comprehensive echocardiographic evaluation including myocardial deformation analysis suggested an infiltrative cardiomyopathy especially in the absence of systemic hypertension . The diagnosis of amyloidosis was further supported by cardiac MRI and was conclusively established by endomyocardial biopsy ; mass spectrometric analysis and genetic mutation testing confirming the diagnosis of ATTRwt .
Cardiac amyloidosis can be broadly divided into light chain ( AL ) amyloidosis , hereditary transthyretin amyloidosis ( ATTRm ) and wild-type transthyretin amyloidosis ( ATTRwt ). Systemic amyloidosis from Amyloid A and other types of amyloidosis infrequently affects the heart . AL amyloidosis is a plasma cell dyscrasia and can complicate multiple myeloma . ATTRm results from inherited mutations in transthyretin leading to formation of an aggregation prone – amyloid forming mutant protein . On the other hand ATTRwt results from sporadic changes resulting in destabilization and abnormal fibril formation of “ normal ” transthyretin protein . 1
In several autopsy studies on elderly individuals > 80 yrs , the frequency of amyloid deposits in the heart were as high as 25 %. 2 Cardiac amyloidosis due to ATTRwt is an underdiagnosed disease and its incidence is unknown . Dyspnea on exertion ( 86 %) and peripheral edema ( 64 %) are the most common clinical symptoms . 1 Atrial fibrillation was present in around 50 % of patients . The incidence of atrial fibrillation is increased in ATTRwt compared to ATTRm or AL disease . 3 This could partly be explained by the advanced age at diagnosis as well the presence of concomitant risk factors such as a hypertension .
Non-invasive diagnostic methods like ECG , ECHO , Cardiac MRI , and nuclear scintigraphy aid in the diagnosis of ATTRwt . Though low-voltage ECG along with q-wave or t-wave changes are considered to be related to amyloidosis , they are not specific for ATTRwt disease . 3 Echocardiography is useful for identifying and monitoring cardiac amyloid disease and is one of the best imaging techniques for assessing ventricular diastolic function . Interventricular septal thickness of > 12mm in the absence of aortic valve disease or systemic hypertension , speckling appearance of myocardium , small LV chamber volume , atrial enlargement , and features of restrictive diastolic filling are suggestive of cardiac amyloidosis . But these changes may not be present in early stages of the disease . Myocardial deformation analysis using longitudinal strain assessment reveals an apical soaring pattern
Figure 2 : Mitral inflow showing severe atrial mechanical dysfunction despite achieving sinus rhythm , which explains the increased risk of thrombus in these patients even when in sinus rhythm . Arrow corresponds to lack of atrial contraction in echo during p-wave in ECG .
which occurs in most cases of amyloidosis as well as some cases of other causes of LV hypertrophy such as systemic hypertension . Late gadolinium enhancement cardiac MRI ( CMR ) can identify cardiac amyloidosis with a sensitivity and specificity of around 90 % compared to cardiac biopsy . Global transmural or subendocardial late gadolinium enhancement is the most common pattern seen . In contrast , territorial enhancement is seen in myocardial infarction . 4 Studies on both CMR and echo imaging suggest that wall thickness and mass are greater in TTR compared to AL disease , but they fail to differentiate between the various types of amyloid . 3 , 5 Although not definitive , nuclear scan using 99mTc-DPD has been able to differentiate the type of amyloid . Positive 99mTc-DPD strongly suggest ATTR disease when performed in cardiac amyloid . Further studies in this regard are currently ongoing .
Cardiac biopsy is the gold standard for the diagnosis of amyloid cardiomyopathy . Amyloid can be identified by congo red staining . Immunohistochemistry / mass spectrometry can be useful in analyzing the type of AL amyloid deposition . Mass spectrometric analysis can help identify the various types of amyloid protein while gene analysis is needed to further differentiate between ATTRm and ATTRwt .
Treatment of ATTRwt cardiac amyloidosis mainly involves management of heart failure and cardiac conduction abnormalities , along with therapies that slow deposition of amyloid . Fluid optimization using diuretics and spironolactone form mainstay in treatment of heart failure . ACE-inhibitors and beta-blockers are poorly tolerated by many patients due to symptomatic hypotension . 6 Calcium channel blockers and digoxin are considered contraindicated in ATTR cardiac amy-
More Than Healthcare , Correct Care Solutions .
WHO WE ARE CCS is a national public healthcare leader caring for underserved patients in correctional settings , psychiatric hospitals and residential treatment facilities .
Opportunities for : Physician Locations throughout Arkansas
Full-time , part-time and PRN available
Comprehensive Benefits • 401K Tuition Reimbursement Competitive Compensation • So Much More ...
Empathy
CALL TODAY OR APPLY ONLINE Chris Phillips ( 615 ) 844-5513 or email CAPhillips @ CorrectCareSolutions . com ccs . careers
Compassion
CCS IS PROUDLY AN EQUAL OPPORTUNITY EMPLOYER
NUMBER 3 SEPTEMBER 2018 • 67