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Biomedical subjects

J Guenthard

Publications and source records attributed to J Guenthard.

8 recordsLinked to original sources
PubMed1996

Arm-leg pressure gradients on late follow-up after coarctation repair. Possible causes and implications.

Seventeen years after coarctation repair, 36 patients were studied by magnetic resonance imaging and exercise testing to measure residual anatomical stenosis and hormonal response to exercise, and to evaluate their effect on arm-leg gradients and on exercise hypertension. The systolic arm pressure, leg pressure and arm-leg gradient were measured at rest and during exercise. Active renin and catecholamines were measured in the plasma at rest and after peak exercise. On magnetic resonance imaging 18 patients had residual stenosis of less than 30% (group I) and 18 had residual stenosis of equal to or more than 30% (group II). At peak exercise, the arm pressure was 235 (133-296) mmHg in group I and 241 (157-286) mmHg in group II (ns), the leg pressure was 138 (111-173) mmHg in group I and 114 (75-154) mmHg in group II (P = 0.002). The adrenalin increase from rest to exercise was 32.7 +/- 9.1 pg.ml-1 in the patients with exercise hypertension and 3.1 +/- 4.7 pg.ml-1 in the patients who remained normotensive during exercise (P = 0.02). In conclusion, residual anatomical stenosis leads to a pressure drop in the legs, which influences the arm-leg gradient. Arm hypertension is not related to anatomical narrowing but to interaction of enhanced sympathetic nerve activity and structural and functional abnormality of the precoarctation vessels.

Adolescent↗
PubMed1995

Exercise-induced hypertension in the arms due to impaired arterial reactivity after successful coarctation resection.

Exercise-induced hypertension of the arms is a well-known late complication after coarctation repair. Residual narrowing at the anastomosis site as well as abnormalities of the precoarctation arterial system may be the cause of this problem. Blood pressure response to exercise and flow-mediated arterial dilatation of the arms and legs were studied in 29 young adults after successful coarctectomy in childhood and compared with 13 control subjects. Peak exercise systolic blood pressure was significantly higher in patients than in control subjects: 238 versus 199 mm Hg (p = 0.007). Both groups had a positive systolic arm-leg gradient during exercise: 59 versus 37 mm Hg (p = 0.05). Flow-mediated dilatation of the brachial artery was significantly reduced in patients compared with that in control subjects: 4.2% (range 0% to 9.4%) versus 9.4% (range 3.7% to 16%) (p < 0.0001). Flow-mediated dilatation of the femoral artery was similar in both groups. Dilatation of the brachial artery was inversely correlated to peak exercise systolic pressure in the study patients (r = -0.427, p = 0.02). A positive arm-leg exercise gradient partly represents physiologic circulatory adaptation to ergometry and is therefore not appropriate for evaluation of residual narrowing. Exercise-induced hypertension of the arms late after coarctation repair is caused by impaired arterial reactivity, which results from structural or functional abnormality, or both.

Adolescent↗
PubMed1995

Cardiomyopathy in respiratory chain disorders.

Disorders of mitochondrial oxidative phosphorylation may disturb cardiac energy metabolism and cause cardiomyopathy. Twenty one cases from the literature and one further patient with cardiomyopathy due to biochemically defined respiratory chain defects were reviewed for clinical course, morphology, and pathophysiological mechanisms of the cardiomyopathy. All cases showed concentric hypertrophy of the myocardium without an outflow tract obstruction. In most patients the cardiomyopathy was diagnosed early in infancy and showed rapid deterioration with death before the age of 2 years. Hypertrophy of the myocardium appears to result from swelling of the cardiomyocytes caused by accumulation of mitochondria and by morphologically abnormal megamitochondria.

Cardiomyopathy, Hypertrophic↗
PubMed1994

Possible genes for left heart formation on 11q23.3.

A case of balanced translocation t (10; 11) (q 24; q 23) is presented. This female newborn showed no other malformation than hypoplastic left heart syndrome. According to several cases of 11q- and hypoplastic left heart in the literature and to this observation the authors postulate genes for left heart formation on chromosome 11q23.3.

Adult↗
PubMed1990

Hepatic venous connection to a persistent inferior caval vein in left isomerism.

In 22 cases of left atrial isomerism studied at the Brompton Hospital, four cases were found to have an unusual arrangement of the abdominal vessels. There was persistence of an inferior caval vein, partially anomalous hepatic venous connection and additional continuation of part of the venous return from the lower body through the azygos venous system. This venous pattern had surgical implications in our index case, since redirection of the inferior caval venous return was necessary.

Female↗
PubMedDate not supplied

Complete atrioventricular septal defect and Ebstein anomaly.

The newborn reported here presented with congestive heart failure and cyanosis on the first day of life. Echocardiographic examination revealed complete atrioventricular septal defect and Ebstein anomaly, a rare combination that has not been previously reported in the literature.

Ebstein Anomaly↗
PubMedDate not supplied

Doppler echocardiography during exercise to predict residual narrowing of the aorta after coarctation resection.

Blood pressure measurements and Doppler echocardiography at rest and during exercise were performed in 36 patients at an average 17 years after coarctation resection. Interest focused on the study of Doppler systolic and diastolic gradients and half-times during exercise. Blood pressure gradients and Doppler values were compared with the degree of narrowing at the site of the anastomosis measured by magnetic resonance imaging. A systolic half-time of >110 ms together with a diastolic gradient of >/=17 mmHg on exercise Doppler sonography predicted a residual isthmic narrowing of >30%. We propose the use of this noninvasive method for identifying patients with narrowing of >30% at the site of the anastomosis after coarctation resection. In these cases evaluation by an imaging technique is necessary to confirm the need for surgery.

Adolescent↗