Elizabeth Bernard

Role of ischemia and infarction in late right ventricular dysfunction after atrial repair of transposition of the great arteries

OBJECTIVESnThis study was conducted to assess whether myocardial ischemia and/or infarction are involved in the pathogenesis of late right ventricular dysfunction in adult survivors of atrial baffle repair for transposition of the great arteries in infancy.nnnBACKGROUNDnThe medium-term success of intraatrial baffle repair for transposition of the great arteries is good, with many patients surviving into adult life, but prognosis can be limited by progressive right ventricular dysfunction. We hypothesized that ongoing myocardial ischemia and/or infarction are important factors in the pathogenesis of this complication. Radionuclide techniques offer an opportunity to study both myocardial perfusion and concomitant ventricular wall motion.nnnMETHODSnDipyridamole sestamibi single-photon emission computed tomography followed by rest sestamibi single-photon emission computed tomography was used to assess right ventricular myocardial perfusion, wall motion, wall thickening and ejection fraction in 22 adolescents/young adults who had undergone atrial baffle repair for simple transposition of the great arteries at median 6.7 (range 0.5 to 54) months of age. The patients were aged 10 to 25 (median 15.5) years; 19 in New York Heart Association class I, 2 in class II and 1 in class III. All were in a regular cardiac rhythm during the studies. The right ventricular tomographic images were examined in three parallel and two orthogonal planes, analyzed in 12 segments.nnnRESULTSnPerfusion defects were evident in all patients in at least one segment, in either the rest or stress images. Twelve patients (55%) demonstrated fixed defects only, nine (41%) had fixed and reversible defects and one (4.5%) had reversible defects only. Concomitant wall-thickening abnormalities occurred in 83% of segments with fixed perfusion defects, mirrored by a reduction in wall motion in 91% of segments analyzed. Right ventricular ejection fraction was correlated with age (R = 0.62; p = 0.002), and with wall-thickening abnormalities (R = 0.60; p < 0.005).nnnCONCLUSIONSnReversible and fixed perfusion defects with concordant regional wall motion abnormalities occur in the right (systemic) ventricle 10 to 20 years after Mustard repair for transposition of the great arteries; this may be important in the pathogenesis of late right ventricular dysfunction in this group.

Myocardial perfusion defects and associated systemic ventricular dysfunction in congenitally corrected transposition of the great arteries

Background Patients with systemic ventricles of right ventricular morphology are at high risk of contractile dysfunction, the cause of which has not been fully elucidated. Objective To assess whether ischaemia or infarction contributes to ventricular impairment in unoperated patients with uncomplicated congenitally corrected transposition of the great arteries (TGA) by studying myocardial perfusion and function. Setting Paediatric and adult congenital cardiac clinics of a tertiary referral centre. Patients Five patients with congenitally corrected TGA but without associated structural cardiac defects (aged 3.5 to 34 years). Interventions Maximal exercise stress testing using standard or modified Bruce protocols. Sestamibi (technetium-99m methoxy isobutyl isonitrile) scanning after isotope injection at maximal exercise and rest. Main outcome measures Maximum exercise capacity; right ventricular myocardial perfusion, regional wall motion, and thickening; right ventricular ejection fraction. Results The two youngest patients (3.5 and 11 years) had normal exercise capacity for age, while the others had reduced exercise performance. Sestamibi scanning showed reversible myocardial ischaemia in four patients and fixed defects indicating infarction in five. Irreversible defects were mostly associated with impaired wall motion and thickening. The ejection fraction was normal (65%) in the youngest patient but < 55% in the others (mean (SD) 47(11)%). Conclusions Patients with unoperated congenitally corrected TGA have a high prevalence of myocardial perfusion defects, with consequent abnormalities of regional wall motion and thickening, and impaired ventricular contractility. These data suggest that ischaemia and infarction are important in the pathogenesis of ventricular failure in this condition.

Right ventricular dysfunction in congenitally corrected transposition of the great arteries

Although right ventricular (RV) dysfunction is an important complication in subjects with congenitally corrected transposition of the great arteries, its pathogenesis is poorly understood. We assessed the role of RV myocardial perfusion and found perfusion defects at rest in all 20 patients, involving 4.6 +/- 2.3 of a total of 12 segments; the extent of the resting perfusion defects correlated inversely with the RV ejection fraction.

Myocardial infarction complicating neonatal enterovirus myocarditis

Abstract: A 10‐week‐old, 31‐week gestation preterm boy re‐presented with heart failure after an initial episode of neonatal aseptic meningitis with positive CSF enterovirus polymerase chain reaction. Investigation demonstrated global myocardial dysfunction with left ventricle posterolateral myocardial infarction. The boy’s heart failure was controlled with medical treatment but his myocardial dysfunction persisted 9 months after presentation.

The musculoskeletal complications of cystic fibrosis

To determine the spectrum of musculoskeletal complications of cystic fibrosis (CF) in a paediatric population in Australia.

Moderate T1-201 chloride uptake in cerebral infarction.

A 58-YEAR-OLD WOMAN was hospitalized with right-sided hemiparesis and dysphasia. A computed tomographic (CT) scan of the brain performed 6 days from the onset of symptoms revealed a 3-cm hypodense lesion in the left frontal lobe (precentral gyrus) that indicated a possible cerebral tumor. Magnetic resonance imaging showed some patchy peripheral enhancement after gadolinium administration, consistent with a primary glioma. A subsequent Tl-201 chloride brain SPECT study (performed 25 days after onset of symptoms and 19 days after the CT brain scan) showed moderately increased tracer uptake compared with the contralateral brain (ratio, 1.6:1). A stereotactic biopsy of the lesion showed no malignant cells but had features consistent with a recent cerebral infarction. Because a carotid angiogram showed 90% to 95% stenosis of the left internal carotid artery, the patient underwent carotid endarterectomy with subsequent clinical improvement.

TI-201 positive, Ga-67 negative hepatoblastoma : A case report of a 12-year-old boy

Hepatoblastoma is a primary liver neoplasm in which prompt diagnosis and resection are critical to long-term survival. Nuclear scintigraphy plays an important role in the characterization of hepatic masses. The authors present an unusual case of hepatoblastoma in a 12-year-old boy in whom Ga-67 scintigraphy and serum alpha-fetoprotein were negative. Positive Tl-201 scintigraphy pointed toward the true malignant nature of the mass and should be considered in the investigation of hepatic masses in childhood.

Myocardial Perfusion Defects and Associated Systemic Ventricular Dysfunction in Congenitally Corrected Transposition of the Great Arteries (ccTGA)

A normal heart is divided into two sides. The right side pumps blood from the body into the lungs. The left side pumps the blood from the lungs out to the body. Each side has an atrium and a ventricle. The atrium acts like a “waiting room” for the blood. The ventricle does the hard work of pushing the blood out to the lungs or body. At the entrance and exit from each ventricle is a valve, which acts like a door. These valves allow the ventricle to fill with blood from one side, and then push it out the other.