Puerperal Cardiomegaly

Synonyms

Peripartum heart muscle disease. Peripartum cardiomyopathy. Postpartum cardiomyopathy (or cardiomegaly). Cardiomegaly of pregnancy. Meadow syndrome.

Geographic Distribution

This type of puerperal cardiomegaly occurs worldwide but is rare in Caucasians and occurs almost exclusively in blacks and those of mixed race. It is found throughout Africa, particularly West Africa, and in China, the Indian subcontinent, and Saudi Arabia. It has been reported from South America.

Etiology

The cause is unknown, but possibly some preexisting heart muscle disease deteriorates under the stress, or some other factor, of pregnancy, particularly in the final months. In African women it has been blamed on excessive sodium intake.

Pathology

The cardiac changes are similar to those of idiopathic cardiomegaly, except that there is very seldom any pericardial effusion. Also different are the focal areas of necrosis, with infiltration of lymphocytes, and occasionally neutrophils and eosinophils, none of which usually occur in the idiopathic form.

Clinical Characteristics

Although pregnancy is the usual precipitating event, it may not be the increased physiological work load which is responsible, because the cardiomegaly may occur at any time within a few months before or after delivery. Lactation has a similar effect, and recovery is more rapid if breast feeding is discontinued. There is usually full clinical recovery, but often a relapse occurs during the next pregnancy. However, in some women the failure continues between or after pregnancies.

The clinical signs are those of ventricular failure and arrhythmias. There is dyspnea, liver enlargement, and peripheral edema. There may be transient hypertension, but this reverts to normal with cardiac recovery. In some cases there may be scattered arterial emboli.

Imaging Diagnosis

On a frontal chest radiograph the changes are those of cardiomegaly, with pulmonary venous hypertension. Depending on the clinical stage, there may be pulmonary edema. There are no specific features to distinguish rheumatic or any other etiology, but the association with pregnancy and lactation, and in most patients the rapid return to normal cardiac size and function will indicate the diagnosis.

Fig. 25.27. Some of the synonyms (with dates) for aortitis: the "name-tree" is still growing.

Idiopathic Aortitis

There are so many synonyms for this "aortitis" that simplicity may be the best! Some names are clearly incorrect, e.g. the "aortic arch syndrome" because it affects the whole aorta, and the commonly used "Takayasu's disease", because it was described first by Adams (Fig. 25.27). A full list is given below, which should be read with interest to see how many names can be given to the same unexplained disease! No doubt there are others.

Synonyms

Idiopathic arteritis. Takayasu's disease. Pulseless disease. Pulseless men's disease. Pulseless women's disease. Young female arteritis. Aortic arch syndrome. Aorta-arteritis. Arcus aortae syndrome. Giant cell aortitis. Arteritis of obscure aetiology. Arteritis brachiocephalica. Arteritis epiaortica. Brachiocephalic aortitis. Obliterative brachiocephalic arteritis. Brachial arteritis. Carotid-subclavian arteritis. Chronic subclavian-carotid artery obstruction. Primary arteritis in children. Anomalous or epiaortic arteritis. Idiopathic medial aortopathy and arteriopathy. Abdominal coarctation. Elongate coarctation. Inversed coarctation. Reversed coarctation. Stenosing aortitis. Panarteritis brachiocephalica. Middle aortic syndrome. Danaraj disease. Martorell syndrome. Martorell-Fabre syndrome. Tersell syndrome. Raeder-Harbitz syndrome. Takayasu-Onishi syndrome. Thromboangiitis obliterans subclaviocarotica.

(Temporal or giant cell arteritis is a separate entity; it affects an older age group and has a different pathogenesis. It is uncommon in the tropics; similarly, peripheral arterial disease of any variety is not included in this category).

Definition

A progressive aortitis of unknown etiology which affects the aorta and its immediate elastic branches, and occasionally other major arteries of the body. It is characterized by segmental periarteritis, associated perivascular cuffing, endarteritis, and disruption of the media. The clinical criteria developed by the American College of Rheumatology may not be sufficiently comprehensive to include all of the patients seen in the tropics who undoubtedly have the same idiopathic aortitis. There are good Japanese Standard criteria.

Geographic Distribution

The disease was first reported in Ireland by Adams in 1827. It is now seen throughout the world, but is most frequent in Southeast Asia, Japan, North and tropical Africa, India, Arabia, the Caribbean, and Latin America. Cases have occurred in North America and Europe.

Etiology

In spite of the plethora of names and publications, no one really knows the cause. It seems unlikely that any simple genetic or environmental factor can explain the wide geographic distribution and the diversity of ethnic groups affected. Tuberculosis was blamed long ago; this hypothesis fell into disfavor but new evidence has made this a possible explanation once more, perhaps as an atypical effect. In one series 37.5%, and in another series 20% of patients had tuberculosis documented, with an antigen in the media of involved arteries. However many still favor an auto-immune process, because of IgG, IgM, and IgA alterations combined with the presence of anti-aorta antibodies. This aortitis is most common in children, and in young women, particularly from puberty to 25 years. The youngest reported case is a boy aged 4 years; it is uncommon in either sex over the age of 40 years. When first diagnosed later in life, it is almost always possible to trace early symptoms to childhood or the late teenage years. Progress may be very insidious.

Pathology

The disease was originally thought to be restricted to the arch of the aorta and its major brachiocephalic branches, but subsequently it has been found to involve most of the major arteries of the body. For example, a series of 55 patients in Thailand showed extensive involvement of the aorta and branches in 67% of the patients, of the abdominal aorta and branches in 22%, and only of the aortic arch and its branches in 11%. There must be some geographic variation, because in 38 cases reported from Japan, the subclavian, carotid, and brachiocephalic branches (with associated dilatation of the ascending aorta) were the common sites and only 12% showed involvement elsewhere. In various African series it has been seen frequently in the thoracic and abdominal aorta, the innominate, vertebral, and carotid arteries, the subclavian, pulmonary and renal vessels, and even the arteries of the lower limbs, with large femoral aneurysms being reported. The coronary arteries and the endocardium have also been involved. A microscopically similar lesion involves the iliac veins.

The pathologist rarely has the opportunity of studying tissue from the early stages of the disease, whereas the radiologist can follow the complete morphological progression. The disorder involves all layers of the aorta, but initially is believed to begin as inflammation of the adventitia, with round cell infiltration followed by some giant cell arteritis, and an occlusive endarteritis of the vasa vasorum.

Microscopically, although all layers of the artery are affected, maximum damage occurs in the media. In the early stages there is infiltration of lymphocytes, histocytes and plasma cells, which is both perivascular and within the media. The elastic wall of the artery is damaged and subsequently becomes fibrosed. Giant cells have been reported (one of the reasons why the cause was originally thought to be tuberculosis), and may be of the Langhans or foreign body type.

As the process spreads to the media of the artery, the disturbance of the elastic layers results in localized "blowout" dilatations, probably exacerbated by the frequent coexisting renal hypertension. Elsewhere at this stage the vessel wall is segmentally thickened. Then, as the intima becomes involved, mural thrombi form. Cicatricial narrowing develops, leading to stenosis. Calcification of the vessel wall occurs late in the disease. In the later stages the media is thinned, the elastic fibers disrupted, and there will be thick fibrosis of the adventitia and intima. Thus the initial stages may show vessel wall thickening followed by constriction or outpouchings. Vascular occlusion with obliteration of the lumen is common and then collateral pathways may form to maintain flow, including steal syndromes in the coronary, subclavian, and other arteries. The pulmonary arterial vasculature can also be involved.

If there is a lesion in the anterior aortic arch, it can affect the aortic annulus, leading to aortic incompetence. The occasional development of aortic dissection has been emphasized by Japanese writers. Some authors have suggested that the middle aortic syndrome differs from the aortic arch disease, because vessel wall inflammation may not be present; whether this distinction is valid is by no means certain. The clinical and imaging pattern of the disease seems consistent along the whole aorta. Further studies with spiral CT and MRI may give more information.

Laboratory Diagnosis

There are no definitive tests but when the disease is active the ESR may be raised and the C-reactive protein test may be positive. The serum a-globulin may be raised.