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Biomedical subjects

M Michaelsson

Publications and source records attributed to M Michaelsson.

12 recordsLinked to original sources
PubMed2003

Proposal for a new definition of congenital complete atrioventricular block.

The classic old definition of congenital heart block by Yater (1929) is still generally accepted: 'Heart block established in a young patient. There must be some evidence of the existence of the slow pulse at a fairly early age and absence of a history of any infection which might cause the condition after birth: notably diphtheria, rheumatic fever, chorea and congenital syphilis'. However, other definitions are used. We systematically reviewed 1825 cases from 38 separate studies. We conclude that complete AV blocks detected in utero in the absence of structural abnormalities differ from blocks detected later in life with respect to pathogenesis (they are generally associated with maternal anti-Ro/SSA antibodies), poorer childhood prognosis, increased risk of developing late-onset dilated cardiomyopathy, different maternal clinical features and increased risk of recurrence in future pregnancies. For these reasons we propose a new modern definition of congenital complete AV block which might be acceptable to cardiologists, rheumatologists, pediatricians and obstetricians: 'an AV block is defined as congenital if it is diagnosed in utero, at birth or within the neonatal period (0-27 days after birth)'.

Autoantibodies↗
PubMed1997

Natural history of congenital complete atrioventricular block.

An update of studies on the natural history of congenital complete AV block is presented. A risk for heart failure, syncope, and sudden death is present at any age including fetal life. Unfavorable prognostic signs in utero are low and decreasing ventricular rate (VR), hydrops, AV valve regurgitation, and low aortic flow velocity. Indications for pacing in infancy are congestive heart failure, ventricular rate < 55 beats/min in isolated block and < 65 beats/min with associated disease, prolonged OTc, syncope attacks, frequent ventricular ectopic beats, and alternating ventricular pacemakers. Indications for immediate pacing in childhood and adult life are syncope, presyncope, VR rates lower than median for age, periods of junctional exit block, prolongation of QTc and mitral regurgitation, and change of ventricular pacemaker. Pacing is recommended to all patients older than 15 years.

Adolescent↗
PubMed1990

Friedreich's ataxia in 13 children: presentation and evolution with neurophysiologic, electrocardiographic, and echocardiographic features.

Thirteen children with Friedreich's ataxia were reviewed. The clinical presentation and evolution of the disease was compared to that observed in large series--based mainly on adult patients--and the few studies in children. The mean age of onset (5.3 +/- 2.7 years) was lower than that reported in the former studies. Progressive unremitting ataxia of all four limbs was the earliest and most consistent finding, whereas dysarthria and loss of joint or vibration sense occurred with less frequency than that reported in adult series. The tendon jerks were absent or reduced in the lower limbs in almost all children. The universal absence of lower limb reflexes was shown to be too rigid to be obligatory for the diagnosis of early cases of Friedreich's ataxia. Electrophysiologic investigations revealed typical findings, ie, normal or low-normal motor conduction velocities and absent sensory responses. Electromyography showed more features of denervation in the lower limbs than in the upper limbs. Cardiac symptoms and signs were minimal, whereas electrocardiographic abnormalities occurred in 92% of patients, presenting mostly as significant T-wave changes. Concentric symmetric thickening of both the interventricular and left ventricular posterior walls was the major echocardiographic finding.

Adolescent↗
PubMed1987

The internal mammary artery as subclavian artery substitute in repair of coarctation of the aorta with subclavian flap technique.

In three children, aged 11, 11 and 13 years, long isthmic tubular hypoplasia of the aorta technically precluded resection and end-to-end anastomosis. The coarctation was instead corrected by means of a subclavian flap. Anastomosis between the distal end of the left internal mammary artery and the descending aorta permitted perfusion of the remaining portion of the subclavian artery. At invasive reexamination 6 months after surgery, there was adequate functional and anatomic relief of coarctation in all three children. The three mammary artery-aorta anastomoses were patent, which probably prevented the potential ischemia of the left arm after ligation of the subclavian artery.

Adolescent↗
PubMed1986

Cuff pressures and Doppler gradients after coarctectomy. A long-term follow-up.

Fourty-six adult patients operated on as children with resection and end to end anastomosis because of coarctation of the aorta were studied. The age at operation was 7 to 13 years (mean age 10 years) and at follow-up 18 to 28 years (mean age 21 years). Arm and thigh cuff pressure was measured at rest, during and immediately after submaximal exercise. The systolic gradients were also estimated using continuous wave Doppler. Systolic blood pressure at rest was 150 mmHg or more in 12 patients (26%). The cuff pressure at rest correlated well with arm-leg gradients at rest and at work, and also with the Doppler gradients at rest. Doppler gradients slightly underestimated invasively measured gradients. The results imply that postoperative hypertension was explained by residual mechanical obstruction.

Adolescent↗