Efficacy of ulipristal acetate for emergency contraception and its effect on the subsequent bleeding pattern when administered before or after ovulation.

STUDY QUESTION: Does ulipristal acetate (UPA) have similar efficacy as emergency contraception (EC) when administered before and after ovulation? SUMMARY ANSWER: The efficacy of UPA-EC was significantly better when administered before than after ovulation. WHAT IS KNOWN ALREADY: Levonorgestrel (LNG) is effective as EC only when administered before, but not after ovulation. LNG EC taken in the pre-ovulatory and post-ovulatory phase results in shortening and lengthening of the index menstrual cycle, respectively. Whether the same applies to UPA is not known. STUDY DESIGN, SIZE, DURATION: Prospective, open-label clinical cohort study conducted on 700 women between May 2011 and March 2014. PARTICIPANTS, SETTING, METHODS: Seven hundred women requesting EC within 120 h after a single act of unprotected sexual intercourse in the index menstrual cycle were recruited at a community family planning clinic in Hong Kong. Each subject received a single oral dose of UPA 30 mg, and 693 of them completed follow-up. Ovulatory status at the time of UPA administration was determined by serum progesterone level supplemented by menstrual history and ultrasound tracking. The main outcome measure was the percentage of pregnancies prevented (PPP). MAIN RESULTS AND THE ROLE OF CHANCE: The PPP was significantly higher in subjects who were pre-ovulatory (77.6%) compared with those who were post-ovulatory (36.4%) at the time of UPA administration (P < 0.0001). The observed pregnancy rate following UPA administration was significantly lower than the expected pregnancy rate only in the pre-ovulatory group (P < 0.0001), but not the post-ovulatory group (P = 0.281). The overall failure rate was 1.7% (1.4 versus 2.1% in the pre- and post-ovulatory groups, respectively). Pre-ovulatory administration of UPA resulted in a small delay (median of 3 days), whereas post-ovulatory administration resulted in a minimal advancement (median of 1 day) of the next menstruation, compared with that predicted from previous menstrual pattern. More pre-ovulatory subjects (19.1%) than post-ovulatory subjects (7.8%) had deviation of the next menses of more than 7 days (P < 0.001). LIMITATIONS, REASONS FOR CAUTION: The ovulatory status of the subjects was determined based only on menstrual history and a spot sonographic finding together with serum hormonal profile at the time of recruitment. WIDER IMPLICATIONS OF THE FINDINGS: Our findings confirmed comparable efficacy of UPA in the Asian population as in western populations. The comparison between pre- and post-ovulatory use of UPA is a novel finding, which provides insights to its possible pharmacological action. STUDY FUNDING/COMPETING INTERESTS: The UPA tablets were provided free of charge by Laboratoire HRA Pharma, who were not involved in the design and execution of the study, or the drafting and final approval of the manuscript. The authors have no other conflicts of interest to declare. TRIAL REGISTRATION NUMBER: The University of Hong Kong Clinical Trials Registry (reference number: HKUCTR-1197).

Ultrasound-guided thrombin injection for pseudoaneurysms: a case series at a local hospital.

Post-catheterization pseudoaneurysms are increasingly prevalent due to widespread use of endovascular procedures. Ultrasound-guided thrombin injection has emerged as a treatment of choice for these pseudoaneurysms. We review our experience performing this procedure for a series of cases from 2007 to 2010 with different clinical manifestations at a single hospital in Hong Kong. We achieved a high technical success rate with no complications.

The Changing Landscape for the Treatment of Painful Spinal Metastases: is Stereotactic Body Radiation Therapy the New Standard of Care?

Due to advancements in systemic targeted and immunotherapies resulting in improved disease control and overall survival, and the increasing use of computed tomography and spine magnetic resonance imaging surveillance, the number of patients presenting with both asymptomatic and symptomatic spinal metastases is increasing. The need for versatile tumour ablative local management strategies, beyond the limits afforded by conventional palliative external beam radiation therapy (cEBRT), is increasingly more important. Stereotactic body radiation therapy (SBRT) was developed to meet such a need. This highly conformal technique allows the delivery of high biologically effective doses of radiation to the vertebral target, while controlling the differential dose exposure to the adjacent critical neural tissue. Identifying patients with painful spine metastases who would gain the most benefit from this important therapeutic option can be challenging. Here we summarise the randomised evidence specific to spine SBRT, comparing cEBRT with SBRT for pain control in patients with spine metastases in the palliative setting to better understand the role of spine SBRT in modern oncological spinal care.

Survey of current practices from an international task force for gynecological stereotactic ablative radiotherapy.

BACKGROUND: Stereotactic Ablative Radiotherapy (SABR) is an effective treatment that improves local control for many tumours. However, the role of SABR in gynecological cancers (GYN) has not been well-established. We hypothesize that there exists considerable variation in GYN-SABR practice and technique. The goal of this study is to describe clinical and technical factors in utilization of GYN-SABR among 11 experienced radiation oncologists. MATERIALS AND METHODS: A 63 question survey on GYN-SABR was sent to 11 radiation oncologists (5 countries) who have published original research, conducted trials or have an established program at their institutions. Responses were combined and analyzed at a central institution. RESULTS: Most respondents indicated that salvage therapy (non-irradiated or re-irradiated field) for nodal (81%) and primary recurrent disease (91%) could be considered standard options for SABR in the setting of inability to administer brachytherapy. All other indications should be considered on clinical trials. Most would not offer SABR as a boost in primary treatment off-trial without absolute contraindications to brachytherapy. Multi-modality imaging is often (91%) used for planning including PET, CT contrast and MRI. There is a wide variation for OAR tolerances however small bowel is considered the dose-limiting structure for most experts (91%). Fractionation schedules range from 3 to 6 fractions for nodal/primary definitive and boost SABR. CONCLUSIONS: Although SABR has become increasingly standard in other oncology disease sites, there remains a wide variation in both clinical and technical factors when treating GYN cancers. Nodal and recurrent disease is considered a potential indication for SABR whereas other indications should be offered on clinical trials. This study summarizes SABR practices among GYN radiation oncologists while further studies are needed to establish consensus guidelines for GYN-SABR treatment.

Acceptability of human papillomavirus vaccination among Chinese women: concerns and implications.

OBJECTIVE: To explore Chinese women's perceptions of human papillomavirus (HPV) vaccination and their intention to be vaccinated. DESIGN: A cross-sectional community-based survey study. SETTING: Thirteen community women's health centres of The Family Planning Association of Hong Kong. SAMPLE: A total of 1450 ethnic Chinese women aged 18 or above who attended the health centres. METHODS: Participants completed a written consent and an anonymous questionnaire onsite. MAIN OUTCOME MEASURES: Knowledge and beliefs about HPV and HPV vaccination against cervical cancer and participants' own intention to be vaccinated. RESULTS: About 38% of the participants (n = 527) had heard of HPV and 50% (n = 697) had heard of vaccination against cervical cancer. HPV infection was perceived to be stigmatising and detrimental to intimate, family and social relationships. Despite misconceptions and a grossly inadequate knowledge about HPV and HPV vaccination, 88% of the participants (n = 1219) indicated that they would likely be vaccinated. Majority of the participants believed that sexually experienced women should be vaccinated, while 27% opposed vaccinating sexually naive women. Younger age women who perceived a disruptive impact of HPV infection on intimate relationship and their partners' approval were significantly associated with a positive intention to be HPV vaccinated. CONCLUSIONS: The easy acceptability of HPV vaccination among the mostly sexually experienced Chinese participants and their knowledge deficit on the subject may implicate potential misuse of the vaccines and a false sense of security against cervical cancer. There is a dire need for culturally sensitive and tailored education for the public, women of different ages and their partners about HPV and HPV vaccination. Emphasis must be placed on the prophylactic nature of the current vaccines, the uncertain effects when given to sexually experienced women, the importance of adolescent vaccination and the need for continued cervical screening whether vaccinated or not.

Arachnoiditis ossificans.

Arachnoiditis ossificans is a rare type of chronic arachnoiditis characterised by the presence of calcification or ossification of the spinal arachnoid. There are a few reports of this condition in Japanese and western populations but no case has been reported in a Chinese population before. We describe a 35-year-old woman with typical findings of arachnoiditis ossificans. A brief review of the literature is also presented.

Outcome of distal gastric cancer with pyloric stenosis after curative resection.

AIMS: Pyloric stenosis usually presents with symptoms, and this may lead patients to consult their physician. We evaluate whether distal gastric cancer patients with pyloric stenosis had a better outcome than those without. METHODS: A total of 551 distal gastric cancer patients who received curative subtotal gastrectomy between January 1988 and December 2003 at Taipei Veterans General Hospital were analyzed. Among them, 174 patients were sorted into the pyloric stenosis group according to obstructive symptoms. Their clinicopathological features, survival and prognostic factors were evaluated. RESULTS: The 5-year overall and disease-free survival rate of distal third gastric adenocarcinoma for the pyloric stenosis group was significantly lower than those without pyloric stenosis. Multivariate analysis revealed the pyloric stenosis group had deeper cancer invasion (relative to pT1, RR of pT2 3.1, p=0.009; pT3 6.1, p<0.001; pT4 16.5, p<0.001), and more lymph node metastasis (RR 3.6; p=0.001). The pyloric stenosis group had a tendency to lymph node metastasis toward the hepatoduodenal ligament, but this did not reach statistical difference. However, the pyloric stenosis group had significantly higher lymph node metastasis in the retropancreatic region (5.17% vs. 0.53%; p=0.001). CONCLUSIONS: Distal gastric cancers with pyloric stenosis have worse biological behavior than those without, and consequently have a poor outcome.

Increased expression of T-cell markers of immunological memory associated with protection from type I diabetes. A study of identical twins.

Disturbances in the balance of CD4+ helper T-lymphocytes expressing the surface molecules CD45RA and CD45R0, which define naive and memory populations, respectively, are present at diagnosis of type I diabetes. In a prospective study over 10 years, these subsets were analyzed in samples obtained from 18 identical twins of patients with type I diabetes, 8 of whom became diabetic (prediabetic twins), whereas the rest remained nondiabetic after at least 8 years follow-up and are now unlikely to develop the disease (diabetes-protected twins). At the beginning of the study, percentage levels of naive (CD45RA+) CD4+ lymphocytes were significantly elevated in prediabetic twins compared with diabetes-protected twins (P < 0.05) and remained so throughout the study (P < 0.01). Percentage levels of naive cells in diabetes-protected twins were significantly reduced compared with control subjects both at the beginning and throughout the study (P < 0.05, P < 0.01, respectively). In contrast, diabetes-protected twins at the beginning of the study had elevated percentage levels of memory (CD45R0+) CD4+ lymphocytes that persisted throughout the study compared with prediabetic twins (P < 0.05 for both). Percentage levels of memory cells in prediabetic twins were significantly reduced compared with control subjects both at the beginning and throughout the study (P < 0.01, P < 0.05, respectively). Increased percentage levels of a population of CD4+ lymphocytes coexpressing CD45RA and CD45R0 were seen in both twin groups compared with control subjects at entry into and during the study (P < 0.05 for all), but persisted only in the prediabetic twins.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies to GAD and tryptic fragments of islet 64K antigen as distinct markers for development of IDDM. Studies with identical twins.

Insulin-dependent diabetes mellitus (IDDM) is associated with antibodies to a 64,000-M(r) islet cell protein, at least part of which is identified as glutamic acid decarboxylase (GAD). These antibodies are detected as two distinct antibody specificities to 50,000-M(r) and 37,000/40,000-M(r) tryptic fragments of the autoantigen (50K and 37K antibodies, respectively). We determined the frequencies of antibodies to intact GAD, tryptic fragments of islet 64,000-M(r) antigen, islet cell antibodies (ICAs), and insulin autoantibodies (IAAs) in sera from 58 nondiabetic identical twins of patients with IDDM, of whom 12 subsequently developed diabetes. ICA, antibodies to intact GAD, and those to tryptic fragments were detected at similar frequencies in prediabetic twins (67-75%), but only 25% had IAA. Of 46 twins who remain nondiabetic, GAD antibodies, 50K antibodies, and ICA were detected in 6 (13%), 7 (15%), and 5 (11%), respectively, whereas only 1 (2%) possessed 37K antibodies and 2 (4%) had IAA. Eight of 9 twins with 37K antibodies and all 6 twins with ICA greater than 20 Juvenile Diabetes Foundation U have developed diabetes. Antibodies to GAD are sensitive markers for diabetes development but may also be present in genetically susceptible individuals who are unlikely to develop disease. Antibodies to 37,000/40,000-M(r) fragments of the 64,000-M(r) antigen or high-titer ICA were the best markers for diabetes development in these twins.

Stage migration influences on stage-specific survival comparison between D1 and D3 gastric cancer surgeries.

AIMS: We evaluate the influency stage migration in a randomised trial comparing D1 (N 1 lymphadenectomy) and D3 (N 1, 2 and 3 lymphadenectomy) dissections. METHODS: Two hundred and thirteen curatively resected patients were analysed, with this TNM data. RESULTS: After applying D3 patients' data according to simulated D1 staging, D3 resections were associated with up-staging to N2-3 levels in 8% of patients according to the N stage. The likelihood of N-status migration increased with increasing depth of invasion into the gastric wall. The increases in the calculated survival rate after stage migration on known 5-year survival rates were: 2% in stage IB, 1% in stage II, 4% in stage IIIA, and 1% in stage IIIB. CONCLUSIONS: Stage migration secondary to meticulous lymph node dissection affects stage-specific survival rates. True therapeutic survival benefit of D3 resection can only be assessed in this context.

Bone loss associated with long-term use of depot medroxyprogesterone acetate.

On 17 November 2004, the United States Food and Drug Administration issued a black box warning on the long-term use of depot medroxyprogesterone acetate stating that bone loss might be irreversible with use of more than 2 years. Despite the seriousness of such a safety warning, the Food and Drug Administration provided no clinical recommendations. Various professional bodies have made different recommendations on the management of women prescribing such long-term injections but there is no consensus on the best practice. Thus individual institutions need to revise service protocols. The Health Services Subcommittee of the Family Planning Association of Hong Kong has reviewed the scientific evidence from international and local studies and made its recommendations in a meeting held on 1 March 2005. This article aimed to share our opinion with other medical professionals in Hong Kong.

Information on type 1 diabetes mellitus and QT interval from identical twins.

To determine whether QT interval is influenced by genetic factors and whether QT-interval prolongation occurs in type 1 diabetes or is related to diabetic autonomic neuropathy, QT intervals were measured, and autonomic function was assessed in 44 pairs of identical twins who were discordant for type 1 diabetes. Twins were compared with 44 normal control subjects of similar age and sex. QT intervals were corrected for heart rate (QTc). QTc in diabetic twins correlated with that in their nondiabetic co-twins (r = 0.41; p = 0.006). Diabetic twins had significantly longer QTc than did their nondiabetic co-twins and control subjects (416 +/- 18 vs 407 +/- 16 and 403 +/- 19 ms, respectively; p < 0.005). A greater number of abnormal autonomic function tests were detected in diabetic twins than in their nondiabetic co-twins and control subjects (8 vs 2 and 0%, respectively; p < 0.01). Diabetic twins with disease duration > 14 years (n = 22) had longer QTc than did their nondiabetic co-twins (420 +/- 17 vs 402 +/- 14 ms; p < 0.0005). Twins with diabetes for > 14 years had a greater frequency of abnormal autonomic function tests than did those with diabetes < 14 years (15 vs 2%; p < 0.001). QTc did not correlate with autonomic function in diabetic twins. It is concluded that QT interval is influenced by genetic factors, and in type 1 diabetes, QTc can be prolonged independently of autonomic neuropathy.

Randomized trial of three types of gastrojejunostomy in unresectable periampullary cancer.

BACKGROUND: A gastrojejunostomy with duodenal partition was designed to clarify whether so-called circulus vomiting exists and, if so, its clinical significance, by comparing it with two other types of gastrojejunostomy commonly used for gastric bypass in unresectable periampullary cancer. METHODS: Forty-five patients with unresectable periampullary cancer complicated by gastric outlet obstruction (GOO) were recruited into this study between May 1992 and November 1995. They were randomized to receive one of the three types of gastrojejunostomy. The anastomosis in type I gastrojejunostomy was performed at the jejunum 20 cm distal to the ligament of Treitz. Type II was similar to type I except that in type II a duodenum partition was done by linear stapler 1 cm beyond the pylorus. Type III gastrojejunostomy was performed at the Roux-limb jejunum 60 cm distal to biliojejunostomy. RESULTS: "Food reentry" was noted in three (21%) of the type I patients, as determined by upper gastrointestinal (UGI) study. Of the three, one patient had severe circulus vomiting, one had anorexia, and one had no major symptoms. When patients were evaluated immediately after oral diet intake resumed, the incidence (27%) of clinical GOO symptoms and mean value of gastric emptying time (GET1/2, 118.1 +/- 39.2 min) were significantly lower in type II patients than in types I and III patients. When evaluated I month after operation, the incidence (7% and 17%, respectively) of clinical symptoms of GOO and mean value of GET1/2 (42.0 +/- 23.0 and 35.6 +/- 5.4 min, respectively) were significantly lower in both type II and type III patients than in type I patients. The type II patients resumed oral diet after operation 3.5 days earlier than type I patients, p < 0.05. CONCLUSIONS: Circulus vomiting induced by food reentry does exist if the gastrojejunostomy is performed as the type I gastrojejunostomy in this study. The newly designed type II gastrojejunostomy with duodenal partition is an easy, safe, and effective gastric bypass and avoids the problem of food reentry.

Structure-function studies on the bradykinin potentiating peptide from Chinese snake venom (Agkistrodon halys Pallas).

A bradykinin potentiating peptide (BPP) was purified from the Chinese snake venom (Agkistrodon halys Pallas). The amino acid sequence of this BPP was determined to be pyroGlu-Gly-Arg-Pro-Pro-Gly-Pro-Pro-Ile-Pro-Pro. Removal of the N-terminal residue with pyroglutamate aminopeptidase enhanced two-fold the activity of BPP, the resulting despyroGlu-BPP gradually lost its activity on further Edman degradation. However, around 90% of the original activity was still present in the C-terminal tripeptide Ile-Pro-Pro. Some analogs of this tripeptide were synthesized by the conventional method, and investigated by two biological assays, i.e., potentiating response on bradykinin (BK) and inhibitory activity on angiotensin converting enzyme (ACE). It was shown that the two biological activities inherent in the synthetic analogs were not parallel to each other. In addition, the isolated guinea pig ileum strips treated with chelating agent to irreversibly inactivate kininase (the same enzyme ACE) still responded to BPP. Consequently the potentiating effect of BPP on BK in vitro bioassay might be due to its influence on the binding receptor for BK rather than the inhibitory effect on kininase.

Results of curative gastrectomy for carcinoma of the distal third of the stomach.

BACKGROUND: Carcinoma of the distal stomach metastasizes to lymph nodes along the bile duct, pancreatic head, and duodenum. We reviewed the results of patients who underwent operation for carcinoma of the stomach, and placed special emphasis on survival related to lymph node metastasis. STUDY DESIGN: We conducted a prospective study of 258 consecutive patients with adenocarcinoma of the distal third of the stomach who underwent curative gastrectomies. RESULTS: Most of the patients (193 [75 percent]) had advanced cancer (extension beyond the submucosa). A subtotal gastrectomy was the procedure most commonly performed (89 percent). Combined organ resection was performed in 100 patients (39 percent). The operative morbidity was 17 percent; the most frequent complications were chylous leakage, anastomotic insufficiency, and intra-abdominal infection. Ninety-four patients (36 percent) had tumor recurrence, with local recurrence occurring in 45 patients. In 40 of the 45 cases, the local recurrence resulted from remnant lymph nodes (LNs), or soft tissues in the gastric bed. Lymph node metastases were observed in 152 patients (59 percent). Excluding five patients (2 percent) who died, the overall five-year cumulative survival rate was 53 percent. The five year survival rate was 98 percent for patients with TNM stage I disease; 68 percent for patients with stage II disease; 40 percent for patients with stage III disease; and 10 percent for patients with stage IV disease. The survival rate for patients with n0, n1, n2, and n3 disease was respectively 92 percent, 45 percent, 30 percent, and 20 percent. For patients with metastatic LNs in the hepatoduodenal ligament, the five-year survival rate was 20 percent. CONCLUSIONS: These data suggest that survival rate relates to the extent of LN metastasis. It appears that systematic lymph node dissection may have a beneficial effect. However, the efficacy of radical lymph node dissection can only be determined by prospective, randomized clinical trials with a proper study design.

Comparison of resectable and unresectable periampullary carcinomas.

Two hundred and fifty-eight patients with pathologically proved periampullary carcinomas who underwent surgical treatment between the years 1965 and 1992 were evaluated. Comparison was carried out between the resectable and unresectable groups. Carcinoma of the pancreatic head occurred in less than one-half (47 percent) of the patients, and only 23 percent were resectable. In contrast, carcinoma of the ampulla of Vater had a similar rate of occurrence, but a much higher resectable rate (86 percent). Thus, carcinoma of the pancreatic head was the minor group (19 percent) in the resectable patients we studied. The main clinical presentations and durations of symptoms before diagnosis did not differ in the resectable and unresectable groups, so it was impossible to predict the resectability by symptoms. Incidences of diabetes mellitus and diarrhea increased twofold in the unresectable group. Preoperative biopsy was difficult to perform for those with carcinoma of the pancreatic head. Comparing pancreatoduodenectomy and palliative operation, pancreatoduodenectomy resulted in a higher complication rate (43 versus 13 percent), a higher surgical mortality rate (17 versus 9 percent) and a longer hospitalization period (31 versus 20 days), but there was no statistical difference in the median survival time between the resectable and unresectable carcinomas of the pancreatic head (seven and one-half versus five months). Most of the patients (81 percent in the resectable group and 70 percent in the unresectable group) we studied died of cachexia with tumor recurrence. Although the advantage of pancreatoduodenectomy for resectable carcinoma of the pancreatic head was questioned, we still recommend this procedure for all periampullary carcinomas to avoid depriving the occasional patients with pancreatic carcinomas of long term survival and forfeiting the chance of cure for some misdiagnosed patients with other more favorable periampullary carcinomas.

Morbidity and mortality after radical gastrectomy for patients with carcinoma of the stomach.

BACKGROUND: This study sought to analyze the morbidity and mortality rates after radical gastrectomy for carcinoma, since the operation has been criticized as too morbid for the benefits it may provide. STUDY DESIGN: A prospective study of 474 patients who underwent radical gastrectomy was conducted. RESULTS: The overall morbidity and mortality rates were 20.1 and 3.0 percent, respectively. The morbidity and mortality rates fell significantly from 27.0 to 15.7 percent (p = 0.003) and 5.5 to 1.1 percent (p < 0.001), respectively, after the first 200 cases. By logistic regression analysis, it was found that male gender, combined organ(s) resection, extended lymphadenectomy, respiratory system disease, and tumor location were significantly related to postoperative morbidity. In regard to the extent of lymphadenectomy, relative to R2 resection (n = 102), the odds ratio for morbidity after R3 resection (n = 217) was 2.13, and for R4 resection (n = 155) it was 3.12. Age older than 65 years, total gastrectomy, combined organ(s) resection, and respiratory system disease were factors that negatively affected operative mortality. CONCLUSIONS: These observations suggested that radical gastrectomy can be performed with an acceptable risk of morbidity and mortality in a general hospital.

QT interval and dispersion in primary autonomic failure.

OBJECTIVE: To investigate the role of the autonomic nervous system in determining QT interval and dispersion. PATIENTS AND METHODS: 32 patients with chronic primary (idiopathic) autonomic failure (19 men, mean age 60 years) and 21 normal controls (11 men, mean age 59) without symptoms of ischaemic heart disease were studied retrospectively. Autonomic failure was diagnosed by a combination of symptomatic postural hypotension, subnormal plasma noradrenaline response to head-up tilt, and abnormal cardiovascular responses to standing, Valsalva manoeuvre, mental stress, cutaneous cold, isometric exercise, and deep breathing. QT intervals were measured from surface electrocardiograms and QT dispersion was defined as maximum QT--minimum QT occurring in any of the 12 leads. RESULTS: Mean heart rate (RR intervals) was similar in patients with autonomic failure and controls (S2 lead: 865 (132) v 857 (108) ms, P = NS; V2 lead: 865 (130) v 868 (113) ms, P = NS). QT intervals measured from electrocardiogram leads S2 and V2 were significantly longer in patients than in controls (401 (40) v 376 (16) ms, P < 0.01; and 403 (41) v 381 (20) ms, P < 0.05 respectively). The mean maximum QT interval in any lead, which is the best estimate of the maximum duration of electrical systole, was significantly longer in the patients than in controls (417 (48) v 388 (23) ms, P < 0.005). Linear regression analysis of QT and RR intervals for both groups showed a significant difference between the slopes of the two regression lines (F = 8.4, P < 0.001). However, QT dispersions were similar between patients and controls. CONCLUSIONS: Patients with primary autonomic failure have prolongation of QT intervals, indicating that the autonomic nervous system is an important determinant of QT interval. However, QT dispersion does not seem to be affected by chronic primary autonomic denervation.