Margaret O'Connor

Sitting and standing blood pressure measurements are not accurate for the diagnosis of orthostatic hypotension

INTRODUCTIONnOrthostatic hypotension (OH) is associated with troublesome symptoms and increased mortality. It is treatable and deserving of accurate diagnosis. This can be time consuming. The current reference standard for its diagnosis is head-up tilt (HUT) testing with continuous beat-to-beat plethysmography. Our objective was to assess the accuracy of sit-stand testing with semi-automatic sphygmomanometry for the diagnosis of OH.nnnDESIGNnRetrospective test of diagnostic accuracy.nnnMETHODSnThis was a retrospective study performed using a database maintained by a busy syncope unit. HUT testing was performed using an automated tilt table with Finometer monitoring. A 3 min 70 degrees HUT was performed following 5 min supine. Sitting blood pressure (BP) was measured following 3 min rest. Standing BP was measured within 30 s of assuming the upright posture. The results of sit-stand testing were compared with HUT testing as a reference standard. Both tests happened within 5 min of each other and patients underwent no intervention between tests.nnnRESULTSnFrom a total of 1452 consecutive HUTs, we identified 730 with pre-test measures of sitting and standing BP. The mean age of this group was 70.57 years (SD = 15.1), 62% were female. The sensitivity of sit-stand testing was calculated as 15.5%, specificity as 89.9%, positive predictive value as 61.7%, negative predictive value as 50.2% and the likelihood ratio as 1.6. The area under the Receiver Operator Curve was 0.564.nnnCONCLUSIONnWe have demonstrated that sit-stand testing for OH has very low diagnostic accuracy. We recommend that the more time-consuming reference standard method of diagnosis be used if the condition is suspected.

Specialist medication review does not benefit short-term outcomes and net costs in continuing-care patients

OBJECTIVESnto evaluate specialist geriatric input and medication review in patients in high-dependency continuing care.nnnDESIGNnprospective, randomised, controlled trial.nnnSETTINGntwo residential continuing care hospitals.nnnPARTICIPANTSntwo hundred and twenty-five permanent patients.nnnINTERVENTIONnpatients were randomised to either specialist geriatric input or regular input. The specialist group had a medical assessment by a geriatrician and medication review by a multidisciplinary expert panel. Regular input consisted of review as required by a medical officer attached to each ward. Reassessment occurred after 6 months.nnnRESULTSnone hundred and ten patients were randomised to specialist input and 115 to regular input. These were comparable for age, gender, dependency levels and cognition. After 6 months, the total number of medications per patient per day fell from 11.64 to 11.09 in the specialist group (P = 0.0364) and increased from 11.07 to 11.5 in the regular group (P = 0.094). There was no significant difference in mortality or frequency of acute hospital transfers (11 versus 6 in the specialist versus regular group, P = 0.213).nnnCONCLUSIONnspecialist geriatric assessment and medication review in hospital continuing care resulted in a reduction in medication use, but at a significant cost. No benefits in hard clinical outcomes were demonstrated. However, qualitative benefits and lower costs may become evident over longer periods.

Cervical artery dissection following a turbulent flight

BACKGROUNDnCervical artery dissection is a common cause of stroke in young patients without vascular risk factors and may affect the carotid or vertebral arteries. The risk of spontaneous dissection is higher in those with genetic predisposing factors while other cases may be precipitated by an event involving head or neck movement or associated with direct neck trauma.nnnCASE REPORTnWe present the case of a previously well young woman with a history of migraine who developed internal carotid artery dissection following a turbulent short-haul commercial flight while restrained using a seatbelt.nnnDISCUSSIONnWe propose that repetitive flexion-hyperextension neck movements encountered during the flight were the most likely precipitant of carotid artery dissection in this case and review the therapeutic options available.

Development and evaluation of new blood pressure and heart rate signal analysis techniques to assess orthostatic hypotension and its subtypes.

Orthostatic hypotension (OH) is a clinical condition, which frequently results in symptoms such as syncope, dizziness during standing, weakness, blurred vision and fatigue. It is defined as a sustained drop in blood pressure exceeding 20 mmHg systolic or 10 mmHg diastolic occurring within 3 min of assuming upright posture, and is a common causal factor for falls in the elderly. Since 1986, tilt-table testing has become widely used in the diagnosis of OH. The Finometer provides non-invasive monitoring of haemodynamic changes during tilt-table testing. In this study, new algorithms for parameter extraction from Finometer data were developed, with specific reference to the diagnosis of OH. Algorithms were developed to assess the rates of change of haemodynamic variables in response to head-up tilt testing, a previously unexamined aspect of tilt-table testing. These algorithms were applied to the Finometer measurements of 20 patients, who underwent tilt-table testing in the Mid-Western Regional Hospital, Limerick. The data extraction algorithms were shown to accurately record changes in haemodynamic variables for further analysis. It was also demonstrated that the rate of change of blood pressure during the head-up tilt-table testing could have prognostic significance for OH.

What is the optimal duration of tilt testing for the assessment of patients with suspected postural tachycardia syndrome

AIMSnThe aim of this study is to define the optimal duration of tilt testing for the assessment of patients with suspected postural tachycardia syndrome (POTS).nnnMETHODS AND RESULTSnThis was a case-control study. Cases were identified retrospectively from a database of patients referred with orthostatic intolerance (OI). All met the diagnostic criteria for POTS. Controls were enrolled prospectively. All subjects underwent tilting to 70 degrees for 40 min if tolerated. Continuous monitoring was provided by a Finometer. Analysis of responses to tilting was performed on 28 cases and 28 controls. The mean age in the case group was 23.6 and in the control group was 26.2. The majority was female in both groups (cases = 4F:3M, controls = 2F:1M). All cases met the criteria for POTS within 7 min of orthostasis. No controls demonstrated a sustained tachycardia. The prevalence of vasovagal syncope (VVS) was 36% in cases vs. 7% in controls (P = 0.02) and 25% in the remaining patients (n = 233) on the OI database (P = 0.259).nnnCONCLUSIONnA 10 min tilt will diagnose POTS in the majority of patients. It will not, however, be sufficient to identify the overlap that exists between POTS and VVS. The optimal duration of tilt testing in patients suspected of POTS is 40 min.

A footswitch evaluation of the gait of elderly fallers with and without a diagnosis of orthostatic hypotension and healthy elderly controls

Gait abnormalities are a recognised risk factor for falling in the elderly and variability in gait has been shown to be a measurable predictor of falls. We carried out a footswitch evaluation of the temporal parameters of gait of elderly fallers with a primary diagnosis of Orthostatic Hypotension, elderly fallers without a diagnosis of Orthostatic Hypotension and a control group of healthy elderly non-fallers. We hypothesized that elderly persons with Orthostatic Hypotension are falling purely as a consequence of their vascular abnormalities and are not falling for the same reasons as regular elderly fallers, including biomechanical irregularities. Therefore it was assumed that their gait pattern would not be similar to that of regular elderly fallers but instead would resemble that of healthy elderly non-fallers. Results show that elderly fallers with or without a diagnosis of Orthostatic Hypotension tend to spend more time in the stance phase of gait, possibly due to a fear of falling. Elderly fallers with a diagnosis of Orthostatic Hypotension have similar levels of gait variability as healthy elderly Controls. These are significantly less than elderly fallers without Orthostatic Hypotension. Therefore elderly fallers with a diagnosis of Orthostatic Hypotension may not be falling for the same reasons as regular elderly fallers.

A new blood pressure and heart rate signal analysis technique to assess Orthostatic Hypotension and its subtypes

Orthostatic Hypotension is a sudden drop in blood pressure upon assumption of upright posture. This drop in blood pressure is often results in symptoms such as dizziness, light-headedness, blurred vision, and syncope. Since 1986, tilt table testing has become widely used in the diagnosis of Orthostatic Hypotension. In this study, new algorithms for artifact removal and data extraction in Finometer data were developed. Algorithms were also developed to assess the rates of change of haemodynamic variables in response to head up tilt testing. These algorithms were applied to the Finometer measurements of 20 patients, who underwent tilt table testing in the Mid-Western Regional Hospital, Limerick. The techniques developed were shown to effectively reduce artifact noise without loss of clinically relevant data. The data extraction algorithms were shown to accurately record changes in haemodynamic variables. It was also demonstrated that rate of change of blood pressure during head-up tilt table testing could have prognostic significance for orthostatic hypotension.

Accelerometer versus footswitch evaluation of gait unsteadiness and temporal characteristics of gait in two elderly patient groups

We examined anterior-posterior and medio-lateral head and trunk movements during gait using accelerometers, and a footswitch evaluation of temporal gait parameters of elderly fallers with a primary diagnosis of Orthostatic Hypotension, elderly fallers without Orthostatic Hypotension, and a control group of healthy elderly non-fallers. We wanted to evaluate whether both sets of measures can be used to differentiate between patient groups. We were able to significantly differentiate between the three elderly groups to the same extent using both sets of measures.