Postoperative assessment of the univentricular repair by dynamic radionuclide studies

Background

The purpose of this investigation was to determine the role of radionuclide studies in evaluating postoperative Fontan hemodynamics and to quantify its diagnostic accuracy.

Methods

One hundred five patients (105), aged 11 months to 35 years old, who had undergone univentricular repair, underwent first-pass and multigated acquisition scan 1 month to 10 years after univentricular repair. Forty-five patients with evidence of Fontan failure underwent radionuclide studies using Technetium-99 m as well as cardiac catheterization (group 1). The remaining sixty randomly selected patients with excellent functional status received radionuclide studies alone (group 2). The receiver operating characteristic curve analysis was done to quantify the diagnostic accuracy of the first-pass study.

Results

There was paradoxical filling of the right lung after femoral injection in all cases of tunnel or conduit obstruction. A first-pass transit time of 16 to 25 seconds (mean ± standard deviation [SD] = 18.82 ± 2.69) was always associated with Fontan failure and high right atrial pressure (range = 20 to 24 mm Hg, mean ± SD = 22.02 ± 1.58). A first-pass transit time of 16 seconds was associated with a sensitivity of 100% and a specificity of 93.33%. The predictive accuracy of a positive or negative result was 91.8% and 100% respectively. The area measured under the receiver operating characteristic curve indicates that 99.41% (SE ± 0.0035) of the time, the value of first-pass time is higher for the Fontan failure group (group 1) compared to the normal group (group 2; p = 0.000).

Conclusions

Our data indicate that Fontan circuit can be reliably evaluated for both anatomic and functional flaws by radionuclide studies; radionuclide first-pass time may be used to predict the chances of Fontan failure postoperatively as well as its presence; and in the presence of atrial fibrillation with fast ventricular rate, analysis using first-pass radionuclide may be impossible and gated equilibrium radionuclide angiocardiography may be the preferred method. Inspection of the systemic ventricular time-activity curve is of crucial importance in this regard.     

Redo mitral valve surgery-a long-term experience

BACKGROUND: Our experience with reoperative mitral valve (MV) surgery over a 27-year period is presented here. METHODS: From January 1975 to June 2002, 11,908 operations were performed for MV disease. Out of these 744 were reoperations. The mean age at primary operation was 23.6 +/- 10.1 years (range 2 to 53 years) and at reoperation was 36.0 +/- 11.0 years (range 6 to 65 years) with a mean interval of 11.5 +/- 2.5 years. Mitral valve replacement (MVR) was performed following previous closed mitral valvotomy (CMV) in 408 patients, open mitral commissurotomy (OMC) in 21 patients, and MV repair in 58 patients, MVR in 80 patients, homograft mitral valve replacement (HMVR) in 11 patients. The reasons for reoperation were mainly progression of lesions. Valve thrombosis and endocarditis were indications for reoperation following MVR. Twenty-eight patients underwent redo CMV, 53 patients underwent OMC, and 14 patients underwent MV Repair. RESULTS: Early mortality was 5.64% (n = 42). Hemorrhage and low cardiac output were the major causes. Follow-up was 124.8 +/- 30.5 months (2 to 300 months). Follow-up was 88%. There were no late deaths in the valve repair group. There were three episodes of thromboembolism in this group (0.3% per patient-year). In the valve replacement group there were six late deaths; three due to valve thrombosis, one due to infective endocarditis, and two due to anticoagulant-related hemorrhage. There were 13 episodes of thromboembolism in this group (0.6% per patient-year). CONCLUSION: Redo MV surgery is safe and can be undertaken with acceptable mortality and morbidity.     

Genetic polymorphisms in MDR1 and CYP3A4 genes in Asians and the influence of MDR1 haplotypes on cyclosporin disposition in heart transplant recipients

Intestinal cytochrome P450 3A4 (CYP3A4) and P-glycoprotein (P-gp) both play a vital role in the metabolism of oral cyclosporine (CsA). We investigated the genetic polymorphisms in CYP3A4(promoter region and exons 5, 7 and 9) and MDR1 (exons 12, 21 and 26) genes and the impact of these polymorphisms on the pharmacokinetics of oral CsA in stable heart transplant patients (n = 14). CYP3A4 polymorphisms were rare in the Asian population and transplant patients. Haplotype analysis revealed 12 haplotypes in the Chinese, eight in the Malays and 10 in the Indians. T-T-T was the most common haplotype in all ethnic groups. The frequency of the homozygous mutant genotype at all three loci (TT-TT-TT) was highest in the Indians (31%) compared to 19% and 15% in the Chinese and Malays, respectively. In heart transplant patients, CsA exposure (AUC(0-4 h), AUC(0-12 h) and C(max)) was high in patients with the T-T-T haplotypes compared to those with C-G-C haplotypes. These findings suggest that haplotypes rather than genotypes influence CsA disposition in transplant patients.     

CYP3A5*3 and *6 single nucleotide polymorphisms in three distinct Asian populations

OBJECTIVE: To determine the frequencies of two functional single nucleotide polymorphisms, CYP3A5*3 and CYP3A5*6, in the CYP3A5 gene in three distinct Asian ethnic groups, namely, the Chinese, Malays and Indians. METHODS: Single nucleotide polymorphism analyses of CYP3A5*1, *3 and *6 were performed in 296 healthy subjects (108 Chinese, 98 Malays and 90 Indians) using the polymerase chain reaction-restriction fragment length polymorphism method. RESULTS: The *1 allele frequency was 25% in Chinese compared with 40% in Malays and Indians ( P=0.001). The *3 allele frequency was also higher in the Chinese population, being 76% versus 60% in the Malays and Indians ( P=0.001). The Malays and Indians also had allele frequencies significantly different from Caucasian, Japanese and African-American populations (each P相似文献   

Frequency of C3435T single nucleotide MDR1 genetic polymorphism in an Asian population: phenotypic-genotypic correlates

AIMS: To investigate the frequency of the single nucleotide polymorphism C3435T in exon 26 of the MDR1 gene in Asians and to determine the functional significance of this SNP with the clinical pharmacokinetics of oral cyclosporin (Neoral) in 10 stable heart transplant patients. METHODS: The MDR1 C3435T polymorphism was investigated in 290 healthy Asian subjects (98 Chinese, 99 Malays and 93 Indians). We also compared the MDR1 polymorphism between the Asian population studied here and the published data on Africans and Caucasians. The clinical relevance of this SNP on oral bioavailability of a known P-gp substrate, cyclosporin, was assessed in 10 stable Chinese heart transplant patients. RESULTS: The homozygous TT genotype was observed in 32%, 28% and 43% of Chinese, Malays and Indians. The homozygous CC genotype was found in 25% of Chinese and Malays compared with 18% of Indians. The Indians had a lower frequency of the C allele [0.38 (0.31-0.45)] compared with the Chinese [0.46 (0.39-0.53)] and Malays [0.48 (0.42-0.55)]. Chi-squared test showed that the distribution of allele frequencies between the Malays and Indians differed significantly (P = 0.04). In this Asian population, the overall distribution of genotypes (CC, CT and TT) and allele frequencies were significantly different from those in Africans (P < 0.001). The results were also significant when the Chinese, Malays and Indians were compared separately with the African group (P < 0.001). Compared with the Caucasian data, the overall distribution of genotype and allele frequencies in the Asian population were also significantly different (P < or = 0.05). However, when each Asian ethnic group was compared separately with the Caucasians, only the Indians were found to be significantly different (P < or = 0.004). Genotypic-phenotypic correlations of this SNP were assessed in 10 stable Chinese heart transplant patients. The median AUC(0,4 h) was 11% lower in patients with CC genotype compared with subjects with TT genotype. However, the interpatient variability in AUC(0,4 h) was high in patients, especially in those with CC genotype. CONCLUSIONS: The distribution of the SNP C3435T in exon 26 in the Chinese and Malay population was found to be similar to the Caucasians whereas the Indians were different. The Asian population also differed significantly from the African and Caucasian population in the distribution of the C3435T SNP. The low frequency of the T allele in the Indian population implies lower expression of P-gp and may have important therapeutic and prognostic implications for use of P-gp dependent drugs in individuals of Indian origin.     

An epidemiological study of smoking in urban school boys of Ajmer

In a survey of 1000 school boys aged 8–16 years, 52 (5.2%) were smokers Thirty of them were regular smokers, of whom 27 took to smoking between 10–14 years of age. Only six children thought that they smoked for pleasure. None of the children, whose mothers had university or higher vocational education smoked, (P<0.01) Parental smoking also seemed to influence smoking behaviour of their children. Type of the family-nuclear or joint-did dot affect the smoking prevalence, but children occupying special position in the family smoked more frequently, (P<0.001). Most of the smokers belonged to middle or poor socio-economic group and none to upper socioeconomic group (P<0.001).     

Normal testicular volume in school children

A cross sectional study was conducted on 1000 school children between the ages of 8–16 years, to find out the normal testicular volume. At 8 years the testicular volume averaged 1.4 ml. This increased at the rate of 0.5 ml per year, till it reached 2.9 ml at the age of 11 years. A spurt in testicular growth (increment of 1.6 ml) was recorded between 11 and 12 years. This accelerated growth continued at a rate of about 2.5 ml to 4.0 ml/year, so as to attain a mean testicular volume of 15.6 ml by 16 years of age. It is suggested that a testicular size upto 2.0 ml may be considered infantile as this size correlated with prepubertal stages G1 and PH1 and an increase in the size beyond this may be regarded as the earliest evidence of puberty.     

Ultrasonic Scalpel for Hemostasis in Pacemaker‐Dependent Patients During Open‐Heart Surgery

Abstract We successfully used the ultrasonically activated scalpel to secure hemostasis in a temporary pacemaker‐dependent patient following repair of Ebstein's anomaly. The advantages of using this modality are briefly discussed. (J Card Surg 2010;25:357‐358)     

Total anomalous pulmonary venous drainage beyond childhood

We studied the anatomic characteristics and results of surgery in 27 patients with total anomalous pulmonary venous drainage who were 15 years or older between January 1997 and July 2007. Mean age was 19.7+/-11.6 years (15-48 years). The anatomic subtypes were supracardiac (n=15), cardiac (n=7), and mixed (n=5). Fourteen patients were in NYHA class II and 13 were in NYHA class III. Eleven patients had severe and the rest had moderate pulmonary arterial hypertension; six patients had significant right ventricular dysfunction. All patients underwent complete repair. A small inter-atrial communication was left open in four patients and in two patients, a fenestrated unidirectional valved patch was used to close the atrial septal defect. There were no early or late deaths. Follow-up was 3-127 months (mean 61.2+/-36.1 months). Twenty patients were in NYHA class I and seven were in class II. Echocardiography showed normal right and left ventricular function in all patients with reduction of pulmonary arterial pressures in 26 patients. One patient underwent radiofrequency ablation for new onset atrial flutter. Surgery can be safely undertaken in a few naturally selected group of patients with total anomalous pulmonary venous drainage who survive beyond childhood.