The effects of ALDH2 Glu487Lys polymorphism on vasovagal syncope patients undergoing head-up tilt test supplemented with sublingual nitroglycerin.

BACKGROUND AND OBJECTIVE: Head-up tilt test (HUTT) is clinically advantageous for diagnosing patients with vasovagal syncope (VVS). Nitroglycerin is mainly used as a stimulant during HUTT, and mitochondrial aldehyde dehydrogenase 2 (ALDH2) is involved in the metabolism of nitroglycerin (NTG). ALDH2 Glu487Lys polymorphism (ALDH2 rs671) is the most common variant in the East Asian population. This study aimed to assess the effects of ALDH2 rs671 on VVS patients undergoing HUTT supplemented with sublingual NTG (HUTT-NTG).  METHODS: Patients with recurrent VVS (at least 2 times) who were admitted to the syncope center of our hospital were enrolled. All VVS patients have undergone HUTT. The polymorphism of Glu487Lys gene of ALDH2 was measured by the DNA Microarray Chip Method. The results of HUTT-NTG of VVS patients with different ALDH2 genotypes were compared and their hemodynamic characteristics were assessed. RESULTS: A total of 199 VVS patients were enrolled, including 101 patients in the ALDH2*1/*1 group and 98 patients in the ALDH2*2 group. Among patients undergoing HUTT-NTG, 70.3% of patients in the ALDH2*1/*1 group and 68.4% of patients in the ALDH2*2 group were positive, and the difference between the two groups was not statistically significant (P = 0.77). The proportions of VASIS I, VASIS II, and VASIS III were 40.6%, 8.9%, and 20.8% in the ALDH2*1/*1 group, respectively, and the corresponding proportions in the ALDH2*2 group were 36.7%, 11.2%, and 20.4%, respectively. There was no statistically significant difference between the two groups (P = 0.91). The hemodynamic characteristics of different genotypes in VVS patients undergoing HUTT-NTG were compared, and no statistically significant difference was found. The median time of syncopal episode occurred after NTG administration in the ALDH2*1/*1 group was 6 min (interquartile range [IQR]: 5.0-9.0), and it was 6.0 min in the ALDH2*2 group (IQR: 4.25-8.0, P = 0.64). CONCLUSION: ALDH2 Glu487Lys polymorphism did not affect the outcome of VVS patients undergoing HUTT-NTG, and no significant change in the hemodynamic characteristics of different genotypes was found.

Iloprost for pulmonary vasodilator testing in idiopathic pulmonary arterial hypertension.

The aim of this study was to confirm the utility of aerosolised iloprost for identifying long-term responders to calcium channel blockers (CCBs) in patients with idiopathic pulmonary arterial hypertension (IPAH). While undergoing right heart catheterisation, 74 patients with IPAH sequentially received incremental infusions of adenosine and aerosolised iloprost. The effects of the two vasodilators on haemodynamic parameters were recorded. All acute responders identified by aerosolised iloprost were subsequently treated with high doses of a CCB and were re-evaluated after 12 months. Both adenosine and iloprost produced significant decreases in mean pulmonary arterial pressure and pulmonary vascular resistance, and significant increases in cardiac index. Adverse effects were experienced by 35 out of the 74 patients with adenosine, but by only two with iloprost. Aerosolised iloprost identified more acute responders than infused adenosine (10 versus eight, respectively) according to the criteria recommended in recent consensus guidelines. Nine responders identified by iloprost were followed-up after 12 months of high-dose CCB therapy. Five had normal or near-normal haemodynamics and a World Health Organization functional classification of I or II after 12 months. Aerosolised iloprost is an appropriate new agent to identify long-term responders to CCBs in patients with IPAH. It is as effective in this regard as infused adenosine but is better tolerated.

VIP gene variants related to idiopathic pulmonary arterial hypertension in Chinese population.

A variety of studies has linked vasoactive intestinal peptide (VIP) to idiopathic pulmonary arterial hypertension (IPAH). In this study, we investigated the correlation between VIP gene variants and IPAH in Chinese population. A total of 81 consecutive unrelated patients diagnosed as IPAH from 2006 to 2008 and 250 controls were included in the study. VIP gene variants were screened by direct sequencing, and VIP serum level was determined by enzyme-linked immunosorbent assay. Clinical and hemodynamic data of all patients were also obtained. The variant g.8129T-->C in exon 7 was found to be the only variant in the coding region of VIP gene with a significantly higher frequency in patients (40.7%) than in control samples (15.2%). Moreover, there was marked difference in VIP serum level and hemodynamic data between IPAH patients with and without the variant. The variant g.8129T-->C in exon 7 of VIP gene was correlated with the clinical phenotype of lower VIP serum level, higher mean pulmonary artery pressure and pulmonary vascular resistance in patients with IPAH comparing to those in patients without this variant. The VIP gene variant g.8129T-->C may be one of the risk factors in the pathogenesis of IPAH.

[Comparative study of transesophageal atrial pacing and intracardiac electrophysiology in patients with supraventricular tachycardia].

The diagnostic value of transesophageal atrial pacing in supraventricular tachycardia (SVT) has been discussed according to the comparison of the results of intracardiac and transesophageal electrophysiological study. Some quantitative criteria for the differential diagnosis of atrioventricular node reentrant tachycardia (RT-AVN) and atrioventricular reciprocating tachycardia (RT-AP) has been proposed. We found that RT-AVN and RT-AP could be separated by noninvasive transesophageal atrial pacing. We also suggested that induced SVT would be RT-AVN if (1) SR conductive curve was not continuous and SR jump greater than 70 ms, (2) AV interval less than 60 ms, and it would be RT-AP if (1) SR curve was continuous and there was no SR jump phenomenon, (2) VA interval greater than 100 ms. Thus, transesophageal atrial pacing was very helpful in distinguishing the mechanisms of SVT and could provide a simple clinical cardiac electrophysiological procedure in diagnosing SVTs.

Vardenafil treatment for patients with pulmonary arterial hypertension: a multicentre, open-label study.

BACKGROUND: Vardenafil is a new phosphodiesterase-5 inhibitor that has shown some efficacy in the treatment of pulmonary arterial hypertension (PAH). OBJECTIVE: To examine the long-term effects of vardenafil in patients with PAH. METHODS: A multicentre, open-label study of 1-year's duration was undertaken in 45 patients with PAH to determine the long-term safety and efficacy of vardenafil (5 mg once daily for the first 4 weeks, then 5 mg twice daily) and make a preliminary assessment of its monthly acquisition cost compared with other PAH-active treatments. The patients' clinical features, exercise capacity, WHO functional class and haemodynamic variables were measured at baseline and at 3 and at least 9 months after initiating vardenafil treatment. RESULTS: At the 3 months and a mean (SD) of 14 (3) months (range 9-18) follow-up assessments, the 6 min walking distance was significantly increased from baseline by 70.7 (78.4) m (p<0.001) and 83.4 (91.8) m (p<0.001), respectively. Furthermore, long-term treatment with vardenafil for a mean duration of >1 year was also associated with improvements in haemodynamic parameters, WHO functional class and serum uric acid concentrations. Overall, vardenafil treatment was well tolerated. No patients were withdrawn owing to adverse events and none died during the course of the study. CONCLUSION: Long-term treatment with vardenafil is well tolerated and has sustained beneficial effects on PAH, as measured by patients' exercise capacity, WHO functional class and haemodynamic parameters.

[Three AV-nodal pathways in a patient with atypical AV-nodal reentry tachycardia]. / Drei AV-Knoten-Bahnen bei einer Patientin mit atypischer AV-Knoten-Reentry-Tachykardie.

In a female patient with paroxysmal AV nodal reentrant tachycardias the electrophysiological study revealed three AV nodal pathways. During atrial extrastimulation a sudden AH interval prolongation of more than 50 ms ("break" phenomenon) was observed twice at one basic cycle length. During ventricular extrastimulation a sudden prolongation of the AH interval of the anterograde AV nodal conduction of the induced echo beats was recorded. Three AV nodal pathways were thus present. The atypical form of AV nodal reentrant tachycardia was induced, showing a varying cycle length (290-340 ms). After radiofrequency catheter ablation of the fast conducting beta-pathway, another tachycardia was initiated, now showing a constant cycle length, using the two remaining, more slowly conducting alpha-pathways. One of these was eliminated in another ablation procedure.