Postpartum syncope and noncompaction in suspected encephalomyopathy.

To the Editor: Left ventricular hyper-trabeculation (LVHT), also known as noncompaction, is an increasingly recognized cardiac manifestation of various neuromuscular disorders (NMDs) and other rare genetic disorders. (1-3) To our knowledge, detection of LVHT following diagnostic workup after syncope has not been reported.

A 39-year-old, HIV-negative woman experienced syncope 1 hour after delivering a healthy girl while sitting upright on the edge of the bed. The patient was 159cm tall, weighed 45 kg, and had a previous history of palpitations since childhood, asthma during adolescence, and anemia. Except for a kidney problem in her mother, the family history was noncontributory. The delivery was associated with marked blood loss (hemoglobin 7.8) and arterial hypotension (blood pressure 80/33 mm Hg). Following delivery, the patient lost consciousness and fell over, striking her head, which resulted in a fracture of the left occipital bone. After regaining consciousness, she complained of headache, vertigo, and dizziness, which repeatedly recurred during the following four days.

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Clinical neurologic investigation one day after the syncopal episode revealed a short stature, madarosis, sore neck muscles, a prominent masseter reflex, reduced patellar tendon reflexes, and absent Achilles tendon reflexes. Blood work revealed slight leukocytosis, anemia, and hyperlipidemia. Electroencephalography revealed diffuse and focal slowing in the left temporal projection. Cerebral MRI showed a 5 mm subdural hematoma over the right fronto-temporal region and multiple focal white matter lesions in both hemispheres. Nerve conduction studies of the left median, right peroneal, and right sural nerve and electromyography of the left anterior tibial muscle were normal. Clinical cardiac examination, blood pressure, electrocardiogram, and ambulatory 24-hour electrocardiogram were noncontributory. Echocardiography showed slightly thickened left ventricular myocardium (12 mm), and, surprisingly, LVHT of the lateral and posterior wall with a ratio of noncompacted to compacted myocardium >2 (Fig.). Doppler sonography showed no signs of diastolic dysfunction. No family screening for LVHT or NMD has been carried out.

LVHT is a cardiac abnormality of unknown origin, characterized by a meshwork of interwoven myocardial strings, all lined with endocardium, forming a layer clearly distinct from the compacted myocardium. (3) LVHT may be congenital or acquired. (4) Congenital LVHT is attributed to an impaired compaction process during embryonal cardiogenesis. Acquired LVHT is explained by a number of different speculations, but the true cause and pathogenesis of congenital and acquired LVHT remains speculative. LVHT is associated with NMDs in up to 80% of the cases. The cause of LVHT in the described patient remains speculative. Whether she suffered from NMD or another undetected disease is questionable. Assuming that she had a NMD, the most likely is an encephalomyopathy. Arguments for an encephalomyopathy are that LVHT has been previously described in association with these disorders, (3,4) the clinical findings, laboratory findings, and the white matter lesions on cerebral MRI. Even if the patient had an encephalomyopathy, it is uncertain if LVHT was causally related to it. On the contrary, syncope was unequivocally attributable to the combination of postpartum anemia and postpartum hypovolemia.

This case shows that neurologic diagnostic workup of postpartum syncope may reveal LVHT. Detection of LVHT requires neurologic investigations. Detection of NMD requires cardiological investigations.

Josef Finsterer, MD, PhD

Krankenanstalt Rudolfstiftung

Vienna, Asutria

Claudia Stollberger, MD

2nd Medical Department

Krankenanstalt Rudolfstiftung

Vienna, Asutria

References

1. Ichida F, Tsubata S, Bowles KR, et al. Novel gene mutations in patients with left ventricular noncompaction or Barth syndrome. Circulation 2001;103:1256-1263.

2. Pignatelli RH, McMahon CJ, Dreyer WJ, et al. Clinical characterization of left ventricular noncompaction in children: a relatively common form of cardiomyopathy. Circulation 2003;108:2672-2678.

3. Stollberger C, Finsterer J. Left ventricular hypertrabeculation/noncompaction. J Am Soc Echocardiogr 2004;17:91-100.

4. Finsterer J, Stollberger C, Schubert B. Acquired left ventricular hypertrabeculation/noncompaction in mitochondriopathy. Cardiology 2004;102:228-230.

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