Scintigraphic diagnosis of a right to left shunt in end-stage lung disease

PURPOSE: The presence of a right to left shunt influences the surgical approach to lung transplantation in patients with end-stage pulmonary disease. The purposes of this study included comparing contemporaneous lung scintigraphy with cardiac catheterization in the detection of intracardiac shunts in patients with end-stage lung disease and the point prevalence of right to left shunting was determined in patients with several different types of end-stage lung disease. METHODS: Hundred and twenty six patients with end-stage lung disease who were candidates for lung transplantation underwent perfusion images of the lungs with Tc-99m-labeled macro-aggregated albumin (MAA). Planar scans of the brain and the kidneys were performed contemporaneously. Statistical analyses included correlation ofthe clinical, laboratory and scintigraphic variables. Group means were compared with the students t-test (two-tailed P-value). RESULTS: There were 21 patients with primary pulmonary hypertension (PPH), 72 with emphysematous lung disease (COPD), 22 with pulmonary fibrotic disease (PF) and 11 with congenital heart disease (CHD) leading to pulmonary hypertension. Only 13 patients (10.3%) were found to have a right to left shunt. Of these, 4 had PPH, 2 had PF, and 7 had CHD. No shunts were found in patients with emphysema. All the positive studies had abnormally increased activity in both the brain and the kidneys. However, there were 25 cases with renal activity and none of these patients had brain activity or clinical evidence of a shunt. Increased pulmonary artery pressure was associated with scintigraphic presence of a shunt. There were no cases of a right to left shunt with a mean pulmonary artery pressure less than 50 mm Hg. In the subset of patients with a pulmonary pressure greater than 50 mm Hg, approximately 40% of the patients had a right to a left shunt. There were no measurable differences in the spirometry results, right ventricular ejection fraction (RVEF) or left ventricular ejection fraction (LVEF) in the subgroup of patients with PPH and right to left shunt in comparison with patients with PPH but without a right to left shunt. CONCLUSIONS: The findings indicate that images of the brain, but not the kidneys, are an effective way to diagnose extrapulmonary right to left shunts in patients with end-stage pulmonary disease. The problem of a right to left shunt is uncommon in patients with emphysematous lung disease and relatively common in patients with primary pulmonary hypertension.     

Right coronary artery issuing from the pulmonary artery: review of the literature apropos of a case

A new case of right coronary artery abnormally issued from the pulmonary trunk is reported. The patient was an asymptomatic young man in whom a continuous cardiac murmur was discovered by chance and an angiographic examination disclosed the coronary abnormality. A review of the literature yielded 37 cases of this anomalous origin which was either isolated, as in the case reported here, or associated with another congenital or acquired cardiopathy. The diagnosis may be suspected on the presence of a continuous murmur in an usually asymptomatic subject and is confirmed by angiography. The abnormality is generally well tolerated owing to an inter-coronary collateral circulation resulting in retrograde perfusion of the right coronary artery from the left coronary artery. This good tolerance explains why an isolated abnormality of that type is often discovered belatedly, in contrast with the anomalous origin of the left coronary artery from the pulmonary trunk, which is usually revealed at birth by clinical signs of acute coronary insufficiency. However, the likelihood of either cardiac failure due to the left-to-right shunt in elderly people or, chiefly, acute myocardial ischaemia by coronary steal with a risk of sudden death in young people makes it imperative in such cases to perform reimplantation surgery.     

Single coronary ostium - a right coronary artery arising from the left main coronary artery

Single coronary ostium is a very rare congenital anomaly with an incidence of 0.024% in angiographic series. This is the third case of Shirani-Roberts subtype IB4: solitary ostium in the left coronary sinus associated with a retroaortic-coursing right coronary artery that arises from the left main coronary artery. The patient is a 45-year-old male with no past medical history, and who was seen in the clinic for evaluation of a murmur. Echocardiography showed rheumatic heart disease with mild mitral regurgitation and moderate aortic regurgitation; no shunts were present. Coronary and aortic root angiography did not show a vessel originating from the right coronary cusp. The right coronary artery originated from the left main coronary artery and had an aberrant course which was dorsal to the ascending aorta. No associated congenital heart disease was present.     

Anomalous origin of the right coronary artery from the pulmonary artery

Two patients with an anomalous right coronary artery arising from the pulmonary artery are presented. The first patient was asymptomatic and had a continuous murmur. The correct diagnosis was established by cardiac catheterization and selective angiography. There was a moderate sized shunt from the dilated left anterior descending coronary artery to the right coronary artery, which arose from the main pulmonary artery. The second patient was also asymptomatic but died several days after a sudden cardiorespiratory arrest. On postmortem examination she was demonstrated to have anomalous origin of the right coronary artery from the pulmonary artery. The left coronary artery was completely occluded at the orifice by a thrombus, and microscopic examination demonstrated evidence of both acute and chronic left ventricular ischemia and infarction. The pathophysiologic alterations and potential danger to patients with this anomaly are discussed.     

The pulmonary vasculature in a neonatal porcine model with increased pulmonary blood flow and pressure

INTRODUCTION: Hypertension and hyperperfusion of the pulmonary vascular bed in the setting of congenital cardiac malformations may lead to progressive pulmonary vascular disease. To improve the understanding of the basic mechanisms of this disease, there is a need for clinically relevant animal models which reflect the disease process. MATERIAL AND RESULTS: We randomly allocated 45 newborn pigs, at the age of 48 hrs, to groups in which there was either construction of a 3 mm central aorto-pulmonary shunt, undertaken in 9, or ligation of the left pulmonary artery, achieved in 13. Controls included sham operations in 13, or no operations in 10 pigs. Follow-up was continued for three months. The interventions were compatible with survival in most pigs. The shunts resulted in an acute 85% increase in systolic pulmonary arterial pressure, and a more than twofold increase in pulmonary blood flow. By three months of age, nearly all shunts had closed spontaneously, and haemodynamics were normal. Ligation of the left pulmonary artery resulted in a normal total pulmonary blood flow, despite only the right lung being perfused, and a 33% increase in systolic pulmonary arterial pressure. These haemodynamic changes were maintained throughout the period of study. In both groups, histomorphometry revealed markedly increased muscularity of the intra-acinar pulmonary arteries. Circulating levels of endothelin were normal in the shunted animals, and elevated in those with ligation of the left pulmonary artery. CONCLUSION: In neonatal porcine models of pulmonary vascular disease, created by construction of 3 mm central aorto-pulmonary shunts and ligation of one pulmonary artery, we observed histopathological changes of the pulmonary vasculature similar to early hypertensive pulmonary vascular disease in humans. Elevated circulating levels of endothelin were associated with abnormal haemodynamics rather than abnormal pathology. These findings could be valuable for future studies on the pathogenesis of hypertensive pulmonary vascular disease associated with congenital cardiac malformations.     

A young female with an unusual cause of dyspnea

Within the context of coronary artery anomalies, coronary fistulas are classified by termination. A coronary artery fistula (CAF) involves a sizable communication between a coronary artery and a heart chamber (coronary-cameral fistula) or a segment of the systemic or pulmonary system (coronary artery arteriovenous fistula). These are often due to deviations from normal embryological development. CAF may be present in patients at any age, but is usually suspected in early childhood and accounts for 0.08-0.4% of congenital cardiac anomalies. They may also be acquired by trauma or from invasive cardiac procedures. The majority of CAF arises from the right coronary artery (55%) and the left anterior descending coronary artery, with the circumflex rarely involved. The outcome of these connections depends upon the termination site. The pathophysiology of these lesions is identical. Coronary artery anomalies are difficult to detect clinically. Most are benign but some may produce symptoms that can be life threatening. We present a female with an unusual cause of dyspnea found to have a continuous heart murmur, cardiac catheterization showed an evidence of a long tract arising from the origin of the right coronary artery with flow directed towards the right atrium and the right atrial appendage.     

Aortic origin of the left pulmonary artery: Variant of tetralogy of fallot

A case of tetralogy of Fallot with aortic origin of the left pulmonary artery is presented. This rare malformation should be suspected in a child with stunted growth, cyanosis, a continuous murmur over the pulmonary area and a hypervascular left lung on chest roentgenogram. Final diagnosis depends upon cardiac catheterization and angiocardiography. During surgical correction of the tetralogy, the left pulmonary artery can be divided from the aorta and anastomosed to the main pulmonary artery.     

Bidirectional shunt in uncomplicated atrial septal defect

The presence of right to left shunts at atrial level in 40 patients with an uncomplicated atrial septal defect was determined by measuring the pulmonary vein to systemic artery oxygen stepdown . In six patients (group 1) a sizeable right to left shunt was found: left atrial oxygen stepdown was greater than or equal to 0.7 vol%, mean right to left shunt 0.67 1/min/m2 (range 0.36-1.0), and arterial oxygen saturation between 84% and 90.5%. The patients in group 1 did not show any differences from those with left to right shunts alone (group 2) as regards sex, cardiac rhythm, heart rate, "a" wave and mean right atrial pressure, end diastolic right ventricular pressure, morphology of diastolic right ventricular pressure curves, pulmonary to systemic vascular resistance ratio, size of the defect, and coexistence of anomalous pulmonary venous drainage. Patients with coexisting right to left shunts were, however, significantly older and had smaller left to right shunts. Thus an appreciable number of patients with uncomplicated atrial septal defects have major right to left shunts which are unrelated to pulmonary hypertension or right heart failure. These shunts may be detected by the usual oximetric techniques and apparently develop with age, which suggests that they result from changes associated with chronic right volume overload.     

Transcatheter Closure of Right‐to‐Left Interatrial Shunts to Resolve Hypoxemia

Background. Right‐to‐left interatrial shunts through an atrial septal defect or patent foramen ovale may result from congenital and acquired conditions. Right‐to‐left shunts may occur with normal pulmonary artery pressure and resistance as in right ventricular outflow tract obstruction leading to hypertrophy and reduced diastolic function, in right ventricle ischemia, myocarditis or cardiomyopathy and in orthodeoxia–platypnea syndrome. Methods. We have tested the tolerance of trans‐catheter closure of right‐to‐left interatrial shunts in 5 selected patients in whom the morphology and hemodynamics implied that it would be well‐tolerated and improve functional capacity. Right‐to‐left shunt was demonstrated in 5 profoundly cyanotic patients by trans‐thoracic and trans‐esophageal echocardiography with intravenous injection of agitated saline. The patients were catheterized for hemo‐dynamic study and tested for tolerance of transient balloon occlusion of the defects. Results. Diastolic right ventricular dysfunction with elevated end‐diastolic pressure was the primary cause of right‐to‐left shunt. Most shunts occur via atrial septal defects. Patients' ability to tolerate temporary balloon occlusion of the defects predicted a favorable outcome following permanent device occlusion. Cyanosis resolved in all patients following closure of the defects without congestive right heart failure. A marked improvement in functional capacity was observed in 4 patients. One died of preinterventional hypoxic brain damage. Conclusion. Transcatheter closure of right‐to‐left shunts is well‐tolerated and a rewarding approach. It should be applied in selected patients following careful morphologic and hemodynamic evaluation. Tolerance of temporary occlusion of the defect is predictive of a favorable procedural outcome.     

Bidirectional shunt in uncomplicated atrial septal defect.

The presence of right to left shunts at atrial level in 40 patients with an uncomplicated atrial septal defect was determined by measuring the pulmonary vein to systemic artery oxygen stepdown . In six patients (group 1) a sizeable right to left shunt was found: left atrial oxygen stepdown was greater than or equal to 0.7 vol%, mean right to left shunt 0.67 1/min/m2 (range 0.36-1.0), and arterial oxygen saturation between 84% and 90.5%. The patients in group 1 did not show any differences from those with left to right shunts alone (group 2) as regards sex, cardiac rhythm, heart rate, "a" wave and mean right atrial pressure, end diastolic right ventricular pressure, morphology of diastolic right ventricular pressure curves, pulmonary to systemic vascular resistance ratio, size of the defect, and coexistence of anomalous pulmonary venous drainage. Patients with coexisting right to left shunts were, however, significantly older and had smaller left to right shunts. Thus an appreciable number of patients with uncomplicated atrial septal defects have major right to left shunts which are unrelated to pulmonary hypertension or right heart failure. These shunts may be detected by the usual oximetric techniques and apparently develop with age, which suggests that they result from changes associated with chronic right volume overload.     

Subclavian and pulmonary steal phenomenon in isolated left subclavian artery with left lung agenesis

Isolated left subclavian artery has been documented to be associated with several congenital cardiac defects, including tetralogy of Fallot and transposition of the great arteries. In some cases subclavian or pulmonary artery steal phenomenon may occur when the isolated left subclavian artery connects to the main pulmonary artery via a ductus arteriosus. The isolated left subclavian artery may be part of the cardiac manifestations in multiple congenital anomalies, such as VACTERL association. We describe subclavian and pulmonary steal phenomenon in a neonate with complex congenital heart disease, including an isolated left subclavian artery, and left lung agenesis. An isolated left subclavian artery is rare and its association with agenesis of the left lung has not been reported previously.     

Hemodynamic effects of nifedipine on pulmonary hypertension secondary to congenital heart disease with shunts

Ten patients (pts) with pulmonary hypertension (PAH) secondary to congenital heart diseases (CHD) with left to right and bidirectional shunts were studied by right heart catheterization. After getting the control hemodynamic data, pts were given nifedipine (NIF) capsule 10-20 mg sublingually and their pulmonary artery pressure (PAP), systemic blood pressure (SBP), heart rate (HR) were monitored for 60 minutes and the hemodynamic data were redetermined. The results showed that the PAP as well as SBP was decreased and the quantity index of left to right shunt (L-R QI) was also reduced by NIF in L-R shunt group (3/10). In bidirectional shunts group (7/10), 4/7 cases showed total pulmonary artery resistance index (TPRI), pulmonary artery resistance index (PARI) were decreased by 29% (P less than 0.01) and 30% (P less than 0.05) respectively without seriously increased R-L shunts. The other 3/7 pts' TPRI, PARI were increased while systemic vascular resistance index (SVRI) was lowered by 41% (P less than 0.05). The quantity index of pulmonary blood flow (Qlp) was decreased by 30 (P less than 0.05) quantity index of right to left shunt R-L QI was increased sharply by 138% (P less than 0.05) while L-R QI decreased by 76% (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Magnetic resonance imaging: evaluation of the Blalock-Taussig shunts and anatomy of the pulmonary artery]

The morphology and circulation of the pulmonary arteries and shunt vessels were evaluated by magnetic resonance imaging (MRI) in 8 patients with cyanotic heart disease after a Blalock-Taussig shunt operation. Their ages ranged from one month to 17 years. MRI permitted assessment of the size and patency of the Blalock-Taussig shunts, as well as the size and morphology of the pulmonary arteries in all patients. Measurements of the vessel diameters on MRI correlated well with the angiographic measurements (main pulmonary artery, r = 0.98; right pulmonary artery, r = 0.98; left pulmonary artery, r = 0.98; and Blalock-Taussig shunt, r = 0.97). MRI successfully imaged 3 of 4 shunt obstructions and 3 of 4 pulmonary stenoses with high resolution. In assessing peripheral pulmonary stenosis or obstruction, MRI was superior to echocardiography, the latter being unable to image peripheral pulmonary arteries satisfactorily. We concluded that MRI is an excellent noninvasive method for serially evaluating the anatomy and function of Blalock-Taussig shunts and pulmonary arteries, which is particularly useful for children with cyanotic congenital heart disease.     

Primary coronary fistulas. Angiographic study of 21 cases

A retrospective study of 21 cases of congenital primary coronary fistulae and a review of the literature underline the exceptional features of 2 of our cases and recall the main features of coronary fistulae. Coronary angiography (18 cases) or aortography (3 cases) confirmed the diagnosis in our 21 cases. Six of them involved the right coronary artery, 12 the left one, and 3 the two coronary arteries. Seven of them involved the right heart (2 right atrium, 5 right ventricle), 11 the main pulmonary artery, 2 the left heart (the left ventricle in both cases), and the last case was a coronaro-bronchial fistula. Our series comprised 11 men and 10 women; the mean age was 33 (range: 4 days to 67 years of age). The main presenting features were: murmur (7 cases), angina (7 cases), angina (7 cases), Stage II or III dyspnoea (5 cases). Clinical examination showed a systolic-diastolic murmur in 12 cases and a systolic murmur in one case. The chest X ray showed signs of left to-right shunt in 6 cases. The right heart catheterisation of 16 of the 19 left-to-right shunts confirmed the shunt in 9 cases. The 7 cases of coronaro-right cardiac fistulae drained directly (4 cases), by aneurysmal dilatation with diaphragm (3 cases); the 2 cases of coronaro-left-ventricular fistulae drained via microfistulae; the 11 cases of proximal coronaro-pulmonary fistulae drained mostly by an angiomatous plexus (9 cases).(ABSTRACT TRUNCATED AT 250 WORDS)     

Left-right shunt caused by anomalous implantation of the left coronary artery in the trunk of pulmonary artery. Detection by contrast echocardiography

The authors describe a case of an anomalous left coronary artery arising from the main pulmonary artery in an 11 year old child suffering from chest pain on effort and with a continuous murmur in the second left intercostal space. Two dimensional echocardiography (2D E) showed dilatations of the first segment of the right coronary artery and the anomalous origin of the left main coronary artery. A peripheral injection of microbubbles showed a left-to-right shunt between the left coronary artery and the pulmonary artery. Semi-quantitative evaluation of LV regional wall motion showed abnormal contraction of the anterolateral walls. Haemodynamic, angiographic data and the operative findings confirmed the diagnosis. The abnormal coronary ostium was closed and a bypass graft from the aorta to the left anterior descending artery was performed. Clinical and echocardiographic follow-up 7 months after surgery was completely normal.     

Left ventricular outflow tract pulmonary artery fistula in endocarditis

Patients with infective endocarditis are at risk for the development of a fistulous communication between chambers or great vessels of the heart. The presence of a continuous murmur may suggest the diagnosis. The first case of aortic valve endocarditis complicated by the development of a fistulous communication between the left ventricular outflow tract and the pulmonary artery is reported. Transesophageal Doppler echocardiography did not detect the defect preoperatively. However, pulmonary artery catheterization revealed very high mixed venous oxygen saturation which supported the presence of a left-to-right shunt.     

Congenital absence of the pulmonary valve

The clinical, radiological, electrocardiographic, and haemodynamic findings in 7 patients with the syndrome of congenital absence of the pulmonary valve with ventricular septal defect are reported. Findings included a pansystolic murmur and a low-pitched delayed diastolic murmur at the left sternal border with no pulmonary valve closure sound, an rsR′ pattern in V1 on the electrocardiogram, and a chest x-ray showing a large heart and gross dilatation of the main, left or right pulmonary arteries but normal or reduced vascularity of the peripheral lung fields. Cardiac catheterization showed a left-to-right shunt at ventricular level in every case, though in one the shunt was bidirectional. Despite right ventricular systolic pressures at least 75 per cent of systemic level in every patient, the pulmonary artery pressure was invariably normal. Pulmonary stenosis was shown to exist at infundibular level, at valve ring level, or at both. Selective right ventricular angiography was diagnostic: the main and right or left pulmonary arteries were aneurysmally dilated and there was an abrupt transition in calibre between these vessels and their immediate branches; enlargement of the right pulmonary artery caused distortion and downward displacement of the left atrium in 4 patients; in 2 there was a flat `diaphragm' in the pulmonary valve position.     

Recanalisation of an occluded modified Blalock-Taussig shunt by balloon dilatation.

A four year old boy with pulmonary atresia and ventricular septal defect had an acute cyanotic episode three years after undergoing a right-sided, 6 mm diameter, modified Blalock-Taussig shunt. On admission no continuous murmur could be heard from the shunt and the typical high velocity, continuous flow profile of the shunt could not be identified by Doppler echocardiography. At catheterisation a right subclavian artery angiogram confirmed shunt occlusion. From the subclavian artery, an 0.035 inch wire was used to enter the occluded shunt and then the pulmonary artery. Balloon angioplasty of the entire length of the shunt was performed with 6 mm diameter balloon. After angioplasty the arterial oxygen saturation increased from 63% to 83%. The patient was treated with intravenous heparin followed by warfarin. Repeat catheterisation and angiography eight days later confirmed wide patency of the shunt.     

Direct communication between the left pulmonary artery and the left atrium

A 17-year-old patient was found to have cyanosis. A right-to-left shunt was suspected clinically and confirmed by noninvasive techniques such as perfusion lung scan and contrast echocardiography. Angiography showed this shunt to be between the left pulmonary artery and the left atrium. We believe this to be the first report of a hitherto undescribed congenital anomaly.     

Acquired systemo-pulmonary fistula after pleurectomy responsible for a continuous thoracic murmur

Systemo-pulmonary fistulae are rare. The case of a 27 year-old man, hospitalized for exploration of a continuous thoracic murmur, is reported. A right pleurectomy had been performed 2 years previously because of a recurrent spontaneous pneumothorax, and no murmur was present at that time. Angiography showed a systemo-pulmonary fistula with the right internal mammary artery and branches of the right axillary artery as afferent vessels, and the right pulmonary arteries and veins as efferent vessels. Blood gases measurements demonstrated a left-right shunt. The acquired nature of the fistula was suspected because of the history of right pleurectomy and the acquired nature of the murmur. There was no indication for surgery because of the complexity of the fistula and the absence of symptoms.