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2014 CLASSIFICATION Source
Arbustini E, Narula N, Tavazzi L, et al. The MOGE(S) classification of cardiomyopathy for clinicians. J Am Coll Cardiol. 2014;64:304–318.
This classification of cardiomyopathies takes genetic testing into account.
Many cardiomyopathies are familial diseases, and you will be scanning family members with questions about echo.
MOGE(S):
- Morphofunctional phenotype.
- Organ involvement.
- Genetic inheritance pattern
- Etiology including genetic defect, or underlying disease.
- Functional Status.
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DILATED CARDIOMYOPATHIES
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Echo is the primary imaging modality to establish presence and severity of dilated cardiomyopathy.
Once the diagnosis is established, echo continues to be a valuable resource that helps to guide treatment and helps to estimate prognosis.
Left ventricular chamber size is increased by definition in dilated cardiomyopathy (Fig. 15-1).
Left ventricular stroke volume is decreased.
Doppler evaluation: It is possible to use Doppler VTI measurements to serially follow changes in LV stroke volume.
Technique: Left ventricular outflow tract (LVOT) area multiplied by VTI equals stroke volume. The LVOT area is assumed to remain unchanged from study to study.
Therefore, Doppler VTI measurements alone can represent changes in LV stroke volume.
Two-dimensional and three-dimensional echo techniques are used to determine end-diastolic and end-systolic left ventricular volumes. This is then used to calculate left ventricular ejection fraction.
Another useful measure of global systolic left ventricular function is dP/dt. It calculates the time that it takes the left ventricle to generate 32 mm Hg. The shorter the time, the better the function.
Global longitudinal strain is increasingly being used as a quantitative measure of left ventricular function in cancer patients undergoing certain chemotherapy regimens.
Ischemic versus nonischemic etiology:
- It is useful to know whether a dilated cardiomyopathy is ischemic or nonischemic. Hence, an inquiry about prior cardiac catheterization is always warranted.
- With an ischemic cardiomyopathy, the presence of certain regional left ventricular wall motion abnormalities may help decide when to repeat a coronary angiogram.
- Patients with nonischemic cardiomyopathy may have regional wall motion abnormalities on echo without underlying coronary artery disease.
- The preserved wall motion in nonischemic cardiomyopathy may be confined to the inferior and/or lateral walls.
- By knowing that the etiology is nonischemic, the existing wall motion abnormalities are not used improperly for decisions related to coronary artery disease.
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An illustration of the key role of echocardiography in cardiomyopathies: Transthoracic echo enables differentiation of heart failure with preserved ejection fraction, commonly observed in women with preeclampsia, from that with peripartum cardiomyopathy, in which a reduced ejection fraction is more common.
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