Multiple Coronary Artery–Left Ventricle Microfistulae and Spongy Myocardium
The Eagerly Awaited Link?
A 54-year-old female from Brazil with a 2-month history of anterior chest pain episodes was referred to our hospital. Before admission she underwent an ECG stress test that showed significant ST-segment depression in leads V4–V6 together with anginal symptoms. The patient had a family history of sudden cardiac death (2 sisters died at 36 and 54 years of age) and a past history of hypertension. She had never suffered from syncope or palpitations.
Biochemical blood parameters and urinalysis were in the normal range. Twelve-lead ECG presented ST-T nonspecific abnormalities (Figure 1) and chest x-ray was normal but showed a mild increase in the second right arch (Figure 2).
Echocardiogram revealed thickened left ventricular walls, mostly in the lateral and inferior midventricular and distal segments, and a brightly speckled endocardium during systole without clear trabeculations (Figure 3 and Data Supplement Movie I). Color flow Doppler imaging identified multiple diastolic flow sites within the apical myocardium (Figure 4 and Data Supplement Movie II). Contrast echo (intravenous injection of 10 mL at 200 mg/mL concentration of Levovist, Bayer Schering Pharma AG, Berlin, Germany) demonstrated multiple communications between left ventricle and coronary circulation (Figure 5 and Data Supplement Movie III).
Coronary angiography confirmed residual fetal sinusoidal circulation with wide communication between both coronary arteries and left ventricle; left and right coronary arteries were enlarged and tortuous, but free from atherosclerotic obstructions (Figure 6 and Data Supplement Movies IV and V).
To support the presence of cardiomyopathy, cardiac magnetic resonance with a 1.5-T cardiovascular magnetic resonance system (SignA CV/i, General Electric, Milwaukee, Wis) and sequenced fast imaging employing steady-state acquisition cine imaging acquisition was performed. These imaging techniques showed normal myocardium thickness but reduced thickness in the apical area, with small fine trabeculae of left midventricular and apical endocardium. This pattern was neither conclusive for the diagnosis of noncompaction of the ventricular myocardium nor of hypertrophic cardiomyopathy, whereas it suggested the presence of spongy myocardial tissue (Figures 7 and 8⇓ and Data Supplement Movies VI and VII).
Finally, no ventricular arrhythmias were detected on 48-hour Holter recording performed before patient discharge on angiotensin-converting enzyme inhibitors, β-blockers, and aspirin therapy. The lady was free of cardiovascular event during a 6-month period of follow-up.
Multiple coronary artery–left ventricle microfistulae are quite uncommon and are presumed to originate from an arrest in the fetal coronary circulation development with the persistence of embryonic myocardial sinusoids.1 In this embryogenic phase, myocardium is still a spongy meshwork of fibers, and, in parallel with the development of coronary arteries, it gradually became compact and thus reduced the intertrabecular recesses to capillaries.2
We hypothesize that both coronary artery–left ventricle microfistulae and spongy endocardium detected in the present case derive from a concurrent arrest in the embryogenic development.
Rarely, multiple coronary–left ventricle microfistulae have been diagnosed in cases of apical hypertrophic cardiomyopathy,3 and only 1 postmortem report described an association with spongy myocardium.4
To our knowledge, the present case is the first case diagnosed in vivo, and it emphasizes the complementary role of echocardiography together with cardiac magnetic resonance in the full evaluation of such complex cardiovascular abnormalities.
The online-only Data Supplement, consisting of movies, is available with this article at http://circ.ahajournals.org/cgi/content/full/116/3/e81/DC1.