Arrhythmogenic right ventricular dysplasia is a unique cardiomyopathy defined histologically by progressive replacement of right ventricular myocardium with adipose and fibrous tissue. It has an estimated population prevalence of 1 in 5000, predisposes to ventricular tachyarrhythmias, and is a cause of sudden death, particularly in younger individuals (Agir, 2014; Elliott, 2008). The additional risk of pregnancy in women with arrhythmogenic right ventricular cardiomyopathy is unknown, however, based on their systematic review, Krul and coworkers (2011) counsel against pregnancy.
Restrictive cardiomyopathy is probably the least common type. This inherited cardiomyopathy is characterized by a ventricular illing pattern in which worsening myocardial stifness raises ventricular pressure precipitously and al�ows only a small filling volume (Elliott, 2008). Because of the severe clinical course and poor prognosis in general, pregnancy is not advised (Krul, 2011). Takotsubo cardiomyopathy is a rare form of acute reversible left ventricular apical wall ballooning (Kraft, 2017).
Regardless of the underlying condition that causes cardiac dysfunction, women who develop peripartum heart failure almost always have obstetrical complications that either contribute to or precipitate heart failure. For example, preeclampsia is common and may precipitate afterload failure. Indeed, indings from the Registry on Pregnancy and Cardiac Disease indicate that women with preexisting heart disease who develop preeclampsia have a 30-percent risk of developing heart failure during pregnancy (Ruys, 2014). Moreover, high-output states caused by hemorrhage and acute anemia elevate cardiac workload and magniy the physiological efects of compromised ventricular function. Similarly, infection and sepsis syndrome raise cardiac output and oxygen utilization and depress myocardial function.
In many populations, chronic hypertension with superimposed preeclampsia is the most frequent cause of heart failure in pregnancy. Many of these women have concentric let ventricular hypertrophy (Ambia, 2017). In some, mild antecedent undiagnosed hypertension causes covert cardiomyopathy, and when superimposed preeclampsia develops, together they may cause otherwise inexplicable peripartum heart failure. Obesity is a frequent cofactor with chronic hypertension, and it too is associated with ventricular hypertrophy (Kenchaiah, 2002).
Congestive heart failure can have a gradual onset or may present as acute "flash" pulmonary edema. Heart failure onset is most likely at the end of the second/beginning of the third trimester and peripartum (Ruys, 2014). Of symptoms, dyspnea is universal and others are orthopnea, palpitations, substernal chest pain, a sudden decline in the ability to complete usual duties, and nocturnal cough. Clinical findings include persistent basilar rales, hemoptysis, progressive edema, tachypnea, and tachycardia (Sheield, 1999). Hallmark radiographic findings usually are cardiomegaly and pulmonary edema (see Fig. 49-5).
Acutely, there is usually systolic failure, and echocardiography shows an ejection fraction <0.45 or a fractional shortening <30 percent, or both, and an end-diastolic dimensionr> 2.7 cm/m2 (Hibbard, 1999). Coincidental diastolic failure may also be found, depending on the underlying cause (Redfield, 2016).