Novel Z Scores to Correct Biases Due to Ventricular Volume Indexing to Body Surface Area in Adolescents and Young Adults

BackgroundReference values for cardiac magnetic resonance imaging (cMRI) in children and young adults are scarce. This leads to risk stratification of patients with congenital heart diseases being based on volumes indexed to body surface area (BSA). We aimed to produce cMRI Z score equations for ventricular volumes in children and young adults and to test whether indexing to BSA resulted in an incorrect assessment of ventricular dilation according to sex, body composition, and growth.MethodsWe retrospectively included 372 subjects aged < 26 years with either normal hearts or conditions with no impact on ventricular volumes (reference group), and 205 subjects with repaired tetralogy of Fallot (TOF) aged < 26 years. We generated Z score equations by means of multivariable regression modelling. Right ventricular dilation was assessed with the use of Z scores and compared with indexing to BSA in TOF subjects.ResultsVentricular volume Z scores were independent from age, sex, and anthropometric measurements, although volumes indexed to BSA showed significant residual association with sex and body size. In TOF subjects, indexing overestimated dilation in growing children and underestimated dilation in female compared with male subjects, and in overweight compared with lean subjects.ConclusionsIndexed ventricular volumes measured with cMRI did not completely adjust for body size and resulted in a differential error in the assessment of ventricular dilation according to sex and body size. Our proposed Z score equations solved this problem. Future studies should evaluate if ventricular volumes expressed as Z scores have a better prognostic value than volumes indexed to BSA.     

RFLPs of the phenylalanine hydroxylase gene in the Italian population

Summary Different mutations of the phenylalanine hydroxylase (PAH) gene leading to phenylketonuria (PKU) have been described associated with specific haplotypes in several European countries. In order to investigate the distribution of DNA haplotypes in Italy, restriction fragment length polymorphism (RFLP) analysis of the PAH gene was performed in nine Italian PKU patients from eight unrelated families, and in the available relatives. The analysis of eight polymorphic sites revealed haplotypes 1 and 6 in association with PKU. This pattern appears to differ from those reported for other European populations.The majority of the 14 PKU subjects studied showed compound heterozygosity for different haplotypes, as observed for other European series.RFLP analysis at the PAH locus allowed us to offer the possibility of prenatal diagnosis to six of the studied families. One prenatal diagnosis was performed and a normal fetus was diagnosed.     

Hemothorax and hemomediastinum in patients with hemophilia

Three patients with hemophilia presented with hemothoraces which resolved within 1-3 weeks following treatment with factor concentrates. Drainage of blood was not necessary. Eight previously reported cases are reviewed, and therapy and complications are summarized. We suggest that treatment of this rare complication of hemophilia with factor concentrates and avoidance of surgical intervention is indicated.     

Assessment of patient performance of the HandiHaler compared with the metered dose inhaler four weeks after instruction

The HandiHaler is a novel breath-actuated dry powder system designed for the delivery of tiotropium 18microg daily in the treatment of COPD. We compared patient ability to use the HandiHaler or metered dose inhaler (MDI) device correctly 4 weeks after receiving brief instructions and device demonstration. A single-blind study was conducted in COPD patients in two centers in Denmark. ALL patients (n = 151) received one placebo capsule via the HandiHaler daily and ipratropium (20 microg) two actuations via the MDI q.i.d. Mean FEV1 for all patients was 1.25 + 0.54 (46% predicted). Twelve instructions establishing proper device use were evaluated for the MDI and Handihaler. Error scores were analyzed by number of patients with less, equal or more errors when using HandiHaler compared to MDI in the total efficacy population (n = 139) and according to those who had not previously used an MDI for at least 12 months (MDI beginners) (n = 74) and those who had used an MDI (MDI experienced) (n = 65). Four weeks after device instruction, a higher proportion of patients in the total population (P < 0.01) had fewer errors with the HandiHaler (35.3%) compared to the MDI (15.1%). The number of errors was equal in 50% of patients. Similar findings were observed in the subgroup of patients who were MDI beginners (42% vs. 11%, P < 0.01) with non-significant trends in favor of the HandiHaler in those patients who were MDI experienced (29.7% vs. 18.9%, P = 0.096). Similar results in favor of HandiHaler were noted across different age and sex strata. The proportion of patients correctly using the device on the first of three attempts was 59.7% and 54.7% for the HandiHaler and MDI, respectively (P = 0.399). In summary, use of the HandiHaler can be easily taught with fewer errors compared to the MDI. Furthermore, patient performance using the HandiHaler was superior to that with an MDI despite prior MDI experience and more frequent usage.     

Pulmonary function and bronchial reactivity in asthmatics during low-level formaldehyde exposure

This study evaluated whether formaldehyde, at concentrations similar to those found in the indoor environment, could produce adverse effects on the lower airway of 15 asthmatic persons with documented bronchial hyperresponsiveness who were exposed for 90 min in a climate chamber to clean air containing formaldehyde vapor at levels of 0.85 mg/m3, 0.12 mg/m3, and 0.008 mg/m3. No significant changes in forced expiratory volume in 1 sec (FEV1), airway resistance (Raw), specific airway resistance (SRaw), and flow-volume curves could be detected during formaldehyde exposure. Furthermore, histamine challenge tests performed immediately after formaldehyde exposure showed no evidence of changes in bronchial reactivity. No late reactions were registered during the first 14-16 hr after exposure. The results suggest that residential levels of formaldehyde are of minor importance in the emergence of pulmonary symptoms. Discrepancies between the present study and previous data may be due to differences in environmental conditions.