|Year : 2014 | Volume
| Issue : 2 | Page : 145-148
Restrictive cardiomyopathy a missed cause of cardioembolic stroke in young patients
Manish Gutch1, Nirdesh Jain2, Avinash Agarwal1, Sukriti Kumar3
1 Department of Internal Medicine, King George's Medical University, Lucknow, Uttar Pradesh, India
2 Department of Cardiology, King George's Medical University, Lucknow, Uttar Pradesh, India
3 Department of Radiodiagnosis, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India
|Date of Web Publication||3-Oct-2014|
Department of Internal Medicine, KGMU, Lucknow, Uttar Pradesh
Source of Support: None, Conflict of Interest: None
Restrictive cardiomyopathy is characterized by restrictive filling and reduced diastolic volume of either or both ventricles with normal or near-normal systolic function and wall thickness. Here, author reports a case of 18-year-old boy who presented with cardioembolic stroke. On further workup, restrictive physiology was identified and possibility of constrictive pericarditis (CP) could not be ruled out on two-dimensional echocardiographic examination, which was subsequently ruled out by 64 slice cardiac computed tomography scan. The identification of the condition is important for the point of diagnosis and management; rheumatic valvular diseases are prevalent most commonly and are a source of embolism for ischemic stroke in young patients. CP is also common due to high prevalence of tuberculosis in India, which poses diagnostic difficulties.
Keywords: Cardioembolic stroke, endomyocardial fibrosis, restrictive cardiomyopathy
|How to cite this article:|
Gutch M, Jain N, Agarwal A, Kumar S. Restrictive cardiomyopathy a missed cause of cardioembolic stroke in young patients. Nig J Cardiol 2014;11:145-8
| Introduction|| |
Restrictive cardiomyopathy (RCM) is the least common type of cardiomyopathy.  The hallmark of RCM is diastolic dysfunction that results in impaired ventricular filling, normal or decreased diastolic volume of either or both ventricles, and increased left ventricular wall thickness.  As many as one-third of patients with idiopathic RCM may present with thromboembolic complications.  Cardioembolic stroke is now thought to be responsible for an estimated 20% of ischemic strokes, with probably even higher rates in developing countries. Advanced diagnostic techniques have been developed and additional causative cardiac abnormalities and their association with stroke are being recognized.  Although, the incidence of rheumatic fever and rheumatic heart disease has dramatically declined, rheumatic heart disease is still a very important cause of brain embolism, particularly in India. , Here, the author reports a case of RCM which presented with cardioembolic stroke. The pathogenesis, clinical features, and management of RCM are also briefly discussed here.
| Case report|| |
An 18-year-old young male was admitted for acute unconsciousness following an episode of partial seizure with secondary generalization. Past history revealed complaints of breathlessness for the past 2 years for which he was not investigated. General examination findings were - average built, unconscious state (Glasgow coma score [GCS] 10; E3M4V3), afebrile, pulse - 104/min, irregularly irregular, blood pressure - 90/60 mmHg, and presence of pedal edema. Jugular venous pressure was raised (10 cm) with prominent - "y" descent. Cardiac apex was in left 5 th intercostal space at mid clavicular line and was hyperdynamic. Auscultation revealed S3 and pansystolic murmur of Grade III, best heard in the mitral area and also heard all over the back. Neurological examination showed complete hemiparesis of left side of the body with power of 3/5 in the upper extremity and 2/5 (Medical Research Council scale) in the lower extremity. Per abdomen examination showed hepatomegaly. Rest other systems did not have any abnormality. Laboratory examination showed normal complete blood picture, arterial blood gas, serum electrolytes, urea, creatinine, and liver function tests. Cardiac silhouette was unduly enlarged on chest X-ray [Figure 1]. Electrocardiogram showed atrial fibrillation [Figure 2]. Computed tomography (CT) scan brain shows acute infarct in the right tempo-parietal region. Patient was evaluated for cardiac source of embolism for which two-dimensional echocardiography showed constrictive pericarditis (CP), but in view of bi-atrial enlargement and pulmonary arterial hypertension possibility of RCM had to be ruled out [Figure 3]a and b. 64 slice CT scan thorax was done, which showed cardiomegaly with normal ventricular size and bi-atrial enlargement with mild pericardial effusion suggestive of RCM [Figure 4]a and b. In addition, serum ferritin (156 μg/L) was done for hemochromatosis, which was normal. Serum NT pro-brain natriuretic peptide (NT pro-BNP) levels were 1275 ng/L (normal value - 125 ng/L). Patient was anticoagulated with heparin and was maintained on anticoagulation for 5 days along with administration of oral warfarin 5 mg once daily. Tablet diltiazem 30 mg thrice a day was given for ventricular rate control. Sodium valproate was given for seizure.
|Figure 1: Chest X-ray shows enlarged computed tomography ratio, shadow of left atrial enlargement is clearly seen on both anteroposterior as well as in lateral view|
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|Figure 2: 12 lead standard electrocardiography shows atrial fibrillation with ventricular rate of around 100/min|
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|Figure 3: (a) Apical four chamber view on echocardiography shows bi-atrial enlargement with relatively normal ventricle size, (b) Continuous-wave Doppler echocardiography showed tricuspid regurgitation jet velocity 3.47 cm/s and pressure gradient of 49 mmHg|
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|Figure 4: Cardiac computed tomography sagittal view shows enlarged left atrium (a) and coronal view shows enlarged right atrium, (b) While the sizes of the both ventricles are near-normal with mild pericardial effusion suggestive of restrictive cardiomyopathy|
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Supportive care in the form Ryle's tube feeding, urinary bladder catheterization, and physiotherapy of limbs was provided to the patient. The patient's general condition showed gradual improvement and he regained consciousness on the day 4 (GCS-14), the muscle power raised to 4/5 in the affected limb. On the 10 th day, the patient was discharged on oral warfarin 5 mg once a day along with tablet diltiazem 30 mg thrice a day. At the time of discharge, his GCS was 15 and muscle power was 4/5 in affected limbs. He was advised to visit fortnightly at outdoor with the report of an international normalized ratio.
| Discussion|| |
Restrictive cardiomyopathy may be idiopathic or associated with other diseases (e.g. amyloidosis and endomyocardial disease with or without hypereosinophilia). The underlying cause of RCM may not be obvious on presentation and endomyocardial biopsy is required.
Clinical symptoms of RCM include dyspnea, paroxysmal nocturnal dyspnea, orthopnea, peripheral edema, and ascites, as well as general fatigue and weakness. Patients may complain of palpitations (atrial fibrillation), which are common in idiopathic RCM. Angina may be the presenting symptom in amyloidosis. The jugular venous pulse wave and the degree of elevation of the jugular venous pressure indicate the severity of the hemodynamic impairment. Rapid x and y descents may be present in sinus rhythm, but the most prominent wave is the y descent. The jugular venous pulse fails to fall during inspiration and may actually rise (Kussmaul's sign). Peripheral edema and ascites are present in advanced cases, and the liver is enlarged and pulsatile. The left ventricular systolic impulse is usually normal. The first heart sound is usually normal, and the second heart sound is split normally. Splitting widens in the normal way during inspiration, and the pulmonary component is not accentuated. There is usually a third heart sound that is right or left ventricular in origin, and less commonly a fourth heart sound. In advanced cases, the carotid and peripheral pulses may show evidence of a low-output state, with sinus tachycardia and low pulse volume. In advanced cases, all the signs of heart failure are present except cardiomegaly. In contrast, our patient had an enlarged cardiac silhouette which was the result of bi-atrial enlargement. Depending on the etiology, patients may have a prior history of radiation therapy, heart transplantation, chemotherapy, or a systemic disease.
Initially, based on the clinical findings; irregularly irregular pulse, presence of S3, pansystolic murmur, it seemed to be a straightforward case of cardioembolic stroke caused due to rheumatic valvular disease (mitral insufficiency with atrial fibrillation). On further workup, two-dimensional -echocardiography showed mild pericardial effusion, a finding in favor of CP. The presence of bi-atrial enlargement and pulmonary arterial hypertension was favoring RCM. Bi-atrial enlargement with normal ventricular size on echocardiography along with cardiac Doppler studies of restrictive physiology is the most consistent finding of diagnosis of RCM. Here, the importance of an accurate diagnosis of RCM was to distinguish this condition from CP, a clinically and hemodynamically similar entity that also presents with restrictive physiology, but is frequently curable by surgical intervention. This distinction is difficult to make but crucial because the treatment options and prognoses for the two conditions are entirely different. Though rarely, RCM and CP can occur in sarcoidosis as the disease involves all cardiac chambers. Endomyocardial fibrosis is the most common form of RCM encountered in tropical regions, including Southern parts of India. 
Our patient required cardiac catheterization and hemodynamic studies, which would help differentiate RCM from CP and also obtaining an endomyocardial biopsy, but the procedure could not be performed as his relative did not consent to it. The first indication of the procedure would have been to exclude systemic infiltrative disorders or storage diseases. However, in our patient, there was no thickening of the myocardial walls which renders infiltrative disorders rather unlikely. Secondly, the use of 64 slice CT scan has cleared the dilemma in distinguishing CP from RCM. In addition, serum NT pro-BNP level was raised. In their small study, Leya et al. have shown that BNP levels were nearly-normal in heart failure of constrictive physiology and grossly elevated (generally greater than 5 times) in patients with restrictive physiology, despite nearly identical clinical, and hemodynamic presentation. The postulated hypothesis was that in patients with CP the myocardium may be "intrinsically normal and myocardial stretch may be prevented by the constraining pericardium."  This finding was reproduced by Babuin et al. in patients with idiopathic CP the BNP levels were relatively normal and then they stated that the higher levels of BNP cannot distinguish between CP and RCM, especially in patients with secondary CP (they can be raised).  Sengupta et al. have also reported higher levels of BNP in secondary CP than idiopathic CP.  Since this finding has not been validated for all types of CP, therefore, raised BNP level in our patient other than indicating heart failure, may also provide only weak support for the diagnosis in favor of RCM. Though the definitive diagnosis of RCM was not established, but by excluding CP by CT thorax the diagnosis of RCM was considered. As we could not get right heart catheterization and biopsy done the exact etiology was not known; but, it would probably be idiopathic or endomyocardial fibrosis without hypereosinophilia. The course of RCM varies depending on the pathology, and treatment is often unsatisfactory. Prognosis generally is poor in the adult population, with progressive deterioration. The natural history of RCM is especially poor in children with heart failure.
Adults experience a prolonged course of heart failure and may have complications of cardiac cirrhosis and thromboembolism. Treatment options for RCM are limited. The treatment of RCM is palliative and is similar to that of DCM and heart failure. The underlying cause should be treated if possible. Medical intervention includes the use of diuretics, and antiarrhythmic and anticoagulant medications. Diuretics can help, but excessive diuresis can produce worsening symptoms. The role of ACE inhibitors is not established in patients with RCM with normal systolic function. Patients who are refractory to supportive therapy usually die of low-output cardiac failure unless cardiac transplantation is an option.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4]