[Acute intravascular hemolysis after complete occlusion of a patent ductus arteriosus by detachable coils]

A case of acute intravascular haemolysis after complete occlusion of a patent ductus arteriosus by detachable coils in a 10 months old child is reported. The child had a patent ductus arteriosus, a small secundum atrial defect, mild valvular pulmonary stenosis, and stenosis of branches of the pulmonary artery not diagnosed before closure of the ductus. Haemolysis developed several hours after complete occlusion of the ductus by two detachable coils. The mechanism of the haemolysis was thought to be the presence of metallic spirals in the left pulmonary artery, just beyond stenosis situated at the origin of this artery. Simple balloon dilatation of the left pulmonary artery stenosis resulted in the complete regression of haemolysis.

Global left ventricular cardiac function: comparison between magnetic resonance imaging, radionuclide angiography, and contrast angiography

RATIONALE AND OBJECTIVES

Cardiac magnetic resonance imaging (MRI) has been shown to be a robust and noninvasive method to assess left ventricular (LV) cardiac function. This study sought to assess volumes and mass calculated with MRI using fast techniques for acquisition and postprocessing, and to compare results in terms of cost-effectiveness with those of radionuclide angiography (RNA) or contrast angiography (CA).

METHODS

Thirty-five patients and 15 healthy volunteers were studied. All patients underwent an MRI examination during the same period that they underwent ventriculography (26 patients) or radiography (25 patients). From 7 to 11 short-axis slices were acquired with a breath-hold fast-gradient echo-segmented sequence from apex to base. Contours were drawn with an automated border detection software.

RESULTS

Ejection fraction (EF) correlated well between modalities (r = 0.77, P<0.001, for MRI and RNA; r = 0.72, P< 0.001, for MRI and CA).

CONCLUSIONS

Cardiac MRI is a fast and accurate technique for estimation of LV volumes, EF, and mass.

Optimal right ventricular pacing site in chronically implanted patients: a prospective randomized crossover comparison of apical and outflow tract pacing

OBJECTIVES

To evaluate the long-term functional and hemodynamic effects of right ventricular outflow tract (RVOT) pacing by comparison with right ventricular apical (RVA) pacing.

BACKGROUND

Acute studies have suggested that RVOT pacing could significantly improve cardiac performance in comparison with RVA pacing but no data are available in chronically implanted patients.

METHODS

Sixteen patients with chronic atrial tachyarrhythmia and complete AV block were included. Left ventricular ejection fraction (LVEF) was > or =40% in ten and <40% in six. Patients were implanted with a standard DDDR pacemaker connected to two ventricular leads. A screw-in lead was placed at the RVOT and connected to the atrial port. A second lead was positioned at the RVA and connected to the ventricular port. Right ventricular outflow tract and RVA pacing was achieved by programming either the AAIR or the VVIR mode respectively. Four months later patients were randomized so as to undergo either RVOT or RVA pacing for three months according to a blind crossover protocol. Apart from the pacing mode, programming remained unchanged throughout the study. At the end of each period, NYHA class, LVEF, exercise time and maximal oxygen uptake were assessed.

RESULTS

No significant difference was observed between the two modes for all the parameters analyzed. These identical results were observed in all patients globally, in patients with LVEF > or =40% as in those with LVEF <40%.

CONCLUSIONS

Within the limits of this study, no symptomatic improvement or hemodynamic benefit was noted after three months of RVOT pacing, by comparison with RVA pacing.

Airway compression in children due to congenital heart disease: value of flexible fiberoptic bronchoscopic assessment

OBJECTIVE

To evaluate the frequency and severity of airway compression due to congenital heart disease in children and validate the use of the fiberoptic bronchoscope to assess them.

DESIGN

A retrospective study.

SETTING

A single-institutional study in a university hospital.

PARTICIPANTS

Seventy-two children with congenital heart disease.

INTERVENTIONS

Airway endoscopy was performed in an awake child in cases of clinical and/or radiologic respiratory signs or in cases of preoperative assessment of a cardiac abnormality that is known to accompany airway compression.

MEASUREMENTS AND MAIN RESULTS

Endoscopy was well tolerated; 71% of the children had endoscopic abnormalities and 50% had airway compression. The locations of these compressions are the same as those described in the literature in the cases of vascular rings and left-to-right shunts. The other endoscopic findings were laryngeal and bronchial abnormalities, tracheobronchial malacia, respiratory signs of gastroesophageal reflux, and positive bacteriologic sputum samples.

CONCLUSION

Endoscopy in an awake patient is the only way to evaluate the functional component of a compression due to malacia; the resulting collapse of the airway can cause trapping of air and secretions. Furthermore, fiberoptic bronchoscopy offers a complete examination of the airways and can help detect airway abnormalities that are potential causes of complications. Fiberoptic bronchoscopy is a suitable and well-tolerated examination that is easy to perform at the bedside of the child. This technique optimizes the preoperative assessment of children with congenital heart disease.

Explosive Deep Water Basalt in the Sumisu Backarc Rift

Eruption of 1-million-year-old tholeiitic basalt >1800 meters below sea level (>18 megapascals) in a backarc rift behind the Bonin arc produced a scoriaceous breccia similar in some respects to that formed during subaerial eruptions. Explosion of the magma is thought to have produced frothy agglutinate which welded either on the sea floor or in a submarine eruption column. The resulting 135-meter-thick pyroclastic deposit has paleomagnetic inclinations that are random at a scale of <2.5 meters. High magmatic water content, which is about 1.3 percent by weight after vesiculation, contributed to the explosivity.

[Diagnosis of chronic coronary failure by clinical aspects, ECG and myocardial scintigraphy after infusion of isoprenaline. Comparison with coronarography]

The purpose of this study was to assess the ability of isoproterenol (IPNA) to provoke chest pain, electrocardiographic (ECG) changes and transient defects on thallium 201 myocardial scintigraphy for coronary artery disease (CAD) diagnosis. Thirty patients without prior myocardial infarction who underwent coronary angiography were included. Significant stenosis was found in 15 and absent in the other 15. The most relevant clinical and ECG data were observed in the few minutes that followed IPNA perfusion: 1) angina pectoris occurred in ten patients of whom eight had CAD (sensitivity: 53 p. cent + 13 p. cent; specificity: 87 p. cent + 9 p. cent); 2) ST segment depression was observed in 11 CAD and 3 non-CAD patients (sensitivity: 73 p. cent + 11 p. cent; specificity: 30 p. cent + 10 p. cent); 3) reversible perfusion defects on planar myocardial thallium 201 scintigrams occurred in 16 patients of whom 13 had CAD. Thallium scintigraphy sensitivity was 87 p. cent + 9 p. cent and specificity was 80 p. cent + 10 p. cent. The combined interpretation and stochastic sequential analysis of two or three presumed independent criteria increased significantly the diagnostic value of the test. We conclude that the isoproterenol test is a safe and reliable method to provoke myocardial ischemia with clinical, ECG and myocardial scintigraphic expression. It has an information content nearly identical to exercise stress test for CAD detection. Because it allows a three step sequential probability analysis, the diagnosis is more reliable than with other pharmacological tests which apply only to scintigraphy.

[Cardiac angioscintigraphy at equilibrium coupled with isoproterenol perfusion. Method of diagnosing chronic coronary insufficiency]

The effects of isoproterenol (IPNA) on global and regional left ventricular wall motion were studied by cardiac angioscintigraphy at equilibrium performed under basal conditions, during IPNA administration (per IPNA) and 10 minutes after (post IPNA) in 50 patients classified by coronary angiography as coronary (C) (n = 37) and non-coronary (NC) patients (n = 13), 5 reference subjects (REF) and 8 non-coronary pathology. The effects were assessed from variations of global LV function and from indices of regional wall function (12 regional ejection fractions - REF). The IPNA perfusion was well tolerated, even in patients with severe coronary lesions. 1. Diagnosis of myocardial dysfunction due to coronary artery disease: it was possible to separate the patients into C and NC groups according to the variations in EF, end systolic (ESV) and REF, especially post IPNA: NC group: per IPNA: 12/13 NC patients showed an increase in EF (+10.7%), a decrease in ESV (-41%) and increased or stable REFs. Post IPNA: 10/13 had raised EF (+4.6%), 9/13 had a reduced ESV (-17.4%) and 10/13 had stable or increased REF. C group: per IPNA: 15/37 C patients showed decreased EF, 12/37 had increased ESV and 15/37 had a decrease in at least two ref greater than or equal to 5%. Post IPNA: 25/37 had decreased EF, 21/37 increased ESV, 34/37 had at least two reduced REFs. These results show that decreased ref post IPNA (sensitivity 91.9%, specificity 66.9%) was a better indicator of coronary artery disease than VEF (sensitivity 68%, specificity 54%), increased ESV (sensitivity 57%, specificity 77%) or ECG changes (sensitivity 54%, p 0.05; specificity 91%, p less than 0.1). 2. Diagnosis of the extent of coronary artery disease: the post IPNA abnormal ref were situated in zones compatible with the coronary lesions: 10/13 single vessel disease (2 false negatives, 1 false localisation); 8/11 double vessel disease (1 false negative, 2 single vessel disease); 5/10 triple vessel disease (2 single vessel and 3 double vessel disease); 2/3 left main stem disease (1 single vessel disease). The study of REF demonstrated at least 2 diseased zones in 15/24 patients with multiple diseased vessels. Independently, the diagnosis of multivessel disease may be suspected by the fall in EF per IPNA (4/13 single vessel cases compared to 11/24 multivessel disease) and, more generally, by the fact that the EF and ZSV per and post IPNA appear more pathological with respect to the reference group when the coronary lesions are most diffuse.(ABSTRACT TRUNCATED AT 400 WORDS)

[Isotopic phlebography for control of venous surgery of the lower limb]

Isotopic phlebography with microspheres containing 99 mTc aggregated human albumin is a simple and easily reproducible means of controlling the results of venous surgery of the lower limb and ilio-caval confluent. A comparison in 34 cases with the results obtained by conventional contrast phlebography showed close correlation between the two methods. However, since the images are not as sharp as with contrast phlebography, isotopic phlebography cannot be used for planning procedures prior to reconstructive venous surgery and should be reserved to post-operative control.