
|
Cardiac amyloidosis Microchapters |
|
Diagnosis |
|---|
|
Treatment |
|
Case Studies |
|
Cardiac amyloidosis medical therapy On the Web |
|
American Roentgen Ray Society Images of Cardiac amyloidosis medical therapy |
|
Risk calculators and risk factors for Cardiac amyloidosis medical therapy |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Raviteja Guddeti, M.B.B.S. [2]; Aarti Narayan, M.B.B.S [3]; Cafer Zorkun, M.D., Ph.D. [4]; Lakshmi Gopalakrishnan, M.B.B.S. [5]
Overview
Major cardiac manifestations of systemic amyloidosis include heart failure and fatal arrhythmias. Therefore treatment of cardiac amyloidosis includes treatment of heart failure and arrhythmias and treatment of the underlying disease. Treatment of heart failure associated with cardiac amyloidosis differs from therapy usually attempted in patients with systolic or diastolic dysfunction.
Medical Therapy
Treatment of Heart Failure
Heart failure in cardiac amyloidosis (CA) is due to extracellular deposition of amyloid fibrils which results in reduced myocardial compliance and myonecrosis. This extensive infltration of amyloid results in non-compliant, small ventricles leading to impaired filling. Infiltration of the atria further worsens the situation as it impairs atrial contraction.
Acute Pharmacotherapy
Pharmacotherapy in heart failure associated with amyloidosis is different from heart failure due to other causes in that loop diuretics are the main stay of treatment and beta-blockers and ACE inhibitors may be harmful.
- Loop diuretics are the drugs of choice in the treatment of heart failure in CA.
- Hospitalization and IV diuretics are recommended in the presence of severe symptoms. Careful monitoring of blood pressure and renal function is warranted as rigorous use of diuretics can progress to azotemia. Addition of an aldosterone antagonist like spironolactone to loop diuretics is well tolerated.
- Beta-blockers have been shown to have no proven benefit in the treatment of heart failure associated with amyloidosis. Moreover their use may worsen the condition in patients in whom cardiac output is dependent on heart rate due to presence of a low, fixed stroke volume.
- Clinical experience with ACE inhibitors in this scenario has shown that these agents are often associated with profound hypotension in AL type CA. The reason for that is possibly by exposing a subclinical neuropathy.
- Digoxin and calcium channel blockers bind to the amyloid fibrils and thereby have been reported to increase the incidence of congestive heart failure and produce arrhythmias. Hence, these drugs may be avoided in patients with both AL and TTR cardiac amyloidosis.[1][2][3]
- In patients with symptomatic bradycardia, pacemakers may be indicated.[4][5]
Supportive Measures
Physical activity may continue as long as the patient can tolerate it.
Diet restrictions vary with the extent of cardiomyopathy and heart failure. These may include salt and/or fluid restrictions.
References
- ↑ Gertz MA, Skinner M, Connors LH, Falk RH, Cohen AS, Kyle RA (1985). "Selective binding of nifedipine to amyloid fibrils". The American Journal of Cardiology. 55 (13 Pt 1): 1646. PMID 4003315. Unknown parameter
|month=ignored (help);|access-date=requires|url=(help) - ↑ Gertz MA, Falk RH, Skinner M, Cohen AS, Kyle RA (1985). "Worsening of congestive heart failure in amyloid heart disease treated by calcium channel-blocking agents". The American Journal of Cardiology. 55 (13 Pt 1): 1645. PMID 4003314. Unknown parameter
|month=ignored (help);|access-date=requires|url=(help) - ↑ Rubinow A, Skinner M, Cohen AS (1981). "Digoxin sensitivity in amyloid cardiomyopathy". Circulation. 63 (6): 1285–8. PMID 7014028. Retrieved 2012-02-13. Unknown parameter
|month=ignored (help) - ↑ Mathew V, Olson LJ, Gertz MA, Hayes DL (1997). "Symptomatic conduction system disease in cardiac amyloidosis". The American Journal of Cardiology. 80 (11): 1491–2. PMID 9399732. Retrieved 2012-02-13. Unknown parameter
|month=ignored (help) - ↑ Mathew V, Chaliki H, Nishimura RA (1997). "Atrioventricular sequential pacing in cardiac amyloidosis: an acute Doppler echocardiographic and catheterization hemodynamic study". Clinical Cardiology. 20 (8): 723–5. PMID 9259166. Unknown parameter
|month=ignored (help);|access-date=requires|url=(help)