Nonischemic cardiomyopathies Flashcards
refers to specific diseases of the myocardium, most commonly caused by ischemic heart disease
cardiomyopathies
now considered the reference standard for assessing chamber size, left ventricular function and ventricular mass in cardiomyopathies
Cardiac MRI
as cardiac MRI is CI in some patients, this also serves as a tool to diagnose certain nonischemic cardiomyopathies through detailed evaluation of cardiac function and morphology
ECG-gated cardiac CTA
an autosomal dominant genetic cardiomyopathy seen in 0.05% to 0.2% of the population and is the leading cause of sudden cardiac death in young adults and athletes
hypertrophic cardiomyopathy
imaging hallmark of HCM on cardiac MRI
focal, regional or diffuse LV hypertrophy with measurements often exceeding 20mm as measured at end-diastole. LV is generally not dilated and EF is usually normal or increased, leading to obliteration of the LV cavity during systole
most common form of HCM
asymmetric septal involvement
HCM is differentiated from hypertension-related hypertrophy by the presence of
myofiber disarray with focal areas of necrosis and subsequent fibrosis, most often seen in the midmyocardium; hazy midmyocardial enhancement or nodular enhancement in the interventricular septum at the RV insertion points
delayed enhancement is identified in over 80% of HCM patients and is associated with
increased incidence of ventricular tachyarrhythmias which can lead to sudden cardiac death
in asymmetric septal HCM, the commonly involved segment is the
anteroseptal segments, most notable at the base of the LV
20 to 30% of patients with asymmetric septal HCM develop
hypertrophic obstructive cardiomyopathy
complication of asymmetric septal HCM where there is narrowing of the LV outflow tract by the hypertrophies myocardium causing flow acceleration across the LVOT
hypertrophic obstructive cardiomyopathy
HCM variant characterized by pronounced ventricular hypertrophy at the LV apex, which leads to the characteristic “spade-like” configuration of the LV on vertical long axis view of the heart
apical HCM variant
this HCM variant is associated with HPN, but has an overall better prognosis as it is less commonly associated with sudden cardiac death
apical HCM variant
5% of all HCMs with left apical involvement develop ______, which increase the risk for thromboembolic disease and the development of clinical heart failure
left apical aneurysms
In T1-tissue mapping, higher T1 values will be seen in HCM or hypertensive disease?
HCM; but both will lead to increased T1 values
an x-linked disorder which results in the pathologic accumulation of glycosphingolipid within different tissues, including the heart; clinical and morphologic cardiac manifestations may mimic those of HCM
Fabry disease
in fabry disease as compared to HCM, hazy midmyocardial enhancement is often isolated where
inferolateral segments of LV despite relatively diffuse hypertrophy
one of the best ways to differentiate between Fabry disease, HCM and cardiac amyloidosis is through
T1-tissue mapping
Since fat has a shorter native T1 than myocardium, lipid accumulation in Fabry disease causes
significant shortening of native T1 relaxation with values reported at 853 +/- 53 ms at 1.5 T
aside from fabry disease, this other cardiomyopathy also demonstrates such a low native T1 myocardium
cardiac iron overload
as compared with HCM, amyloidosis usually have what T1 value
higher native T1 value of around 1100 ms at 1.5 T; HCM is usually around 1000 ms
a restrictive cardiomyopathy that is caused by the random abnormal deposition of extracellular amyloid fibrils within the heart, including within the myocardium, atria, coronary arteries and valves
cardiac amyloidosis
most common etiology of cardiac amyloidosis
AL amyloidosis
caused by deposition of fibrils of monoclonal immunoglobulin light chains associated with B-cell dyscrasias such as multiple myeloma
AL amyloidosis
physiologically, amyloid deposition in the heart leads to
thickening of myocardium with impaired myocardial relaxation and diastolic dysfunction
while systolic dysfunction does occur, LV EF in patients with amyloid is usually
only mildly reduced
gold standard for diagnosis of amyloidosis
tissue biopsy; apple-green birefringence on polarizing light microscopy
in MRI, it appears as diffuse concentric LV hypertrophy of the myocardium which initially leads to an elevated LV mass index with inital decrease in ventricular volumes
cardiac amyloidosis
in cardiac amyloidosis, this is often present secondary to increased ventricular pressures from the diastolic dysfunction
biatrial dilation
another clue to diagnosis of this disease is the presence of circumferential subendocardial hypoperfusion on dynamic first pass perfusion sequence obtained during the administration of gadolinium
cardiac amyloid
the deposition of amyloid in the myocardium leads to dramatic expansion of the extracellular space and thus produce enhancement or nonenhancement?
enhancement
delayed gadolinium enhancement is most classically described as
diffuse subendocardial LV enhancement
constellation of LV hypertrophy, diffuse subendocardial hypoperfusion and delated enhancement in the setting of biatrial enlargement, diastolic dysfunction and abnormal T1 kinetics before (T1-tissue mapping) and after (abnormal myocardial nulling) the administration of contract can allow one to reliably make the diagnosis of
cardiac amyloid
defined by peripheral blood eosinophilia which can lead to multiple system dysfunction and damage
hypereosinophilic syndrome
classic manifestation of hypereosinophilic syndrome is
Loeffler endocarditis
a restrictive cardiomyopathy which can involve one or both ventricles. on delayed enhancement sequences, a classic circumferential subendocadial pattern of fibrosis is present corresponding to the eosinophilic destruction of this portion of the myocardium
Loeffler endocarditis
characterized by cardiac chamber dilatation coupled with impaired contractility of the LV or both the LV and RV
Nonischemic-dilated cardiomyopathies
approximately 50% of dilated cardiomyopathies are _____ in origin
idiopathic or genetic
idiopathic-dilated cardiomyopathies are typically seen in what age group
younger patients
all cardiomyopahties demonstrate ___ systolic and diastolic volumnes with ____ EF
increase systolic and diastolic volumes with decreased EF
ventricular thickness in dilated cardiomyopathies is often
mildly thinned to normal and is associated with increased end-diastole volumes, greater than 140 mL for the LV and greater than 150 mL for the RV
gadolinium enhancement in dilated cardiomyopathy
often not seen; if present, it characteristically appears as thin, linear midmyocardial enhancement most often involving the interventricular septum
accounts for 5% of the cases of sudden cardiac death in patients less than 35 y.o and therefore the diagnosis is aggressively pursued so treatment can be initiated as soon as possible
arrythmogenic RV cardiomyopathy or RV dysplasia
presents with RV dilation, reduced RV RF and focal areas of RV dyskinesia leading to small “aneurysms”
arrythmogenic RV cardiomyopathy or RV dysplasia
most reliable features of early ARVC
regional wall motion abnormalitis in RV
classically described as RV predominant disease, genetic testing and imaging advantage has increased our awareness of the LV dominant and biventricular phenotypes of disease
ARVC/ARVD
in excess of 75% of ARVC have _____ in advance disease
LV involvement
focal inflammation of the myocardium, most commonly triggered by a viral infection and can lead to a new dilated cardiomyopathy in an otherwise healthy patient
myocarditis
in acute inflammatory phase of myocarditis, T2W images can demonstrate
global or regional areas of increased intenstiy to signify myocardial edema
when the average signal of myocardium is twice that of skeletal muscle as measured on T2W nonfat saturated images, a diagnosis of ____ can be made
myocardial edema
an abnormal global relative enhancement ratio is defined as greater than ____ and occurs secondary to acute cell membrane rupture which leads to increased intracellular gadolinium deposition
3.2:1
presence of two out of three criteria allow one to reliably make the diagnosis of myocarditis, namely
myocardial edema ratio, global relative enhancement, characteristic delayed enhancement pattern
systemic inflammatory disorder characterized by the deposition of noncaseating nonnecrotic granulomas in affected organs
sarcoidosis
diagnosis of cardiac sarcnoid can be confirmed through
either by the presence of noncaseating granulomas on endomyocardial biopsy or clinical criterial which include abnormalitis on ECG, cardiac echo, RMI and radionuclide imaging
in early phase of cardiac sarcoidosis, there is focal wall thickening on SSFP or T1W, edema on T2W and regional wall motion abnormalities. enhancement in sarcoidosis is characterized as
delayed enhancement that is extremely variable with biventricular linear and/or nodular lesions occuring predominantly in a subepicardial/ midmyocardial distribution
in the late stages of cardiac sarcoidosis, it can mimic _____ with wall thinning and transmural enhancement atlthough the enhancement does not correspond to a vascular territory and foci or subepicardial and midmyocardial are often present
ischemic cardiomyopathy
since late stages of sarcoidosis may mimic ischemic cardiomyopathy, this feature of enhancement is uncommon in ischemic cardiomyopathy
RV delated enhancement
genetocally heterogeneous disease seen in both pediatric and adult populations, where the normal morphogenesis of myocardial tissue into compact myocardium is disrupted
LV noncompaction
appears as highly trabeculated LV myocardium and ultimately can cause heart failur, arrhythmias and sudden cardiac death
LV noncompaction
hypertrabeculation in LV noncompaction spares the ____ but often involves the anterolateral, and inferolateral segments at the base and mid-cavity levels and much of the cardiac apex
septum
delayed enhancement in LV noncompaction is more commonly detected in ____ and is seen both in areas of hypertrabeculation and in the adjacent midmyocardium
children/adults
when athletes with hypertrabeculation were compared t patients with LVNC, those with LVNC demonstrated a
significantly increased LV end diastolic volume and reduced LV EF
also known as apical ballooning syndrome or “broken heart” syndrome, is stress-induced cardiomyopathy, most frequently seen in postmenopausal women after a severe emotional or physical event
Takotsubo cardiomyopathy
hallmark of Takotsubo cardiomyopathy is a
transient hypokinesis or akinesis of the mid and apical segment of LV with hypercontractility of basilar segments (resembling a japanese pot used to catch octopi)
edema in Takotsubo cardiomyopathy often resolves when, which is in contrast to STEMI and myocarditis where it can persist 2 to 3 months after cardiac event
within 2 weeks of symptom onset
enhancement pattern in Takotsubo cardiomyopathy
no perfusion defects or delayed enhancements
occurs secondary to iron deposition in the myocardium, either related to genetic disorders of iron metabolism of increased circulating iron related to transfusion
iron overload cardiomyopathy
iron overload cardiomyopathy ultimately results in
dilated or restrictive phenotypes of iron overload cardiomyopathy, resulting to clinical heart failure, conduction abnormalities and pulmonary hypertension
MR sequence that can be used for quantitative assessment of iron deposition as iron deposition generates local fiel inhomogeneities which result in T2* shortening
Cardiac MR T2*
normal range of T2* values
> 20 ms
T2* value indicating mild to moderate iron loading
10 to 20 ms
T2* value indicating severe iron loading
<10 ms
