A survey of current management of Benign Paroxysmal Positional Vertigo (BPPV) by physiotherapists' interested in vestibular rehabilitation in the UK

OBJECTIVES

Benign Paroxysmal Positional Vertigo (BPPV) is the most common cause of dizziness. Extensive research has identified the best assessment and treatment manoeuvres for each subtype of BPPV. Education in vestibular rehabilitation (VR) is inconsistent. It is unclear if the evidence has been adopted by UK physiotherapists in clinical practice and no research has investigated this specifically.

DESIGN

An online survey with closed- and open-text answers.

PARTICIPANTS

A purposive sample of physiotherapists interested in VR. A response rate of 67% (100/150) was obtained, from which 20 responses were excluded.

RESULTS

Participants had good evidence-based awareness in assessment (79/80, 99%) and treatment (72/80, 90%) of posterior BPPV. Horizontal BPPV assessment awareness was lower than treatment (37/80, 46% vs 60/80, 75%). Differential diagnosis was poor in subjective (20/80, 25%) and objective stages of assessment (34/80, 43%). Thirty six percent (29/80) were able to list ≥3 test precautions with all three nystagmus characteristics described by 29% (23/80). Eighty one percent (65/80) encourage activity restrictions post-treatment. Only 28% (22/80) were aware of practice guidelines or Cochrane reviews in BPPV. External courses were rated the top method for learning how to manage BPPV. Lack of peer support (26/77, 34%) was the main challenge faced whilst learning. Recommendations for improving BPPV education included more external courses (23/87, 26%) and competency guidelines (13/87, 15%).

CONCLUSIONS

Good awareness of research evidence was observed in some aspects of BPPV management but many areas require development. Translation and implementation of evidence remains poor and suggests changes in education and knowledge dissemination are warranted.

The role of nuclear imaging in pulmonary hypertension

Pulmonary hypertension (PH) is a disease characterized by a chronic elevation of pulmonary artery pressure from various causes. Pulmonary artery hypertension (PAH) is one of subtype which results in premature death often as a result of right ventricular (RV) dysfunction. In spite of the recent progress in novel cardiac imaging techniques and new drugs for PAH, there remain significant unresolved issues including a need for earlier diagnosis, refinement of risk stratification, and monitoring the effects of treatment. Cardiac and pulmonary imaging with transthoracic echocardiography (TTE) with Doppler, magnetic resonance imaging (MRI), and computed tomography (CT) are done routinely in many clinical centers. However, routine and emerging nuclear techniques may have a pivotal role of assessment of the patient with PH, and is currently the subject of significant research. Potential Roles for Nuclear Imaging in the Evaluation of the PH Patient: (1) Evaluation of cardiac structure and function (RNA) (non-nuclear techniques would include TTE, CT, and MRI). (2) Functional imaging. This includes the use of ventilation-perfusion scintigraphy (V/Q scan) to diagnose chronic thromboembolic pulmonary hypertension (CTEPH), 123l-metaiodobenzylguanidine (MIBG) imaging to evaluate the cardiac sympathetic nervous system (non-nuclear techniques include invasive right heart catheterization and TTE). (3) Measurement of RV perfusion (with gated SPECT studies). (4) Evaluation of cardiac and pulmonary metabolism (PET scans). This review article will summarize the pathophysiology, classification, natural history, and diagnostic approach of PH. Current and emerging nuclear techniques will be discussed under the four themes of evaluation of structure, functional imaging, flow, and metabolism. These will be compared to current and emerging nuclear and non-nuclear diagnostic tests in the evaluation and management of patients with PH. We will also discuss research applications exploring new insights into flow and metabolism in the right heart and lung and the application of new radioligands.

Reduced appetite and body mass index with delayed puberty in a mother and son: association with a rare novel sequence variant in the leptin gene

INTRODUCTION

Leptin deficiency caused by mutations within the leptin gene (LEP) results in severe early onset obesity, hypogonadism, pubertal delay and immune system abnormalities. Constitutional delay in growth and puberty (CDGP) is a common condition seen in paediatric clinics, in which children present with delayed growth and puberty but usually also have a slim body habitus. We hypothesized that LEP variants may play a role in the phenotype seen in CDGP.

AIM

To screen a group of children with CDGP for pathogenic sequence variants in LEP.

PATIENTS AND METHODS

Denaturing HPLC was used to screen for LEP sequence variants in DNA samples from 78 children with CDGP (predominantly white males) and 112 control subjects. DNA fragments with a WAVE pattern deviant from wild type were directly sequenced. A STAT3 luciferase reporter assay in human embryonic kidney (HEK293) cells transiently transfected with the leptin receptor was used to test activity of mutant leptin.

RESULTS

One child with CDGP was identified to be heterozygous for a novel missense variant (c.68C>G), which results in a proline to arginine substitution (p.P23R). This sequence variant was not identified in any of the other control subjects, but was identified in his mother who shared a similar phenotype of slim body habitus, reduced appetite and pubertal delay (menarche aged 15 years). The leptin variant showed similar stability in serum compared with wild type and did not demonstrate increased activity in an in vitro reporter gene assay.

CONCLUSIONS

This is the first report of a sequence variant within the LEP gene associated with reduced body mass index rather than obesity. We hypothesize that this variant has increased bioactivity in vivo.

Assessment of cyclosporine pharmacokinetic parameters to facilitate conversion from C0 to C2 monitoring in heart transplant recipients

BACKGROUND

Cyclosporine (CsA) 2-hour postdose (C2) monitoring is recommended to assess CsA exposure and predict clinical outcomes among heart transplant recipients. We correlated pharmacokinetic parameters and clinical outcomes in stable long-term heart transplant recipients monitored with C0 to develop an algorithm to convert patients from C0 to C2 monitoring.

METHODS

Paired CsA C0-C2 measurements and serum creatinine levels were obtained from 35 heart transplant recipients more than 2 years posttransplantation (mean 8.8+/-4.7 years).

RESULTS

The mean CsA dose and C0, C2, and C0/C2 ratio were 85+/-23 mg/12 hours, 123+/-41 ng/mL, 572+/-274 ng/mL and 4.8+/-2.1, respectively. C0 correlated weakly with C2 (r=.42, P=.011). The CsA dose correlated better with C2 (r=.58; P<.001) than with C0 (r=.37; P=.026). A good correlation was noted between C2 and the C2/C0 ratio (r=.73; P<.001), but none between C0 and the C2/C0 ratio. A borderline significant inverse correlation was noted between C0 and the worst endomyocardial biopsy score (r=-.34; P=.045), whereas none was noted with C2. Serum creatinine level did not correlate with either C2 or C0. Among patients with C0 within our target of 100 to 150 ug/L, six had C2 above 300 to 600 ug/L as suggested by the literature.

CONCLUSIONS

In long-term heart transplant recipients, we could not identify a single pharmacokinetic parameter that could be used to develop an algorithm to convert from C0 to C2 monitoring; however, C2 may be better than C0 for identifying patients at risk of overexposure to CsA.

In vivo and in vitro examination of the functional significances of novel lamin gene mutations in heart failure patients

CONTEXT

Lamin A/C (LMNA) gene variations have been reported in more than one third of genotyped families with dilated cardiomyopathy (DCM). However, the relationship between LMNA mutation and the development of DCM is poorly understood.

METHODS AND RESULTS

We found that end stage DCM patients carrying LMNA mutations displayed either dramatic ultrastructural changes of the cardiomyocyte nucleus (D192G) or nonspecific changes (R541S). Overexpression of the D192G lamin C dramatically increased the size of intranuclear speckles and reduced their number. This phenotype was only partially reversed by coexpression of the D192G and wild type lamin C. Moreover, the D192G mutation precludes insertion of lamin C into the nuclear envelope when co-transfected with the D192G lamin A. By contrast, the R541S phenotype was entirely reversed by coexpression of the R541S and wild type lamin C. As lamin speckle size is known to be correlated with regulation of transcription, we assessed the SUMO1 distribution pattern in the presence of mutated lamin C and showed that D192G lamin C expression totally disrupts the SUMO1 pattern.

CONCLUSION

Our in vivo and in vitro results question the relationship of causality between LMNA mutations and the development of heart failure in some DCM patients and therefore, the reliability of genetic counselling. However, LMNA mutations producing speckles result not only in nuclear envelope structural damage, but may also lead to the dysregulation of cellular functions controlled by sumoylation, such as transcription, chromosome organisation, and nuclear trafficking.

Potential utility of rubidium 82 PET quantification in patients with 3-vessel coronary artery disease

BACKGROUND

Standard perfusion imaging may underestimate the extent of disease in 3-vessel coronary atherosclerosis. This study determined whether positron emission tomography quantification of perfusion reserve by use of rubidium 82 net retention defined a greater extent of disease than the standard approach in patients with 3-vessel disease.

METHODS AND RESULTS

Rb-82 net retention was quantified as an estimation of absolute perfusion at rest and with dipyridamole stress by use of dynamic positron emission tomography imaging. The percent of abnormal myocardial sectors, as compared with a normal database, for a standard and quantification approach was determined. Twenty-three patients were evaluated. Defect sizes were larger in patients with 3-vessel disease (n = 13) by use of quantification methods: 44% +/- 18% of the myocardial sectors were abnormal by use of the standard approach versus 69% +/- 24% of sectors when measured by quantification of the stress-rest perfusion difference (P =.008). In patients with single-vessel disease (n = 10), defect sizes were smaller with quantification methods.

CONCLUSIONS

Quantification of Rb-82 net retention to measure the stress-rest perfusion difference in the myocardium defined a greater extent of disease than the standard approach in this group of patients with triple-vessel disease. More accurate measurement of the extent of coronary artery disease could facilitate better risk stratification and identify more high-risk patients in whom aggressive intervention is required.

Defective auditory interhemispheric transfer in a patient with a PAX6 mutation

Heterozygous PAX6 mutation is associated with an absent or hypoplastic anterior commissure and a reduction in the area of the corpus callosum. The authors found deficient auditory interhemispheric transfer in a 53-year-old woman with a PAX6 mutation who had an absent anterior commissure but normal callosal volume.

Herpes simplex encephalitis. A study of seven patients and their immunological response prior to routine acyclovir treatment

OBJECTIVES

A retrospective study on cerebrospinal fluid (CSF) samples was made possible by access to a large CSF bank, which has been supplemented by the well characterised prior collection of CSF from patients with Herpes simplex encephalitis (including serial samples from some patients and kindly donated by Professor Maurice Longson, Manchester). These samples are of particular interest because they were collected prior to the routine administration of acyclovir.

METHODS

Although an earlier study had shown that there was indeed a correlation between higher titres of antibody and a better outcome, the data did not emerge with statistical significance. The current study was based upon an improved method, which demonstrates the antigen-specific clonality of the immune response.

RESULTS

The primitive polyclonal anamnestic response was contrasted with the strong antigen-specific response, which was manifested by a monoclonal pattern in some patients. A clear distinction emerged between two sub-groups of patients on the basis of these findings, which showed a statistically significant (P<0.03) correlation with outcome.

CONCLUSIONS

This has allowed us to further support the hypothesis that a strong immunological response has positive prognostic value during the course of the disease.

Menstrual cycle effects on hypothalamic dopamine receptor function in women with a history of puerperal bipolar disorder

Neuroendocrine challenge tests of hypothalamic dopamine receptor function in the early postpartum period suggest that the sensitivity of these receptors is increased in women with a history of bipolar disorder after childbirth. We tested the hypothesis that, in women predisposed to bipolar disorder in the puerperium, hypothalamic dopamine receptor function is more sensitive to changes in circulating ovarian hormone concentrations than in women without such histories. Eight fully recovered and drug-free women who had had at least one episode of bipolar illness following childbirth were compared with nine normal controls. Growth hormone (GH) responses to apomorphine (APO 0.005 mg s.c.) were measured in the early follicular phase, when plasma concentrations of ovarian hormones are low, and in the mid-luteal phase, when they are relatively high. The recovered bipolar subjects and the controls did not differ from each other in their follicular and midluteal oestrogen and progesterone concentrations. In the midluteal phase, both groups had increased oestrogen and progesterone levels. The recovered bipolar subjects did not differ from controls in baseline concentrations of GH in either of the menstrual phases. The APO-GH responses of the two groups did not differ in the follicular phase, but in the midluteal phase, when female sex steroids are relatively increased, the recovered group had significantly enhanced APO-GH responses [MANOVA for repeated measures: (i) area under the curve, group by phase effect: p < 0.04; (ii) GH peak rise after APO, group by phase effect: p < 0.056] and the responses were not related to concurrent measures of mood. The results of this small study of women predisposed to bipolar disorder in the puerperium shows an increased dopaminergic receptor sensitivity in the luteal phase of the menstrual cycle. It suggests that their dopaminergic systems have increased sensitivity to changes in circulating female sex steroids. This may be aetiologically relevant to the pathogenesis of puerperal bipolar disorder.

The use of ultrasound to demonstrate small bowel polyps in a patient with Peutz-Jeghers syndrome

A 21-year-old woman presented to the accident and emergency department with a 2-day history of lower abdominal pain. Her lips had the stigma of melanosis. Previously, she had received a diagnosis of Peutz-Jeghers syndrome, although no polyps had been detected in small and large bowel barium studies performed approximately 8 years before. Clinically, the patient had mild deep lower abdominal tenderness, and a mass was palpable in the suprapubic region. Urgent ultrasound showed ileoileal intussusception and small polyps in the lumen of the small bowel. At laparotomy, ileoileal intussusception was confirmed. It was not possible to reduce it because of nonviable small bowel, so 20 cm of the ileum, including the intussusception, was excised. After this, intraoperative enteroscopy was performed, showing further polyps in the small bowel distal and proximal to the intussusception, which were excised locally. Only a few reports in the literature describe ultrasound used to diagnose to condition. Intraoperative enteroscopy has been recommended as the treatment of choice because it allows identification of polyps that previously would have been missed.

Positional down beating nystagmus in 50 patients: cerebellar disorders and possible anterior semicircular canalithiasis

OBJECTIVES

To clarify the clinical significance of positional down beat nystagmus (pDBN).

METHODS

A discussion of the neuro-otological findings in 50 consecutive patients with pDBN.

RESULTS

In 38 patients there was evidence of CNS disease (central group) but in 12 there was not (idiopathic group). In the CNS group, presenting symptoms were gait, speech, and autonomic dysfunction whereas in the idiopathic group patients mostly reported positional vertigo. The main neurological and oculomotor signs in the CNS group were explained by cerebellar dysfunction, including 13 patients with multiple system atrophy. In patients with multiple system atrophy with a prominent extrapyramidal component, the presence of pDBN was helpful in the differential diagnosis of atypical parkinsonism. No patient with pDBN had the Arnold-Chiari malformation, a common cause of constant down beat nystagmus (DBN). In the idiopathic group, the pDBN had characteristics which suggested a peripheral labyrinthine disorder: vertigo, adaptation, and habituation. In six patients an additional torsional component was found (concurrently with the pDBN in three). Features unusual for peripheral disorder were: bilateral positive Dix-Hallpike manoeuvre in nine of 12 patients and selective provocation by the straight head-hanging manoeuvre in two.

CONCLUSION

It is argued that some patients with idiopathic pDBN have benign paroxysmal positional vertigo (BPPV) with lithiasis of the anterior canal. The torsional component may be weak, because of the predominantly sagittal orientation of the anterior canal, and may not be readily seen clinically. Nystagmus provocation by bilateral Dix-Hallpike and straight head-hanging may be explained by the vertical upwards orientation of the ampullary segment of the anterior canal in the normal upright head position. Such orientation makes right-left specificity with the Dix-Hallpike manoeuvre less important than for posterior canal BPPV. This orientation requires a further downwards movement of the head, often achieved with the straight head-hanging position, to provoke migration of the canaliths. The straight head-hanging manoeuvre should be carried out in all patients with a history of positional vertigo and a negative Dix-Hallpike manoeuvre.

Symptoms, disability and handicap in unilateral peripheral vestibular disorders. Effects of early presentation and initiation of balance exercises

The aim of this study was to obtain a profile of disability and handicap in patients with unilateral peripheral vestibular disorders presenting to a specialist tertiary care unit. Two validated questionnaires were sent to patients who had a unilateral peripheral vestibular disorder as defined by strict criteria. Some patients still suffered moderate handicap and disability 5 years after the initial symptoms related to a unilateral vestibular disorder, although the duration of symptoms (onset to questionnaire completion) did not correlate with severity of disability and handicap, as judged by questionnaire scores. However, patients presenting to the unit within 6 months of onset of vertigo commenced balance exercises significantly earlier and had significantly lower disability scores than patients presenting later. A high proportion of non-compliance with, and delay in initiation of, vestibular rehabilitation exercises was noted in the total patient sample, while compliance with, and early initiation of, Cooksey Cawthorne exercises were significantly correlated with low disability and questionnaire scores. These findings suggest that early referral to a specialist balance unit for patients with persistent dizziness is associated with better outcome.

Evaluation of brain damage resulting from penetrating and non-penetrating captive bolt stunning using lambs

OBJECTIVE

To compare the brain damage in sheep resulting from penetrating and non-penetrating captive bolt stunning.

DESIGN

The unrestrained heads of anaesthetised lambs were impacted in the temporal region with penetrating and non-penetrating captive bolt pistols (humane stunners) using a constant charge. Two hours after head impact, brains were perfusion-fixed with 4% paraformaldehyde. Coronal sections were stained with haematoxylin and eosin and immunohistochemically for amyloid precursor protein, a sensitive marker of axonal and neuronal reaction in brains after trauma. Pathological changes in these brains were then quantified by morphometric analysis.

RESULTS

The skull was fractured in 50% of lambs after a non-penetrating head impact and in all animals after a penetrating head wound. Impact contusions were present in 80% of lambs receiving a non-penetrating head injury and in all of those with a penetrating wound. Total contusion area was similar in both groups. Amyloid precursor protein-positive axons and neurons, and haemorrhage, were widely distributed in the brain after both head impact types, but there was no statistically significant difference between the two groups. Multifocal necrosis of the cerebellar granular layer was found in all lambs with non-penetrating head injury, but in none with a penetrating injury.

CONCLUSIONS

The structural brain damage, a mixture of focal and diffuse injury, produced by penetrating and non-penetrating captive bolt pistols was overall similar and of sufficient severity to suggest that both types of weapon are acceptable for euthanasia.

Interatrial conduction of atrial tachycardia in heart transplant recipients: potential pathophysiology

Surgical suture lines formed at the site of anastamosis have been considered to be electrically inert and thus present a line of block to conduction. However, a number of reports have suggested that conduction is occasionally possible across suture lines. Most of these cases have reported conduction between donor and recipient atria following cardiac transplantation. We report an illustrative case successfully treated with radiofrequency ablation, and present pathology findings that may give insight into the pathophysiology.

Stenting of an unprotected left main coronary artery stenosis in a cardiac transplant patient

Cardiac allograft vasculopathy is the leading cause of death in cardiac transplant patients who survive the first year. Retransplantation is limited by shortage of donors and reduced survival rates compared with the initial transplant. Recent reports of successful stenting in these patients may offer some hope, although randomized trials are lacking. Successful stenting of an 'unprotected' left main coronary artery stenosis under cardiopulmonary support is presented in a cardiac transplant patient. A 16-month follow-up angiogram demonstrated a patent stent without restenosis and no interim clinical events.

Circulatory support for cardiogenic shock due to acute myocardial infarction: a Canadian experience

BACKGROUND

Cardiogenic shock due to acute myocardial infarction (AMI) is associated with high mortality. Circulatory support devices may be used to assist these patients while they await cardiac transplantation.

METHODS AND RESULTS

From 1986 to 1997, 25 patients in cardiogenic shock complicating AMI within 3.6+/-0.7 days of the event were supported with artificial hearts. Of the 25 patients, 21 were men with a mean age of 48.4 +/- 1.8 years. The age range was 26 to 62 years. Patients were considered for a device when the following criteria were met: cardiac index less than 1.8 L/min/m2, wedge pressure greater than 20 mmHg despite one or two inotropes and/or intra-aortic balloon support. They received either a CardioWest total artificial heart (n=13), a Thoratec biventricular assist device (n=6) or left ventricular assist device (LVAD) (n=6). Three patients were not considered transplant candidates and died while on the devices (two with multiorgan failure and one found to have a bronchogenic carcinoma after implant), with 22 undergoing cardiac transplantation within 8.6+/-2.2 days of device implant. Six patients died in hospital after the transplants (27.3% mortality). Complications included bleeding or tamponade in seven (28%), pneumonia in six (24%) and right ventricular failure in three LVAD patients (12%). Post-transplant actuarial one-, two- and five-year survival rates were 71.4%, 71.4% and 51%, respectively.

CONCLUSIONS

Circulatory support devices offer a means to maintain organ perfusion in patients who develop cardiogenic shock due to AMI. Patients can then undergo transplantation with a reasonable expectation for survival when the alternative is death. Eventually the availability of permanent support devices may obviate the need for transplant in these patients.

Discoordinate modulation of natriuretic peptides during acute cardiac allograft rejection in humans

BACKGROUND

Increased circulating levels of the cardiac polypeptide hormones atrial natriuretic factor (ANF) and brain natriuretic peptide (BNP) may be observed after orthotopic cardiac transplantation. Both the hypertrophic and inflammatory processes in the allograft may contribute to this increase, but no mechanistic explanation has been suggested for this observation.

METHODS AND RESULTS

Plasma immunoreactive ANF and BNP determinations were performed in 10 consecutive transplant patients. These were correlated with degree of rejection as reflected by histopathological findings at serial endomyocardial biopsies. Three patients had associated hemodynamic measurements and blood samples 24 hours before and after transplantation. All rejection episodes that received treatment were accompanied by a marked increase in BNP plasma levels to > approximately 400 pg/mL. Steadily increasing BNP levels preceded overt rejection as assessed by histopathological criteria. The increase in plasma BNP was not always accompanied by an increase in ANF, which suggests the specific upregulation of BNP gene expression during acute rejection episodes. Treatment of the acute rejection episodes led to a substantial decrease of BNP plasma levels.

CONCLUSIONS

The significant selective increase in plasma BNP levels found in the present study has not been previously described. This finding provides a new insight into the mechanism of allograft rejection and the modulation of natriuretic peptide synthesis and release. Furthermore, although preliminary, the data suggest that BNP plasma levels could form the basis for a new, noninvasive screening test to predict acute cardiac allograft rejection. Because treatment with the antilymphocyte monoclonal antibody OKT3 (murine monoclonal antibody to the CD3 antigen of the human T-cell) decreased BNP plasma levels, cytokine production by T-cells may mediate the selective increase in circulating BNP.

The effect of severity of unilateral vestibular dysfunction on symptoms, disabilities and handicap in vertiginous patients

This study compares the symptoms, disabilities and handicap, as assessed by means of a questionnaire, in two groups of patients with a unilateral peripheral vestibular disorder: those with a total canal paresis and those with a partial canal paresis, as judged by the duration parameter using the Fitzgerald Hallpike caloric test in the absence of optic fixation. The results of the study indicate that the severity of dizziness, the Dizziness Index (severity x frequency) and the overall level of disabilities related to visual vertigo are less severe in unilateral profound or total loss of vestibular function than in unilateral mild vestibular loss.

Vestibular hypersensitivity to clicks is characteristic of the Tullio phenomenon

OBJECTIVES

The frequency of pathologically reduced click thresholds for vestibular activation was explored in patients with the Tullio phenomenon (sound induced vestibular activation).

METHODS

Seven patients (eight affected ears) with symptoms of oscillopsia and unsteadiness in response to loud external sounds or to the patient's own voice were examined. In all but one patient, vestibular hypersensitivity to sound was confirmed by the fact that eye movements could be produced by pure tones of 110 dB intensity or less. Conventional diagnostic imaging was normal in all cases and three of the patients had normal middle ears at surgical exploration. Thresholds for click evoked vestibulocollic reflexes were compared with those of a group of normal subjects. Galvanic stimulation was used as a complementary method of examining the excitability of vestibular reflexes.

RESULTS

All the patients showed a reduced threshold for click activation of vestibulocollic reflexes arising from the affected ear. Short latency EMG responses to clicks were also present in posterior neck and leg muscles, suggesting that these muscles receive vestibular projections. Galvanic stimulation produced a normal pattern of body sway in four of the five patients tested.

CONCLUSIONS

A pathologically reduced threshold to click activation (< or = 70 dB NHL (average normal hearing level)) seems to be a consistent feature of the Tullio phenomenon and a useful diagnostic criterion. This in turn is most likely to be due to an increased effectiveness of the transmission of sound energy to saccular receptors. Activation of these receptors probably contributed to the vestibular symptoms experienced by the patients.

Catecholamines and heart function in heart transplant patients: effects of beta1- versus nonselective beta-blockade

OBJECTIVES

To evaluate cardiac responses to norepinephrine and epinephrine in heart transplant patients compared with patients with mild essential hypertension and to evaluate the contribution of beta2-receptors versus beta1-receptors to the cardiac responses by assessing the effects of the 2 agonists after treatment with placebo compared with the beta1-selective blocker atenolol and the nonselective blocker nadolol.

METHODS

A double-blind, randomized crossover design was used to study patients after administration of placebo, atenolol, or nadolol for 2 weeks. Infusion of norepinephrine was performed at incremental rates of 12.5, 25, 50, and 100 ng/kg/min and of epinephrine at rates of 20, 40, 80, and 120 ng/kg/min. Blood pressure, heart rate, left ventricular function (by echocardiogram), and venous plasma concentrations were assessed at rest and at the end of each infusion rate.

RESULTS

Infusion of epinephrine and norepinephrine was associated with 3-fold and 2-fold higher increases, respectively, in plasma concentrations in the transplant patients versus patients with hypertension. Enhanced blood pressure responses to either agonist were found in the transplant patients, but not when venous plasma concentrations were considered. Norepinephrine decreased heart rate and cardiac index in patients with hypertension receiving placebo and more markedly when receiving atenolol and nadolol. In contrast, heart transplant patients showed increases in heart rate, ejection fraction, and cardiac index, which largely were blocked (but not reversed into decreases) by atenolol and nadolol. In patients with hypertension receiving placebo, epinephrine increased heart rate, ejection fraction, and cardiac index. These responses were enhanced in transplant patients, also relative to plasma concentrations. Atenolol had only minor effects on these cardiac responses. On nadolol epinephrine decreased heart rate, stroke volume, and cardiac index in the patients with hypertension, whereas the transplant patients receiving nadolol showed no longer increases in cardiac function by epinephrine.

CONCLUSIONS

Both absence of parasympathetic buffering and diminished systemic clearance contributed to the enhanced cardiac responses to infusion of norepinephrine and epinephrine in heart transplant patients compared with patients with essential hypertension. Cardiac beta2-receptors mediate most of the chronotropic and inotropic responses to epinephrine in both patients with hypertension and heart transplant patients.

Pilot study of multiple chemotherapy resistance modulators plus epirubicin in the treatment of resistant malignancies

We studied the toxicity and efficacy of adding to epirubicin five resistance modulators in the treatment of resistant solid tumors. Additional drugs were added in successive cohorts of patients, such that cohort 1 patients received two drugs along with their epirubicin, while cohort 4 patients received five modulators along with their epirubicin. Metronidazole, tamoxifen (cohort 1), dipyridamole (cohort 2), ketoconazole (cohort 3) and cyclosporin (cohort 4) were administered with epirubicin. A total of 22 patients were treated. Nausea and vomiting was usually mild to moderate. There was an unexpectedly high incidence of possible cardiac toxicity associated with treatment, although in some patients it was uncertain whether or not observed cardiac events were related to treatment. Granulocytopenia was significant in all four cohorts, but it was unclear whether it was increased by the modulators. There were two febrile neutropenic events in cohorts 1 and 2 successfully treated with antibiotics, and three septic deaths (one in each of cohorts 1, 2 and 4). It was elected to discontinue enrollment on the study prematurely in light of cardiac and other toxicity seen in the first two patients accrued in cohort 4. A single response was observed. While this approach is feasible, the observed toxicity and the difficulty patients experienced in ingesting the large number of prescribed pills will make further exploration of this approach difficult.

Migraine-associated vertigo

A retrospective analysis was performed on a consecutive series of 363 patients presenting with vertigo; 32% had migraine. Of the 224 patients with no pathology other than migraine or vestibular dysfunction, migraineurs had a significantly higher prevalence of normal, central, and combined central and peripheral vestibular dysfunction compared to non-migraineurs. The combination of central and peripheral vestibular signs was a feature of migraine with aura. The results support the hypothesis that migraine-associated vertigo is a diagnostic entity.

The growth hormone response to apomorphine at 4 days postpartum in women with a history of major depression

We have examined the responsiveness of dopamine sensitive neurones in the postpartum period in woman with a history of major depression who are at high risk of experiencing a recurrence of illness in the postpartum period. Fourteen women were assessed at 36 weeks of pregnancy and during the 3 months following delivery, using the Schedule for Affective Disorders and Schizophrenia, including its change version. They were not depressed at initial assessment. Five of the 14 women went on to experience a postpartum relapse (2 major depressive disorder, 2 generalised anxiety disorder, 1 panic disorder). On the fourth day postpartum, i.e., before relapse, the growth hormone response to the dopamine agonist apomorphine was measured as an index of the functional state of hypothalamic dopamine D2 receptors. Women who subsequently relapsed had a significantly greater growth hormone response to apomorphine than those who remained well. This was particularly marked in women with anxiety/panic. The development of increased sensitivity of hypothalamic dopamine D2 receptors in the postpartum period appears to predict the onset of depressive and anxiety disorders.

Bacterial pericarditis after heart transplantation: successful management of two cases with catheter drainage and antibiotics

OBJECTIVE

To describe the diagnosis and management of bacterial pericarditis after heart transplantation.

PATIENTS AND METHODS

Two patients with Staphylococcus aureus pericarditis after heart transplantation were successfully treated conservatively with closed catheter drainage and antibiotics.

RESULTS

The patients were alive three and six years, respectively, following surgery. At follow-up, right heart catheterization demonstrated normal hemodynamics in one patient and a pattern of constrictive pericarditis in the other patient which was man-aged with furosemide.

CONCLUSIONS

Conservative management of bacterial pericarditis by closed catheter drainage and antibiotics can be considered in selected patients after heart transplantation.

Cardiac transplantation after mechanical circulatory support: a Canadian perspective

BACKGROUND

To assess the relative efficacy of cardiac transplantation after mechanical circulatory support with a variety of support systems, we analyzed our consecutive series of patients who had and did not have mechanical support before transplantation.

METHODS

A review of 209 patients undergoing cardiac transplantation from 1984 to May 1995 was performed. Group 1 consisted of 110 patients who were maintained on oral medications while awaiting transplantation, and group 2 consisted of 60 patients who required intravenous inotropic support. Group 3 included 39 patients who had transplantation after mechanical circulatory support for cardiogenic shock. The indication for device implantation was acute onset of cardiogenic shock in 38 patients and deterioration while awaiting transplantation in 1 patient. The support systems were an intraaortic balloon pump in 13 (subgroup 3A), a ventricular assist device in 7 (subgroup 3B), and a total artificial heart in 19 patients (subgroup 3C).

RESULTS

After transplantation, infection was more common in group 3 (56%) than in group 1 (28%) or group 2 (32%) (p = 0.005). Survival to discharge was lower for group 3 (71.7%) than for group 1 (90.9%) or 2 (88.3%) (p = 0.009). For mechanically supported patients, survival to discharge was 84.6% in subgroup 3A, 71.4% in subgroup 3B, and 63.1% in subgroup 3C (p = not significant).

CONCLUSIONS

Transplantation after mechanical support offers acceptable results in this group of patients for whom the only alternative is certain death. Patient selection and perioperative management remain the challenge to improving these results.

A fenestrated aortic valve contributing to iatrogenic aortic insufficiency post mitral valve replacement

A case of an unusual local complication of cardiac valvular surgery is presented. Distortion of the geometry of the aortic valve base by a prosthetic mitral valve sewing ring allowed aortic insufficiency through the aortic valve's central orifice, as well as through an aortic valve cusp fenestration. During the 6 years after valve surgery, this patient developed chronic left heart failure contributed to by the aortic insufficiency and eventually, at age 65, required cardiac transplantation. Surgeons and pathologists should be aware of this unusual local complication of cardiac valve surgery, as it may have serious consequences.

Angiographic underestimation of coronary artery disease in a cardiac transplant donor

There has been a great deal of attention given to the development of post-transplant arteriopathy in the cardiac transplant patient. Preexisting donor heart disease may be of equal importance in the development of allograft failure due to ischemia. The case of a 64-year-old female who received the heart of a 52-year-old female is reported. Death of the recipient occurred due to intraoperative complications. Despite normal pretransplant coronary angiography, autopsy found severe atherosclerotic coronary artery disease in the donor heart. This case report illustrates some of the limitations of angiography in the detection of coronary artery lesions in donor hearts.

A new, simple and accurate method for determining ejection fraction by Doppler echocardiography

OBJECTIVE

To evaluate the feasibility, accuracy and reproducibility of a new and simple method for determining ejection fraction by Doppler echocardiography. This method should theoretically be less influenced by the distortions of left ventricular geometry caused by prior myocardial infarction.

DESIGN

Two groups of patients (total 114) were evaluated independently at the Quebec and Ottawa Heart Institutes (60 and 54 patients, respectively). All were referred for radionuclide angiography performed within 24 h of the echocardiogram. Regional asynergy was present in 59% of Quebec patients and 37% of Ottawa patients. The new method for calculating ejection fraction consisted of dividing Doppler derived stroke volume in the left ventricular outflow tract by left ventricular end-diastolic volume calculated by Teichholz's formula; for comparison, ejection fraction was also measured by single plane area length or multiple disc planimetry as well as by the Quinones method at the Quebec Heart Institute.

RESULTS

Feasibility of the new method was 97% in Quebec and 100% in Ottawa. Compared with radionuclide angiography, the correlation coefficient for the new method was 0.92 (standard error of estimate [SEE] = 7.3) in Quebec compared with 0.88 (SEE = 8.5 and 8.1) for both the Quinones and single plane area length methods, and 0.84 (SEE = 12.0) in Ottawa compared with 0.77 (SEE = 10.9) for the single plane multiple disc method. Correlations in patients with regional asynergy were 0.90 in Quebec and 0.75 in Ottawa compared with 0.81 and 0.54 with planimetry. Correlation coefficients for interobserver variability in 12 patients were 0.97 with the new method compared with 0.83 with the Quinones method and 0.85 with single plane planimetry.

CONCLUSION

This new and simple method is feasible, accurate and reproducible even in patients with regional asynergy. Provided there is no significant mitral regurgitation, it is a time-saving alternative for the routine evaluation of ejection fraction by Doppler echocardiography.

Dizziness following head injury: a neuro-otological study

Dizziness is a frequent and debilitating complications of head injury and accounts for increasing numbers of medico-legal claims. A detailed neuro-otological study was carried out from the records of 100 patients with post-traumatic dizziness to explore the neuro-otological basis of their symptoms: 50 patients presenting for medico-legal purposes (group I) and 50 presenting for management of their vestibular symptoms (group II). The two groups showed a similar sex distribution, a similar range of causes of head injury and similar severity of head injury (72 minor, 24 moderate and 4 severe). Of the 100, 88 showed at least one audio-vestibular abnormality on testing. Vertigo of the benign positional paroxysmal type was the commonest vestibular diagnosis in both groups (61/100), and only 8 patients showed central vestibular abnormalities. Fifty-three patients had audiometric abnormalities attributable to the head injury, the commonest of which was a high-tone sensorineural hearing loss. There was no significant difference in the incidence of any of the abnormalities in the medico-legal group (group I) when compared with the symptom management group (group II). The results provide strong evidence for an organic basis to recurring dizziness after head injury, whether or not a claim for compensation is pending, and emphasize the need for specialist neuro-otological investigation if abnormalities are to be identified and managed correctly.

Determinants of hospital survival after cardiac transplantation

To identify the preoperative factors that influence hospital survival after transplantation we analyzed our consecutive experience of 183 transplantations in 179 patients over a 10-year period. There were 151 male and 29 female transplant recipients ranging in age from 10 days to 70 years (mean, 48 +/- 1 years). Diagnoses included coronary disease in 110 patients, cardiomyopathy in 55 patients, valvular disease in 6 patients, and congenital heart disease in 9 patients. Seventy-seven had undergone a previous cardiac operation, and 30 patients required preoperative mechanical support. Forty patients received hearts from donors who were 40 years old or older (range, 40 to 62 years). Ischemic time was greater than 240 minutes in 32 cases, and pulmonary vascular resistance was greater than 3 Wood units in 40 patients (range, 3.1 to 10.0 Wood units). Cyclosporine induction was used in 52 patients, whereas 128 recipients received polyclonal antibody prophylaxis. There were 25 hospital deaths. Recipient diagnosis, use of mechanical support, donor age, and the immune suppression protocol were related to hospital survival according to univariate analysis. Using multiple logistic regression, only the method of immune suppression induction and the use of mechanical assists were significant independent determinants of survival. In conclusion, we believe that extended ischemic times and donor age do not adversely affect the early success of transplantation, whereas induction with immune globulin may reduce early mortality. Patients requiring mechanical support before transplantation continue to be a challenge.

Role of cardiac beta 2-receptors in cardiac responses to exercise in cardiac transplant patients

BACKGROUND

In healthy human hearts, beta 2-receptor-mediated chronotropic and inotropic responses contribute to the cardiac responses to beta-agonists. A (patho)physiological relevance for beta 2-receptor-mediated responses has so far not been demonstrated, in part because beta 1-receptor-mediated responses to cardiac neuronally released norepinephrine can mask beta 2-receptor-mediated responses.

METHODS AND RESULTS

In the present study, we evaluated the blood pressure and heart rate responses to bicycle exercise in cardiac transplant patients (n = 7) compared with patients with essential hypertension (n = 8) on placebo and two doses of the beta 1-selective beta-blocker atenolol (25 and 50 mg/d) and the nonselective beta-blocker nadolol (20 and 40 mg/d), each dose for 1 week using a double-blind, randomized, crossover design. Exercise was performed 3 hours after dosing, using a stepwise increase in load until exhaustion. Exercise performance was less in the transplant patients and significantly further (25%) decreased by nadolol. Exercise caused equivalent increases in plasma norepinephrine in the two groups, but more marked increases in plasma epinephrine in the transplant patients despite less exercise. In the essential hypertension patients, systolic blood pressure increased by 80 mm Hg on placebo and 60 mm Hg on either blocker. The increase in heart rate (by about 75 beats per minute) was inhibited by 10% and 20% by the lower and higher doses, respectively, similar for the two blockers. In contrast, in the transplant patients, systolic blood pressure increased by 60 mm Hg on placebo, but this increase was totally blocked by either blocker. The heart rate increase (by 50 beats per minute on placebo) was blunted (dose related) by either blocker but 50% more by nadolol versus atenolol.

CONCLUSIONS

The present study shows that cardiac beta 2-receptors contribute to a clear extent to the heart rate responses to endogenous circulating catecholamines in the absence of cardiac neuronally released norepinephrine. Nonselective beta-blockade probably is less well tolerated in cardiac transplant patients compared with beta 1-selective blockade.

Measurement of left ventricular ejection fraction by acoustic quantification and comparison with radionuclide angiography

Left ventricular (LV) ejection fraction (EF) is an important measure of systolic function, with radionuclide angiography being the accepted standard for its determination. Echocardiography is ideal for repeated measurements of EF, but most methods are either subject to error in the presence of regional wall abnormalities or require cumbersome off-line analysis. Acoustic quantification is a recently introduced method that allows for the continuous on-line display of LV cavity dimensions, but the on-line algorithm for the measurement of EF has not been validated against an independent standard in the clinical setting. This study attempted to validate acoustic quantification in the determination of EF by comparison with off-line echocardiographic analysis and radionuclide angiography in 54 patients referred for this latter procedure. Acoustic quantification correlated well with off-line analysis in both the apical 4-chamber (r = 0.89, n = 43) and 2-chamber (r = 0.86, n = 26) views. Similarly, it also correlated well with radionuclide angiography in the 4-chamber (r = 0.81, n = 44) and 2-chamber (r = 0.83, n = 26) views. The correlation between the 2 methods was further improved when only the last 30 patients were assessed (r = 0.91, n = 25 for 4-chamber views; r = 0.86, n = 16 for 2-chamber views). The correlation was worse in patients with regional asynergy (r = 0.69, n = 17 for 4-chamber views; r = 0.76, n = 10 for 2-chamber views). Moreover, acoustic quantification tended to underestimate EF when compared with radionuclide angiography.(ABSTRACT TRUNCATED AT 250 WORDS)