A Rare Case of Pregnancy with Restrictive Cardiomyopathy.

Restrictive cardiomyopathy (RCM) is a relatively rare form of cardiomyopathy with high mortality which is characterized by impaired filling of the ventricles in the presence of normal wall thickness and systolic function. RCM is generally seen in association with infiltrative, storage, or systemic diseases. We present a rare case of familial RCM with pregnancy which was successfully managed.

INTRODUCTION

Restrictive cardiomyopathies are defined as restrictive ventricular physiology in the presence of normal or reduced diastolic volumes (of one or both ventricles), normal or reduced systolic volumes, and normal ventricular wall thickness.[1] Restrictive cardiomyopathies are the least common of the cardiomyopathic disorders.[2] Usually, patients develop severe symptoms of heart failure over a short period, and the majority die within a few years following diagnosis unless they receive a cardiac transplant.[3] Genetic investigations have shown that the condition may be caused by mutations in sarcomeric disease genes or genes for desmin and even may coexist with hypertrophic cardiomyopathy in the same family as seen in our case.

CASE REPORT

A 25-year-old woman, gravida 4, para 1, living 1, abortion 2, presented to us at 34 weeks of gestation with antepartum hemorrhage. The patient had symptoms of chest pain and palpitations of a week's duration. Her past pregnancies were uneventful. On examination, pulse was 112/min and blood pressure was 120/80 mm Hg. Respiratory system showed bilaterally equal, normal vesicular breath sounds with no rhonchus or crepitations. Cardiovascular system showed loud S3 and no added sounds and murmur. Obstetric scan showed a single live intrauterine gestation without any evidence of placenta previa/abruption. Her electrocardiogram (ECG) showed biatrial enlargement and partial right bundle branch block pattern. Echocardiography showed dilated left and right atria, concentric left ventricular hypertrophy with mild mitral and tricuspid regurgitation, normal left ventricle systolic function, ejection fraction 60%, pulmonary artery hypertension (pulmonary artery systolic pressure-45 mmHg) with small pericardial effusion [Figure 1]. Doppler showed increased early diastolic filling (E) to atrial filling (A) (E/A) ratio (2.4) of the mitral inflow signal, mitral flow (E-0.85, A-0.35), and pulmonary flow (0.90 m/s) [Figure 2]. In light of these results, the possibility of restrictive cardiomyopathy (RCM) was considered. A detailed family history revealed that her brother was diagnosed to have hypertrophic cardiomyopathy. Genetic counseling of the family was done and genetic testing was advised, but the patient declined testing. Several biochemical tests were done to rule out causes for RCM. Rectal biopsy of the patient showed no deposits of amyloidosis. Absolute eosinophil count was found to be normal (380 cells/cc). Connective tissue disorders were ruled out (antinuclear antibody and antiphospholipid antibody were negative). Metabolic disorders were ruled out by serum creatine phosphokinase (CPK) (112.8 U/L) and serum lactate (1.4 mmol/L) which were found to be normal. She went into spontaneous labor 10 days later, and she had a preterm vaginal delivery of a live female baby weighing 2 kg. The patient is on diuretics and she continues to be on regular clinical follow-up.

Figure 1

Echocardiography reveals biatrial enlargement with normal systolic function

Figure 2

Doppler shows increased early diastolic filling to atrial filling ratio (1.6)

DISCUSSION

Common etiologies of RCM include infiltrative (amyloidosis, sarcoidosis), storage (hemochromatosis), noninfiltrative (scleroderma, idiopathic), and endomyocardial processes (endomyocardial fibrosis, hypereosinophilic syndrome, carcinoid, radiation, malignancy, anthracycline toxicity).[4] Feld and Caspi reported a cardiomyopathy with variable hypertrophic and restrictive features that affected three generations of a family with a shared human leukocyte antigens haplotype.[5] In our case, the sibling had hypertrophic cardiomyopathy. Depending on the stage of the disease, the fourth heart sound or third heart sound may be present.[6] In our patient, the only positive examination finding was loud S3. ECG may show progressive atrioventricular (AV) conduction delay due to disease of the AV node, or His-Purkinje system is common in many genetic diseases that affect the myocardium,[7] and in this case, ECG showed biatrial enlargement and partial right bundle branch block pattern. Certain signs and symptoms that could raise the suspicion of specific diagnoses grouped according to the main echocardiographic phenotype such as learning difficulties and mental retardation (Noonan syndrome), paresthesia/sensory abnormalities/neuropathic pain with bilateral carpal tunnel syndrome (amyloidosis) and muscle weakness generally distal progressing to proximal (desminopathies).[7] In our patient, there were no such signs and symptoms indicative of specific diagnoses. The classical Doppler finding is the restrictive pattern-mitral inflow pattern E/A > 1.5 as seen in our case. Several biochemical tests were done to rule out causes for RCM. Increased creatine kinase is seen in desminopathies, and increased proteinuria is seen in amyloidosis.[7] In our case, rectal biopsy was done and it did not show any deposits of amyloidosis and CPK was normal. Patients with established RCM have a poor prognosis. Treatment is usually palliative, directed at symptomatic relief. Most patients are treated symptomatically with diuretics. Cardiac transplantation can be considered in patients with refractory symptoms in idiopathic or familial restrictive cardiomyopathies.

CONCLUSION

The present case report shows the importance of careful evaluation of patients so that risk stratification can be done to avoid adverse disease complications and diminish the rate of sudden death.

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Conflicts of interest

There are no conflicts of interest.